bitrex <user@example.net> wrote:
> On 4/4/2024 7:56 AM, Phil Hobbs wrote:
>> Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:
>>> On 01-04-2024 09:01, Jan Panteltje wrote:
>>>> On a sunny day (Sun, 31 Mar 2024 18:41:18 +0100) it happened Cursitor Doom
>>>> <cd@notformail.com> wrote in <9k7j0jlnbhs8qfg5m17pium0835meean83@4ax.com>:
>>>>
>>>>> Hi all,
>>>>>
>>>>> I'm starting to get a bit fed up with having my test equipment blow up
>>>>> just when it's needed. This is the drawback with vintage gear; if it's
>>>>> not used frequently then it can go *bang* the next time you switch it
>>>>> on. It makes for good practice in repairing stuff, but wastes a lot of
>>>>> time which could be better spent doing other things.
>>>>> I think it's time I modernised my test gear. I was just wondering if
>>>>> anyone has any recommendations they can share. Is there a particular
>>>>> piece of test equipment you couldn't live without? Something you're
>>>>> particularly impressed with? I'd be interested to know so I can
>>>>> perhaps acquire said item and thereby reduce the number of explosions
>>>>> I experience.
>>>>>
>>>>> Thanks,
>>>>>
>>>>> CD.
>>>>
>>>> My 10 MHz Trio dual trace analog scope is from 1979 or there about, I
>>>> blew up a channal once myself in the first week
>>>> when I accidently touched a booster diode in a TV I was repairing with
>>>> it, fixed it locating the problem with the other channel.
>>>> Later I cracked the graticule when a soldering station fell on it from
>>>> the table (scope stands on the ground)
>>>> Made a new graticule.
>>>> So, and still working perfectly, OK for all things I build with micros.
>>>> For RF to about 1.6 GHz I use RTL_SDR USB sticks and the spectrum analyzer I wrote.
>>>> and for AC DC measurements I have some made in China digital meters and an analog one.
>>>> also a Voltcraft clamp-on meter for current when you do not - or cannot
>>>> interrupt things with the meter impedance.
>>>> Also have a Voltcraft soldering station.
>>>> Blew up one of my digital meters a while back (volts on the resistance
>>>> scale) but fixed it again (replaced resistor).
>>>> Many other test equipment I designed and build, like amplifiers LF and
>>>> RF, SWR meter, radiation meters, gamma spectrometer,
>>>> GHz stuff for satelite, transmitters low and very high power, what not,
>>>> a frequency converter to use the RTL-SDR sticks and so the spectrum
>>>> analyzer on higher and lower frequencies.
>>>> Have a SARK100 SWR analyzer too.
>>>> Things last forever here...
>>>> Scope used on a regular basis..
>>>> RTL-SDR stick 24/7.
>>>> Digital meters used every day.
>>>> Use my self designed lab power supply every day..
>>>> What more do you need?
>>>> Learn to use the stuff, understand what's important, and that is it
>>>> When I started in electronics as a kid I did not even _have_ a meter,
>>>> still stuff worked.
>>>> Build my own scope at some point back then
>>>> when I somehow got the parts
>>>> Not much pocket mony as a kid.
>>>> UNDERSTAND your systems, what electrons do.
>>>> Showing of with boat anchors may impress people, especially the clueless...
>>>> But it does not help you one bit.
>>>> Anything with an accuracy better than 1 percent in most cases is just
>>>> like apes screaming load trying to impress other apes.
>>>>
>>>
>>> Very true about specifically the 1% statement. Sidebar, at an earlier
>>> employment, we needed to equip a new lab. Guys wanted GHz scopes. When
>>> asked if the ever looked at edges faster than 1ns, no one did.
>>>
>>>
>>
>> It’s true that there are a lot of relatively undemanding jobs in
>> electronics. You can get on fine with a 200-MHz scope if all you’re doing
>> is PIC and Pi and ham radio and analog TV.
>>
>> It’s also true that you can often make do with what you have—the most
>> important test instrument is the one between your ears.
>>
>> In the before times, doctors were much better with stethoscopes than they
>> are now.
>>
>> But I’d sure prefer a cardiologist who could use tomography and ultrasound
>> over the best stethoscope guy.
>>
>> And it’s a lot easier finding gigahertz oscillations if you aren’t limited
>> to a 10-MHz
>> scope with scale marks in cuneiform.
>>
>> Good boat anchors make capability like that very affordable. My lab is full
>> of top-of-the-line gear (over $2M at list price), for which I’ve paid about
>> 2-3 cents on the dollar. (Not counting a few very helpful donations early
>> on.) Of course I have some good newer stuff, such as a two-channel arb, a
>> NanoVNA2, and a logic analyzer with protocol decoding.
>>
>> It’s a bit old-school-looking, so it doesn’t impress visitors unless they
>> actually know something, and that suits me perfectly well.
>>
>> But by all means don’t buy any, so it’ll keep being cheap for me. ;)
>>
>> Cheers
>>
>> Phil Hobbs
>>
>
> My most useful old machine dollar for dollar is my 8012B pulse generator!
>
> <https://imgur.com/a/2GaSZVq>
>
> $50 "not working." It was just a burned-out pilot lamp and dirty controls.
>

I used to have an 8013B, which is the dual channel version.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC /
Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics

On 5/04/2024 2:04 am, John Larkin wrote:
> On Thu, 4 Apr 2024 11:56:23 -0000 (UTC), Phil Hobbs
> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>
>> Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:
>>> On 01-04-2024 09:01, Jan Panteltje wrote:
>>>> On a sunny day (Sun, 31 Mar 2024 18:41:18 +0100) it happened Cursitor Doom
>>>> <cd@notformail.com> wrote in <9k7j0jlnbhs8qfg5m17pium0835meean83@4ax.com>:
>>>>
>>>>> Hi all,
>>>>>
>>>>> I'm starting to get a bit fed up with having my test equipment blow up
>>>>> just when it's needed. This is the drawback with vintage gear; if it's
>>>>> not used frequently then it can go *bang* the next time you switch it
>>>>> on. It makes for good practice in repairing stuff, but wastes a lot of
>>>>> time which could be better spent doing other things.
>>>>> I think it's time I modernised my test gear. I was just wondering if
>>>>> anyone has any recommendations they can share. Is there a particular
>>>>> piece of test equipment you couldn't live without? Something you're
>>>>> particularly impressed with? I'd be interested to know so I can
>>>>> perhaps acquire said item and thereby reduce the number of explosions
>>>>> I experience.
>>>>>
>>>>> Thanks,
>>>>>
>>>>> CD.
>>>>
>>>> My 10 MHz Trio dual trace analog scope is from 1979 or there about, I
>>>> blew up a channal once myself in the first week
>>>> when I accidently touched a booster diode in a TV I was repairing with
>>>> it, fixed it locating the problem with the other channel.
>>>> Later I cracked the graticule when a soldering station fell on it from
>>>> the table (scope stands on the ground)
>>>> Made a new graticule.
>>>> So, and still working perfectly, OK for all things I build with micros.
>>>> For RF to about 1.6 GHz I use RTL_SDR USB sticks and the spectrum analyzer I wrote.
>>>> and for AC DC measurements I have some made in China digital meters and an analog one.
>>>> also a Voltcraft clamp-on meter for current when you do not - or cannot
>>>> interrupt things with the meter impedance.
>>>> Also have a Voltcraft soldering station.
>>>> Blew up one of my digital meters a while back (volts on the resistance
>>>> scale) but fixed it again (replaced resistor).
>>>> Many other test equipment I designed and build, like amplifiers LF and
>>>> RF, SWR meter, radiation meters, gamma spectrometer,
>>>> GHz stuff for satelite, transmitters low and very high power, what not,
>>>> a frequency converter to use the RTL-SDR sticks and so the spectrum
>>>> analyzer on higher and lower frequencies.
>>>> Have a SARK100 SWR analyzer too.
>>>> Things last forever here...
>>>> Scope used on a regular basis..
>>>> RTL-SDR stick 24/7.
>>>> Digital meters used every day.
>>>> Use my self designed lab power supply every day..
>>>> What more do you need?
>>>> Learn to use the stuff, understand what's important, and that is it
>>>> When I started in electronics as a kid I did not even _have_ a meter, still stuff worked.
>>>> Build my own scope at some point back then when I somehow got the parts
>>>> Not much pocket mony as a kid.
>>>> UNDERSTAND your systems, what electrons do.
>>>> Showing of with boat anchors may impress people, especially the clueless...
>>>> But it does not help you one bit.
>>>> Anything with an accuracy better than 1 percent in most cases is just
>>>> like apes screaming load trying to impress other apes.
>>>>
>>>
>>> Very true about specifically the 1% statement. Sidebar, at an earlier
>>> employment, we needed to equip a new lab. Guys wanted GHz scopes. When
>>> asked if the ever looked at edges faster than 1ns, no one did.
>>>
>>>
>>
>> It’s true that there are a lot of relatively undemanding jobs in
>> electronics. You can get on fine with a 200-MHz scope if all you’re doing
>> is PIC and Pi and ham radio and analog TV.
>>
>> It’s also true that you can often make do with what you have—the most
>> important test instrument is the one between your ears.
>>
>> In the before times, doctors were much better with stethoscopes than they
>> are now.
>>
>> But I’d sure prefer a cardiologist who could use tomography and ultrasound
>> over the best stethoscope guy.
>>
>> And it’s a lot easier finding gigahertz oscillations if you aren’t limited
>> to a 10-MHz
>> scope with scale marks in cuneiform.
>
> We have a product in development, a new digital delay generator, that
> had too many picoseconds of excess, erratic jitter. Turns out that the
> 50 MHz LC oscillator squeggs at about 6 GHz, which I guess is my
> fault. We found that with a spectrum analyzer, not a scope.
>
> My new oscillator, using a BUF602 as the gain element, looks good.
> Jitter is under 10 ps RMS at 5 usec out, which is great for a
> triggered LC.

But it's rubbish for a free-running oscillator

https://ieeexplore.ieee.org/document/7331424

https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines-even-the-best-atomic-clocks

You need a system architecture that can exploit a free running clock. I
came up with one that worked in 1988, and I'm sure that there are others.

--
Bill Sloman, Sydney

On a sunny day (Thu, 4 Apr 2024 11:56:23 -0000 (UTC)) it happened Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote in
<uum4h6$kmdl$1@dont-email.me>:

>Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:
>> On 01-04-2024 09:01, Jan Panteltje wrote:
>>> On a sunny day (Sun, 31 Mar 2024 18:41:18 +0100) it happened Cursitor Doom
>>> <cd@notformail.com> wrote in <9k7j0jlnbhs8qfg5m17pium0835meean83@4ax.com>:
>>>
>>>> Hi all,
>>>>
>>>> I'm starting to get a bit fed up with having my test equipment blow up
>>>> just when it's needed. This is the drawback with vintage gear; if it's
>>>> not used frequently then it can go *bang* the next time you switch it
>>>> on. It makes for good practice in repairing stuff, but wastes a lot of
>>>> time which could be better spent doing other things.
>>>> I think it's time I modernised my test gear. I was just wondering if
>>>> anyone has any recommendations they can share. Is there a particular
>>>> piece of test equipment you couldn't live without? Something you're
>>>> particularly impressed with? I'd be interested to know so I can
>>>> perhaps acquire said item and thereby reduce the number of explosions
>>>> I experience.
>>>>
>>>> Thanks,
>>>>
>>>> CD.
>>>
>>> My 10 MHz Trio dual trace analog scope is from 1979 or there about, I
>>> blew up a channel once myself in the first week
>>> when I accidently touched a booster diode in a TV I was repairing with
>>> it, fixed it locating the problem with the other channel.
>>> Later I cracked the graticule when a soldering station fell on it from
>>> the table (scope stands on the ground)
>>> Made a new graticule.
>>> So, and still working perfectly, OK for all things I build with micros.
>>> For RF to about 1.6 GHz I use RTL_SDR USB sticks and the spectrum analyzer I wrote.
>>> and for AC DC measurements I have some made in China digital meters and an analog one.
>>> also a Voltcraft clamp-on meter for current when you do not - or cannot
>>> interrupt things with the meter impedance.
>>> Also have a Voltcraft soldering station.
>>> Blew up one of my digital meters a while back (volts on the resistance
>>> scale) but fixed it again (replaced resistor).
>>> Many other test equipment I designed and build, like amplifiers LF and
>>> RF, SWR meter, radiation meters, gamma spectrometer,
>>> GHz stuff for satelite, transmitters low and very high power, what not,
>>> a frequency converter to use the RTL-SDR sticks and so the spectrum
>>> analyzer on higher and lower frequencies.
>>> Have a SARK100 SWR analyzer too.
>>> Things last forever here...
>>> Scope used on a regular basis..
>>> RTL-SDR stick 24/7.
>>> Digital meters used every day.
>>> Use my self designed lab power supply every day..
>>> What more do you need?
>>> Learn to use the stuff, understand what's important, and that is it
>>> When I started in electronics as a kid I did not even _have_ a meter, still stuff worked.
>>> Build my own scope at some point back then when I somehow got the parts
>>> Not much pocket mony as a kid.
>>> UNDERSTAND your systems, what electrons do.
>>> Showing of with boat anchors may impress people, especially the clueless...
>>> But it does not help you one bit.
>>> Anything with an accuracy better than 1 percent in most cases is just
>>> like apes screaming load trying to impress other apes.
>>>
>>
>> Very true about specifically the 1% statement. Sidebar, at an earlier
>> employment, we needed to equip a new lab. Guys wanted GHz scopes. When
>> asked if the ever looked at edges faster than 1ns, no one did.
>>
>>
>
>It’s true that there are a lot of relatively undemanding jobs in
>electronics. You can get on fine with a 200-MHz scope if all you’re doing
>is PIC and Pi and ham radio and analog TV.

Bull,
I have been using my Trio 10 MHz dual channel for digital TV too
see
https://panteltje.nl/panteltje/raspberry_pi_dvb-s_transmitter/
GHz output..

Its is about UNDERSTANDING the systems
You cannot repair a TV set in a short time if you do not UNDERSTAND every part of the circuit and its function, the whole system
neither with a 10 MHz or with a 10 GHz scope.
Fault finding had been my job most of the time, sometimes with 'the show must go on'
or rocket must launch or whatever.

In an environment a million times more complex than your back-room with boat anchors.
And always delivered.. unlike some that dropped out or broke down.
It is indeed about what is between the ears as you mentioned.

>It’s also true that you can often make do with what you have—the most
>important test instrument is the one between your ears.
>
>In the before times, doctors were much better with stethoscopes than they
>are now.
>
>But I’d sure prefer a cardiologist who could use tomography and ultrasound
>over the best stethoscope guy.

Only useful if you can read the screens, these days they train AI to find cancer in the scans.....
Yes I worked in an Uni hospital too.
How many people die each year because of medical errors?
https://www.cnbc.com/2018/02/22/medical-errors-third-leading-cause-of-death-in-america.html
Remember Jim Thompson stating 'they are giving me ... but I had a warning I was not supposed to get that'
Few days later he was dead.

>And it’s a lot easier finding gigahertz oscillations if you aren’t limited
>to a 10-MHz
>scope with scale marks in cuneiform.

Giggle Hertz oscillations are not happening in LC circuits of specific kind
where those can happen you can figure from the parts used, no giggle Hz in a BC109.
look at the components used.
I worked on a missile launch system once that did strange things that were tracked down to an oscillating emitter follower...
Replacing that transistor by exactly the same part fixed it.. not one transistor is the same it seems, especially from different manufacturers..
but those were not very high frequency oscillations and I had a faster scope there.
In broadcast I ran around with a big Tec on a cart all day...
A TV studio complex and control is something vastly bigger than your back room.
https://www.mediapark.nl/
and every second counts
Yes without in depth knowledge of all that stuff you would not even know where to start .
And THAT in depth knowledge is the key.

>Good boat anchors make capability like that very affordable. My lab is full
>of top-of-the-line gear (over $2M at list price), for which I’ve paid about
>2-3 cents on the dollar. (Not counting a few very helpful donations early
>on.) Of course I have some good newer stuff, such as a two-channel arb, a
>NanoVNA2, and a logic analyzer with protocol decoding.
>
>It’s a bit old-school-looking, so it doesn’t impress visitors unless they
>actually know something, and that suits me perfectly well.
>
>But by all means don’t buy any, so it’ll keep being cheap for me. ;)

I won't, if I specifically want to KNOW some thing I build something for that purpose,
I better not ask if you per accident contributed to that F35 crap.
Anyways, carry on, makes me feel safer...

>Cheers

Do not drink when doing 'tronics

On a sunny day (Thu, 4 Apr 2024 12:20:19 -0400) it happened bitrex
<user@example.net> wrote in <660ed343$0$1258343$882e4bbb@reader.netnews.com>:

>My most useful old machine dollar for dollar is my 8012B pulse generator!
>
><https://imgur.com/a/2GaSZVq>

Nice, real components...

>$50 "not working." It was just a burned-out pilot lamp and dirty controls.

mm 50 dollars,
even today with people using dollars for wallpaper,
buys you a nice pulse generator on ebay..

555 timer works fine too
Or use sox in Linux for all sort of audio, including sweeps:
https://www.audiosciencereview.com/forum/index.php?threads/howto-sox-audio-tool-as-a-signal-generator.4242/
or just use a Raspberry Pi as signal generator:
https://panteltje.nl/panteltje/newsflex/download.html#freq_pi

Jan Panteltje <alien@comet.invalid> wrote:

> Giggle Hertz oscillations are not happening in LC circuits of specific
> kind where those can happen you can figure from the parts used, no giggle
> Hz in a BC109.

Back in the 1970s I found that a BC109 could be used as a self-
oscillating transmitter output stage at 100 Mc/s on a 1.5v supply (it
was for small animal cardiography). Most "R.F." transistors wouldn't
work under those circumstances.

--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

On a sunny day (Fri, 5 Apr 2024 09:24:53 +0100) it happened
liz@poppyrecords.invalid.invalid (Liz Tuddenham) wrote in
<1qrjb8o.u2ipkmlx8gzsN%liz@poppyrecords.invalid.invalid>:

>Jan Panteltje <alien@comet.invalid> wrote:
>
>> Giggle Hertz oscillations are not happening in LC circuits of specific
>> kind where those can happen you can figure from the parts used, no giggle
>> Hz in a BC109.
>
>Back in the 1970s I found that a BC109 could be used as a self-
>oscillating transmitter output stage at 100 Mc/s on a 1.5v supply (it
>was for small animal cardiography). Most "R.F." transistors wouldn't
>work under those circumstances.

That is MHz, not giggle Hertz
Early sixties I uses a transistor in my small FM transmitter.
It was powered by a battery via a dynamic microphone.
The few mV power supply variations that mike caused when any sound present were enough to make Cce Ccb variations
to cause the frequency to change so much that you could hear a clock ticking in the room listening
to that transmitter on the radio.
I still use transistors as varicap if I need one.

On Fri, 05 Apr 2024 07:49:30 GMT, Jan Panteltje <alien@comet.invalid>
wrote:

>On a sunny day (Thu, 4 Apr 2024 11:56:23 -0000 (UTC)) it happened Phil Hobbs
><pcdhSpamMeSenseless@electrooptical.net> wrote in
><uum4h6$kmdl$1@dont-email.me>:
>
>>Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:
>>> On 01-04-2024 09:01, Jan Panteltje wrote:
>>>> On a sunny day (Sun, 31 Mar 2024 18:41:18 +0100) it happened Cursitor Doom
>>>> <cd@notformail.com> wrote in <9k7j0jlnbhs8qfg5m17pium0835meean83@4ax.com>:
>>>>
>>>>> Hi all,
>>>>>
>>>>> I'm starting to get a bit fed up with having my test equipment blow up
>>>>> just when it's needed. This is the drawback with vintage gear; if it's
>>>>> not used frequently then it can go *bang* the next time you switch it
>>>>> on. It makes for good practice in repairing stuff, but wastes a lot of
>>>>> time which could be better spent doing other things.
>>>>> I think it's time I modernised my test gear. I was just wondering if
>>>>> anyone has any recommendations they can share. Is there a particular
>>>>> piece of test equipment you couldn't live without? Something you're
>>>>> particularly impressed with? I'd be interested to know so I can
>>>>> perhaps acquire said item and thereby reduce the number of explosions
>>>>> I experience.
>>>>>
>>>>> Thanks,
>>>>>
>>>>> CD.
>>>>
>>>> My 10 MHz Trio dual trace analog scope is from 1979 or there about, I
>>>> blew up a channel once myself in the first week
>>>> when I accidently touched a booster diode in a TV I was repairing with
>>>> it, fixed it locating the problem with the other channel.
>>>> Later I cracked the graticule when a soldering station fell on it from
>>>> the table (scope stands on the ground)
>>>> Made a new graticule.
>>>> So, and still working perfectly, OK for all things I build with micros.
>>>> For RF to about 1.6 GHz I use RTL_SDR USB sticks and the spectrum analyzer I wrote.
>>>> and for AC DC measurements I have some made in China digital meters and an analog one.
>>>> also a Voltcraft clamp-on meter for current when you do not - or cannot
>>>> interrupt things with the meter impedance.
>>>> Also have a Voltcraft soldering station.
>>>> Blew up one of my digital meters a while back (volts on the resistance
>>>> scale) but fixed it again (replaced resistor).
>>>> Many other test equipment I designed and build, like amplifiers LF and
>>>> RF, SWR meter, radiation meters, gamma spectrometer,
>>>> GHz stuff for satelite, transmitters low and very high power, what not,
>>>> a frequency converter to use the RTL-SDR sticks and so the spectrum
>>>> analyzer on higher and lower frequencies.
>>>> Have a SARK100 SWR analyzer too.
>>>> Things last forever here...
>>>> Scope used on a regular basis..
>>>> RTL-SDR stick 24/7.
>>>> Digital meters used every day.
>>>> Use my self designed lab power supply every day..
>>>> What more do you need?
>>>> Learn to use the stuff, understand what's important, and that is it
>>>> When I started in electronics as a kid I did not even _have_ a meter, still stuff worked.
>>>> Build my own scope at some point back then when I somehow got the parts
>>>> Not much pocket mony as a kid.
>>>> UNDERSTAND your systems, what electrons do.
>>>> Showing of with boat anchors may impress people, especially the clueless...
>>>> But it does not help you one bit.
>>>> Anything with an accuracy better than 1 percent in most cases is just
>>>> like apes screaming load trying to impress other apes.
>>>>
>>>
>>> Very true about specifically the 1% statement. Sidebar, at an earlier
>>> employment, we needed to equip a new lab. Guys wanted GHz scopes. When
>>> asked if the ever looked at edges faster than 1ns, no one did.
>>>
>>>
>>
>>It’s true that there are a lot of relatively undemanding jobs in
>>electronics. You can get on fine with a 200-MHz scope if all you’re doing
>>is PIC and Pi and ham radio and analog TV.
>
>Bull,
>I have been using my Trio 10 MHz dual channel for digital TV too
>see
> https://panteltje.nl/panteltje/raspberry_pi_dvb-s_transmitter/
>GHz output..
>
>Its is about UNDERSTANDING the systems
>You cannot repair a TV set in a short time if you do not UNDERSTAND every part of the circuit and its function, the whole system
>neither with a 10 MHz or with a 10 GHz scope.
>Fault finding had been my job most of the time, sometimes with 'the show must go on'
>or rocket must launch or whatever.

Does anyone still repair TVs? TV repair shops used to be common but
seem to be gone now.

TVs are insanely cheap and reliable now. I suspect that a failure
under an over-priced "extended warranty" gets you a replacement.

Nobody makes schematics available now, and a TV is full of exotic
custom chips.

On Fri, 5 Apr 2024 09:24:53 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:

>Jan Panteltje <alien@comet.invalid> wrote:
>
>> Giggle Hertz oscillations are not happening in LC circuits of specific
>> kind where those can happen you can figure from the parts used, no giggle
>> Hz in a BC109.
>
>Back in the 1970s I found that a BC109 could be used as a self-
>oscillating transmitter output stage at 100 Mc/s on a 1.5v supply (it
>was for small animal cardiography). Most "R.F." transistors wouldn't
>work under those circumstances.

I learned at an early age that emitter followers tend to oscillate. I
did a powerup reset circuit with an RC feeeding a 2N2219 emitter
follower feeding a TTL schmitt gate. The NPN oscillated at 100 MHz or
so and never pulled up the gate. A series gate resistor fixed it.

My recent 50 MHz SAV541-based Colpitts oscillator couldn't be tamed
with a gate resistor or with a bead, so I gave up on the phemt. I
think the wire bonds are a basic hazard.

https://www.dropbox.com/scl/fi/bak4p5bty2os2wtrs0091/9.jpg?rlkey=91e37ctc70189hvka9g1ufar3&raw=1

On 2024-04-05 11:31, John Larkin wrote:
> On Fri, 5 Apr 2024 09:24:53 +0100, liz@poppyrecords.invalid.invalid
> (Liz Tuddenham) wrote:
>
>> Jan Panteltje <alien@comet.invalid> wrote:
>>
>>> Giggle Hertz oscillations are not happening in LC circuits of specific
>>> kind where those can happen you can figure from the parts used, no giggle
>>> Hz in a BC109.
>>
>> Back in the 1970s I found that a BC109 could be used as a self-
>> oscillating transmitter output stage at 100 Mc/s on a 1.5v supply (it
>> was for small animal cardiography). Most "R.F." transistors wouldn't
>> work under those circumstances.
>
> I learned at an early age that emitter followers tend to oscillate. I
> did a powerup reset circuit with an RC feeeding a 2N2219 emitter
> follower feeding a TTL schmitt gate. The NPN oscillated at 100 MHz or
> so and never pulled up the gate. A series gate resistor fixed it.
>
> My recent 50 MHz SAV541-based Colpitts oscillator couldn't be tamed
> with a gate resistor or with a bead, so I gave up on the phemt. I
> think the wire bonds are a basic hazard.
>
> https://www.dropbox.com/scl/fi/bak4p5bty2os2wtrs0091/9.jpg?rlkey=91e37ctc70189hvka9g1ufar3&raw=1
>
>
>

Try putting BLF03VK600 beads in source and drain. Besides being rated at
3 GHz instead of 100 MHz, it has really nice low Q everywhere.

My cascoded lab amp proto is using three SAV-331+'s in parallel like
that, running about 2.5 mA each, and shows no sign of trouble.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Fri, 5 Apr 2024 11:38:43 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>On 2024-04-05 11:31, John Larkin wrote:
>> On Fri, 5 Apr 2024 09:24:53 +0100, liz@poppyrecords.invalid.invalid
>> (Liz Tuddenham) wrote:
>>
>>> Jan Panteltje <alien@comet.invalid> wrote:
>>>
>>>> Giggle Hertz oscillations are not happening in LC circuits of specific
>>>> kind where those can happen you can figure from the parts used, no giggle
>>>> Hz in a BC109.
>>>
>>> Back in the 1970s I found that a BC109 could be used as a self-
>>> oscillating transmitter output stage at 100 Mc/s on a 1.5v supply (it
>>> was for small animal cardiography). Most "R.F." transistors wouldn't
>>> work under those circumstances.
>>
>> I learned at an early age that emitter followers tend to oscillate. I
>> did a powerup reset circuit with an RC feeeding a 2N2219 emitter
>> follower feeding a TTL schmitt gate. The NPN oscillated at 100 MHz or
>> so and never pulled up the gate. A series gate resistor fixed it.
>>
>> My recent 50 MHz SAV541-based Colpitts oscillator couldn't be tamed
>> with a gate resistor or with a bead, so I gave up on the phemt. I
>> think the wire bonds are a basic hazard.
>>
>> https://www.dropbox.com/scl/fi/bak4p5bty2os2wtrs0091/9.jpg?rlkey=91e37ctc70189hvka9g1ufar3&raw=1
>>
>>
>>
>
>Try putting BLF03VK600 beads in source and drain. Besides being rated at
>3 GHz instead of 100 MHz, it has really nice low Q everywhere.
>
>My cascoded lab amp proto is using three SAV-331+'s in parallel like
>that, running about 2.5 mA each, and shows no sign of trouble.
>
>Cheers
>
>Phil Hobbs

We tried various fixes, no joy. The circuit is complex, lots of diodes
and comparators and varicaps and stuff, so there are too many resonant
stubs.

We prototyped the new sorta-Colpitts circuit, using the BUF602 as the
gain element, and it's great. Having a closed-loop near-perfect
follower is nice.

On Fri, 05 Apr 2024 07:49:30 GMT, Jan Panteltje <alien@comet.invalid>
wrote:

>On a sunny day (Thu, 4 Apr 2024 11:56:23 -0000 (UTC)) it happened Phil Hobbs
><pcdhSpamMeSenseless@electrooptical.net> wrote in
><uum4h6$kmdl$1@dont-email.me>:
>
>>Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:
>>> On 01-04-2024 09:01, Jan Panteltje wrote:
>>>> On a sunny day (Sun, 31 Mar 2024 18:41:18 +0100) it happened Cursitor Doom
>>>> <cd@notformail.com> wrote in <9k7j0jlnbhs8qfg5m17pium0835meean83@4ax.com>:
>>>>
>>>>> Hi all,
>>>>>
>>>>> I'm starting to get a bit fed up with having my test equipment blow up
>>>>> just when it's needed. This is the drawback with vintage gear; if it's
>>>>> not used frequently then it can go *bang* the next time you switch it
>>>>> on. It makes for good practice in repairing stuff, but wastes a lot of
>>>>> time which could be better spent doing other things.
>>>>> I think it's time I modernised my test gear. I was just wondering if
>>>>> anyone has any recommendations they can share. Is there a particular
>>>>> piece of test equipment you couldn't live without? Something you're
>>>>> particularly impressed with? I'd be interested to know so I can
>>>>> perhaps acquire said item and thereby reduce the number of explosions
>>>>> I experience.
>>>>>
>>>>> Thanks,
>>>>>
>>>>> CD.
>>>>
>>>> My 10 MHz Trio dual trace analog scope is from 1979 or there about, I
>>>> blew up a channel once myself in the first week
>>>> when I accidently touched a booster diode in a TV I was repairing with
>>>> it, fixed it locating the problem with the other channel.
>>>> Later I cracked the graticule when a soldering station fell on it from
>>>> the table (scope stands on the ground)
>>>> Made a new graticule.
>>>> So, and still working perfectly, OK for all things I build with micros.
>>>> For RF to about 1.6 GHz I use RTL_SDR USB sticks and the spectrum analyzer I wrote.
>>>> and for AC DC measurements I have some made in China digital meters and an analog one.
>>>> also a Voltcraft clamp-on meter for current when you do not - or cannot
>>>> interrupt things with the meter impedance.
>>>> Also have a Voltcraft soldering station.
>>>> Blew up one of my digital meters a while back (volts on the resistance
>>>> scale) but fixed it again (replaced resistor).
>>>> Many other test equipment I designed and build, like amplifiers LF and
>>>> RF, SWR meter, radiation meters, gamma spectrometer,
>>>> GHz stuff for satelite, transmitters low and very high power, what not,
>>>> a frequency converter to use the RTL-SDR sticks and so the spectrum
>>>> analyzer on higher and lower frequencies.
>>>> Have a SARK100 SWR analyzer too.
>>>> Things last forever here...
>>>> Scope used on a regular basis..
>>>> RTL-SDR stick 24/7.
>>>> Digital meters used every day.
>>>> Use my self designed lab power supply every day..
>>>> What more do you need?
>>>> Learn to use the stuff, understand what's important, and that is it
>>>> When I started in electronics as a kid I did not even _have_ a meter, still stuff worked.
>>>> Build my own scope at some point back then when I somehow got the parts
>>>> Not much pocket mony as a kid.
>>>> UNDERSTAND your systems, what electrons do.
>>>> Showing of with boat anchors may impress people, especially the clueless...
>>>> But it does not help you one bit.
>>>> Anything with an accuracy better than 1 percent in most cases is just
>>>> like apes screaming load trying to impress other apes.
>>>>
>>>
>>> Very true about specifically the 1% statement. Sidebar, at an earlier
>>> employment, we needed to equip a new lab. Guys wanted GHz scopes. When
>>> asked if the ever looked at edges faster than 1ns, no one did.
>>>
>>>
>>
>>It’s true that there are a lot of relatively undemanding jobs in
>>electronics. You can get on fine with a 200-MHz scope if all you’re doing
>>is PIC and Pi and ham radio and analog TV.
>
>Bull,
>I have been using my Trio 10 MHz dual channel for digital TV too
>see
> https://panteltje.nl/panteltje/raspberry_pi_dvb-s_transmitter/
>GHz output..
>
>Its is about UNDERSTANDING the systems
>You cannot repair a TV set in a short time if you do not UNDERSTAND every part of the circuit and its function, the whole system
>neither with a 10 MHz or with a 10 GHz scope.
>Fault finding had been my job most of the time, sometimes with 'the show must go on'
>or rocket must launch or whatever.
>
>In an environment a million times more complex than your back-room with boat anchors.
>And always delivered.. unlike some that dropped out or broke down.
>It is indeed about what is between the ears as you mentioned.
>
>
>
>
>>It’s also true that you can often make do with what you have—the most
>>important test instrument is the one between your ears.
>>
>>In the before times, doctors were much better with stethoscopes than they
>>are now.
>>
>>But I’d sure prefer a cardiologist who could use tomography and ultrasound
>>over the best stethoscope guy.
>
>Only useful if you can read the screens, these days they train AI to find cancer in the scans.....
>Yes I worked in an Uni hospital too.
>How many people die each year because of medical errors?
> https://www.cnbc.com/2018/02/22/medical-errors-third-leading-cause-of-death-in-america.html
>Remember Jim Thompson stating 'they are giving me ... but I had a warning I was not supposed to get that'
>Few days later he was dead.

Jim had pancreatic cancer, which is notoriously tricky to diagnose due
to the misleading symptoms it gives rise to.

On Fri, 5 Apr 2024 09:24:53 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:

>Jan Panteltje <alien@comet.invalid> wrote:
>
>> Giggle Hertz oscillations are not happening in LC circuits of specific
>> kind where those can happen you can figure from the parts used, no giggle
>> Hz in a BC109.
>
>Back in the 1970s I found that a BC109 could be used as a self-
>oscillating transmitter output stage at 100 Mc/s on a 1.5v supply (it
>was for small animal cardiography). Most "R.F." transistors wouldn't
>work under those circumstances.

We used to make bugging devices using '109s with button cap
microphones that worked on that VHF broadcast band. They were highly
effective as I recall.

On Fri, 05 Apr 2024 08:13:07 -0700, John Larkin <jl@997PotHill.com>
wrote:

>On Fri, 05 Apr 2024 07:49:30 GMT, Jan Panteltje <alien@comet.invalid>
>wrote:
>
>>On a sunny day (Thu, 4 Apr 2024 11:56:23 -0000 (UTC)) it happened Phil Hobbs
>><pcdhSpamMeSenseless@electrooptical.net> wrote in
>><uum4h6$kmdl$1@dont-email.me>:
>>
>>>Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:
>>>> On 01-04-2024 09:01, Jan Panteltje wrote:
>>>>> On a sunny day (Sun, 31 Mar 2024 18:41:18 +0100) it happened Cursitor Doom
>>>>> <cd@notformail.com> wrote in <9k7j0jlnbhs8qfg5m17pium0835meean83@4ax.com>:
>>>>>
>>>>>> Hi all,
>>>>>>
>>>>>> I'm starting to get a bit fed up with having my test equipment blow up
>>>>>> just when it's needed. This is the drawback with vintage gear; if it's
>>>>>> not used frequently then it can go *bang* the next time you switch it
>>>>>> on. It makes for good practice in repairing stuff, but wastes a lot of
>>>>>> time which could be better spent doing other things.
>>>>>> I think it's time I modernised my test gear. I was just wondering if
>>>>>> anyone has any recommendations they can share. Is there a particular
>>>>>> piece of test equipment you couldn't live without? Something you're
>>>>>> particularly impressed with? I'd be interested to know so I can
>>>>>> perhaps acquire said item and thereby reduce the number of explosions
>>>>>> I experience.
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> CD.
>>>>>
>>>>> My 10 MHz Trio dual trace analog scope is from 1979 or there about, I
>>>>> blew up a channel once myself in the first week
>>>>> when I accidently touched a booster diode in a TV I was repairing with
>>>>> it, fixed it locating the problem with the other channel.
>>>>> Later I cracked the graticule when a soldering station fell on it from
>>>>> the table (scope stands on the ground)
>>>>> Made a new graticule.
>>>>> So, and still working perfectly, OK for all things I build with micros.
>>>>> For RF to about 1.6 GHz I use RTL_SDR USB sticks and the spectrum analyzer I wrote.
>>>>> and for AC DC measurements I have some made in China digital meters and an analog one.
>>>>> also a Voltcraft clamp-on meter for current when you do not - or cannot
>>>>> interrupt things with the meter impedance.
>>>>> Also have a Voltcraft soldering station.
>>>>> Blew up one of my digital meters a while back (volts on the resistance
>>>>> scale) but fixed it again (replaced resistor).
>>>>> Many other test equipment I designed and build, like amplifiers LF and
>>>>> RF, SWR meter, radiation meters, gamma spectrometer,
>>>>> GHz stuff for satelite, transmitters low and very high power, what not,
>>>>> a frequency converter to use the RTL-SDR sticks and so the spectrum
>>>>> analyzer on higher and lower frequencies.
>>>>> Have a SARK100 SWR analyzer too.
>>>>> Things last forever here...
>>>>> Scope used on a regular basis..
>>>>> RTL-SDR stick 24/7.
>>>>> Digital meters used every day.
>>>>> Use my self designed lab power supply every day..
>>>>> What more do you need?
>>>>> Learn to use the stuff, understand what's important, and that is it
>>>>> When I started in electronics as a kid I did not even _have_ a meter, still stuff worked.
>>>>> Build my own scope at some point back then when I somehow got the parts
>>>>> Not much pocket mony as a kid.
>>>>> UNDERSTAND your systems, what electrons do.
>>>>> Showing of with boat anchors may impress people, especially the clueless...
>>>>> But it does not help you one bit.
>>>>> Anything with an accuracy better than 1 percent in most cases is just
>>>>> like apes screaming load trying to impress other apes.
>>>>>
>>>>
>>>> Very true about specifically the 1% statement. Sidebar, at an earlier
>>>> employment, we needed to equip a new lab. Guys wanted GHz scopes. When
>>>> asked if the ever looked at edges faster than 1ns, no one did.
>>>>
>>>>
>>>
>>>It’s true that there are a lot of relatively undemanding jobs in
>>>electronics. You can get on fine with a 200-MHz scope if all you’re doing
>>>is PIC and Pi and ham radio and analog TV.
>>
>>Bull,
>>I have been using my Trio 10 MHz dual channel for digital TV too
>>see
>> https://panteltje.nl/panteltje/raspberry_pi_dvb-s_transmitter/
>>GHz output..
>>
>>Its is about UNDERSTANDING the systems
>>You cannot repair a TV set in a short time if you do not UNDERSTAND every part of the circuit and its function, the whole system
>>neither with a 10 MHz or with a 10 GHz scope.
>>Fault finding had been my job most of the time, sometimes with 'the show must go on'
>>or rocket must launch or whatever.
>
>Does anyone still repair TVs? TV repair shops used to be common but
>seem to be gone now.
>
>TVs are insanely cheap and reliable now. I suspect that a failure
>under an over-priced "extended warranty" gets you a replacement.
>
>Nobody makes schematics available now, and a TV is full of exotic
>custom chips.

All which make repair extremely difficult! There are moves afoot in
Europe, I believe, to introduce some sort of 'compulsory
repairability' law, to enable freelance repairers to fix up stuff
that's gone kaput. That would be an excellent idea, given the massive
amount of electronics that goes into landfill. Our 'throw away
culture' is not doing the environment any favours at all. This is what
needs to be focused on, not some garbage about greenhouse gases.

On Fri, 05 Apr 2024 17:33:12 +0100, Cursitor Doom <cd@notformail.com>
wrote:

>On Fri, 05 Apr 2024 07:49:30 GMT, Jan Panteltje <alien@comet.invalid>
>wrote:
>
>>On a sunny day (Thu, 4 Apr 2024 11:56:23 -0000 (UTC)) it happened Phil Hobbs
>><pcdhSpamMeSenseless@electrooptical.net> wrote in
>><uum4h6$kmdl$1@dont-email.me>:
>>
>>>Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:
>>>> On 01-04-2024 09:01, Jan Panteltje wrote:
>>>>> On a sunny day (Sun, 31 Mar 2024 18:41:18 +0100) it happened Cursitor Doom
>>>>> <cd@notformail.com> wrote in <9k7j0jlnbhs8qfg5m17pium0835meean83@4ax.com>:
>>>>>
>>>>>> Hi all,
>>>>>>
>>>>>> I'm starting to get a bit fed up with having my test equipment blow up
>>>>>> just when it's needed. This is the drawback with vintage gear; if it's
>>>>>> not used frequently then it can go *bang* the next time you switch it
>>>>>> on. It makes for good practice in repairing stuff, but wastes a lot of
>>>>>> time which could be better spent doing other things.
>>>>>> I think it's time I modernised my test gear. I was just wondering if
>>>>>> anyone has any recommendations they can share. Is there a particular
>>>>>> piece of test equipment you couldn't live without? Something you're
>>>>>> particularly impressed with? I'd be interested to know so I can
>>>>>> perhaps acquire said item and thereby reduce the number of explosions
>>>>>> I experience.
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> CD.
>>>>>
>>>>> My 10 MHz Trio dual trace analog scope is from 1979 or there about, I
>>>>> blew up a channel once myself in the first week
>>>>> when I accidently touched a booster diode in a TV I was repairing with
>>>>> it, fixed it locating the problem with the other channel.
>>>>> Later I cracked the graticule when a soldering station fell on it from
>>>>> the table (scope stands on the ground)
>>>>> Made a new graticule.
>>>>> So, and still working perfectly, OK for all things I build with micros.
>>>>> For RF to about 1.6 GHz I use RTL_SDR USB sticks and the spectrum analyzer I wrote.
>>>>> and for AC DC measurements I have some made in China digital meters and an analog one.
>>>>> also a Voltcraft clamp-on meter for current when you do not - or cannot
>>>>> interrupt things with the meter impedance.
>>>>> Also have a Voltcraft soldering station.
>>>>> Blew up one of my digital meters a while back (volts on the resistance
>>>>> scale) but fixed it again (replaced resistor).
>>>>> Many other test equipment I designed and build, like amplifiers LF and
>>>>> RF, SWR meter, radiation meters, gamma spectrometer,
>>>>> GHz stuff for satelite, transmitters low and very high power, what not,
>>>>> a frequency converter to use the RTL-SDR sticks and so the spectrum
>>>>> analyzer on higher and lower frequencies.
>>>>> Have a SARK100 SWR analyzer too.
>>>>> Things last forever here...
>>>>> Scope used on a regular basis..
>>>>> RTL-SDR stick 24/7.
>>>>> Digital meters used every day.
>>>>> Use my self designed lab power supply every day..
>>>>> What more do you need?
>>>>> Learn to use the stuff, understand what's important, and that is it
>>>>> When I started in electronics as a kid I did not even _have_ a meter, still stuff worked.
>>>>> Build my own scope at some point back then when I somehow got the parts
>>>>> Not much pocket mony as a kid.
>>>>> UNDERSTAND your systems, what electrons do.
>>>>> Showing of with boat anchors may impress people, especially the clueless...
>>>>> But it does not help you one bit.
>>>>> Anything with an accuracy better than 1 percent in most cases is just
>>>>> like apes screaming load trying to impress other apes.
>>>>>
>>>>
>>>> Very true about specifically the 1% statement. Sidebar, at an earlier
>>>> employment, we needed to equip a new lab. Guys wanted GHz scopes. When
>>>> asked if the ever looked at edges faster than 1ns, no one did.
>>>>
>>>>
>>>
>>>It’s true that there are a lot of relatively undemanding jobs in
>>>electronics. You can get on fine with a 200-MHz scope if all you’re doing
>>>is PIC and Pi and ham radio and analog TV.
>>
>>Bull,
>>I have been using my Trio 10 MHz dual channel for digital TV too
>>see
>> https://panteltje.nl/panteltje/raspberry_pi_dvb-s_transmitter/
>>GHz output..
>>
>>Its is about UNDERSTANDING the systems
>>You cannot repair a TV set in a short time if you do not UNDERSTAND every part of the circuit and its function, the whole system
>>neither with a 10 MHz or with a 10 GHz scope.
>>Fault finding had been my job most of the time, sometimes with 'the show must go on'
>>or rocket must launch or whatever.
>>
>>In an environment a million times more complex than your back-room with boat anchors.
>>And always delivered.. unlike some that dropped out or broke down.
>>It is indeed about what is between the ears as you mentioned.
>>
>>
>>
>>
>>>It’s also true that you can often make do with what you have—the most
>>>important test instrument is the one between your ears.
>>>
>>>In the before times, doctors were much better with stethoscopes than they
>>>are now.
>>>
>>>But I’d sure prefer a cardiologist who could use tomography and ultrasound
>>>over the best stethoscope guy.
>>
>>Only useful if you can read the screens, these days they train AI to find cancer in the scans.....
>>Yes I worked in an Uni hospital too.
>>How many people die each year because of medical errors?
>> https://www.cnbc.com/2018/02/22/medical-errors-third-leading-cause-of-death-in-america.html
>>Remember Jim Thompson stating 'they are giving me ... but I had a warning I was not supposed to get that'
>>Few days later he was dead.
>
>Jim had pancreatic cancer, which is notoriously tricky to diagnose due
>to the misleading symptoms it gives rise to.

He talked constantly about wine. That can kill your pancreas.

There are people who drink bottles per day.

John Larkin <jl@997PotHill.com> wrote:

[...]
> >> I learned at an early age that emitter followers tend to oscillate.

The Bath Radio Club had a saying" "Amplifiers oscillate - oscillators
don't".

--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

On Fri, 5 Apr 2024 18:35:21 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:

>John Larkin <jl@997PotHill.com> wrote:
>
>[...]
>> >> I learned at an early age that emitter followers tend to oscillate.
>
>The Bath Radio Club had a saying" "Amplifiers oscillate - oscillators
>don't".

My problem is that my oscillators oscillate too much.

On 4/4/2024 9:12 PM, Phil Hobbs wrote:
> bitrex <user@example.net> wrote:
>> On 4/4/2024 7:56 AM, Phil Hobbs wrote:
>>> Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:
>>>> On 01-04-2024 09:01, Jan Panteltje wrote:
>>>>> On a sunny day (Sun, 31 Mar 2024 18:41:18 +0100) it happened Cursitor Doom
>>>>> <cd@notformail.com> wrote in <9k7j0jlnbhs8qfg5m17pium0835meean83@4ax.com>:
>>>>>
>>>>>> Hi all,
>>>>>>
>>>>>> I'm starting to get a bit fed up with having my test equipment blow up
>>>>>> just when it's needed. This is the drawback with vintage gear; if it's
>>>>>> not used frequently then it can go *bang* the next time you switch it
>>>>>> on. It makes for good practice in repairing stuff, but wastes a lot of
>>>>>> time which could be better spent doing other things.
>>>>>> I think it's time I modernised my test gear. I was just wondering if
>>>>>> anyone has any recommendations they can share. Is there a particular
>>>>>> piece of test equipment you couldn't live without? Something you're
>>>>>> particularly impressed with? I'd be interested to know so I can
>>>>>> perhaps acquire said item and thereby reduce the number of explosions
>>>>>> I experience.
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> CD.
>>>>>
>>>>> My 10 MHz Trio dual trace analog scope is from 1979 or there about, I
>>>>> blew up a channal once myself in the first week
>>>>> when I accidently touched a booster diode in a TV I was repairing with
>>>>> it, fixed it locating the problem with the other channel.
>>>>> Later I cracked the graticule when a soldering station fell on it from
>>>>> the table (scope stands on the ground)
>>>>> Made a new graticule.
>>>>> So, and still working perfectly, OK for all things I build with micros.
>>>>> For RF to about 1.6 GHz I use RTL_SDR USB sticks and the spectrum analyzer I wrote.
>>>>> and for AC DC measurements I have some made in China digital meters and an analog one.
>>>>> also a Voltcraft clamp-on meter for current when you do not - or cannot
>>>>> interrupt things with the meter impedance.
>>>>> Also have a Voltcraft soldering station.
>>>>> Blew up one of my digital meters a while back (volts on the resistance
>>>>> scale) but fixed it again (replaced resistor).
>>>>> Many other test equipment I designed and build, like amplifiers LF and
>>>>> RF, SWR meter, radiation meters, gamma spectrometer,
>>>>> GHz stuff for satelite, transmitters low and very high power, what not,
>>>>> a frequency converter to use the RTL-SDR sticks and so the spectrum
>>>>> analyzer on higher and lower frequencies.
>>>>> Have a SARK100 SWR analyzer too.
>>>>> Things last forever here...
>>>>> Scope used on a regular basis..
>>>>> RTL-SDR stick 24/7.
>>>>> Digital meters used every day.
>>>>> Use my self designed lab power supply every day..
>>>>> What more do you need?
>>>>> Learn to use the stuff, understand what's important, and that is it
>>>>> When I started in electronics as a kid I did not even _have_ a meter,
>>>>> still stuff worked.
>>>>> Build my own scope at some point back then
>>>>> when I somehow got the parts
>>>>> Not much pocket mony as a kid.
>>>>> UNDERSTAND your systems, what electrons do.
>>>>> Showing of with boat anchors may impress people, especially the clueless...
>>>>> But it does not help you one bit.
>>>>> Anything with an accuracy better than 1 percent in most cases is just
>>>>> like apes screaming load trying to impress other apes.
>>>>>
>>>>
>>>> Very true about specifically the 1% statement. Sidebar, at an earlier
>>>> employment, we needed to equip a new lab. Guys wanted GHz scopes. When
>>>> asked if the ever looked at edges faster than 1ns, no one did.
>>>>
>>>>
>>>
>>> It’s true that there are a lot of relatively undemanding jobs in
>>> electronics. You can get on fine with a 200-MHz scope if all you’re doing
>>> is PIC and Pi and ham radio and analog TV.
>>>
>>> It’s also true that you can often make do with what you have—the most
>>> important test instrument is the one between your ears.
>>>
>>> In the before times, doctors were much better with stethoscopes than they
>>> are now.
>>>
>>> But I’d sure prefer a cardiologist who could use tomography and ultrasound
>>> over the best stethoscope guy.
>>>
>>> And it’s a lot easier finding gigahertz oscillations if you aren’t limited
>>> to a 10-MHz
>>> scope with scale marks in cuneiform.
>>>
>>> Good boat anchors make capability like that very affordable. My lab is full
>>> of top-of-the-line gear (over $2M at list price), for which I’ve paid about
>>> 2-3 cents on the dollar. (Not counting a few very helpful donations early
>>> on.) Of course I have some good newer stuff, such as a two-channel arb, a
>>> NanoVNA2, and a logic analyzer with protocol decoding.
>>>
>>> It’s a bit old-school-looking, so it doesn’t impress visitors unless they
>>> actually know something, and that suits me perfectly well.
>>>
>>> But by all means don’t buy any, so it’ll keep being cheap for me. ;)
>>>
>>> Cheers
>>>
>>> Phil Hobbs
>>>
>>
>> My most useful old machine dollar for dollar is my 8012B pulse generator!
>>
>> <https://imgur.com/a/2GaSZVq>
>>
>> $50 "not working." It was just a burned-out pilot lamp and dirty controls.
>>
>
> I used to have an 8013B, which is the dual channel version.
>
> Cheers
>
> Phil Hobbs
>
Looks like it was designed in the late 60s! From the date code I believe
mine is a 1982 model. It's still listed in the 1987 HP catalog for a
list price of $1750. The 8013B is listed at $1650, maybe those prices
are swapped. I wonder when they finally stopped selling it. It's quite a
bit cheaper than the fully-programmable HP-IB equipped 8112A which
listed for $4775.

On 4/5/2024 3:49 AM, Jan Panteltje wrote:
> On a sunny day (Thu, 4 Apr 2024 12:20:19 -0400) it happened bitrex
> <user@example.net> wrote in <660ed343$0$1258343$882e4bbb@reader.netnews.com>:
>
>> My most useful old machine dollar for dollar is my 8012B pulse generator!
>>
>> <https://imgur.com/a/2GaSZVq>
>
> Nice, real components...
>
>
>> $50 "not working." It was just a burned-out pilot lamp and dirty controls.
>
> mm 50 dollars,
> even today with people using dollars for wallpaper,
> buys you a nice pulse generator on ebay..

It cost $1700 USD in the 1987 catalog, about $4500 equivalent today!

> 555 timer works fine too
> Or use sox in Linux for all sort of audio, including sweeps:
> https://www.audiosciencereview.com/forum/index.php?threads/howto-sox-audio-tool-as-a-signal-generator.4242/
> or just use a Raspberry Pi as signal generator:
> https://panteltje.nl/panteltje/newsflex/download.html#freq_pi

Am 05.04.24 um 19:35 schrieb Liz Tuddenham:
> John Larkin <jl@997PotHill.com> wrote:
>
> [...]
>>>> I learned at an early age that emitter followers tend to oscillate.
>
> The Bath Radio Club had a saying" "Amplifiers oscillate - oscillators
> don't".

I heard that as "amplifiers will, oscillators won't"

:-) Gerhard

On Fri, 5 Apr 2024 16:26:49 -0400, bitrex <user@example.net> wrote:

>On 4/5/2024 3:49 AM, Jan Panteltje wrote:
>> On a sunny day (Thu, 4 Apr 2024 12:20:19 -0400) it happened bitrex
>> <user@example.net> wrote in <660ed343$0$1258343$882e4bbb@reader.netnews.com>:
>>
>>> My most useful old machine dollar for dollar is my 8012B pulse generator!
>>>
>>> <https://imgur.com/a/2GaSZVq>
>>
>> Nice, real components...
>>
>>
>>> $50 "not working." It was just a burned-out pilot lamp and dirty controls.
>>
>> mm 50 dollars,
>> even today with people using dollars for wallpaper,
>> buys you a nice pulse generator on ebay..
>
>It cost $1700 USD in the 1987 catalog, about $4500 equivalent today!
>
>> 555 timer works fine too
>> Or use sox in Linux for all sort of audio, including sweeps:
>> https://www.audiosciencereview.com/forum/index.php?threads/howto-sox-audio-tool-as-a-signal-generator.4242/
>> or just use a Raspberry Pi as signal generator:
>> https://panteltje.nl/panteltje/newsflex/download.html#freq_pi

Our DDG is about $4K, addmittedly over the top for a home lab.

http://highlandtechnology.com/DSS/P500DS.shtml

I love my beat-up old unit on my bench. Timing and levels are
brutally quantitative.

Am 02.04.24 um 17:09 schrieb John Larkin:

>
> We still have one Tek 7104 (1 GHz microchannel analog scope) that
> works. One of my guys likes it.
>

Wasn't that the scope that always switched off the beam current
when things got interesting?

Gerhard

On Fri, 5 Apr 2024 23:31:28 +0200, Gerhard Hoffmann <dk4xp@arcor.de>
wrote:

>Am 02.04.24 um 17:09 schrieb John Larkin:
>
>>
>> We still have one Tek 7104 (1 GHz microchannel analog scope) that
>> works. One of my guys likes it.
>>
>
>Wasn't that the scope that always switched off the beam current
>when things got interesting?
>
>Gerhard

Yes, it shuts off the display often, to not wear out the microchannel
plate.

One develops a sophisticated thumb-flic motion to hit the enable
button in milliseconds. You can see a single-shot sweep at 1 ns/cm.

The 719 was a fast CRT scope too, but the screen was about the size of
a postage stamp, and there was no vertical amplifier. I don't want one
of those huge ugly beasts, but I do have a CRT. I dug it out of a 719
in a parking lot in Los Alamos, in the cold rain.

On 05-04-2024 23:22, john larkin wrote:
> On Fri, 5 Apr 2024 16:26:49 -0400, bitrex <user@example.net> wrote:
>
>> On 4/5/2024 3:49 AM, Jan Panteltje wrote:
>>> On a sunny day (Thu, 4 Apr 2024 12:20:19 -0400) it happened bitrex
>>> <user@example.net> wrote in <660ed343$0$1258343$882e4bbb@reader.netnews.com>:
>>>
>>>> My most useful old machine dollar for dollar is my 8012B pulse generator!
>>>>
>>>> <https://imgur.com/a/2GaSZVq>
>>>
>>> Nice, real components...
>>>
>>>
>>>> $50 "not working." It was just a burned-out pilot lamp and dirty controls.
>>>
>>> mm 50 dollars,
>>> even today with people using dollars for wallpaper,
>>> buys you a nice pulse generator on ebay..
>>
>> It cost $1700 USD in the 1987 catalog, about $4500 equivalent today!
>>
>>> 555 timer works fine too
>>> Or use sox in Linux for all sort of audio, including sweeps:
>>> https://www.audiosciencereview.com/forum/index.php?threads/howto-sox-audio-tool-as-a-signal-generator.4242/
>>> or just use a Raspberry Pi as signal generator:
>>> https://panteltje.nl/panteltje/newsflex/download.html#freq_pi
>
> Our DDG is about $4K, addmittedly over the top for a home lab.
>
> http://highlandtechnology.com/DSS/P500DS.shtml
>
> I love my beat-up old unit on my bench. Timing and levels are
> brutally quantitative.
>
I bought a Siglent DDS SDG6022X for 1300USD, 200MHz thingie. I knew
forehand that it could be hacked to 500MHz, so "saved" 3000 USD for 1
hours work :-)

https://www.batronix.com/shop/waveform-generator/Siglent-SDG6022X.html

EEVBLOG has hacking details if anyone is interested...

Am 05.04.24 um 17:55 schrieb John Larkin:
> On Fri, 5 Apr 2024 11:38:43 -0400, Phil Hobbs

>>
>> Try putting BLF03VK600 beads in source and drain. Besides being rated at
>> 3 GHz instead of 100 MHz, it has really nice low Q everywhere.
>>
>> My cascoded lab amp proto is using three SAV-331+'s in parallel like
>> that, running about 2.5 mA each, and shows no sign of trouble.
>>
>> Cheers
>>
>> Phil Hobbs
>
> We tried various fixes, no joy. The circuit is complex, lots of diodes
> and comparators and varicaps and stuff, so there are too many resonant
> stubs.
>
> We prototyped the new sorta-Colpitts circuit, using the BUF602 as the
> gain element, and it's great. Having a closed-loop near-perfect
> follower is nice.
>

Do you have slowish feedback into the source? From the FETs POV
that makes it look like a capacitively loaded follower. It translates
directly into a negative real part of the input impedance.

<
https://www.flickr.com/photos/137684711@N07/34701106245/in/datetaken/lightbox/
>

It is the input impedance of 2*IF3602 and the negative real part
can get REALLY large, out of bead-land.
In the Smith diagram, S11 is decoded at the marker positions.
Where the trajectory gets out of the circle through 0 and inf,
there comes more energy back from the DUT than the VNA sends to it.
Cannot happen with passive DUTs.

It is a really hard problem and even in AOE3 is a bad example.

I got an array of 16* CPH-3910 stable with feedback via a
3 GHz CFB amplifier. But CFB's 1/f noise easily dwarfed the
noise of the 16 FETs even after 40 dB of gain.

I tried driving the feedback with 2 * BFQ19S BJTs as a follower.
It seems it kinda works in simulation. Generates a lot of heat.
Not yet built.

<
https://www.flickr.com/photos/137684711@N07/53634537164/in/dateposted-public/
>

opinions or proposals?

Is it possible to get .ac and .noise analysis in LTspice in the
same run without constantly editing the commands & the display???

Cheers, Gerhard

On 4/5/2024 11:13 AM, John Larkin wrote:
> On Fri, 05 Apr 2024 07:49:30 GMT, Jan Panteltje <alien@comet.invalid>
> wrote:
>
>> On a sunny day (Thu, 4 Apr 2024 11:56:23 -0000 (UTC)) it happened Phil Hobbs
>> <pcdhSpamMeSenseless@electrooptical.net> wrote in
>> <uum4h6$kmdl$1@dont-email.me>:
>>
>>> Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:
>>>> On 01-04-2024 09:01, Jan Panteltje wrote:
>>>>> On a sunny day (Sun, 31 Mar 2024 18:41:18 +0100) it happened Cursitor Doom
>>>>> <cd@notformail.com> wrote in <9k7j0jlnbhs8qfg5m17pium0835meean83@4ax.com>:
>>>>>
>>>>>> Hi all,
>>>>>>
>>>>>> I'm starting to get a bit fed up with having my test equipment blow up
>>>>>> just when it's needed. This is the drawback with vintage gear; if it's
>>>>>> not used frequently then it can go *bang* the next time you switch it
>>>>>> on. It makes for good practice in repairing stuff, but wastes a lot of
>>>>>> time which could be better spent doing other things.
>>>>>> I think it's time I modernised my test gear. I was just wondering if
>>>>>> anyone has any recommendations they can share. Is there a particular
>>>>>> piece of test equipment you couldn't live without? Something you're
>>>>>> particularly impressed with? I'd be interested to know so I can
>>>>>> perhaps acquire said item and thereby reduce the number of explosions
>>>>>> I experience.
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> CD.
>>>>>
>>>>> My 10 MHz Trio dual trace analog scope is from 1979 or there about, I
>>>>> blew up a channel once myself in the first week
>>>>> when I accidently touched a booster diode in a TV I was repairing with
>>>>> it, fixed it locating the problem with the other channel.
>>>>> Later I cracked the graticule when a soldering station fell on it from
>>>>> the table (scope stands on the ground)
>>>>> Made a new graticule.
>>>>> So, and still working perfectly, OK for all things I build with micros.
>>>>> For RF to about 1.6 GHz I use RTL_SDR USB sticks and the spectrum analyzer I wrote.
>>>>> and for AC DC measurements I have some made in China digital meters and an analog one.
>>>>> also a Voltcraft clamp-on meter for current when you do not - or cannot
>>>>> interrupt things with the meter impedance.
>>>>> Also have a Voltcraft soldering station.
>>>>> Blew up one of my digital meters a while back (volts on the resistance
>>>>> scale) but fixed it again (replaced resistor).
>>>>> Many other test equipment I designed and build, like amplifiers LF and
>>>>> RF, SWR meter, radiation meters, gamma spectrometer,
>>>>> GHz stuff for satelite, transmitters low and very high power, what not,
>>>>> a frequency converter to use the RTL-SDR sticks and so the spectrum
>>>>> analyzer on higher and lower frequencies.
>>>>> Have a SARK100 SWR analyzer too.
>>>>> Things last forever here...
>>>>> Scope used on a regular basis..
>>>>> RTL-SDR stick 24/7.
>>>>> Digital meters used every day.
>>>>> Use my self designed lab power supply every day..
>>>>> What more do you need?
>>>>> Learn to use the stuff, understand what's important, and that is it
>>>>> When I started in electronics as a kid I did not even _have_ a meter, still stuff worked.
>>>>> Build my own scope at some point back then when I somehow got the parts
>>>>> Not much pocket mony as a kid.
>>>>> UNDERSTAND your systems, what electrons do.
>>>>> Showing of with boat anchors may impress people, especially the clueless...
>>>>> But it does not help you one bit.
>>>>> Anything with an accuracy better than 1 percent in most cases is just
>>>>> like apes screaming load trying to impress other apes.
>>>>>
>>>>
>>>> Very true about specifically the 1% statement. Sidebar, at an earlier
>>>> employment, we needed to equip a new lab. Guys wanted GHz scopes. When
>>>> asked if the ever looked at edges faster than 1ns, no one did.
>>>>
>>>>
>>>
>>> It’s true that there are a lot of relatively undemanding jobs in
>>> electronics. You can get on fine with a 200-MHz scope if all you’re doing
>>> is PIC and Pi and ham radio and analog TV.
>>
>> Bull,
>> I have been using my Trio 10 MHz dual channel for digital TV too
>> see
>> https://panteltje.nl/panteltje/raspberry_pi_dvb-s_transmitter/
>> GHz output..
>>
>> Its is about UNDERSTANDING the systems
>> You cannot repair a TV set in a short time if you do not UNDERSTAND every part of the circuit and its function, the whole system
>> neither with a 10 MHz or with a 10 GHz scope.
>> Fault finding had been my job most of the time, sometimes with 'the show must go on'
>> or rocket must launch or whatever.
>
> Does anyone still repair TVs? TV repair shops used to be common but
> seem to be gone now.
>
> TVs are insanely cheap and reliable now. I suspect that a failure
> under an over-priced "extended warranty" gets you a replacement.
>
> Nobody makes schematics available now, and a TV is full of exotic
> custom chips.

They've become reliable enough that there isn't enough business to
support lots of shops, but even a smaller city like Boston still has a
couple. There are Facebook groups dedicated to sharing tips for
repairing them, too.

Not all TVs are "extremely cheap", some large displays cost several
thousand dollars and since the most common faults are with the power
supply, capacitors, LEDs etc. and often don't need a detail schematic to
diagnose, they can definitely be economical to repair.

Video cards/GPUs are expensive enough nowadays that they're often
economical to repair, too, they're a lot easier to ship than TVs so this
one shop probably handles a significant fraction of the GPU repairs in
the US:

<https://www.youtube.com/@NorthridgeFix>