"Brian Gaff" <brian1gaff@gmail.com> wrote in message
news:u3lepd$1id48$1@dont-email.me...
> Another dodge for records that crackle a lot due to the muck that comes
> in due to static, is to use one of those knowin record cleaning baths with
> water and fairy liquid, Play the tracks you want while wet and the muck is
> in suspension.

Been there, done that. Need to clean the crap off the needle after copying
each track.

I remember adverts for record-cleaning devices which rotated the disc inside
a small hub which contained a soap solution and which partially enclosed a
sector of the disc which was rotated to clean the whole disc.

When I was copying some of my dad's old LPs, I found that some of them were
so bad that I needed to drip water onto each track in turn so there was a
"lake" covering the grooves, and playing with the needle immersed in that
water.

On 19/05/2023 15:43, NY wrote:

>> It is marginal, but the record amplifier uses more current when there
>> is more signal being fed to the head. This may affect the speed
>> slightly depending on just how flat the batteries are. This would be
>> more evident when the recorder uses a permanent magnet erase head, DC
>> bias and a mechanical governor, as many cheap recorders used to.
>
> And this *was* a cheap recorder - might have been my first one as a
> child which was
>
> Phillips EL3302

I have one of the model before that here, the EL3301. Two part
microphone (The microphone and remote control switch coould be
separated),and no interlock to prevent accidentally over recording
cassette albums. It all still works, with the original motor, which had
a mechanical governor.

At the time, they were actually not cheap. They were originally sold as
a premium tool to allow executives to dictate stuff while out and about.

The EL3301 was one of, if not *the* first portable cassette recorder.

--
Tciao for Now!

John.

John Williamson <johnwilliamson@btinternet.com> wrote:

> On 19/05/2023 15:43, NY wrote:
>
> >> It is marginal, but the record amplifier uses more current when there
> >> is more signal being fed to the head. This may affect the speed
> >> slightly depending on just how flat the batteries are. This would be
> >> more evident when the recorder uses a permanent magnet erase head, DC
> >> bias and a mechanical governor, as many cheap recorders used to.
> >
> > And this *was* a cheap recorder - might have been my first one as a
> > child which was
> >
> > Phillips EL3302
>
> I have one of the model before that here, the EL3301. Two part
> microphone (The microphone and remote control switch coould be
> separated),and no interlock to prevent accidentally over recording
> cassette albums. It all still works, with the original motor, which had
> a mechanical governor.
>
> At the time, they were actually not cheap. They were originally sold as
> a premium tool to allow executives to dictate stuff while out and about.
>
> The EL3301 was one of, if not *the* first portable cassette recorder.

The EL3301 was the first - and it used germainum transistors; the
EL3302 was mechanically almost identical, apart from the record-inhibit
latch, but used silicon transistors. The Class-B output stage did not
operate during recording and all the other electronics were Class-A, so
there shouldn't have been any change in battery current during loud
recording peaks (apart from the modulation meter, which only drew about
1 mA).

The design of those machines is described in great detail in the
"Philips Technical Review".

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

NY <me@privacy.invalid> wrote:

> "Brian Gaff" <brian1gaff@gmail.com> wrote in message
> news:u3lepd$1id48$1@dont-email.me...
> > Another dodge for records that crackle a lot due to the muck that comes
> > in due to static, is to use one of those knowin record cleaning baths with
> > water and fairy liquid, Play the tracks you want while wet and the muck is
> > in suspension.
>
> Been there, done that. Need to clean the crap off the needle after copying
> each track.
>
> I remember adverts for record-cleaning devices which rotated the disc inside
> a small hub which contained a soap solution and which partially enclosed a
> sector of the disc which was rotated to clean the whole disc.
>
> When I was copying some of my dad's old LPs, I found that some of them were
> so bad that I needed to drip water onto each track in turn so there was a
> "lake" covering the grooves, and playing with the needle immersed in that
> water.

That is the best way; the surface noise becomes even worse if you allow
the record to dry out after wetting it.

Obviously, that is also the safest way of playing partially-decomposed
nitrate 'direct cut' discs - scraping a potentially explosive material
with a diamond is best done under water.

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

NY <me@privacy.net> wrote:
> When I copied the tape to my PC (via its soundcard) much more recently,
> I noticed something that I couldn't hear: the 15625 Hz line frequency.
> This set me thinking: perhaps some form of servo system could be devised
> (either in hardware, controlling the tape recorder's motor, or in
> software, post-processing the digital copy of the tape, so as to keep
> the tone at exactly 15625 Hz?

I don't think that would be difficult to do in software. Do an FFT based on
(say) a second's worth of samples, look for a peak at 15625 +/- X (eg
X=10%). Measure the frequency of the peak. Subtract the from 15625 to get
the sample rate correction. If you slide this across (do an FFT every 50ms
of the previous second) then it would be a fairly smoothly varying
correction that follows the wow of the tape. When you have the corrected
sample rate for each period, interpolate your source samples back to a
baseline constant 44.1kHz (for example) sampling rate.

Theo

In message <u481ur$mufp$1@dont-email.me> at Fri, 19 May 2023 15:39:36,
NY <me@privacy.invalid> writes
>"J. P. Gilliver" <G6JPG@255soft.uk> wrote in message
>news:eZL97LX7J0ZkFwAZ@255soft.uk...
[]
>> But the sound would not have been coming from the cassette recorder's
>>speaker, would it - or were you monitoring, and using a very long mike
>>lead to avoid feedback? Most portable cassette machines mute the
>>speaker on record, at least when recording from a microphone. So
>>unless the TV was also running on battery ...
>
>I wasn't implying that the sound was coming from the speaker *during
>the recording*. I was meaning that when the tape was played back
>afterwards, the pitch rose during loud sounds which equates to the
>motor slowing down at those points during recording - assuming that on
>playback the motor is able to run at constant speed.

Hmm. Although another has said the record current rises a _little_ with
large amplitude signals, I'd be surprised if it would have a noticeable
effect. (Having said that, I can't otherwise explain what you describe.)
[]
>> Was this just an intellectual thought, or is it a recording you'd
>>really like to retrieve: in other words, what was/is the music? We
>>can probably find you a recording; virtually everything is on YouTube
>>these days (-:!
>
>It's an intellectual thought-experiment. I think the music may have
>been from the testcard ;-) I'd be impressed if I ever managed to
>identify it on a compilation of library music.

I suspected as much, and am enjoying the discussion. But if you do seek
it: "The test card circle" put out a CD not _too_ long ago (meaning
somewhere in the last couple of decades, I think!) of "test card music",
arguing that some of it was of unrecognised (by the general public) high
quality and should not be lost. (Technically, they had a point. Of
course, I bought the CD - but can't say I can at this point think of
anything on it I consider the musical equivalent of deathless prose.)
>
>And now I think about it, I may have recorded from an old 405-line TV,
>so the whistle would have been at 10125 rather than 15625 Hz. Either

And as well as being more within normal hearing range anyway, tended to
be louder for various reasons - components looser, especially when
thermal cycling has had its effect.

>way, when I generated a live spectrum of the digital recording made
>from the tape, there was a clear peak at around one frequency or the
>other, and when I generated an offline spectrum of a few seconds of
>*stable* recording (ie not when it was wowing all over the place), the
>peak narrowed enough to be able to say that it was close to one value
>or the other. That was using CoolEdit software, though I imagine that
>Audacity can do something similar.

(I think almost any audio processing software has such a function; I use
GoldWave, since I bought it before Audacity came out and am used to it.)
>
>It's a long time since I noticed the problem. I don't know which tape
>it was recorded on or where the digital WAV file of it is.
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

A perfectionist takes infinite pains and often gives them to others

On 19/05/2023 17:40, John Williamson wrote:
> On 19/05/2023 15:43, NY wrote:

>> And this *was* a cheap recorder - might have been my first one as a
>> child which was
>>
>> Phillips EL3302
>
> I have one of the model before that here, the EL3301. Two part
> microphone (The microphone and remote control switch could be
> separated),and no interlock to prevent accidentally over recording
> cassette albums. It all still works, with the original motor, which had
> a mechanical governor.
>
> At the time, they were actually not cheap. They were originally sold as
> a premium tool to allow executives to dictate stuff while out and about.
>
> The EL3301 was one of, if not *the* first portable cassette recorder.

I remember the two-part, slightly conical microphone, with a switch
capable of being separated from the mike itself.

I can remember using the EL3302 at a house which we left in 1969, so we
had it no later than that. Given that this model was launched in 1967,
we must have been early adopters.

Looking at photos, mine was the 3302 which has a rectangular rather then
circular record button.

Dad used it for dictating when we was working from home - I can remember
very clearly his "posh voice" when he was dictating for the secretary to
type ;-) When he later got a handheld dictation recorder that used
B-shaped cassettes (*), I was able to play with the Philips recorder.

Interesting that the 3301 didn't apparently have the record-inhibit
switch that used the absence of the tab to prevent overwriting.

(*) So not the tiny micro-cassettes that were found in some telephone
answering machines. May have been this format
https://youtu.be/GHGiEogVFeQ?t=18 although the recorder was a lot
smaller. I remember that the playback wasn't muted during rewind or
fast-forward so I got used to hearing the squawk every time Dad rewound
to correct the wording of something.