I noticed this morning that the Blake DML26WB I fitted in 2008 for
Crystal Palace was now vertical – in the sense of pointing down towards
the ground. On investigation the end of the alloy boom had rotted where
it was in contact with the steel clamp. Known problem?

Anyhow I’ve bodgered the clamp on further down on the basis that another
10~15 years will see us out.

PS
I only noticed because I looked up to see if the blackbird was using the
aerial as usual for his singing: TVs and PVR were still 100% signal
quality :)

--
Robin
reply-to address is (intended to be) valid

Robin wrote:

> I noticed this morning that the Blake DML26WB I fitted in 2008 for
> Crystal Palace was now vertical – in the sense of pointing down towards
> the ground.  On investigation the end of the alloy boom had rotted where
> it was in contact with the steel clamp.  Known problem?

Yep, same happened to mine ...

On 30/05/2023 21:08, Robin wrote:
> I noticed this morning that the Blake DML26WB I fitted in 2008 for
> Crystal Palace was now vertical – in the sense of pointing down towards
> the ground. On investigation the end of the alloy boom had rotted where
> it was in contact with the steel clamp. Known problem?

<https://en.wikipedia.org/wiki/Galvanic_corrosion>

--

Jeff

On Tuesday, 30 May 2023 at 21:08:13 UTC+1, Robin wrote:
> I noticed this morning that the Blake DML26WB I fitted in 2008 for
> Crystal Palace was now vertical – in the sense of pointing down towards
> the ground. On investigation the end of the alloy boom had rotted where
> it was in contact with the steel clamp. Known problem?
>
> Anyhow I’ve bodgered the clamp on further down on the basis that another
> 10~15 years will see us out.
>
> PS
> I only noticed because I looked up to see if the blackbird was using the
> aerial as usual for his singing: TVs and PVR were still 100% signal
> quality :)
>
> --
> Robin
> reply-to address is (intended to be) valid

Yes - electrolytic corrosion. A small piece of insulation tape wrapped around the boom where the clamp attaches would avoid this.
See https://en.wikipedia.org/wiki/Galvanic_corrosion

My conservatory is aluminium and secured to a wall with 100mm steel wall anchors in brass "plated" cup washers. when I was building it I wanted plastic disks or similar both to allow for thermal movement and to insulate the aluminium frame from the steel screws. In the event I bought the builders' merchants entire stock of half inch tap washers (for 5p each). That was in 1987. No sign of strain nor corrosion 36 years later.

On 31/05/2023 07:23, Jeff Layman wrote:
> On 30/05/2023 21:08, Robin wrote:
>> I noticed this morning that the Blake DML26WB I fitted in 2008 for
>> Crystal Palace was now vertical – in the sense of pointing down towards
>> the ground.  On investigation the end of the alloy boom had rotted where
>> it was in contact with the steel clamp.  Known problem?
>
> <https://en.wikipedia.org/wiki/Galvanic_corrosion>
>

And if I'd known in 2008 I'd have mitigated the effect - probably by
taking the plate off the boom to paint both (as the fit is a bit tight
for tape). But I can see that neither manufacturers nor fitters have an
incentive to do so.
--
Robin
reply-to address is (intended to be) valid

On Tuesday, 30 May 2023 at 21:08:13 UTC+1, Robin wrote:
> I noticed this morning that the Blake DML26WB I fitted in 2008 for
> Crystal Palace was now vertical – in the sense of pointing down towards
> the ground. On investigation the end of the alloy boom had rotted where
> it was in contact with the steel clamp. Known problem?

Yep.

Bill

You could probably get a good signal on a coat hanger then. I think my
Antiference one is still OK. I do know that later versions of logs tended to
be held at one end, and often a black plastic square to round adaptor is in
the clamp and this tends to go brittle and fall to bits leaving the aerial
dangling. Our atmosphere is pretty corrosive. I have galvanised mast clamps
that rusted through in about 5 years. When I say galvanised, it looks more
like a cadmium and pasivation, as its gold when new. These were the jaws
type with the bent bolts. Not very impressed with those.
Brian

--

--:
This newsgroup posting comes to you directly from...
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Note this Signature is meaningless.!
"Robin" <rbw@outlook.com> wrote in message
news:55becc91-2b10-904b-d833-fbf74e35b6f7@outlook.com...
>I noticed this morning that the Blake DML26WB I fitted in 2008 for Crystal
>Palace was now vertical - in the sense of pointing down towards the ground.
>On investigation the end of the alloy boom had rotted where it was in
>contact with the steel clamp. Known problem?
>
> Anyhow I've bodgered the clamp on further down on the basis that another
> 10~15 years will see us out.
>
> PS
> I only noticed because I looked up to see if the blackbird was using the
> aerial as usual for his singing: TVs and PVR were still 100% signal
> quality :)
>
> --
> Robin
> reply-to address is (intended to be) valid

On Wednesday, 31 May 2023 at 18:35:44 UTC+1, wrights...@f2s.com wrote:
> On Tuesday, 30 May 2023 at 21:08:13 UTC+1, Robin wrote:
> > I noticed this morning that the Blake DML26WB I fitted in 2008 for
> > Crystal Palace was now vertical – in the sense of pointing down towards
> > the ground. On investigation the end of the alloy boom had rotted where
> > it was in contact with the steel clamp. Known problem?
> Yep.
>
> Bill

A mate lives in a top floor flat.

One day he reports TV not working and is thinking of buying a new one. He lives in a top floor flat and we are ~30km from Winter Hill

I couldn't find my old set top aerial, so I took a large paper clip and an aerial extension lead. Unwound the clip and plugged it into the end of the lead and hung it on the wall - perfect picture on all channels.

Central distribution amp had blown.