Annunciator Repairers wanted!

[Busby67]

Hello, can anyone recommend a repairer in the UK who specialises in vintage bell box repairs, please. The type with printed flags behind glass in a cabinet. I believe they're called annunciators?

[Station X]

i don't offer a repair service, but in this thread I describe how I repaired my own:-

https://www.vintage-radio.net/forum/...ad.php?t=64450

What's wrong with yours?

[Busby67]

Originally Posted by Station X

i don't offer a repair service, but in this thread I describe how I repaired my own:-

https://www.vintage-radio.net/forum/...ad.php?t=64450

What's wrong with yours?

It's all intact and coils and wires all present, although there are a couple of breaks visible that could easily be repaired, but if I wire up a 6V battery and touch to + -, then I only have 2 of the 9 indicators working.

[Station X]

Can you post a clear picture of the guts please so that we can advise you how to investigate further.

[Dave Moll]

If you have a multimeter, you could start by checking continuity of each coil and the wiring to it. You may find that the seven indicators that don't work either have an open-circuit coil or a break in the wiring that's not easily seen.

As Graham says though, a clear picture would be helpful to enable more detailed advice.

I would not expect there to be anything complicated in terms of wiring. Certainly mine has nothing more than a terminal for each indicator wired to one end of each coil and the other ends connected together to a common terminal, which is fairly representative of others I've seen, with exception of sometimes a bell in series at the common side.

[Station X]

Yup! The worst possible scenario is that one or more indicator coils are open circuit. Easily checked with a meter.

[Busby67]

Pictures attached.

[Station X]

You'll need to fix the broken brass "bus bar" by soldering a strip of brass or a copper wire across the gap.

The coils use thick wire so they won't be open-circuit.

One side of each coil should go to a busbar and the other side to an individual terminal on the RHS of the board.

One side of battery goes to bell. Other terminal of bell goes to top LH terminal. Other side of battery goes to individual tags on RHS via bell pushes.

BTW indicators should hang down, but my references to R, H, top and bottom are to the pictures

[Busby67]

Many thanks for posting those for me, Graham. I'm down at my Parents Wednesday. They're my 'Bubble'! My Dad was a TV and Radio engineer in the 60's so he can have a look, make those basic repairs and test the circuits. What is the most likely fault to be causing the fails and can it be remedied, or replaced?

[Station X]

Those look like slide in indicator cards. You could photograph a good one and print new ones, at the correct size, onto card.

[Busby67]

I think they are. They're very fragile. I'll try and keep them if possible as I like the originality, but if they get too, bad, then yes, I'll have to replace them.

[Station X]

Originally Posted by Busby67

Many thanks for posting those for me, Graham. I'm down at my Parents Wednesday. They're my 'Bubble'! My Dad was a TV and Radio engineer in the 60's so he can have a look, make those basic repairs and test the circuits. What is the most likely fault to be causing the fails and can it be remedied, or replaced?

The faults are undoubtedly down to the breaks. I don't know whether the connecting wires are bare or cotton covered? If the former make sure they don't touch each other.

[pmmunro]

It's not too clear from the photograph showing the full set of coils, but it looks like some coils have an overall covering of some kind or possibly they are wound with fabric (cotton, or just possibly silk) covered wire while those to the lower left of the image are like the single coil shown in the last photograph.

That single coil seems to use enamelled copper wire with a purplish hue. Judging, from admittedly not much expertise, it looks to me as if this coil and the similar looking ones have been rewound in "modern" times. The gauge of wire looks quite large too; I would have expected something considerably finer.

If I am right in this, any fabric covered coils will be the originals and the wire used will have been right for the original application. That would probably have used three Leclanché or dry cells in series, giving about 4.5 volts, but the operating voltage would not be too critical.

The coils would not be difficult to rewind by hand, or with a simple mechanical arrangement. The main challenge, if you want authenticity, would be to find suitable fabric covered wire.

PMM

[Busby67]

Thank you for the reply. I think itxmay just be the photograph that is making them look different. Visually I'd say they're all the same. They're is a very fine layer of dust on some which is catching the light in the photo, which iss maybe why some look as though they have a cotton covering. Interesting that they may be able to be rewound though. My Dad was a TV and Radio engineer in the 60's and he's going to hsbe a look at it for me. Sounds like something he could take on?

[Station X]

I had a look at the coils in my own unit and they're all wound with enamelled copper wire of a fairly heavy gauge just like yours. Only the imterconnecting wire is fabric covered.

Your father will have no difficulty fixing your unit.

[Busby67]

Thanks Graham. I'll post some pics when it's all done and working.