Dac90a Knobs - UK Vintage Radio Repair and Restoration Discussion Forum

DON THOMSON · 20th Nov 2005, 1:25 pm

My later DAC 90A has the knobs with the inlaid "silver" circles embellishment, now tired and worn. Has any one successfully replaced these rings and if so, with what and how, please?

Hunts smoothing bomb · 21st Nov 2005, 12:39 am

Hi Don,

I have a DAC90A also but mine has no silver rings inset to the knobs, they are just plain, I don't know if thats cos it's an earlier version or weather yours may have the incorrect knobs, I'm not sure.
Maybe someone can shed some light on this?

Lee

Paul_RK · 21st Nov 2005, 3:28 am

Three different types of knobs were used on the DAC90A in succession, and it's only the last ones, with a perspex plate at the back, that have the circular inset. The first such set to come my way was a cream one, and, not knowing what finish the insets should have, I bent some heavy gauge copper wire into shape and glued that in place: hardly something I'd recommend, though if I'll admit that, if I suspend my knowledge of what should be there, it looks quite as appropriate to me as the silvered ring given that nothing else on the set is silver in colour...

Paul

Aerodyne · 21st Nov 2005, 10:10 am

Unless you can find scrap knobs with the same size of ring AND successfully prise them out, I find the easiest alternative is to fill the grooves with silver paint, using a fine artist's watercolour brush. Allow it to harden off for a day or two them tidy up with Brasso. With care, the effect will be quite convincing.

-Tony

newlite4 · 21st Nov 2005, 6:04 pm

I have had a few of these late 90a's pass through my hands over recent years. It is quite usual for one or both of the chrome rings to be missing. I have used correction fluid to fill the (cleaned out) circular groove and polished this up with Brasso, this gives it an aged - not done yesterday - appearance. The clear perspex 'skirts' seem to be a greater problem though since their internal diameter seems to shrink with the passing of time. Careful positioning and use of Araldite is usually called for here.
Neil

avro · 21st Nov 2005, 6:08 pm

I always thought these were gold but on closer inspection they are silver

. If anyone has a good perspex backing please let me know as one of mine is cracked and this sort of thing can drive me to distraction

.

Avro near rainy Bruggen

Colin · 21st Nov 2005, 6:30 pm

I made the fatal mistake of using araldite to glue the clear perspex rings back together (they were both broken). The perspex seems to have reacted badly and they're now opaque and slightly 'crazed' - a bit like me come to think about it

I've tried polishing them but they're not what they were ... I'm learning to live with it!

mikelect · 21st Nov 2005, 6:55 pm

Quote:

Originally Posted by DON THOMSON

My later DAC 90A has the knobs with the inlaid "silver" circles embellishment, now tired and worn. Has any one successfully replaced these rings and if so, with what and how, please?

Hi Don there is something I want to try for this kind of job but so far haven't had the opprotunity

it is some stuff called embossing powder my wife uses it for greeting card making it is a metallic powder which when heated gently amalgamates together and expands to a very nice smooth metallic finish

I'm pretty sure it would do what you require maybe you'd need to experiment

a bit to get the hang of it but I reckon it must be worth a try

HTH

Mike

DON THOMSON · 23rd Nov 2005, 9:13 pm

Hi All

Thanks for your responses and interest. I was hoping to restore the set to as original a state as poss and also that some genius had come up with some way of getting the knobs to that brilliant chrome finish. If I come across a busted knob will experiment. Meantime have spent a lot of time with a teaspoon coaxing/coercing the plating or foil or whatever it is to lie flat. I am modestly pleased with the results, the set's appearance is original but used and not too tatty.

Regards

Don

20th Nov 2005, 1:25 pm	#1
DON THOMSON Retired Dormant Member Join Date: Nov 2005 Location: CHELMSFORD, ESSEX,UK Posts: 26	Dac90a Knobs My later DAC 90A has the knobs with the inlaid "silver" circles embellishment, now tired and worn. Has any one successfully replaced these rings and if so, with what and how, please?

21st Nov 2005, 12:39 am	#2
Hunts smoothing bomb Octode Join Date: Oct 2005 Location: Wimborne, Dorset, UK. Posts: 1,407	Re: Dac90a Knobs Hi Don, I have a DAC90A also but mine has no silver rings inset to the knobs, they are just plain, I don't know if thats cos it's an earlier version or weather yours may have the incorrect knobs, I'm not sure. Maybe someone can shed some light on this? Lee __________________ Lee

21st Nov 2005, 3:28 am	#3
Paul_RK Dekatron Join Date: Nov 2003 Location: Fakenham, Norfolk, UK. Posts: 4,259	Re: Dac90a Knobs Three different types of knobs were used on the DAC90A in succession, and it's only the last ones, with a perspex plate at the back, that have the circular inset. The first such set to come my way was a cream one, and, not knowing what finish the insets should have, I bent some heavy gauge copper wire into shape and glued that in place: hardly something I'd recommend, though if I'll admit that, if I suspend my knowledge of what should be there, it looks quite as appropriate to me as the silvered ring given that nothing else on the set is silver in colour... Paul

21st Nov 2005, 10:10 am	#4
Aerodyne Octode Join Date: Jun 2004 Location: Hampton Vale, Peterborough, UK. Posts: 1,698	Re: Dac90a Knobs Unless you can find scrap knobs with the same size of ring AND successfully prise them out, I find the easiest alternative is to fill the grooves with silver paint, using a fine artist's watercolour brush. Allow it to harden off for a day or two them tidy up with Brasso. With care, the effect will be quite convincing. -Tony

21st Nov 2005, 6:04 pm	#5
newlite4 Octode Join Date: Nov 2003 Location: Bath, Somerset, UK. Posts: 1,806	Re: Dac90a Knobs I have had a few of these late 90a's pass through my hands over recent years. It is quite usual for one or both of the chrome rings to be missing. I have used correction fluid to fill the (cleaned out) circular groove and polished this up with Brasso, this gives it an aged - not done yesterday - appearance. The clear perspex 'skirts' seem to be a greater problem though since their internal diameter seems to shrink with the passing of time. Careful positioning and use of Araldite is usually called for here. Neil

21st Nov 2005, 6:08 pm	#6
avro Heptode Join Date: Jun 2003 Location: Kapellen, Belgium Posts: 656	Re: Dac90a Knobs I always thought these were gold but on closer inspection they are silver . If anyone has a good perspex backing please let me know as one of mine is cracked and this sort of thing can drive me to distraction . Avro near rainy Bruggen

21st Nov 2005, 6:30 pm	#7
Colin Heptode Join Date: Jun 2004 Location: Ilkley, West Yorkshire, UK. Posts: 656	Re: Dac90a Knobs I made the fatal mistake of using araldite to glue the clear perspex rings back together (they were both broken). The perspex seems to have reacted badly and they're now opaque and slightly 'crazed' - a bit like me come to think about it I've tried polishing them but they're not what they were ... I'm learning to live with it!

23rd Nov 2005, 9:13 pm	#9
DON THOMSON Retired Dormant Member Join Date: Nov 2005 Location: CHELMSFORD, ESSEX,UK Posts: 26	Re: Dac90a Knobs Hi All Thanks for your responses and interest. I was hoping to restore the set to as original a state as poss and also that some genius had come up with some way of getting the knobs to that brilliant chrome finish. If I come across a busted knob will experiment. Meantime have spent a lot of time with a teaspoon coaxing/coercing the plating or foil or whatever it is to lie flat. I am modestly pleased with the results, the set's appearance is original but used and not too tatty. Regards Don