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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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12th Jun 2021, 8:07 pm | #1 |
Heptode
Join Date: Jun 2005
Location: Sunderland, Tyne and Wear, UK.
Posts: 661
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Standard DAC90A Chassis
Hi bought a DAC90A chassis to do a conversion and when it arrived I noticed that it has a grey mains dropper. I read somewhere that the early models had a grey mains dropper. Looked on the smoothing capacitor and it is dated March 1952 the chassis is very clean and never been touched so I have decided to keep it standard and only going to snip out C22 mains filter capacitor & replace C14, C18, C20 and give it a decent soak test.
What do you think? Kind regards, Bob. |
12th Jun 2021, 9:59 pm | #2 |
Dekatron
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
Posts: 7,567
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Re: Standard DAC90A Chassis
Yes apparently the grey ones were less reliable but not sure how true that is....I don't think I've had a failed DAC90A dropper.
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12th Jun 2021, 10:36 pm | #3 |
Pentode
Join Date: Jul 2020
Location: Falkirk, Stirlingshire, UK.
Posts: 200
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Re: Standard DAC90A Chassis
Hi Bob
The DAC90A I am restoring just now has a grey mains dropper, will post pics tomorrow, had it playing in the garden today, complete with the mains pins Norman kindly sent me. Some of the coating has come of the dropper, but still works, my other DAC90A has a green dropper, not sure what the difference is re functionality. Cheers Lee |
13th Jun 2021, 12:56 pm | #4 |
Heptode
Join Date: Jun 2005
Location: Sunderland, Tyne and Wear, UK.
Posts: 661
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Re: Standard DAC90A Chassis
Hi Sideband.
You might be right there i got a chassis a while ago with a grey dropper and it had been got at. It was bodged with an RS Polo Mint resistor so I put in an auto transformer from Ed Dinning. Hi Lee glad you have got your set working look forward to seeing some pictures. Kind regards, Bob. |
13th Jun 2021, 5:14 pm | #5 |
Heptode
Join Date: Jun 2005
Location: Sunderland, Tyne and Wear, UK.
Posts: 661
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Bush DAC90A Grey Mains Dropper
Hi.
Hope I am not boring people about Bush DAC90A's. Here we go forum member Scotorvm and I have a DAC90A's with grey mains droppers. My set dates from March 1952 & Scotorvm's set dates from July 1953. Have any other forum members got sets with grey mains droppers and what year are they? Kind regards, Bob. |
14th Jun 2021, 9:33 am | #6 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,535
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Re: Standard DAC90A Chassis
Since these dates are from the can electrolytic markings, they aren't actual production dates, only dates earlier than which the set could not have been built. Actual production dates will depend on what the supply chain and Bush's internal stockholding delays were.
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14th Jun 2021, 10:34 am | #7 |
Dekatron
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
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Re: Standard DAC90A Chassis
Never seen one myself but were very early production DAC90A sets constructed on DAC90 chassis metalwork? Adaptor plates used for the fitment of the B8A valveholders.
DFWB. |
14th Jun 2021, 10:42 am | #8 |
Dekatron
Join Date: Sep 2006
Location: Kilmarnock, Ayrshire, UK.
Posts: 5,421
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Re: Standard DAC90A Chassis
Now Now David behave!!
Adaptor plates were not invented then. You must hold the patent!!!
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14th Jun 2021, 10:48 am | #9 |
Dekatron
Join Date: Sep 2006
Location: Kilmarnock, Ayrshire, UK.
Posts: 5,421
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Re: Standard DAC90A Chassis
Hi.
I always replace the dropper with a capacitor as the reduction of heat is quite marked. It is a good idea on the cream versions especially, they are more prone to cracks and discolouration than the brown or black ones.
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Cheers, Trevor. MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member |
19th Jun 2021, 4:41 pm | #10 |
Heptode
Join Date: Jun 2005
Location: Sunderland, Tyne and Wear, UK.
Posts: 661
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Re: Standard DAC90A Chassis
UPDATE done what i said in post 1 and replaced the UY41 Valve that was duff (Thanks very much to Adrian H ) now it is playing very well no hum did not have to do the UL 41 pin mod on soak test now nice Standard 1952 radio to my collection
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