Bush DAC90A mains connector. - UK Vintage Radio Repair and Restoration Discussion Forum

FERNSEH · 22nd Dec 2019, 12:34 pm

Last week I repaired a Bush DAC90A for a customer. The repair job itself was easy enough and the fault was the UF41 If amplifier valve had an internal leak causing to the smoothed HT rail to read 45 volts instead of the normal 95 to 100 volts. Also attended to was the removal of the control grid components on the pin 4 tag of the UL41 valveholder.
Noteworthy is the non-reversible mains connector. Seen anything like this before?

DFWB.

ChasHeater · 22nd Dec 2019, 1:47 pm

I reckon looking at it that it's a standard plug that's been modified, good idea though...

Nickthedentist · 22nd Dec 2019, 2:13 pm

Maybe. Neat job if it is though.

I soldered the female bits onto the male on one of mine recently, then fitted the flex and free connector’s halves.

linescan87 · 22nd Dec 2019, 2:14 pm

I like that, it is a very good idea.

ms660 · 22nd Dec 2019, 2:21 pm

Plenty of DAC90a pictures on the web showing that hole between the input pins on the chassis, non for the DAC90 that I can see so far.

Lawrence.

FERNSEH · 22nd Dec 2019, 3:13 pm

Quote:

Originally Posted by ms660

Plenty of DAC90a pictures on the web showing that hole between the input pins on the chassis, non for the DAC90 that I can see so far.

Lawrence.

Including this later production DAC90A.

DFWB.

ms660 · 22nd Dec 2019, 3:28 pm

Yes they're everywhere, here's another with a lower S/No:

http://steveroyall.com/wp-content/up...4/IMG_1404.jpg

Lawrence.

Rubberfingers · 22nd Dec 2019, 3:29 pm

I wonder whether that was required for any juristrictions that the DAC 90A was exported to?. Or perhaps specified for non domestic use, schools maybe?

Alistair D · 22nd Dec 2019, 3:47 pm

From looking at the pictures I get the impression that the blade is original and professionally made. What do you think David?

Al

FERNSEH · 22nd Dec 2019, 3:56 pm

" From looking at the pictures I get the impression that the blade is original and professionally made. What do you think David?"
Hi Al,
I'm sure now that it is a factory part. When the DAC90A was introduced the three pin MK plug came about the same time. It's likely the designers of the set took advantage of the fact that the polarity can't be reversed with the new mains plugs.

DFWB.

stitch1 · 22nd Dec 2019, 5:26 pm

I’ve recently restored mine and never even noticed the ‘slot’ my serial number is close to the one in post #6.

The move from 2 to 3 pin plugs makes sense.

I just need to find the correct one now.

John

slidertogrid · 22nd Dec 2019, 5:38 pm

Maybe it was for when the set was used on D.C Mains? A good Idea though!

Helder Crespo · 14th Jan 2020, 9:38 pm

Quote:

Originally Posted by FERNSEH

Last week I repaired a Bush DAC90A for a customer. The repair job itself was easy enough and the fault was the UF41 If amplifier valve had an internal leak causing to the smoothed HT rail to read 45 volts instead of the normal 95 to 100 volts. Also attended to was the removal of the control grid components on the pin 4 tag of the UL41 valveholder.
Noteworthy is the non-reversible mains connector. Seen anything like this before?

DFWB.

Hi
This is very interesting. I have a 1957 cream DAC90A that has the very same slot in the mains "socket" (actually a plug) holder. My mains plug however is just the standard Bush, without the extra pin. Would it be possible for you to take detailed measurements of the pin (or perhaps just a photo from above next to a ruler for scaling purposes), together with the thickness? I would very much like to build a reproduction for my radio.
Thanks in advance!
Helder

stevehertz · 14th Jan 2020, 9:48 pm

I put a blob of red paint on the plug, and a corresponding blob on the radio socket panel. Ok, it's not foolproof, but I'm not quite a complete fool - yet..

PJL · 15th Jan 2020, 12:10 am

My 90A has the same slot and the Bush plug does not have the fitment. I like the idea it was for DC use. The idea of poking the metal locating pin into the bowels of the set does not fill me with confidence though.

DonaldStott · 15th Jan 2020, 1:37 pm

Like many other Forum members it seems I was blissfully unaware of the small slot between the two mains pins on my DAC90A (Serial No. 73/56971) so it's 0/10 for observational skills!

I just have the standard Bush two pin mains "plug" (technically two sockets) and have taken a similar approach to stevehertz by using red sticky dots to indicate the correct orientation.

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Nickthedentist · 15th Jan 2020, 1:56 pm

I painted "TOP" on one of mine.

22nd Dec 2019, 12:34 pm	#1
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Bush DAC90A mains connector. Last week I repaired a Bush DAC90A for a customer. The repair job itself was easy enough and the fault was the UF41 If amplifier valve had an internal leak causing to the smoothed HT rail to read 45 volts instead of the normal 95 to 100 volts. Also attended to was the removal of the control grid components on the pin 4 tag of the UL41 valveholder. Noteworthy is the non-reversible mains connector. Seen anything like this before? DFWB. Attached Thumbnails

22nd Dec 2019, 1:47 pm	#2
ChasHeater Triode Join Date: Jun 2018 Location: Ash, Surrey, UK. Posts: 38	Re: Bush DAC90A mains connector. I reckon looking at it that it's a standard plug that's been modified, good idea though...

22nd Dec 2019, 2:13 pm	#3
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,865	Re: Bush DAC90A mains connector. Maybe. Neat job if it is though. I soldered the female bits onto the male on one of mine recently, then fitted the flex and free connector’s halves.

22nd Dec 2019, 2:14 pm	#4
linescan87 Heptode Join Date: Mar 2014 Location: Meath, Ireland Posts: 551	Re: Bush DAC90A mains connector. I like that, it is a very good idea. __________________ All the best, John Joe www.youtube.com/c/ojnojirishvintagetvandradio

22nd Dec 2019, 2:21 pm	#5
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Bush DAC90A mains connector. Plenty of DAC90a pictures on the web showing that hole between the input pins on the chassis, non for the DAC90 that I can see so far. Lawrence.

22nd Dec 2019, 3:28 pm	#7
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Bush DAC90A mains connector. Yes they're everywhere, here's another with a lower S/No: http://steveroyall.com/wp-content/up...4/IMG_1404.jpg Lawrence.

22nd Dec 2019, 3:29 pm	#8
Rubberfingers Pentode Join Date: Oct 2012 Location: Dorset, UK. Posts: 240	Re: Bush DAC90A mains connector. I wonder whether that was required for any juristrictions that the DAC 90A was exported to?. Or perhaps specified for non domestic use, schools maybe?

22nd Dec 2019, 3:47 pm	#9
Alistair D Nonode Join Date: Jan 2010 Location: Edinburgh, UK. Posts: 2,008	Re: Bush DAC90A mains connector. From looking at the pictures I get the impression that the blade is original and professionally made. What do you think David? Al __________________ I won't tell you how I discovered that.

22nd Dec 2019, 3:56 pm	#10
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Bush DAC90A mains connector. " From looking at the pictures I get the impression that the blade is original and professionally made. What do you think David?" Hi Al, I'm sure now that it is a factory part. When the DAC90A was introduced the three pin MK plug came about the same time. It's likely the designers of the set took advantage of the fact that the polarity can't be reversed with the new mains plugs. DFWB.

22nd Dec 2019, 5:26 pm	#11
stitch1 Heptode Join Date: Jan 2008 Location: Durham, County Durham, UK. Posts: 826	Re: Bush DAC90A mains connector. I’ve recently restored mine and never even noticed the ‘slot’ my serial number is close to the one in post #6. The move from 2 to 3 pin plugs makes sense. I just need to find the correct one now. John Attached Thumbnails

22nd Dec 2019, 5:38 pm	#12
slidertogrid Octode Join Date: Apr 2005 Location: Peterborough, Cambridgeshire, UK. Posts: 1,898	Re: Bush DAC90A mains connector. Maybe it was for when the set was used on D.C Mains? A good Idea though!

14th Jan 2020, 9:48 pm	#14
stevehertz Dekatron Join Date: Sep 2011 Location: Rugeley, Staffordshire, UK. Posts: 8,834	Re: Bush DAC90A mains connector. I put a blob of red paint on the plug, and a corresponding blob on the radio socket panel. Ok, it's not foolproof, but I'm not quite a complete fool - yet.. __________________ A digital radio is the latest thing, but a vintage wireless is forever..

15th Jan 2020, 12:10 am	#15
PJL Dekatron Join Date: Sep 2005 Location: Seaford, East Sussex, UK. Posts: 5,997	Re: Bush DAC90A mains connector. My 90A has the same slot and the Bush plug does not have the fitment. I like the idea it was for DC use. The idea of poking the metal locating pin into the bowels of the set does not fill me with confidence though.

15th Jan 2020, 1:37 pm	#16
DonaldStott Octode Join Date: Aug 2015 Location: Glasgow, UK. Posts: 1,850	Re: Bush DAC90A mains connector. Like many other Forum members it seems I was blissfully unaware of the small slot between the two mains pins on my DAC90A (Serial No. 73/56971) so it's 0/10 for observational skills! I just have the standard Bush two pin mains "plug" (technically two sockets) and have taken a similar approach to stevehertz by using red sticky dots to indicate the correct orientation. __________________ BVWS Member Last edited by DonaldStott; 15th Jan 2020 at 1:38 pm. Reason: Typo

15th Jan 2020, 1:56 pm	#17
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,865	Re: Bush DAC90A mains connector. I painted "TOP" on one of mine.