UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Offered and Wanted Messages > Sets, Parts and Service Information Wanted (private buyers only, no swaps)

Notices

Sets, Parts and Service Information Wanted (private buyers only, no swaps) If you need help obtaining components, sets or equipment, post a message here. Private buyers only - no traders. No swaps.

Reply
 
Thread Tools
Old 27th Nov 2021, 11:49 am   #1
DonaldStott
Octode
 
DonaldStott's Avatar
 
Join Date: Aug 2015
Location: Glasgow, UK.
Posts: 1,477
Default Bush DAC90A bulbs

From time to time it seems to be the case that the 3.5V 0.15A bulbs for the DAC90A are impossible to find?

Managed to blow both bulbs after accidentally shorting two valve pins!

I have substituted some 6V 0.15A bulbs meantime?

Anyone found a current source for these (pardon the pun)?
__________________
BVWS Member
DonaldStott is offline   Reply With Quote
Old 27th Nov 2021, 6:58 pm   #2
Ed_Dinning
Dekatron
 
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 7,187
Default Re: Bush DAC90A bulbs

Hi Donald, I previously used some RS led bulbs, 6v rated and wired in parallel as the take a low current. Purists may not like these as the have too "white" a glow, but work well.
The auto transformer I designed for these sets will power either a series pair of the 3,5v bulbs or a parallel pair of 6.3v 50mA lamps. These are fed from the 6.3v tap on the transformer and are much better voltage stabilised than in the series heater chain configuration. The bypass resistor is then removed


Ed
Ed_Dinning is offline   Reply With Quote
Old 28th Nov 2021, 6:35 pm   #3
yestertech
Octode
 
yestertech's Avatar
 
Join Date: Dec 2002
Location: Coulsdon, Surrey, UK.
Posts: 1,858
Default Re: Bush DAC90A bulbs

I still have some of these from a batch I had made some years back
PM me if you're still in need.

Andy
yestertech is offline   Reply With Quote
Old 29th Nov 2021, 4:48 pm   #4
agardiner
Heptode
 
agardiner's Avatar
 
Join Date: Sep 2020
Location: Thetford, Norfolk, UK.
Posts: 633
Default Re: Bush DAC90A bulbs

Andy, at risk of you being flooded with requests, do you have many? I could certainly use some if available. Was going to resort to the 6V parallel method.
agardiner is offline   Reply With Quote
Old 29th Nov 2021, 5:04 pm   #5
DonaldStott
Octode
 
DonaldStott's Avatar
 
Join Date: Aug 2015
Location: Glasgow, UK.
Posts: 1,477
Default Re: Bush DAC90A bulbs

Thanks Andy - PM sent.

Still looking, but meantime:-

3.5V 0.2A vs 6V 0.15A

Discuss in the context of the Scale lamps shunt value?
__________________
BVWS Member

Last edited by DonaldStott; 29th Nov 2021 at 5:13 pm.
DonaldStott is offline   Reply With Quote
Old 29th Nov 2021, 7:30 pm   #6
electrogram
Heptode
 
Join Date: Jul 2008
Location: Hereford, UK.
Posts: 650
Default Re: Bush DAC90A bulbs

I use 6v - or are they 6.5v - 100ma in series , with a 180 ohm shunt
electrogram is offline   Reply With Quote
Old 29th Nov 2021, 8:29 pm   #7
Ian - G4JQT
Octode
 
Ian - G4JQT's Avatar
 
Join Date: Jun 2004
Location: Reading/Fakenham, UK.
Posts: 1,118
Default Re: Bush DAC90A bulbs

I've not tried it - or bothered to check the maths - but didn't someone recently say they just re-wired the DAC90A bulb holders for 6.3V 150 mA in parallel? It seems too easy a solution I must admit!

Ian
Ian - G4JQT is offline   Reply With Quote
Old 30th Nov 2021, 5:12 pm   #8
yestertech
Octode
 
yestertech's Avatar
 
Join Date: Dec 2002
Location: Coulsdon, Surrey, UK.
Posts: 1,858
Default Re: Bush DAC90A bulbs

Quote:
Originally Posted by agardiner View Post
Andy, at risk of you being flooded with requests, do you have many? I could certainly use some if available. Was going to resort to the 6V parallel method.
PM sent

A.
yestertech is offline   Reply With Quote
Old 7th Dec 2021, 6:36 am   #9
AD360 Rob
Hexode
 
AD360 Rob's Avatar
 
Join Date: Jun 2012
Location: Chester, Cheshire, UK.
Posts: 403
Default Re: Bush DAC90A bulbs

Quote:
Originally Posted by Ian - G4JQT View Post
I've not tried it - or bothered to check the maths - but didn't someone recently say they just re-wired the DAC90A bulb holders for 6.3V 150 mA in parallel? It seems too easy a solution I must admit!

Ian
I think that was me Ian, someone else had wired the lampholders in paralell which caught me out when I replaced the lamps with the correct 3.5v 150mA ones. I put it back to standard.

Rob
AD360 Rob is offline   Reply With Quote
Reply

Thread Tools



All times are GMT. The time now is 11:22 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2022, vBulletin Solutions, Inc.
Copyright ©2002 - 2021, Paul Stenning.