Trace Elliot lamp

[Jazz P Bass]

I have a Trace Elliot GP12 SMX on the bench.
The repair is complete.
All it needs now is a fluorescent lamp.
Does anybody know of a source for these lamps.
The only marking is" G6 EV".or "EU". Weird font.
It has 3 pins, soldered to board.

[Enzo]

Photo?


Only ones I remember were the 18" black-light bulbs.

[Jazz P Bass]

Trace Elloit lamp

Sorry, no photo.
6mm diameter, 20mm length, frosted, 3 leads.
Internal resistance between lead 1 & 2 is 25.5 ohms.
Nothing between 1, 2 & 3.
The circuit has 24 volts through a 430 ohm 2 watt resistor to pin 1.
Pin 2 is at ground.
Pin 3 has 24 volts through a 1000 ohm 1/4 watt resistor.
I think I will try a 24 volt frosted lamp.
What they are doing with the lamps is lighting a rubber O ring around each control pot. The front panel is bored out so that you can see the ring light up.
Kinda freaky, I had the rings on the bench & I turned out the lights.
They glow in the dark!

[oc disorder]

Hi again Jazz P Bass

British Audio Service has a page of Trace Elliot Lamps.
BRITISH AUDIO SERVICE
Unfortunately they don't seem to have the three legged kind !
May be worth an email as they seem to have more on Trace Elliot than anyone else.

The glowing front panel seemed to be popular then in UK manufacture.
H and H amplifiers had a Electroluminescent panel under the perspex
complete with high voltages.
Also Neve and MCI desks had plasma displays back then but now I gather
they use led's. High voltages in desks like that must have been a pain to service,

As you know the parts list for a Trace shows" BULB 73-FLUOR-TUBE ".
British Audio Service lists :-
73-UVT
18" Ultraviolet Light
Used in Trace Bass Amplifiers
$14.99 Each, USD

Which is what Enzo recalls so I expect there was a change in design at some point.
Funny how the schematic doesn't seem to show any of the illumination.
The Fluro tube would have to have a ballast which British Audio Service also sell.

Diverse Devices, Southampton, England posted about this in sci.tech-archive.net 2007 :-
"Some strange HV stuff here, front panel "lamps" that are 3 legged phosphorescent bulbs -
where would you go to get generic/ not main agent replacements ? no obvious HV wiring"

He may have found out about them by now DIVERSE DEVICES

Perhaps a string of high brightness LED's in a plastic tube might be easier to knock up hey you could even use different colors and a rotary switch to change color schemes !

[Steve Conner]

I think these are probably mercury vapour lamps with a filament inside. Two of the legs will be for the filament, the third one will be some sort of starting electrode to ignite a glow discharge across the filament. Result lots of lovely UV to make the panel glow in the dark, as was Trace's house style.

Lightbulb uber-nerd Don Klipstein mentions some similar lamps in his lighting FAQ: Ultraviolet and UV Lamps

Nowadays it might be easier to use UV LEDs than find a replacement.

As far as I know, the light in older, bigger Traces is just an ordinary blacklight tube with an ordinary magnetic ballast and starter. Ballasts in the UK are quite different to American ones because of our 240V line voltage, so I don't know what Trace used for export models.

I once had a summer job with BBC Scotland, and came across one of those Neve desks with the plasma VU meters. It was in the outside broadcast truck, and Scottish weather being what it is, the high voltage driver circuits were forever shorting out because of damp. The only way to access them was to crawl under the desk and squeeze behind the back of it, which was my job.

[oc disorder]

mmm Learn something new every day...
Guess the UV led's would be the way to go..
Did find the attached thanks to Steve's post

[Jazz P Bass]

UV Lamp

I do not know how you found it OC.
Thanks!
I sent an RFQ to the company.
This should go over swell.
I'll keep you posted.
John G

[Mark Black]

Huh - you guys got me curious about that wacky lamp so I googled the first half of the part number and much to my surprise came up with a hit at Mouser:

BGF717-UV1 JKL Components Ultraviolet Lamps

Looks like it might be a longer-life version.

Slightly different wavelength too...

[Jazz P Bass]

UV lamp

Thanks a bunch Mark.
I never even considered Mouser.
I am ordering one today.
I will keep you posted on the results.

[Jazz P Bass]

Trace Elliot lamp

I received the lamp from Mouser.
Ordered the "white" one. Part# BG717-22.
It has more UV then the original but it is better than a burnt lamp.

Thanks for the assist.