[Scott Dorsey]

In article ,
wrote:
On Thursday, February 3, 2011 at 5:45:47 AM UTC-8, Klay Anderson wrote:
On Feb 1, 10:06=C2=A0pm, nmm wrote:
Both the bulbs are burnt out on my AKG BX-20E reverb. They are a weird
thread, push in and twist, but not the usual style.

Is this something that is still available? Are they some weird
Euro-70s thing?

Anyone know the name and part number I should be looking for?

=20
=20
OK you youngsters. Looking at the BX20 schematic and after
electroshock to recharge my memory, the mains lamp on the power supply
is across the mains primary. Memory says that this was a common (in
Europe) neon discharge bulb with integral resistor. This was also the
case on EMT, Sennheiser and Neumann power supplies. The USA NE2-style
had discharge rods, was bare glass with no resistor, but these cute
little bayonets had two half-moon discharge plates facing up away from
the base and a bit of magnifying glass on the bulb tip for top-
viewing. Resistor was in the base--I think. Neon bulbs get gassy over
time and fade out. One could cobble a replacement from the existing
bulb base, a neon lamp and a resistor. I see the pilot lamp on the
remote is fed from 24VDC and that might be had commercially. It may
be a wedge bulb like Dolby used in the 361s of the time (remember when
Dolby was in the UK?). I actually still have some of those bulbs.

Both bulbs are BA7s base. The 24/28v version is readily available online. T=
he Neon Pilot lamp not so much. I did find a vendor who had a few unmarked =
BA7s Neons and I got lucky.

It just happened that I needed some for a mike power supply recently and
Grainger had them in stock.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."