Attention Old Telephone Equipment Collectors

[58limited]

I have read in past threads that some of the members here have old switchboards and other telephone equipment. I'm looking for GE or Sylvania 48A light bulbs. I've been told that these were very common and were often used on switchboards and other telephone equipment, but now they are hard to find. Me and another person both need some for our Spilhaus Space Clocks - the illumination comes from three of these bulbs for each clock. If you can help, please e-mail me. Thanks, David

 

[huggybear]

Are they a 48 volt slide base? If so, yes they are common and there should be many sources. The more common number is 48PSB - do a Google search for it and you can find them easily. This picture is from Allied Electronics, one source that has them.

They make them in voltages from 6 to 120 volts, you're not stuck with 48 volts.

 

[58limited]

Thanks, I didn't find any sources when I did my search earlier. I'll try the 48PSB number.

Many places cross list the 48A with a 48C, which will not work - it puts out half the light. A few places are now carrying offbrand repros that aren't as good as the originals, so I'd like to find a source for the originals - they supposedly lasted for thousands of hours.

 

[58limited]

OK, it looks like Allied and another site both carry Sylvania 48PSBs. I'll give them a try - the specs look the same as the original 48A, including the 10,000 hour bulb life.

Thanks, Huggybear

 

[tolivac]

At work I have the same problem-our control room console that was built in the early 60's is full of these lights.Its getting harder and harder to get the 48 series bulbs.I am open to sources as well.At one time there were some LED replacements-but the supplier couldn't supply them.Would have been nice-less of a power drain on the 48DC "house" 48V batterey system.

 

[58limited]

48A Vs. 48PSB

Here is the response I got from a guy who restores the Spilhaus Space Clocks - which is what I need these bulbs for. The main difference is the overall length: 1.11" for the 48PSB and 1.69" for the 48A. He has some but they are expensive:

"Unfortunately the replacement you list will not work in our
application. First the filament is not the same and so the lighting characteristics will not be the same. This is not a huge deal but the glow is already minimal in our use. The bigger problem is the length of the base, substantially shorter. I just recently had a clock with these short bulbs and it was not possible to insert the bulb in the hole and position it correctly without disassembling the clock. Here are a couple of links, one to the original lamp and one
to the PSB that you mention. You can see in the lower left of the page, the difference in the base:

original 48A:

http://www.donsbulbs.com/cgi-bin/r/b.pl/48a~usa.html

PSB:

http://www.donsbulbs.com/cgi-bin/r/b.pl/48|psb.html

Another alternative is to convert the clock to #44 bulbs and add a transformer. I have plans for doing this but have not converted a clock yet."