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Old 8th May 2011, 11:24 pm   #1
simon.spanswick
Retired Dormant Member
 
Join Date: May 2011
Location: Hawkhurst
Posts: 1
Default GPO LST4 power supply 86B

I've just managed to acquire something I've dreamt of owning since I first saw it when I was a kid...an LST4 loudspeaking telephone. It appears to be in great condition, with a proper block that doesn't appear to have been used as the break-out for the incoming cable has not been broken.

However, I'm struggling to find a suitable power supply for the LST4. The GPO 50v dc power supply number 86B is nowhere in evidence on the interweb, nor on Ebay where I sourced the LST4 (which in fact turns out to be the very last model produced, the 4265, which was designed to deliver DTMF tones for proprietary PABXs - although I thought I was buying an earlier LST4D with rotary dial).

If anyone has any ideas on where to get an 86B PSU, or has one knocking around they'd like to get rid of to a good home, please let me know. Alternatively, if someone can suggest a suitable modern PSU that would drive the LST4, I'd be grateful for any assistance. There's no indication on what amperage the 86B 50v dc PSU delivered...again, any thoughts from people who understand electrical stuff would be very much appreciated.

It certainly demonstrates how electronics have developed over the past 40 years since we can now drive pretty much all electronic devices from just 9V!
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