|
Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
|
Thread Tools |
16th Aug 2018, 6:31 pm | #1 |
Pentode
Join Date: Jan 2013
Location: Immingham, North East Lincolnshire, UK.
Posts: 174
|
Eddystone EB35
Hello all,
I got this from a mate to repair, it has been used at sea on a trawler so is badly corroded. I have managed to get it working by replacing TR1/2/3 OC171s which had tin whiskers with AF178s. FM worked perfectly but none of the AM bands did. I checked the new transistors before replacement but when I rechecked TR1 it was short from screen to collector. I remember a thread a while back which stated that AF178s didn't suffer from tin whiskers. Anyway FM SW1 SW2 and MW work perfectly. SW3 and LW are dead. All suggestions welcome. John. |
16th Aug 2018, 6:48 pm | #2 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,010
|
Re: Eddystone EB35
Check for dry-joints in the SW3/LW oscillator circuitry: if the LO isn't running you'll not hear anything.
Another receiver, tuned to the expected LO frequency and with a few feet of wire as an antenna, is a great tool to confirm that your problem-radio's LO is actually oscillating] Eddystone quality-control was often rather less-than-perfect: I've got an 870A here which on acquisition was totally dead on its highest-frequency range. Investigation revealed a soldered-joint on the LO coil which had clearly _never_possibly_have_been_ conductive ! |