Murphy A46 silent after recap - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

bosscock · 3rd Apr 2009, 10:56 pm

Steve,
Here's a pic of the T2 and speaker

Station X · 3rd Apr 2009, 11:08 pm

As point 72 is conected directly to point 29 there should be HT on all the valves, but it may be a bit "hummy".

We need to know whether there's HT on point 72. See post #17 above.

Station X · 3rd Apr 2009, 11:19 pm

The loudspeaker in this set has an energised coil (L22) rather than a permanent magnet. It's designated L.S.F (Loud Speaker Field). As well as energising the speaker this coil smooths the HT. It's still there on the speaker with two wires connected to it coloured red and green. The red wire seems to go to the primary of T2 which is correct. The green wire should go to C47. What's the resistance between the two wires? It should be 1400 ohms.

bosscock · 4th Apr 2009, 9:30 pm

Thanks for all the help guys, I'm going to bring it to the meet on sunday and hopefully a quick diagnostic from the ones who know, will put me on the right path..

3rd Apr 2009, 10:56 pm	#21
bosscock Retired Dormant Member Join Date: Mar 2009 Location: southport UK Posts: 49	Re: Murphy A46 silent after recap Steve, Here's a pic of the T2 and speaker Attached Thumbnails

3rd Apr 2009, 11:08 pm	#22
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Murphy A46 silent after recap As point 72 is conected directly to point 29 there should be HT on all the valves, but it may be a bit "hummy". We need to know whether there's HT on point 72. See post #17 above. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

3rd Apr 2009, 11:19 pm	#23
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Murphy A46 silent after recap The loudspeaker in this set has an energised coil (L22) rather than a permanent magnet. It's designated L.S.F (Loud Speaker Field). As well as energising the speaker this coil smooths the HT. It's still there on the speaker with two wires connected to it coloured red and green. The red wire seems to go to the primary of T2 which is correct. The green wire should go to C47. What's the resistance between the two wires? It should be 1400 ohms. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

4th Apr 2009, 9:30 pm	#24
bosscock Retired Dormant Member Join Date: Mar 2009 Location: southport UK Posts: 49	Re: Murphy A46 silent after recap Thanks for all the help guys, I'm going to bring it to the meet on sunday and hopefully a quick diagnostic from the ones who know, will put me on the right path..