HMV 441 volume restored (or read the instructions!) - UK Vintage Radio Repair and Restoration Discussion Forum

Ian B · 25th Oct 2008, 7:57 pm

I restored an HMV 441 (released in 1935) about 2 years ago, including a rebuild of the capacitor block. Despite a full re-alignment and an excellent set of valves it refused to give full output, the volume control had to be set to maximum to hear it. Although it was capable of picking up loads of stations, even without an aerial. I put it away to sort another day.....

Earlier this week I decided to have another look. Instead of the Trader sheet 577 I used the manufacturer's data (from Paul's dvd) going over everything again, every connection. All the voltages were spot on, everything apparently correct.

Then I looked at the diagram again (for about the 100th time). There's a switch to earth the output transformer secondary. It's actually built in to the wavechange switch - because its function is to mute the speaker while changing waveband. So I loosened the screw holding the tag on the pink wire to the terminal block. Result - deafening volume!
Presumably the contacts of the switch have stuck together, but because I hadn't looked closely at that part of the diagram before, I wasn't even aware of the switch. (RTFM!= read the flipping manual).
Doh! I thought it must be something really stupid - trouble is, so am I!

Ian Blackbourn

Robert Darwent · 25th Oct 2008, 8:29 pm

Quote:

Originally Posted by Ian B

Then I looked at the diagram again (for about the 100th time). ...but because I hadn't looked closely at that part of the diagram before, I wasn't even aware of the switch.

Hi Ian,

I think we've all done that at some time or other. Sometimes its hard to see the wood for the trees, and the most obvious and simple of things get overlooked...repeatedly!

Don't be too hard on yourself it probably won't be the last time it happens, certainly not when referring to myself anyway!

Anyhow all that matters is that you've solved the conundrum and got the set working as it should again, well done!

Best wishes and regards

25th Oct 2008, 7:57 pm	#1
Ian B Hexode Join Date: May 2006 Location: Arlesey, Bedfordshire, UK. Posts: 401	HMV 441 volume restored (or read the instructions!) I restored an HMV 441 (released in 1935) about 2 years ago, including a rebuild of the capacitor block. Despite a full re-alignment and an excellent set of valves it refused to give full output, the volume control had to be set to maximum to hear it. Although it was capable of picking up loads of stations, even without an aerial. I put it away to sort another day..... Earlier this week I decided to have another look. Instead of the Trader sheet 577 I used the manufacturer's data (from Paul's dvd) going over everything again, every connection. All the voltages were spot on, everything apparently correct. Then I looked at the diagram again (for about the 100th time). There's a switch to earth the output transformer secondary. It's actually built in to the wavechange switch - because its function is to mute the speaker while changing waveband. So I loosened the screw holding the tag on the pink wire to the terminal block. Result - deafening volume! Presumably the contacts of the switch have stuck together, but because I hadn't looked closely at that part of the diagram before, I wasn't even aware of the switch. (RTFM!= read the flipping manual). Doh! I thought it must be something really stupid - trouble is, so am I! Ian Blackbourn