1954 Ultra Troubadour U7961 AC/DC MW/LW 5 valve compact radio in dark brown - UK Vintage Radio Repair and Restoration Discussion Forum

howard · 30th Dec 2009, 6:52 pm

Hello again,

I restored one of these a few weeks back, a white one, which was straightforward and it turned out well. I also acquired a dark brown (almost black) one for £2 at the last Cowbit auction in scruffy condition which was almost certainly destined for the breakers yard as noone else there was interested in it. It didn't work but under the grime I reckonned it was restorable and fortunately I still had the remains of a scrap white U7961 for any spares I might need. Trader service sheet 1151 covers the Ultra Troubadour U6961 and U7961 models.

Someone had already had a go at fixing this set as there was fitted a new polyester 0.01uf AF coupling capacitor next to the UL41, a large polyester LCR 1500v 0.047uF mains filter capacitor and a new 2 core mains lead. I took out all the valves and tested them in my other U7961 and they were all good so I cleaned all the sockets and refitted them. The waveband switch and off/on/volume pot were also cleaned with Servisol 10 and the chassis cleaned with white spirit. The previous restorer had managed to tear the loudspeaker cone so I stuck that back together with a thin layer of Evo Stik timebond adhesive. The amp stage was now working as rocking the UL41 caused a lot of crackling, indeed the socket was so rusty and worn that I replaced it. I then replaced most of the remaining capacitors (including the mains filter capacitor with an X2) but still no signal. So I checked out its resistors and found 6 (!) which were 20+% out of spec so they were replaced and at last the set sort of worked, picking up one station covering the entire MW band but nothing on LW. So I took the set over to Ron Bryan for assistance.

A scope was attached and the operation of the tuning capacitor was checked and the frequency wasn't changing and as everything was correctly connected the oscillator tracking capacitor C10 was disconnected and another 680pf capacitor tacked in its place and away she went. An original 680pf mica capacitor was pinched from the scrap set, tested and then soldered permanently into place. IF alignment at 471 khz was still fine so RF alignment was performed. This was done twice as we'd missed adjusting C23 when realigning MW so LW didn't align successfully, but on the second attempt it tweaked up very well.

I took the dial and loudspeaker grille/cardboard baffle out of the case and cleaned the case and trim with B&Q upholstery cleaner and polished the outside of the case with Brasso. As the original dial was missing much of its print I replaced it with the perfect one in the scrap set. The frame aerial was hanging off the rear cover and had lost all its small pieces of tape so I replaced those with small pieces of masking tape and stuck the aerial back with a little Evo stik.

Unlike the white set this one took a lot of effort to get it working well. These aren't particularly well built as they were cheap and cheerful AC/DC sets in their day so I can understand why collectors don't bother with them nowadays. Still, it's a pretty little radio especially in this dark colour and this one now in nice condition works well and is very sensitive since realignment and sounds quite good via its little loudspeaker. My thanks to Ron Bryan for his help in diagnosing the fault in the set.

Howard

Steve_P · 30th Dec 2009, 7:24 pm

They aren't that bad. I've seen worse... For the 'second set' market maybe.

The Wavechange Switch causes problems sometimes. Glad it's OK on that one.

Cheers,

Steve P.

murphyv310 · 30th Dec 2009, 7:46 pm

Wow Howard!
I really cannot believe it!! What you have done here is exactly the same as I did on one of these two weeks ago.
The one I did would only tune on the top of medium wave no bottom end or long wave.
I also found the 3.3k resistor in series with the osc coil up to 5k and the 100pf osc feed back cap down to 30pf (it lives on the top of the chassis next to the tuning cap).
My customer was well pleased with the repair and commented it is working better than when new, I am surprised though as she is quite deaf now.
Nice job.
Trevor

howard · 30th Dec 2009, 11:12 pm

Quote:

Originally Posted by Steve_P

They aren't that bad. I've seen worse... For the 'second set' market maybe. The Wavechange Switch causes problems sometimes. Glad it's OK on that one. Cheers, Steve P.

Yes, definitely a second set. Surprisingly it was similar in price to the Bush DAC90A but it doesn't feel as robust as the Bush. The waveband switches were fine, and I still have a spare one in the scrap set if anyone wants it.

Howard

howard · 30th Dec 2009, 11:28 pm

Quote:

Originally Posted by murphyv310

Wow Howard!
I really cannot believe it!! What you have done here is exactly the same as I did on one of these two weeks ago.
The one I did would only tune on the top of medium wave no bottom end or long wave.
I also found the 3.3k resistor in series with the osc coil up to 5k and the 100pf osc feed back cap down to 30pf (it lives on the top of the chassis next to the tuning cap).
My customer was well pleased with the repair and commented it is working better than when new, I am surprised though as she is quite deaf now.
Nice job.
Trevor

Hello Trevor,

I guess then that future restorers of these Troubadours will now know where to look first for problems ! That 3.3k resistor R3 was way out of spec on mine too and was replaced, but the 100pf Hunts capacitor on the top of the chassis was still working, but I changed it anyway.

This radio had more faulty resistors than any other set that I've restored to date. Still, it has an easy chassis to work on and the total cost of the new components was only around £5 so for £7 in total it's a nice little radio.

As your customer has been using one of these since 1954 and it's still working well it must be better quality than I thought !

Howard

Hermit6345 · 31st Dec 2009, 5:31 am

Another good job Howard. I have one of these in very good order and that suffered from the 100pF cap on top of the chassis going low as well. The symptoms were that set wouldn't work on LW. Hoiked out all the decoupler caps whilst I was in there and it's worked faultlessly ever since. We had one of these new in about 1955 or so and it's still going, so can't be all bad I suppose. Definitely a second set along with the little U960.

Ian.

howard · 31st Dec 2009, 10:03 pm

Thanks Ian,

So yet another Troubadour still going strong after 55 years, it seems that these little sets do last well. I certainly thought that of the white one but this one was well worn.

If anyone wants IFTs or waveband switch etc from the scrap U7961 let me know ASAP as I'll be binning it shortly. The oscillator coil is now taken.

Another £2 Cowbit set now in theatre, a Bush VHF80C, and it's almost finished.

Howard

30th Dec 2009, 6:52 pm	#1
howard Nonode Join Date: May 2005 Location: Godalming, Surrey, UK. Posts: 2,593	1954 Ultra Troubadour U7961 AC/DC MW/LW 5 valve compact radio in dark brown Hello again, I restored one of these a few weeks back, a white one, which was straightforward and it turned out well. I also acquired a dark brown (almost black) one for £2 at the last Cowbit auction in scruffy condition which was almost certainly destined for the breakers yard as noone else there was interested in it. It didn't work but under the grime I reckonned it was restorable and fortunately I still had the remains of a scrap white U7961 for any spares I might need. Trader service sheet 1151 covers the Ultra Troubadour U6961 and U7961 models. Someone had already had a go at fixing this set as there was fitted a new polyester 0.01uf AF coupling capacitor next to the UL41, a large polyester LCR 1500v 0.047uF mains filter capacitor and a new 2 core mains lead. I took out all the valves and tested them in my other U7961 and they were all good so I cleaned all the sockets and refitted them. The waveband switch and off/on/volume pot were also cleaned with Servisol 10 and the chassis cleaned with white spirit. The previous restorer had managed to tear the loudspeaker cone so I stuck that back together with a thin layer of Evo Stik timebond adhesive. The amp stage was now working as rocking the UL41 caused a lot of crackling, indeed the socket was so rusty and worn that I replaced it. I then replaced most of the remaining capacitors (including the mains filter capacitor with an X2) but still no signal. So I checked out its resistors and found 6 (!) which were 20+% out of spec so they were replaced and at last the set sort of worked, picking up one station covering the entire MW band but nothing on LW. So I took the set over to Ron Bryan for assistance. A scope was attached and the operation of the tuning capacitor was checked and the frequency wasn't changing and as everything was correctly connected the oscillator tracking capacitor C10 was disconnected and another 680pf capacitor tacked in its place and away she went. An original 680pf mica capacitor was pinched from the scrap set, tested and then soldered permanently into place. IF alignment at 471 khz was still fine so RF alignment was performed. This was done twice as we'd missed adjusting C23 when realigning MW so LW didn't align successfully, but on the second attempt it tweaked up very well. I took the dial and loudspeaker grille/cardboard baffle out of the case and cleaned the case and trim with B&Q upholstery cleaner and polished the outside of the case with Brasso. As the original dial was missing much of its print I replaced it with the perfect one in the scrap set. The frame aerial was hanging off the rear cover and had lost all its small pieces of tape so I replaced those with small pieces of masking tape and stuck the aerial back with a little Evo stik. Unlike the white set this one took a lot of effort to get it working well. These aren't particularly well built as they were cheap and cheerful AC/DC sets in their day so I can understand why collectors don't bother with them nowadays. Still, it's a pretty little radio especially in this dark colour and this one now in nice condition works well and is very sensitive since realignment and sounds quite good via its little loudspeaker. My thanks to Ron Bryan for his help in diagnosing the fault in the set. Howard Attached Thumbnails

30th Dec 2009, 7:24 pm	#2
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: 1954 Ultra Troubadour U7961 AC/DC MW/LW 5 valve compact radio in dark brown They aren't that bad. I've seen worse... For the 'second set' market maybe. The Wavechange Switch causes problems sometimes. Glad it's OK on that one. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

30th Dec 2009, 7:46 pm	#3
murphyv310 Dekatron Join Date: Sep 2006 Location: Kilmarnock, Ayrshire, UK. Posts: 5,422	Re: 1954 Ultra Troubadour U7961 AC/DC MW/LW 5 valve compact radio in dark brown Wow Howard! I really cannot believe it!! What you have done here is exactly the same as I did on one of these two weeks ago. The one I did would only tune on the top of medium wave no bottom end or long wave. I also found the 3.3k resistor in series with the osc coil up to 5k and the 100pf osc feed back cap down to 30pf (it lives on the top of the chassis next to the tuning cap). My customer was well pleased with the repair and commented it is working better than when new, I am surprised though as she is quite deaf now. Nice job. Trevor __________________ Cheers, Trevor. MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member

31st Dec 2009, 5:31 am	#6
Hermit6345 Rest in Peace Join Date: Oct 2006 Location: North Wiltshire, UK. Posts: 638	Re: 1954 Ultra Troubadour U7961 AC/DC MW/LW 5 valve compact radio in dark brown Another good job Howard. I have one of these in very good order and that suffered from the 100pF cap on top of the chassis going low as well. The symptoms were that set wouldn't work on LW. Hoiked out all the decoupler caps whilst I was in there and it's worked faultlessly ever since. We had one of these new in about 1955 or so and it's still going, so can't be all bad I suppose. Definitely a second set along with the little U960. Ian.

31st Dec 2009, 10:03 pm	#7
howard Nonode Join Date: May 2005 Location: Godalming, Surrey, UK. Posts: 2,593	Re: 1954 Ultra Troubadour U7961 AC/DC MW/LW 5 valve compact radio in dark brown Thanks Ian, So yet another Troubadour still going strong after 55 years, it seems that these little sets do last well. I certainly thought that of the white one but this one was well worn. If anyone wants IFTs or waveband switch etc from the scrap U7961 let me know ASAP as I'll be binning it shortly. The oscillator coil is now taken. Another £2 Cowbit set now in theatre, a Bush VHF80C, and it's almost finished. Howard