Murphy A122M "baffle board" - UK Vintage Radio Repair and Restoration Discussion Forum

ted_ntsx · 21st Jul 2012, 2:24 pm

Not sure if this really belongs in the "success stories" section, as it is only a partial success so far...

This Murphy A122M was found in a barn where it had languished for many years. It had definitely seen better days. The cabinet was rather battered and the back cover showed signs of damp.

A quick visual inspection revealed the original mains lead was just a little bit unsafe(! see photo) but inside it appeared not be have been touched for ages. A thick coating of dust and spiders webs with no obvious disturbance or fingerprints! Some slight corrosion of metalwork, but nothing much. Promising!

The two smoothing caps looked very defunct. Both had swollen, leaked and corroded badly. I suspect this may have been the cause of the radios original demise and why it was consigned to the barn.

I replaced the mains lead, the smoothing caps, and THAT capacitor, and then powered it up via a lamp limiter. No smoke or bangs, so I increased the power at bit. The valves now lit up but nothing else happened apart from the UU6 rectifier putting on a firework display. No HT of course (well, about 10 volts). I temporarily bridged the UU6 with silicon diodes and a surge limiter and tried again. This time it hummed and crackled into faint life. HT was about 150 volts. After removing the lamp limiter the HT went up to 250 volts and the radio started working quite well. Next step was to replace all the other usual waxies, clean the wavechange switch, and replace the blown pilot lamps. The set then worked surprisingly well, with a great sound and plenty of audio power.

Most of the remaining work is now cosmetic. The cabinet is in poor condition, but that's a job that will have to wait a while, and it is missing a knob.

All in all, it performs very well for very little effort considering the state it was in.

I now need a replacement UU6 and a knob, so if anyone had one spare.....

Nickthedentist · 21st Jul 2012, 6:36 pm

You must have found that in a better class of barn, Ted. Most of the "barn find" radios I've seen have been a mass of delaminated plywood, rust, and mouse-infested wiring.

Your cabinet looks promising; some T-cut, Scratch Cover and Danish oil or wax should make it very presentable. Let's hope you find a knob.

Well done for getting it going. The rough-and-ready sets are often the most satisfying to hear working again. It would be fascinating to know how long ago it had been retired. Were there any other clues in the barn?

Nick.

ted_ntsx · 22nd Jul 2012, 8:22 am

No, no other clues. I never saw the "barn" myself, just told that it had been found in one. Other than that I know nothing about its history.

Cabinet repairs are not my strong point, but I will certainly do what I can to make it look good again.

Ted.

Tractorfan · 22nd Jul 2012, 9:33 am

Hi,
I've got two A122s with the same chassis, but different cabinet design. It's interesting to note that yours has a B4 socket for the "gram" input. Mine just have the usual wander plug sockets. They are lovely sets, I was given an A122 when a kid & spent many happy hours slowly trawling the shortwave band. Heaven!

Cheers, Pete

howard · 22nd Jul 2012, 11:29 pm

Hello Ted,

Well done, good to see another baffle board Murphy working again. They do sound good these sets. I'm sure someone here can help you out with the missing knob and rectifier valve.

Howard

Phil G4SPZ · 23rd Jul 2012, 12:05 am

This model was one of my first repairs. I don't claim to have restored it, because there is still a lot of brittle rubber-insulated wiring that really needs replacement, and this seems to be a common issue with post-war Murphys. However the A122 sounds beautiful and can be forgiven!

paulsherwin · 23rd Jul 2012, 12:29 am

I think the cabinet may be too far gone for the T-Cut treatment. If you don't want to do a full semi-pro cabinet restoration, it will look much better if you strip off the old cellulose varnish with Nitromors or similar stripper, then wax the surface with coloured liquid wax like Colron. It won't look original but it will still look very presentable for a minimum of skill and effort.

ted_ntsx · 27th Jul 2012, 9:06 pm

Quote:

Originally Posted by paulsherwin

I think the cabinet may be too far gone for the T-Cut treatment. If you don't want to do a full semi-pro cabinet restoration, it will look much better if you strip off the old cellulose varnish with Nitromors or similar stripper, then wax the surface with coloured liquid wax like Colron. It won't look original but it will still look very presentable for a minimum of skill and effort.

Thanks for that suggestion. Holidays have just interrupted progress (!), but I hope to get around to having a go at the cabinet soon.

Ted.

Nickthedentist · 27th Jul 2012, 9:16 pm

Paul's very probably right, but I'd try some T-Cut first. You can always go down the strip-and-refinish route if the results are disappointing. But it's nice to retain the original finish if you possibly can.

Nick.

21st Jul 2012, 2:24 pm	#1
ted_ntsx Pentode Join Date: Jul 2008 Location: Winterton-on-sea, Great Yarmouth, Norfolk, UK. Posts: 137	Murphy A122M "baffle board" Not sure if this really belongs in the "success stories" section, as it is only a partial success so far... This Murphy A122M was found in a barn where it had languished for many years. It had definitely seen better days. The cabinet was rather battered and the back cover showed signs of damp. A quick visual inspection revealed the original mains lead was just a little bit unsafe(! see photo) but inside it appeared not be have been touched for ages. A thick coating of dust and spiders webs with no obvious disturbance or fingerprints! Some slight corrosion of metalwork, but nothing much. Promising! The two smoothing caps looked very defunct. Both had swollen, leaked and corroded badly. I suspect this may have been the cause of the radios original demise and why it was consigned to the barn. I replaced the mains lead, the smoothing caps, and THAT capacitor, and then powered it up via a lamp limiter. No smoke or bangs, so I increased the power at bit. The valves now lit up but nothing else happened apart from the UU6 rectifier putting on a firework display. No HT of course (well, about 10 volts). I temporarily bridged the UU6 with silicon diodes and a surge limiter and tried again. This time it hummed and crackled into faint life. HT was about 150 volts. After removing the lamp limiter the HT went up to 250 volts and the radio started working quite well. Next step was to replace all the other usual waxies, clean the wavechange switch, and replace the blown pilot lamps. The set then worked surprisingly well, with a great sound and plenty of audio power. Most of the remaining work is now cosmetic. The cabinet is in poor condition, but that's a job that will have to wait a while, and it is missing a knob. All in all, it performs very well for very little effort considering the state it was in. I now need a replacement UU6 and a knob, so if anyone had one spare..... Attached Thumbnails

21st Jul 2012, 6:36 pm	#2
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,844	Re: Murphy A122M "baffle board" You must have found that in a better class of barn, Ted. Most of the "barn find" radios I've seen have been a mass of delaminated plywood, rust, and mouse-infested wiring. Your cabinet looks promising; some T-cut, Scratch Cover and Danish oil or wax should make it very presentable. Let's hope you find a knob. Well done for getting it going. The rough-and-ready sets are often the most satisfying to hear working again. It would be fascinating to know how long ago it had been retired. Were there any other clues in the barn? Nick.

22nd Jul 2012, 8:22 am	#3
ted_ntsx Pentode Join Date: Jul 2008 Location: Winterton-on-sea, Great Yarmouth, Norfolk, UK. Posts: 137	Re: Murphy A122M "baffle board" No, no other clues. I never saw the "barn" myself, just told that it had been found in one. Other than that I know nothing about its history. Cabinet repairs are not my strong point, but I will certainly do what I can to make it look good again. Ted.

22nd Jul 2012, 9:33 am	#4
Tractorfan Dekatron Join Date: Mar 2008 Location: St. Frajou, l'Isle en Dodon, Haute Garonne, France.(Previously: Ellesmere Port, Cheshire, UK.) Posts: 3,183	Re: Murphy A122M "baffle board" Hi, I've got two A122s with the same chassis, but different cabinet design. It's interesting to note that yours has a B4 socket for the "gram" input. Mine just have the usual wander plug sockets. They are lovely sets, I was given an A122 when a kid & spent many happy hours slowly trawling the shortwave band. Heaven! Cheers, Pete __________________ "Hello?, Yes, I'm on the train, I might lose the signal soon as we're just going into a tunn..."

22nd Jul 2012, 11:29 pm	#5
howard Nonode Join Date: May 2005 Location: Godalming, Surrey, UK. Posts: 2,593	Re: Murphy A122M "baffle board" Hello Ted, Well done, good to see another baffle board Murphy working again. They do sound good these sets. I'm sure someone here can help you out with the missing knob and rectifier valve. Howard

23rd Jul 2012, 12:05 am	#6
Phil G4SPZ Dekatron Join Date: Apr 2005 Location: Bewdley, Worcestershire, UK. Posts: 4,748	Re: Murphy A122M "baffle board" This model was one of my first repairs. I don't claim to have restored it, because there is still a lot of brittle rubber-insulated wiring that really needs replacement, and this seems to be a common issue with post-war Murphys. However the A122 sounds beautiful and can be forgiven! __________________ Phil Optimist [n]: One who is not in possession of the full facts

23rd Jul 2012, 12:29 am	#7
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,943	Re: Murphy A122M "baffle board" I think the cabinet may be too far gone for the T-Cut treatment. If you don't want to do a full semi-pro cabinet restoration, it will look much better if you strip off the old cellulose varnish with Nitromors or similar stripper, then wax the surface with coloured liquid wax like Colron. It won't look original but it will still look very presentable for a minimum of skill and effort.

27th Jul 2012, 9:16 pm	#9
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,844	Re: Murphy A122M "baffle board" Paul's very probably right, but I'd try some T-Cut first. You can always go down the strip-and-refinish route if the results are disappointing. But it's nice to retain the original finish if you possibly can. Nick.