1955 PYE P178A AC mains 5 valve MW/LW/SW compact table radio

[howard]

Hello again,

I bought this little PYE P178A at the last Harpenden event Bring and Buy table for £5, and I also found another in a box of old sets bought in the auction. It had a very nice bakelite case and the only bit missing (and unfortunately still is) was its original wavechange switch knob (and there was no knob on the other set either). Still, it came with a knob off another PYE model which fits fine, just as well as PYE spindles have a different profile that those from other manufacturers. The P178A was released in 1955, not that long after the release of its predecessor the P178 in 1954 and has a typical complement of Mullard valves for a mid 1950s AM set, ECH42, EF41, EBC41, EL41 and EZ41, although mine has an EZ40 rectifier. Three sets of service data are available from the Vintage Radio Service Data website above, I used the PYE sheet.

Both sets I considered only suitable for spares but I've still managed to build a very nice one from the two. I dismantled both sets, which is straightforward, take off the back cover, pull off the front knobs (careful cos they're perspex and very brittle), pull off the wavechange knob on the side (that is obviously flimsy as well), undo four screws underneath the case and the chassis can then be moved out the back just clear of the case and then unsolder the loudspeaker wires to free the chassis. I then collected together a complete set of decent looking valves and the better loudspeaker (this set had had a replacement Celestion loudspeaker fitted which was knackered, fortunately the other P178A had an original RA loudspeaker). Restoration then commenced ....

The case
- I removed the perspex dial and its gold painted metal surround which are held in place by six clamps
- I cleaned the case inside and out with upholstery cleaner and then polished it with Brasso and Mr Sheen
- I carefully cleaned the surround and the perspex dial with upholstery cleaner, polished out the light scratches on the dial surface with Brasso and then put it back
- I refitted the better RA loudspeaker
- A couple of little bits of fibreboard were broken on the back cover so I stuck them back together again with Superglue
- I removed the dial cord and then the dark grey painted backplate off the front of the chassis, as its paint was peeling off I stripped it all off with Nitromors and resprayed it with Halfords gunmetal grey aerosol and then refitted the backplate and cord
- I resrayed the pointer with Halfords matt white primer

The chassis
- I tested the mains transformer for leakage with my Megger and that was perfect
- I cleaned all the wax, muck and dust off the chassis with white spirit
- I replaced three wax and Hunts mouldseal capacitors - the audio coupling capacitor had already been replaced with an RS cap
- I fitted a new 3 core mains lead and plug with a 3A fuse
- I cleaned all the valve pins, bases, waveband switch, tuning capacitor earth springs and volume pot with Servisol 10
- I connected a loudspeaker, plugged in, switched on and it worked, not very well though.
- The off/on/voume potentiometer was knackered so I replaced it with a very good original one from the other chassis
- I tried swapping each of the valves in turn to see if any improvement in gain could be achieved but all seemed OK. As I have a load of NOS EL41s I fitted one as the original had lost all its print.

The set was now working, but it wasn't picking up a great deal and didn't sound too good either so I took it over to Ron Bryan to take a look at.

- Ron spotted a Hunts capacitor that I had missed so that was replaced
- HT voltages were checked and they were fine, if just a touch higher than in the PYE manual. LT was spot on.
- IF realignment was performed, no problems with any of the cores, and that made a huge difference
- MW, LW and SW RF alignment was performed and the set tweaked up very well. This takes a while as the dial scale is fitted to the front of the case so the chassis had to be returned to the case in order to position the pointer in the right place at each stage of the alignment.
- The set was now working well but still sounded a touch distorted, especially when played softly so Ron spent a while checking everything over and concluded that the loudspeaker was faulty.
- I found another RA loudspeaker in scrap PYE P78 set won at Harpenden so I fitted that and it then sounded brill.
- I changed the 0.01uf audio coupling capacitor as I noticed that a 0.022uf replacement had been fitted in error
- I noticed that SW was still a bit out of alignment so to save time I made up a paper dial with the alignment points marked on it to fit on the dial backplate and took the set back to Ron to redo SW RF alignment. Once done the set worked well on SW too

This is a pretty little set which picks up everything on MW and LW (it picks up RTE on LW with ease) and picks up loads on SW too. It's sound quality for a compact set is excellent. The only thing which lets this model down is the quality of its knobs which are all rather flimsy. This is my third small PYE set (I have two P43s as well) and I'm so impressed with their performance that I'm going to find a few more compact PYE models to restore now. If anyone has a spare wavechange switch knob pictured below please send me a PM.

Howard

[howard]

I did have one little problem when swapping the valves around, I pulled out the EZ40 and a very odd looking EZ40 it was too ... see below. I had another EZ40 to go in but there was no way it was ever going to fit, cos its base was too wide.

It took me a while to figure out what had gone wrong, the metal collar had come off the bottom of the EZ40 and was stuck in the valve base.

It is an unusual Mullard EZ40, it's actually a Mazda UU9 (it still has U9 on the back) which Mullard sprayed paint over and then put their label on it.....

Howard

[Brian R Pateman]

I remember exactly the same thing happening to one of these sets back in the 1960s. I spent a large part of the afternoon fiddling the metal collar out of the valve base skirt only to find that the paxolin was so badly charred that I had to fit a new base anyway!

Lovely little sets though - but it would be, it's a Pye!

Regards,

[AlanBeckett]

Brian,
You're right, it's a Pye.
Alan

[geofy]

Good restoration as usual Howard though the speaker wiring might need rerouting a little away from the tuner drum. Do you ever try to repair speakers, I have taken them apart sometimes to find a bit of rust or muck in the speech coil or a loose coil. Even if the cone looks tatty they can be patched up.
Many years ago at an old disused wartime airfield I came across what was left of some scrap tvs, all burnt, melted valves and so on but one speaker with baffle had survived, and that had a R&A (what does that stand for, not Richard Allen, Regentone maybe) elliptical speaker which I brought home, strapped to the carrier of my pushbike.

Geof

[howard]

Originally Posted by geofy

........ though the speaker wiring might need rerouting a little away from the tuner drum. Do you ever try to repair speakers......... that had a R&A (what does that stand for, not Richard Allen.....
Geof

Hello Geoff,

I spotted the untidy loudspeaker wiring soon after I'd taken that pic, see below ...

The only loudspeaker repairs I've attempted are strengthening paper cones with PVA, taking them apart looks a bit tricky to me....

I had always assumed that RA or R&A was Richard Allen (Batley, Yorks), who became very well known in more recent years for building hi-fi loudspeakers and who are now known as RA technology and they still build loudspeakers.

Howard

[geofy]

Hi Howard, that looks better

As long as the screws can come out then the speakers can be taken apart quite easily, though they have to be put back together with the magnet centred and free of the coil. Tapping the cone with a finger tells when it is free by the resonant sound. Others can't be taken apart but can still have cones repaired. Some like old Philips have to be treated a bit differently as they have individual parts that all have to be held away from the magnet without trapping the coil.

Not sure about the R&A being RA as Richard Allen where finished in a crackle type light gold paint, Regentone fitted R&A as standard as well as Pye, will have to investigate this one.

But I feel the cold steel of the mods axe creeping up

Geof

[Nickthedentist]

Originally Posted by geofy

Not sure about the R&A being RA as Richard Allen where finished in a crackle type light gold paint, Regentone fitted R&A as standard as well as Pye, will have to investigate this one.

I thought it was something like "Reproducers and Amplifiers Ltd." but I might be wrong.

Nick.

[geofy]

That could be Nick, a new thread from here on RA and R&A and on speaker repairs in general might be of interest, to keep on topic I mention this because of Howard changing a faulty speaker during his renovation. Most speakers can be repaired if they are only a little distorted or scratchy rather than just bin what won't ever be made again.

Geof