Perdio Piccadilly transistor seven

[Trannytuner]

I have just acquired a Perdio Piccadilly radio PR7, it works ok on medium wave, but a little low on volume, but when switched to Long Wave it whistles and motorboats, it does tune into a station, but is very unstable.
One of the problems I found when I got it was a wire from the Long Wave coil was broken, a previous owner had tried to stop the coil from moving on the ferrite rod, using insulating tape, hence the broken wire.
I have reconnected the wire, and the set now works on Long Wave, anyone got an idea what could cause the whistling and motorboating when tuning Long Wave, could it be capacitors needing to be replaced? I am at a loss to what to try next, any help would be greatly appreciated, as the set is in good condition.

[Nuvistor]

I presume the battery is good, these symptoms can be caused by a weak battery.
Otherwise decoupling capacitor across the battery supply could be faulty.
Many other possible causes but those two are easy ones.
Frank

[Trannytuner]

Hi Frank
I am using a new battery, but as you say, it could be the decoupling capacitor, I might change some of them and see if that helps, many thanks.
Les

[Biggles]

Alignment of the antenna coil may be out on LW if indeed it did move from it's original position. Other causes are typically faulty electrolytic capacitors across the supply. Has the original owner tried to "retune" it? It may just need a tweak on LW with the correct alignment info.
Alan.

[Trannytuner]

Hi Alan
Just an update on the set, it is now working on Long Wave, but the sound is muffled, if I switch to Medium Wave and back to Long Wave Radio 4, without moving the tuning dial, it starts motorboating again, to get it to stop, I have to tune down the band and back again whereby R. 4 comes on again, as yet, I have not replaced any capacitors, the radio works well on Medium Wave, loud and clear, I thought it was the wave change switch, so have given it a shot of switch cleaner, but hasn't improved it much, I think I will have to replace the capacitors, but strange how it works well on one waveband, and not the other, many thanks.
Les

[Nuvistor]

Unless you are experienced don't change them all at once, that can cause more problems, if it's something you are used to to doing that's usually ok.
I would go for any electrolytic caps across the supply line first, if you have a capacitor tester you could even use that rather than just replace them.

I would be interested in any photos of the radio, inside and out, I have not seen one for many years.

Frank

[Trannytuner]

Hi Frank

Here are the photos of the Perdio Piccadilly PR7 as requested, I have included a close-up of the LW coil, i have tried to replace it, more or less where it originally was, many thanks.
Les

[Trannytuner]

Frank
I am a relative newby to restoring transistor radios, I have replaced the capacitors in a Philips L3G03T and it is now working fine, but it was quite a task.
I'm not sure which capacitors are the decoupling ones in the Perdio Piccadilly, I don't want to ruin it.
Les

[Nuvistor]

Thanks for posting the photos, it's a nice example of the model.
Just take your time, you will be ok, has Alan states though there are a few causes of instability and it's not possible to say which one with any certainty.

Frank

[Biggles]

I have just realised that my Dad used to have one of these when I was a kid. I could never quite remember which it was except that it was red and plastic. The capacitors you could try changing are the blue ones. They are polarised so make sure the replacements go in the right way. These are normally across the supply and provide decoupling so that one stage doesn't affect another in the circuit, at least that is the theory. Personally I don't think this is where your problem lies. MW would probably be affected too if this was the case. You could try re-positioning the LW coil slightly. You may lose a bit of signal strength but it could stop the instability. The coils usually have three connections in a transistor set. Maybe it's worth checking you have them right. Some sets have the MW and LW coils connected in series so orientation matters, although I am not familiar with this particular set so can't really help you there.
Alan.

[Trannytuner]

Hi Alan

Many thanks to both you and Frank for your help with the Perdio, I will take your suggestions on board, and see what I can do.

All The Best

Les