Unknown transistor radio (Invicta model 30)

[Steve FPV]

Hi,

Can anyone identify this radio please? A friend has asked me to repair it for him. There is no makers label, only the logo which I don't recognize. I have traced out the circuit and should be able to get it going from that but it would be nice to know what it is!

The owner says that it is 61 years old, i.e. purchased in 1956.

Thanks,

Steve.

[ms660]

The logo was used by Invicta:

http://www.radiomuseum.org/r/invicta..._model_30.html

Lawrence.

[Steve FPV]

Ah, thanks for that Lawrence, Invicta model 30, very helpful.

Regards,

Steve.

[ms660]

I think the Pye 123BQ schematic might be the same? Can anyone confirm?

Lawrence.

[KeithsTV]

Certainly the board and battery holders have the look of the Pye.

Keith

[paulsherwin]

Wasn't Invicta a Pye brand at the time? The Radiomuseum page suggests it uses Pye transistors. Did the Pye transistor division morph into Newmarket?

[dazzlevision]

Originally Posted by paulsherwin

Wasn't Invicta a Pye brand at the time?

Did the Pye transistor division morph into Newmarket?

Invicta was the wholesale brand of Pye and yes, Newmarket Transistors Ltd was formed by Pye Ltd to manufacture and market its transistors on a more commercial basis than before.

[AC/HL]

It appears to be the Invicta version of the Pye P123BQ/R, with a lid switch in place of the volume control switch. Interestingly for one of the first transistor radios it uses currently available batteries without modification. Watch out for fragile transistor leadout wires, and knobs. The only unusual component is the 80 ohm centre tapped speaker.
http://www.service-data.com/section.php/6676/1/p123bq-r

[julie_m]

That's brought back some memories! A friend of mine had an identical set, must have been getting on for 20 years ago now. Proper tuning on MW, one fixed station on LW. The fault was that the transistor leads had corroded through.

[Oldcodger]

Case looks remarkably similar to a PYE ?( I think-was 50 years ago) model using D*9x (?) valves.
Difference is that controls were on bottom side , on a chrome plate, with the PCB in same sort of position.
Aerial was a frame coil fitted in the lid.

[Steve FPV]

Thanks for all the information regarding this set, particularly the points to watch out for! Yes, it is interesting to see that it will take modern batteries without modification. The contacts need cleaning up though. I checked a few things with the test meter and the speaker seems to be ok, 80ohms centre tapped driven directly by the output pair. I've not come across that idea before. I may not be able to do much with it over the weekend, but I'll let you know how I get on with it, probably some time next week.

Steve.

[KeithsTV]

I bought my Pye P123 at the NVCF several years ago, got it home, cleaned the battery contacts, inserted a set of batteries and it worked. The only issue is that the fixed LW setting is for 200kHz and the trimmer adjustment is not enough to take it down to 198kHz so a small value capacitor has to be added across the trimmer.

Keith

[60 oldjohn]

I bought the dirtiest Pye P123Q at an antique fair for a fiver, Like Keith I cleaned the contacts and it worked. What was even more amazing was I had been listening to a programme on Radio 4 I switched my workshop radio off to try the dirty Pye, I was surprised when it burst into life tuned to Radio 4 with a continuation of the programme, yes it is pre set tuned on LW but could have been set on MW, but not bad for a 60 year old transistor set.


John.

[McMurdo]

It's also similar to the Pam range; eg PAM720; same company again. I've never seen the attache case version. It looks in extremely good condition.

[Steve FPV]

Hi,

Sorry that I've been so long getting back to this thread. The set is in quite good condition. Internally only the battery boxes needed cleaning out. They were showing signs of cracking at the corners so I put cable ties round them to give a bit more support.

Electronically there was very little to do. A joint to one of the two small capacitors on the print side of the PCB had broken so I tided up the joints around both of them. The heads of the two self tappers holding the PCB to the chassis were full of solder so I couldn't remove it to work on. There were signs that at least two of the transistors have been replaced. In circuit tests with the test meter showed that all the transistors seemed to be working so I applied power from the bench PSU and the set sprang to life. Quite good sound quality considering that the set was face downward on the bench! I soon found that the sound level varied as I tapped the PCB. This turned out to be due to a poor joint on one of the red/black electrolytics near to a replacement transistor. I was able to tune the LW trimmer to 198KHz without having to add extra capacitance.

Externally the worst part of the case is the rear. The hinges are obvious replacements. I guess that there should be long crome hinges reaching from the two "spare" screws up to the lid. One of the front catches is completely broken and the other is badly bent but still just about works.

Steve.

[Heatercathodeshort]

Snap! An Invicta Transistor 30. I pulled this one off the tip around 20 years ago. I thought it was the classic 4 valve attache portable until I opened the lid. They must have used a modified version of the valve case just to use them up. A very early transistor model.

To confuse things slightly. There was another Invicta '30' produced in 1946, a short superhet with Octal valves! John.
PS. Pictures added of the Pye valve model and the Invicta. Strangely the transistor model is somewhat larger. All the hinges etc are identical.

[Steve FPV]

Ah, the light dawns! Thanks Heatercathodeshort, that picture of the inside of the case explains why I found no model number etc. The attached is the inside of this set..... I did wonder about the rough edge; I've no idea why the top part of the paper is missing! The license plate is on the inside of the front of the case in this set. I 'll print out a small label to add that information and indicate the suitable modern battery types.

Thanks also for the rear view showing how the hinges and feet are arranged. I did wonder if there should have been a prop or cord of some sort to stop the lid flopping right back when it is open but it seems not.

Thanks for all the help with this,

Steve.

[Steve FPV]

Just had a thought about the hinges shown in the last picture of post 16. Are they designed to stop the lid folding right back? Clearly the replacements on the set I have here don't do that.

Steve.