11-09-2017, 08:10 PM
The chassis of the Pye 65A is fully reassembled and ready for testing.
The 2 and 120 volt power supply made for the Pye 69B is being used for the 65A.
After connecting up the receiver to the power supply I was greeted with no results, the filaments of the QP25 QPP output valve could be seen glowing, lights out in the workshop in to do this. The fault was quickly traced to the HT supply wire from the on-off switch to the unused pin 7 of the QP22 having not been soldered, mea culpa. Now I'm getting results, a rise in noise level when the top cap of the TP25 frequency changer is touched, but no stations coming in. Eventually the fault was traced to a bad connection on the wavechange switch. However, the performance of the set was no way as good as the 69B. The first IF transformer would not peak up, the second transformer is OK. The reason for the IF transformer failing to peak up is well known fault in these sets, the iron dust cores become detached from the adjusting screws. An attempt was tried to repair the transformer but in due course the only satisfactory solution was to fit a replacement IF transformer. The "new" transformer is a perfect replacement and has the advantage of having the adjustment trimmers on the top of the can. I think the transformer is a pre-war EMI part. It's marked 502Kc/s but peaks up on 465Kc/s without any difficulties.
Just the cabinet to finish off now.
Geordie McBoyne.
The 2 and 120 volt power supply made for the Pye 69B is being used for the 65A.
After connecting up the receiver to the power supply I was greeted with no results, the filaments of the QP25 QPP output valve could be seen glowing, lights out in the workshop in to do this. The fault was quickly traced to the HT supply wire from the on-off switch to the unused pin 7 of the QP22 having not been soldered, mea culpa. Now I'm getting results, a rise in noise level when the top cap of the TP25 frequency changer is touched, but no stations coming in. Eventually the fault was traced to a bad connection on the wavechange switch. However, the performance of the set was no way as good as the 69B. The first IF transformer would not peak up, the second transformer is OK. The reason for the IF transformer failing to peak up is well known fault in these sets, the iron dust cores become detached from the adjusting screws. An attempt was tried to repair the transformer but in due course the only satisfactory solution was to fit a replacement IF transformer. The "new" transformer is a perfect replacement and has the advantage of having the adjustment trimmers on the top of the can. I think the transformer is a pre-war EMI part. It's marked 502Kc/s but peaks up on 465Kc/s without any difficulties.
Just the cabinet to finish off now.
Geordie McBoyne.
