Pye 123BQ

[Neil Purling]

I have one of these early radios. This one has Mullard transistors and the LW is fixed for the Light Programme. At present it is unmolested electronically.
I wanted to know how sensitive were they vs radios that came along shortly after.
Like the Roberts R200, which I have. I can get Caroline on the Roberts, but on the Pye it's in-the-noise.
I have squirted the wave-change contacts with De-Ox-It and checked the batteries. Gave me a surprise when I got a choir & organ on R4 performing Abide With Me.

[MR SPIGOT]

I have one here in East Kent, and it does seem no better or worse than other sets of its time. I had to replace a few of the wax caps around the mixer oscillator stage and a couple of decoupler caps associated with the AGC system. I can get Caroline fine here during the day, but at night it suffers with continental stations muscling in. It is only a 1 kilowatt transmitter from Orfordness after all, but you are not too far away. Perhaps you should check a few caps, unsolder one end and use a multimeter to check them for leakage, ideally there shouldn’t be any. Also get the service data and check the transistor bias voltages are correct within a few millivolts.

Hope this helps .

[Neil Purling]

My Pye has an OC44, V6R2, V6R2, OC71, OC72+OC72.
I think the oldest had Newmarket transistors only and Pye started to buy in Mullard devices.
The last examples having only Mullard transistors.

My Roberts rules the roost as I had it restored by member ronbryan.

I want to get the Pye to work as well as possible.
Locally Caroline is the most distant station I listen to. I do occasionally look in on Manx Radio, which has the usual deep fades.
I can get Manx Radio on the Pye.

[mark pirate]

Mine is an early set, it has all original components and still works well, however, comparing performance against my Bush TR82B & early Roberts RT1, it is less sensitive on weaker stations, selectivity is on a par with the others.

I am sure it's performance would be improved by replacing a few caps, but as not a set in regular use, I intend to keep it original.


Mark

[MR SPIGOT]

Further to my last post, I have been comparing the performance of the pye to a later roberts 200, this one has the AF117 transistors, it seems more selective than the pye, but then it is a later set , The Pye design goes back to the mid fifties and I think pye had trouble manufacturing transistors of a consistent quality, certainly the Mullard devices are superior in my opinion,Also the pye uses a lower IF frequency, 315 kHz, why? Probably because they couldn’t make coils of suffiently high enough Q, or maybe their own transistors were not consistently good enough to cope with the standard IF of 470 kHz .

[Pamphonica]

Originally Posted by MR SPIGOT

The Pye design goes back to the mid fifties and I think pye had trouble manufacturing transistors of a consistent quality, certainly the Mullard devices are superior in my opinion,Also the pye uses a lower IF frequency, 315 kHz, why? Probably because they couldn’t make coils of suffiently high enough Q, or maybe their own transistors were not consistently good enough to cope with the standard IF of 470 kHz .

According to the wonderful reminiscence in "Radio! Radio!" about the development of the Pam 710 (the precursor to the 123BQ), the production IF transformers for that set had a poor Q so the IF was lowered. The local oscillator also struggled to work at the top end of Medium Wave. I suspect that Pye's early "Newmarket" transistors had a low ft, but the superior Mullard standard set did not emerge in time for the 710 launch. Pye was the first company licensed to manufacture transistors under the Bell patent. They paid something like £10-£20K for their licence.
-Jeremy