UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Station Radio C-12

trh01uk · 17th Sep 2017, 6:14 pm

As shown, your C12 is missing a critical part of the set - the ATU. Its only a roller-coaster inductor so if you can't find an original any HF roller coaster should substitute. Study the schematic and you will see what I mean - without the ATU there is no matching circuit or any selectivity at all. The set is designed to operate with the ATU straight into a 8' or 16' whip - and really nothing else.

Even then, you will find the C12 has a serious deficiency which is that it has virtually no front-end selectivity. Breakthrough from broadcast stations can render the set unusable - particularly if you hook it up to a long wire or dipole.

Pye tried to improve on the WS19 - and it was an improvement in that the PA has high level modulation. It gives a far better quality signal than the older WS19 - and it was thought equivalent in "talk power" to the WS19HP - that is the WS19 plus its Amplifier RF No.2. But lack of progress in technology defeated the designers - there was simply not enough room in the box to pack in everything they wanted to include. They didn't help themselves by abandoning the WS19s clever flick system, for a duplication of tuning elements, which take up far more space.

Richard

17th Sep 2017, 6:14 pm	#9
trh01uk Octode Join Date: Nov 2010 Location: Ross-on-Wye, Herefordshire, UK. Posts: 1,654	Re: Station Radio C-12 As shown, your C12 is missing a critical part of the set - the ATU. Its only a roller-coaster inductor so if you can't find an original any HF roller coaster should substitute. Study the schematic and you will see what I mean - without the ATU there is no matching circuit or any selectivity at all. The set is designed to operate with the ATU straight into a 8' or 16' whip - and really nothing else. Even then, you will find the C12 has a serious deficiency which is that it has virtually no front-end selectivity. Breakthrough from broadcast stations can render the set unusable - particularly if you hook it up to a long wire or dipole. Pye tried to improve on the WS19 - and it was an improvement in that the PA has high level modulation. It gives a far better quality signal than the older WS19 - and it was thought equivalent in "talk power" to the WS19HP - that is the WS19 plus its Amplifier RF No.2. But lack of progress in technology defeated the designers - there was simply not enough room in the box to pack in everything they wanted to include. They didn't help themselves by abandoning the WS19s clever flick system, for a duplication of tuning elements, which take up far more space. Richard