Pye Fenman II VHF tuning range. - UK Vintage Radio Repair and Restoration Discussion Forum

ukcol · 21st Jan 2006, 5:47 pm

If any of you who own one of these excellent sets want to extent the VHF tuning range above 100Mhz (sorry Mc/s

) it turns out to be a very straight forward job.

The VHF section is tuned by moving 3 iron dust cores in and out of their respective coils. The mechanism used to achieve this is a pivoted lever plate which rides on a cam at the front of the AM tuning gang. At the high frequency end of the VHF band the cam lifts the the cores from the coils and I found by lifting the lever plate further (i.e. off the cam) the set would tune through several more stations. I only wanted to extent the range by 1Mc/s to receive Classic FM and achieved this by adjusting the 3 cores where they are attached to the lever plate. I turned the tuning knob to a position corresponding to about 99.5Mc/s and then retuned the oscillator core; this is the rear core and it required about 1 1/4 turns anti clockwise. I then turned the two RF cores by the same amount.

As a result of doing this I could receive Classic FM without losing any other stations; this was because there is quite a gap at the bottom end of the tuning before I came to BBC Radio 2. This change does, of course, mean that the scale is reading incorrectly but I can live with that.

The tuner in this set is very sensitive and Classic FM came in very strongly even before I had re-adjusted the RF coils. I live in the East Midlands by the way, in an area not known for strong FM signals and the set is running on its own built in aerial.

I am sure it would be possible to extend the range well beyond 101Mc/s but you would have to lose stations from the bottom end. Another possibility, if you are good with things mechanical, would be to make a cam with a different profile to the original, but that is beyond my skills I'm afraid.

JoshWard · 21st Jan 2006, 5:51 pm

Quote:

Originally Posted by ukcol

The tuner in this set is very sensitive and Classic FM came in very strongly even before I had re-adjusted the RF coils. I live in the East Midlands by the way, in an area not known for strong FM signals and the set is running on its own built in aerial.

Well it would on a Fenman 2 wouldn't it! I was listening to Sounds Of The Sixties (Radio 2) on mine this morning

.

21st Jan 2006, 5:47 pm	#1
ukcol Rest in Peace Join Date: May 2003 Location: Harlaxton, Lincolnshire, UK. Posts: 3,944	Pye Fenman II VHF tuning range. If any of you who own one of these excellent sets want to extent the VHF tuning range above 100Mhz (sorry Mc/s ) it turns out to be a very straight forward job. The VHF section is tuned by moving 3 iron dust cores in and out of their respective coils. The mechanism used to achieve this is a pivoted lever plate which rides on a cam at the front of the AM tuning gang. At the high frequency end of the VHF band the cam lifts the the cores from the coils and I found by lifting the lever plate further (i.e. off the cam) the set would tune through several more stations. I only wanted to extent the range by 1Mc/s to receive Classic FM and achieved this by adjusting the 3 cores where they are attached to the lever plate. I turned the tuning knob to a position corresponding to about 99.5Mc/s and then retuned the oscillator core; this is the rear core and it required about 1 1/4 turns anti clockwise. I then turned the two RF cores by the same amount. As a result of doing this I could receive Classic FM without losing any other stations; this was because there is quite a gap at the bottom end of the tuning before I came to BBC Radio 2. This change does, of course, mean that the scale is reading incorrectly but I can live with that. The tuner in this set is very sensitive and Classic FM came in very strongly even before I had re-adjusted the RF coils. I live in the East Midlands by the way, in an area not known for strong FM signals and the set is running on its own built in aerial. I am sure it would be possible to extend the range well beyond 101Mc/s but you would have to lose stations from the bottom end. Another possibility, if you are good with things mechanical, would be to make a cam with a different profile to the original, but that is beyond my skills I'm afraid.