UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Tricky way to extend 100MHZ FM range to 108MHZ

murphyv310 · 27th Dec 2010, 10:10 pm

Not all FM sets will have sufficient pull in range to do this, notably early valve sets, you might be lucky to get 90-106 mhz.
Remember most valve sets use permeability tuning.

Andy, What you are saying is very hit and miss, when opening the osc trimmer, adjusting the slug will of course offset what you have done with the trimmer, so the range is unlikely to be the full 88-108mhz. Then of course you need to do the same with the aerial side, and then tracking could well be out.
I would leave the set alone but if necessary build the frequency shifter as in the earlier postings.

27th Dec 2010, 10:10 pm	#6
murphyv310 Dekatron Join Date: Sep 2006 Location: Kilmarnock, Ayrshire, UK. Posts: 5,422	Re: Tricky way to extend 100MHZ FM range to 108MHZ Not all FM sets will have sufficient pull in range to do this, notably early valve sets, you might be lucky to get 90-106 mhz. Remember most valve sets use permeability tuning. Andy, What you are saying is very hit and miss, when opening the osc trimmer, adjusting the slug will of course offset what you have done with the trimmer, so the range is unlikely to be the full 88-108mhz. Then of course you need to do the same with the aerial side, and then tracking could well be out. I would leave the set alone but if necessary build the frequency shifter as in the earlier postings. __________________ Cheers, Trevor. MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member Last edited by murphyv310; 27th Dec 2010 at 10:21 pm.