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

G6Tanuki · 6th Nov 2018, 7:24 pm

The L/C ratio, varying as you tune across the MW band, will result in varying selectivity, yes.

[Perhaps look at permeability-tuning?]

I never really had much luck with ZN414-type radios, though I did use one - fixed-tuned to 465KHz - along with a single-transistor BFO to "SSB-ize" a little Daiwa "Search-9" VHF receiver back in the 1970s, following an article in SWM. The result wasn't too good as the Search-9's free-running VFO, though good enough for FM, didn't really match up to the needs of SSB reception.

6th Nov 2018, 7:24 pm	#12
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 14,007	Re: ZN414 and TA7642 radios The L/C ratio, varying as you tune across the MW band, will result in varying selectivity, yes. [Perhaps look at permeability-tuning?] I never really had much luck with ZN414-type radios, though I did use one - fixed-tuned to 465KHz - along with a single-transistor BFO to "SSB-ize" a little Daiwa "Search-9" VHF receiver back in the 1970s, following an article in SWM. The result wasn't too good as the Search-9's free-running VFO, though good enough for FM, didn't really match up to the needs of SSB reception.