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G6Tanuki · 6th Oct 2019, 9:33 pm

Yes, I'm definitely thinking infinite-impedance detector.

Not only would it give good quality [by virtue of its inbuilt near-100% negative-feedback at AF] but also it reflects the lowest-possible load onto its upstream RF tuned-circuit, so said tuned-circuit's selectivity isn't compromised by damping as would be the case with a classic diode-detector.

I remember building - in the 1960s - a TRF MW radio that had two EF50s as RF-amps, an infinite-impedance detector using another EF50, an EF50 and 6V6 being the audio-stages. It was good for listening to Luxembourg, but the lack of AGC made it tiresome if there was any fading.

At least with the 'classic' superhet diode-detector yiou get AGC-for-free.

6th Oct 2019, 9:33 pm	#55
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 14,007	Re: Moreton Cheyney Yes, I'm definitely thinking infinite-impedance detector. Not only would it give good quality [by virtue of its inbuilt near-100% negative-feedback at AF] but also it reflects the lowest-possible load onto its upstream RF tuned-circuit, so said tuned-circuit's selectivity isn't compromised by damping as would be the case with a classic diode-detector. I remember building - in the 1960s - a TRF MW radio that had two EF50s as RF-amps, an infinite-impedance detector using another EF50, an EF50 and 6V6 being the audio-stages. It was good for listening to Luxembourg, but the lack of AGC made it tiresome if there was any fading. At least with the 'classic' superhet diode-detector yiou get AGC-for-free.