Re: Ferrite rod antenna and RF amp for Valve radios
Are the earthy ends of the two windings on the ferrite rod actually connected to the negative line of the circuit? They should be for it to function correctly.
Also 470 ohms seems a bit on the low side for the collector load. Perhaps 1 or 2k may improve things here.
Radio Wrangler's suggestion of a stopper in the base circuit is a good one, as the impedace in that base circuit may be quite low which can cause various unexpected feedback paths to occur. Maybe a different type of transistor may help. A type used in an A.M. I.F. would be probably the best choice.
I made a similar device in the '60s using a 717A pentode valve. A truly startling increase in sensitivity! Tony.
Post crossed with Argus 25
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