[Milsurplus] Solid state BC-611, GRC-9, BC-348 ?!

[Hue Miller]

>Hi Hue,
>
>I notice that the common source output impedance of the 2N4416A is about 
>20k
>ohm. How does this compare with the effective parallel impedance of the 
>IFTs
>used in the BC-348, say?
>
>Thanks,
>
>73, ian K3IMW

That's exactly why i in the clear light of day, later, i  have some 
reservations about
his choice of RF devices.  This load on the tuned circuits would obviously 
be not
good for selectivity.
HR mag, around 1974, had an article on s'ing a BC-348. This was not an 
originalist-
type project, i mean i think it was more of a conversion than just an active 
device
update. One interesting thing tho was a chart of the output impedances of 
the
original tubes and some solid state replacements. Generally the tubes, IIRC, 
were
in the 500k - 1M ohm range and the best MOSFETs were in the range 150k -
200k. I was even thinking it might be wise to tap down the IFTs to better 
deload
the tuned circuits, but as there's no tap there already, this gets into some 
extra
parts and maybe modifications you might or might not want to do.  / Hue 
Miller