[Elecraft] K3 PR6 preamp

[Graham Kimbell (G3TCT)]

Ed
There's a more reliable way of doing this. Turn on the dBV measurement
facility on the K3 and turn off the agc, reduce rf gain a bit. Arrange for
50ohm resistor noise to indicate 0dB and then substitute the 6m antenna and
see the difference.

BTW the preamps won't be "below a 290K source" - they're already at 290K or
more!

73
Graham

> With both preamps on S=4
> Both preamps on with antenna disconnected; S=3
> So its a pretty quiet area with only one s-unit rise in noise.
> For comparison with a 50-ohm termination both preamps see S=4
> This indicates the preamps are low-noise below a 290K source.
>