If I may jump in with a question. I have a jupiter but my Drake 2B rcvr
might need this, after I recap it.
I have a MFJ 259B antenna tester, which will work as a frequency counter
that does resolve to 1 hz. Do I need to build a probe with a clip on
the outboard end, or is placing my antenna close to the circuit
sufficient? There is a max of 5V Peak-to-peak on the input of the counter
Try it and see if you get a count. I don't think you could damage
anything by trying. If the counter can handle 5 V P-P, then there is
probably no way you'll ever damage the counter by placing a pick-up wire
or loop near the BFO circuit, provided it is insulated. A direct
connection to the BFO circuit could get as much as 8 VDC in an Omni VI
(the + REG supply) connected to the counter, so don't try that.
The Drake 2B has tubes and voltages in excess of 100 VDC, right? I still
think as long as your pick-up wire has good insulation, you won't be
able to blow up the counter. Whether the counter is sensitive enough to
count the BFO that way is something you'll have to try to find out. If
you need to make a direct connection to get a strong enough signal for a
count, then you'll have to do some ohms law and voltage divider math to
figure out what sized components will prevent exceeding the 5 V P-P
limit that counter is supposed to be able to handle.
Remember that resolution, accuracy and precision are related, yet
different things. One Hertz resolution is not necessarily 1 Hz accuracy.
DE N6KB
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