I agree with you. But I have found another cheep and dirty way to do the
same thing. I have had good luck with it. Just cut off the center conductor
of the PL-259 used on the coax. You will have a low capacity connection to
the coax.
Curt NU7R
At 01:42 PM 11/25/2004, you wrote:
Eric SENSI wrote:
2. If I can't find this RF bird sampler (the best solution IMO)... then I'll
go for the "T" shaped M/F/F plug on the ANT 1 output... Someone says that
the radio will not see the small impedance bump on HF even with an open
connection on this "T" shaped connector.
It is true that the open circuit stub of a "T" connector will have no
noticable or measurable affect on HF (or probably even VHF) frequencies.
However if you connect a piece of coax to the "T" then the stub is as long
as the coax plus the dimensions of that part of the "T". If you used 10 or
20 feet of coax running to the 1 megohm input of your o'scope this would
look like a 10 or 20 foot open (in a 50 ohm system 1 megohm is nearly
equal to an open circuit) stub, which would have some significant
reactance, possibly acting as a trap at one of the higher HF bands.
Therefore if you do use the "T" method you should use a small value
capacitor or large value resistor in series right at the T before feeding
any cable to run to the o'scope. Then the length of the open stub will
appear only about a centimeter or two long, and only matter at 1296 MHz
and up, as someone else has pointed out.
DE N6KB
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