Thanks to everyone for their suggestions - consensus seems to be that the
homebrew chokes are not enough reactance at 1.8 MHz, so I'll get some
store bought ones at 220 uH or more. I tried battery power for the whole
system, but no difference. I'm going to try battery power for the remote
box and omitting the bias tee entirely, at least as a test.
That doesn't make sense for your complaint. Your choke is a little light,
but you said it changes when you plug the supply in. That probably indicates
you are dumping ripple or noise into the 259. I'm really surprised the
diodes did not pop.
45 uH is about 500 ohms, which is OK for a choke in a 50-75 ohm line.
While it would increase SWR a bit, especially with poor bypassing (.01uF)
and probably no additional decoupling, it is not a disaster.
Read my other post. You are running a risk with the system you have. Never
do what you are doing with a bias T, especially when it has a .1uF isolation
cap. A .01uF is 8 ohms on 160. That is a pathetic bypass cap, but a
reasonable series cap. You might want to step it up to a .05 uF or larger
when you get parts.
The bypass cap has to be a small fraction of the supply impedance and the
choke impedance. I'd use a .33uF there, and some other decoupling. You could
probably step the choke up a little, but don't use the 259 that way!!!
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