JIMMIE wrote:
I was wanting to listen to VHF/UHF SSB. All of my present UHF/VHF
radios are FM. I was thinking of rigging up a simple downconverter
using a mini circuit mixer and my HP signal generator as the local
oscilator that I can connect in front of my HF rig. I have an antenna
mounted pre- amp that I think should suffice for my front end. Any
foreseeable problems short of keying my transmitter while it is
connected.

Jimmie
For best performance these mixers require a constant impedance at all
three ports (usually 50 ohms). The preamp will provide this for the RF
input and the output of your HP signal generator should have a 50 ohm
selectable output. You may need to add an attenuator between the
generator and the mixer if the HP does not provide a 50 ohm termination
using a variable output. You will need to set the oscillator injection
level to the mixers required 7dbm drive level for best conversion
"gain". The output should go through a bandpass filter covering the IF
frequency you are down converting to and provide a 50 ohm impedance.
A duplexer network here is a good idea (provides a 50 ohm termination at
the IF frequency and a low impedance (short) to ground to out of IF
signals).