On 6/14/23 7:44 AM, Dallas wrote:
I have my antenna going thru my MFJ tuner then to the common terminal of a 6 position coax switch. I leave the VNA connected to position 6. Coax 1,2,3&4 each go to different radios I have.
I can quickly switch the VNA to the tuner and adjust for a match and then switch radio to properly tuned antenna.
I¡¯m getting ready to add a second coax switch between the tuner and antenna so I can switch between 3 antennas I have.
Having the VNA a click away is very handy.
Since you've been doing this a while, you don't have an issue, but in general, one would want to make sure the isolation between switch ports is high enough to make sure that when you run 100w to the antenna, the leakage to your VNA is <10 mW or so (my guestimate of "no damage max power" for the VNA. That's 40 dB of isolation, which most relay based switches can do.
But it's good to check (and hey, you could use the NanoVNA to measure it)..
I have a sort of similar setup using RCS-8Vs
Coax to switch and tuner at the antenna. The switch is cabled up so I can connect open, short, load to the end of the coax, as well. At the shack end, more switches to connect rig and VNA to various feedlines.
Lou W7HV