Re: Close-spaced rover antennas


Scott K5TA
 

That’s a good idea (amps) but I’m going to be totally barefoot. I’m thinking I’ll just keep it down to 10 watts or so, and play it by ear. 

-TA


On Jun 1, 2019, at 9:57 PM, Keith Morehouse <w9rm@...> wrote:

I don't know the exact answer, but one thing you can do to protect yourself if you're using any kind of amplifier on the three ports is to T/R all the amps together, even though you're only using one band at a time.

Assuming all the amps are stable into whatever load the 9700 port appears to be while in RX mode, this gives you lots of isolation.

-W9RM

Keith Morehouse
via MotoG

On Sat, Jun 1, 2019, 9:38 PM Scott K5TA <k5ta@...> wrote:

I have a brand-new IC-9700 that I’m itching to try out in the ARRL contest next weekend.  That rig has 3 separate antenna connections, one for each of its bands (144-432-1296).  I have all the antennas ready to go, and am planning a “rover simulator” operation on my own property — i.e. a mast with the yagis, planted in the ground, and a vehicle pulled up next to it with the radio(s).

I have looked at numerous pictures of rover setups, and it seems that most, if not all, have short masts with antennas spaced 1-3 feet apart.  I plan to emulate that design, but since the '9700 has 3 separate antenna ports, and only one transmits at a time, I started to be concerned about frying the front-ends of the non-TX bands.  I posted a question about this on the IC-9700 io group, and received loads of responses, ranging from “no problem except for KW power levels” to “you absolutely need all sorts of relays, sequencers, triplexers, filters, or whatever.”  As has happened many times before, my experience with these fora has been less than satisfying.

I know there are extremely experienced rovers and contesters on this list, and I wonder what your ideas are.

-Scott K5TA

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