Rob,
I have the MFJ-1899T antenna that covers 80m-6m, but haven’t gotten to use it on a summit yet (nearest even 1 pointer is about 2+ hours away from here in central South Carolina). I did build a set of single radials/counterpoise for each band, and set the whip length using my MFJ-259 analyzer. I also use the recommended 90 deg BNC-to-PL-259 adapter to connect to the PL-259 (SO-239?) plug on the back of the FT-817 and not stress the 817’s front BNC connector.
Only used one radial per band due to ending up with a lot of wires. They all terminate in a single alligator clip that clips to the FT-817 chassis. The wires are a little longer (about 6” longer) than the instructions recommend to ensure the bottom CW portion of each band is covered. To set the whip length with the analyzer, I recorded the number of whip sections extended for each band, plus the number of “fingers” on any partial whip element extended (fingers held perpendicular to the whip). This way the number of elements plus “fingers” of a partial element are written down multiple places so I don’t need to carry a ruler/measuring tape. Can easily fine tune the whip for the band portion in use.
A big takeaway is not to have the radials crossing each other. Antenna doesn’t like it. I know it sounds like common sense, but easy to miss when testing and setting up. Experience talking; couldn’t figure why the SWR reading suddenly went south till I noticed that I’d stepped into and tangled the radials.
So far have only been able to test on the air on 80m. Was able to check into a CW Net (Carolinas Slow Net; 3571 kHz; 0000Z) with the net control 150-200 miles away. This was from the wooden gazebo in my back yard using the 817 at 5W with an external battery (7Ah LiFePo). Copy was weak but readable on both ends, but it’s definitely short for an 80m antenna. This was with the counterpoise pointing away from the other station vs toward them. I was actually thrilled after all the work setting up and tuning the antenna and radials to be heard at all, especially on 80m with such a small antenna. Will have to test the other bands when work and family time permits.
It’s not a full sized dipole, but if it works as well on other bands as it does on 80m, it’ll be handy for very quick setup/tear down. Definitely a compromise antenna, but quick to use, and better than not getting on the air due to not having the time/space to put up a more efficient antenna.
Good luck on that next hill,
Mike, N4VBV