Unless FM is your primary mode (and some do great work at that!), for
the moment* I would stick with omni.
A silly multiband colinear vertical can top off a nice H-pol beam stack
for FM -- just jam it in the top of the mast pipe at your rover stop.
I've found I can get away with a 2/440 colinear and a 222 J-Pole jammed
into the same mast pipe, right beside each other! Yes, cross-band QRM
is a "thing", as is pattern distortion, but the match doesn't seem to
suffer. Conserves space. I hope to experiment with a coax "Y" or even
sympathetic coupling to drop a coax line next year (dirty!).
HAGL is key, as always -- so a lightweight, small aperture antenna of
modest gain that can be lashed to a high mast of some sort to gain
elevation I think should be the rover's primary design goal for a
"serious -but-not-too-serious" FM antenna. These Dual-band and
Tri-band homebrew J-pole/Slim-Jim variants fit the bill, and they're
cheap. Again, see above....
* As FM continues to climb in popularity (222 Fall Sprint was upside
down: 8FM, 3CW, 1SSB!), the serious contester may want to explore the
possibility of multi-pole gain antennae on at least 2 and 222 -- be it
circular or switched-pol -- in addition to omni aerials to get the
proverbial "leg up".
Often, I won't work my own grid on 222 without FM.
VY 73 DE KF4YLM
On 11/29/2017 14:57, Mark Spencer wrote:
My $.02 worth...
I focus most of my contesting on modes other than FM. That being said I try
to have a reasonable FM setup for 2M and 1.25M running all the time. I
usually just run mag mount whips on top of the cab of my pickup truck while
roving.
6M, 70 cm, 33 cm and 23cm FM is possible for me but only by prior arrangement.
I don't recall ever making a 6M contest qso.
I believe I have made enough random FM qso's on 2M and 1.25M to make the effort
worthwhile.
Last contest I made a conscious effort to cut down on clutter in the truck
and left the 1.25M whip at home, I ended up picking it up at the tail end of
the contest to gain a final multiplier and had to enter as an unlimited rover
as a result. I won't make that mistake again.
73
Mark S
VE7AFZ
mark@alignedsolutions.com
604 762 4099
On Nov 29, 2017, at 10:49 AM, Sean Waite <waisean@gmail.com> wrote:
Since we're always thinking of the next station improvement, I've been
thinking about the best way to implement FM in the rover.
We've found that it's worth carrying the gear. We don't get many contacts,
but they are out there and having the ability to make them on demand does
get us points. Right now, I have a 2/70 vertical that is used for FM, just
a mobile whip. In January for our run 'n gun I'll probably move to a
triband whip.
For the stop and shoots, though, we'll be better set up to run beams. We
have a couple of the small Arrow yagis available that wouldn't be too
difficult to strap onto a mast and have a v-pol beam available for the FM
radios. Small LPDAs like the Elk satellite antenna are also another option.
This would give us positive gain on FM...but i'm not sure it's worth it. FM
contacts are mostly opportunistic, either a periodic call on 146.52 or just
hearing someone and grabbing the mic real quick. The directivity a yagi
would give us might blind us to some of the nearby stations calling (though
the arrows aren't particularly narrow) if they are off the side of the
beam. The other drawback is that it'll take a little longer to set up if
we've got another beam or three to attach to the mast and cable up.
What do other people do? Maybe better to have some always-connected, more
efficient verticals on the roof the car and sacrifice a bit of gain?
Looking forward to your thoughts.
73,
Sean WA1TE
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