[VHFcontesting] FM antennas

[Josh Arritt]

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 at alignedsolutions.com
> 604 762 4099
>
>> On Nov 29, 2017, at 10:49 AM, Sean Waite <waisean at 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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