Antennas For Mobile/Portable Use
I'm a newbie to VHF+ digital and I'm interested in taking a package along
on a trip and trying WSJT. I plan to take a laptop, a Yaesu FT-100D, and an
array of antennas to Montana in late August. My first question pertains to
the feasibility of using horizontal loops for WSJT on this venture. Would
it be worthwhile, or are directional antennas a must in order to make
contacts? I'd be able to work 6m, 2m & 70cm.
Robin Midgett KB4IDC
- Hi Robin - There are a number of us that are now running mobile and
portable so probably as many opinions as operators! You choice of
antennas will of course depend on a number of factors including how long
will you be in one spot to set up, size of vehicle (or boat!) to tot
them or hang them from. I use loops because I run mostly while
traveling in job related day trips so either truly mobile or in one spot
for short period of time and no good way to haul beam(s) around. Do
they work? Darn good on 6m and just getting into 2m mobile but have
worked K1JT at about 900 miles with stacked KB6KQ 2m loops up about
12-13 feet from a parking lot. Also worked AF4O with JT44 to hand him 4
new 2m grids on two runs to Memphis.
Mostly a 6m person and have about 75 completions (46 initials) from the
truck setup - about 50-50 mobile vs temp portable. I have a KB6KQ 6m
loop but really prefer homebrew copper Squalo for 6m. (except for rain
detuning, if parked - OK mobile with wind blast) Run 100w or less. Best
distance is 1150 miles with a QRO station. I've worked Tip, WA5UFH from
13 oo 15 grids I've been in.
Dave N8OC, Phil N0PB and Mike WB2FKO can share there mobile/rover
experiences and setups on 6 and 2m as can Joe, K9KNW with his recent
Bahamas trip with 2m loops that seemed to do very well for him. I've
not heard reports on anyone running UHF and above but sure there are
some out there.
Others please chime in - Bruce, N5SIX
- Bruce et al:
I have a lot of experience with portable 2m WSJT and limited experience
with 6m. I've made about a dozen grid expeditions over the last two
years. It's difficult to be certain because of variable meteor rates,
propagation, and the quality of the station on the other end, but here's
what I feel comfortable stating:
The limitations of a weak portable station can be overcome with an
excellent operating location. I have worked over 1000 miles on 144 MHz
with 35 Watts and a 5-element beam in under 30 minutes in the middle of
the afternoon, when the sporadic meteor rate is supposed to be low. I
look for places that are high in the sky, clear horizon, and free of RFI.
That said, it makes a huge difference depending on who you are running
with...I've had lots of success with K0PW, WA7GSK, WA5UFH, W3UUM, and
K6AAW...these guys are all running pretty serious stations. They
clearly make up for the deficiencies of a puny portable station.
I have experimented with power, pushing as high as 120 Watts, but haven't
noticed anything dramatic. I also tried stacking two 5-element beams on
144 MHz...not sure if it is worth the trouble. I have used exclusively
yagis on 2-meters, so I can't say anything about what happens there with
N5SIX is the authority on portable 6m. I have used a single KB6KQ loop to
make QSOs via HSMS and JT44 on 50 MHz and found it easier than 144. I
think 50 MHz is probably the place to start to give yourself the best
chance for success. I did it the hard way -- my first HSMS QSOs were on
144 MHz from the car -- almost a year before my home station was
I'd resist the temptation to make it too complicated. Running digital in
the boonies takes a lot of thought and planning. It is essential to set
everything up in the driveway before going out; you'll flush out a lot of
unexpected problems. And never rush your setup in the field, although
when the windchill starts numbing your fingers as you attempt to attach
the coax connectors, you'll definitely be in the hurry-up mode.
If you want more info on portable WSJT, you are welcome to read the
article I wrote for CQ-VHF, available on my website:
- I ran my first little MS grid DXpedition over Field Day weekend in June, and
here is what I was running...
Rig: FT-857 with Rigblaster Nomic
On 2M: Mirage 160w Brick and 6 element Lightning Bolt Quad
The quad fits nicely in the 6-1/2 ft box of my short box,
extended cab Chevy
On 6M: Ran 80-90 watts out of the FT-857
While mobile, ran PAR Electronics OA-50 loop
While stationary, put a 5el KMA 6M log periodic
Clock Sync: Garmin GPS72 with NMEATime software (trial version-30 days)
No problem with QSOs - feel like I needed some more ERP on 2M. Heard lots
and lots more pings from the guys calling than they heard from me obviously.
Next time will take a yagi broke down in sections.
Watched the truck battery voltage on the FT-857 and started up when started
to dip under 11v.
For more details and results of my first trip:
As Mike/FKO stated, make sure to practice setting up at home first - after a
couple times, you find lotsa short cuts and get consistent on steps, you can
get set-up/take-down time down considerably. Also agree with finding the
right places to set up - high and clear spots.
73 and Good Luck
Dave Witucki .......N8OC