[NLRS] Rover advice needed

[Doug Reed]

I have no practical experience with that type of roving, but I have
suggestions. Note that you didn't say what kind of car it will be....
That can be important for deciding what to build and how you will stow
it at every stop. Your roving plans sound ambitious and you might want
to plan fewer stops for a first contest. Murphy lives! And the best
advice seems to be to set a schedule and stick to it.....

And check the rules, I think they changed so you can use APRS for
spotting this year. An APRS beacon on your car can tell everyone where
you are and what bands you are listening. The people at home can use
aprs.fi to search your callsign to get the info. You don't need to
leave it running once you are at the site because aprs.fi
remembers.... Or you can cut your beacons back to once every 25
minutes and the APRS display software will remember.

For the mast base, I suggest something you drive one car wheel on. It
will be the most sturdy you can get without guying. I once used a
2x8(?) plank with 1.5"(?) pipe flange to support a 2M beam at 15-20
feet. The plank was long enough the mast went up the side of the car
about by the door hinge and I could roll the window down and reach out
to turn the antenna for peaking. Attach something as a pointer so you
can see it from the driver seat. This beat the heck out of using a
rotor. I think I had about 2-3 feet of pipe in the flange and dropped
the TV mast down the center for a 1/8"(?) fit. If you want to go
higher you can try adding a guy ring and para-cord guys with 12" barn
nails for hammer-in anchors.

I agree with Glenn about build yourself some VJB Cheap Yagis for 2M &
440. Then with your 6M Moxon you are in the Limited Rover category. I
don't know how much difference it would make, but you could mount the
Moxon at 90 degrees to the other antennas so there is minimum metal
from the Moxon in the 2M & UHF antenna patterns. But having to turn
the antenna to switch bands would be annoying.....
<https://www.google.com/?gws_rd=ssl#q=wa5vjb+cheap+yagi>

Personally, I have a 20' aluminum push-up mast with car tire base I
found at a hamfest 15+ years ago. I usually use it with a 6' Comet
vertical on top for a race course "base" antenna. It has always worked
well without guying. It has been a good investment but too easy to
damage so I don't loan it out.

Another antenna base I made uses two 2x6 planks about 4 feet long,
held together by one carriage bolt in the middle, with a pipe flange
mounted over the nut side of the bolt. The bolt is barely loose so I
can turn the planks out to form an X shape when used as a support.
Since this would "rock" due to uneven height, I cut the last 4"-6" off
both ends of the bottom plank and screwed it to the end of the top
plank so it acts as foot to stabilize the X. I think I cut an extra
1/4" or so gap so the bottom plank would turn without binding. You
could also make the cut at an angle so it acts as a stop. The X will
support a short mast but works best if you drive a car wheel on one
end or use guy ropes on the mast. I most often used the X base with a
inverted vee with about 20-25' of mast and the dipole acting as guys.
For other uses I have a guy ring with four lengths of para-cord
attached ready to go.

I would avoid the PVC mast if at all possible. You just can't support
any useful weight without it acting like a wet noodle. When we had
Rover Row at the Aurora conference each year, I enjoyed seeing how
people solved their problems. I particularly liked the masts based on
nesting sections of "holey" square steel tubing. I most often see it
in the hobby metal section of Home Depot or Menards, but I think one
of the QST advertisers sells it in galvanized steel so it doesn't
rust. But it tends to be expensive. You might need to haunt the scrap
metal yards for a while to find it at any reasonable price. Worst case
you can drill holes into the solid tubing. Then you lift the mast and
put a pin through the tubing to hold it. Unistrut is another nice
material looking for a project..... I suppose you could make your own
mast with nesting sections of aluminum tubing..... Hole location
depends how tight the sections nest?

I have some 3' sections of fiberglass mast from military surplus but
I've never used it because I might not get them apart again. I have
another light duty mast I made for the Inverted Vee based on 1" wood
dowels salvaged from a damaged yard canopy. I like 3' to 4' lengths
because I can start at about 10 feet, set the guys loose, then lift up
the mast and stick another section on the bottom until I hit full
height. I can deploy the inverted vee antenna by myself in a bit over
30 minutes without trying hard..... One key idea was to tie extra
loops in the guy ropes so I knew where to drive the ground anchors
before starting to lift the antenna.

For combining VHF-UHF bands, the VJB LEO Cheap Yagi article has a DIY
diplexer. I made a similar homebrew diplexor from a QST article about
20 years ago. I used double-sided PCB to make the small capacitors. Of
course I first had to measure the capacitance per square inch, then I
could calculate values.... The unit in the LEO article is low power.
You will need something high power capable with your FT-857, so it
might be easier to buy one.....

I agree with the others that you should try to avoid the generator if
you can. Get an extra deep cycle battery, as large as you can, and use
a big (continuous duty) relay to isolate it from the car electrical
system when the engine isn't running. Then invest in a DC power supply
for your laptop, preferably a universal type with adjustable output
voltage and multiple ends so it will work with anything in the future.
I used to find that my old laptop would work fine directly on 12V
instead of the 18 volts it was spec'ed at. But for $20-$25, the laptop
power supply is good insurance. Then get another DC-DC voltage
stabilizer for the rig. Lots of guys are using the 20-30 amp units
sold in QST and on the Internet. They cost $100-$150 usually but they
will keep your radio running longer between charges of the deep cycle
battery. Back when I was running 10GHz, my FT-817 would get squirrelly
when battery voltage went below 12 volts so I added a small DC-DC
supply and solved the problem. I used another similar supply to
provide 22 volts to run some 24-28 volt SMA relays. I used to buy the
$10 surplus laptop supplies then change the voltage set resistor
inside to get the voltage I wanted.

As Jerry said, avoid the cigarette lighter plugs in the car. Run new
wires direct from the battery and don't forget to fuse it at the
battery. I really liked finding old wire harnesses for commercial VHF
mobile rigs because they often had 4ga-6ga wire and 30 amp fuse
holders. It is also fairly easy to find 50-65 amp DC circuit breakers
at the surplus houses. One of the things I liked about the Ford Police
Interceptor package is that it came wired with a 50 amp run to the
front passenger dash and another to the trunk.

Good luck with your project!

73, Doug Reed, N0NAS.