[NLRS] Looking for Mounting Help

Mon Sep 7 17:34:21 EDT 2020

Scott,
You’ve gotten some good advice already. I would just add, keep it simple,
at least for the first couple times you rove, and then add to it based on
your needs and likes.

Are you going to be a solo rover and operate only while parked?  Will you
have a driver and operate on the move?

There’s a lot of experienced rovers in this group that will be happy to
give you pointers. Knowing the above will help us point you in the right
direction.

73 de W0ZF

On Mon, Sep 7, 2020 at 3:31 PM Doug Reed <n0nas at amsat.org> wrote:

> Hi Scott.
>
>
>
> Many NLRS ops run rover in the VHF contests. You didn't say what year
>
> Honda Pilot, does it have a trailer hitch, does it have a roof rack?
>
> Does the little side window near the back open?
>
>
>
> I have never operated rover mobile, only portable, so this is mostly
>
> from observing rigs at our annual Aurora conference in April. I do
>
> take pictures of the ones I liked best. For portable ops, I liked
>
> having a guyed mast outside the drivers door and I could reach out to
>
> point the antenna by hand in seconds, Not well suited for winter
>
> contests. :-)
>
>
>
> Most systems are either mounted on the roof rack or mounted to the
>
> trailer hitch. Cable entry is where ever you can bring them in with
>
> least interference, that usually means a window. Consider some "foam
>
> pipe insulation" over the edge of the glass as protection for the
>
> cable and weather seal. Are you going to drive and operate while
>
> stopped or will someone else drive while you operate? Where will the
>
> equipment be in the car?
>
>
>
> Roof racks are usually either wood or PVC pipe. Most of the time they
>
> will be fixed in the forward direction and you point the car toward
>
> the station. If you really want to turn the antennas while stopped,
>
> you can mount a small tripod to the rack, with a rotor and short mast
>
> for the beam. But remember to always point it forward before you move.
>
> And you will probably need to provide AC to turn any cheap rotor. And
>
> always remember 12ft maximum height above ground to go under bridges,
>
> and that trees and some bridges are lower than that. Trees eat
>
> antennas.
>
>
>
> Many people use the trailer hitch mount. If you have one on the car,
>
> that might be the better option if your roof rack isn't very sturdy.
>
> I'd say that the best masts I've seen are usually square metal tubing
>
> with holes and additional sections are nested inside so they can be
>
> raised for extra height at each stop. I want to suggest the best
>
> option for rotating the mast is with the rotor mounted at the bottom
>
> on the hitch bar. You will want to have a couple sturdy braces from
>
> the mast forward to the roof rack. And you would need some sort of
>
> bearing to allow the mast to rotate in the bracing. The main negatives
>
> for trailer hitch mounting is you can't open the hatch while it is in
>
> place and the antennas are a long overhang in the rear so you need a
>
> flag and I'm sure there is a max overhang length by law.
>
>
>
> If you don't like the rotor at the bottom and bearing option, maybe
>
> you can find a couple of the old Alliance U100 rotors that have a hole
>
> all the way through the rotor for the mast. They are ancient and not
>
> very strong, but I used a pair of them on my house with a pair of
>
> beams through some severe storms and they held up for 10 years. The
>
> trick is to take the motor out of one body and use just the empty
>
> housing as a bearing and support for the mast, with the other unit a
>
> couple feet higher on the support to turn the antennas. They spread
>
> the weight load and the spacing helps keep the mast vertical so it
>
> doesn't destroy a single rotor. Keep in mind that driving 70MPH would
>
> be considered severe weather with broken branches near 3" diameter.
>
> Add a 30MPH headwind and now it is 100MPH wind load, hurricane
>
> strength.
>
>
>
> I would suggest that for the beginner, the roof rack is probably
>
> simplest. Wood is probably more sturdy than PVC, but you would
>
> probably be OK with 2" or 1.5" PVC pipe to get as much strength as
>
> possible. That will come down to how big is the dual band beam?
>
>
>
> A minimum sort of structure might be a large square, the length of the
>
> roof rack and 5ft high. Mount it vertically front and back to a pair
>
> of 2x4 studs that go across the roof and are anchored to the roof rack
>
> on both sides. This structure should stand on its own but will not be
>
> sturdy enough to hold anything until you add ropes as guy wires to
>
> form triangles in all directions. I would brace the top corner to each
>
> end of the 2x4 bottom mount and run two more ropes from corner to
>
> corner of the pipe frame. The simple way to mount the beam would be to
>
> attach it to the top pipe of the frame so it always points forward.
>
>
>
> Don't take this as a suggestion for a proven design. It is just a
>
> guess for a minimum structure that would probably hold a small antenna
>
> without too much difficulty. The only real strength comes from the
>
> rope guys that stress the frame to reduce bending. You might even need
>
> to run an extra pair of guy ropes forward to the front bumper of the
>
> car. I'm really worried about how well the frame will handle the wind
>
> load at highway speed. Personally, I would probably use "550 paracord"
>
> for the rope. It needs to be strong and with minimum stretch. You may
>
> want to add turnbuckles to allow tightening the ropes, or you could
>
> try the cheap alternative of winding a wood dowel into the rope for
>
> tensioning. On second thought, a $10 package of 4 cheap ratchet straps
>
> might be better than ropes.
>
>
>
> And plug the ends of any open pipe because they will sing when you
>
> drive down the road. It becomes very tiring.....
>
>
>
> Probably the best thing about this frame is that it will be pretty
>
> light to install and remove. One person can probably handle it but a
>
> second person would make it easy. But the first step is figure out how
>
> to attach to the roof rack.... U-bolts would be good, or maybe you
>
> have a spare set of cross arms for the roof rack that you can mount
>
> to? How about a 2x2 on the bottom, U-bolted to the cross arm. Two 1x4
>
> on either side up to another 2x2 for the top rail. Use screws & glue,
>
> not nails, maybe add some pipe strap for extra strength? Still want
>
> the ropes or straps to brace everything.... Can't get much cheaper
>
> than that but it would be harder to install without a helper.....
>
>
>
> And don't forget power requirements. You WILL want a deep-cycle
>
> battery to run the radio when stopped. Do not rely on the car battery
>
> for power when stopped or you might be stranded. Keeping the radio
>
> battery charged means running the car or a portable generator. The 2KW
>
> portable Inverter generators are very popular, expensive, and QUIET.
>
> You can estimate how long you can operate from the radio battery
>
> before it needs charging. The charger has to be big enough to charge
>
> while transmitting. Charging a second battery from the car alternator
>
> will probably require some heavier wire run from the existing battery.
>
> I never had any luck when plugged into a cigarette lighter of similar
>
> connection. For winter roving you either run the car heater or use the
>
> portable generator to run a heater. And you will have fun keeping
>
> frost off the windows....
>
>
>
> You will want the option for digital modes too. That means a laptop or
>
> other computer and now you need power for it without relying on the
>
> laptop battery. That means a DC-DC laptop power supply or an AC power
>
> source. And I'd probably say that you should consider getting one of
>
> the DC-DC converters designed to regulate the battery voltage to 13.6V
>
> at all times. Many radios get flakey when the DC voltage drops. The
>
> step-up regulator will keep the radio working while the battery
>
> voltage drops. All these DC-DC converters and AC inverters need to be
>
> tested to prove they don't make RF noise.... Ferrite chokes are your
>
> friend...
>
>
>
> I don't remember if NLRS has any "Rover Row" pictures on the web site,
>
> but I bet they exist somewhere if you search the web. That will get
>
> you a lot more ideas.
>
>
>
> 73, Doug Reed, N0NAS.
>
>
>
> --
>
> I vote the Second Amendment FIRST!
>
>
>
> Enjoy life, it has an expiration date!
>
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