[VHFcontesting] Updating the rover for June

k4gun at comcast.net k4gun at comcast.net
Thu Feb 21 14:34:45 EST 2008


Since the VHF contest reflector has been quiet lately, I thought I'd post an update on my rover upgrades.  I'm making serious progress on this.  In the January contest, I had a 100 watt amp for 2 meters, an HT for 222 with a small homebrew yagi, and the antennas were KU4AB stacked loops for 432 and 144 plus an Elk log periodic dual band and a stressed moxon for 6 meters.  All of these were mounted on reinforced painter's poles in the bed of my truck.

Sine then, I've been making major upgrades.  I'm going to be concentrating on the Limited Rover class which means 4 bands, and the same power limits as SOLP.  

Antennas:  Bill Olsen was good enough to sell me 3 rover special antennas from Directive Systems.  I have one each for 144, 222 and 432 and will continue to use the Moxon for 6 meters.  These are the 8' boom models and I have all three assembled and ready.

Amps:  I found a couple of used amps.  They are both TE Systems.  The 2 meter is a 160 watt that everybody seems to think can really put out about 200 and the other is the 100 watt 432 model, thereby maxing out the power limits.

Transverter:  I just ordered a DEMI 222-28 transverter with common IF.  I got the new 60 watt output version.  Since I'm limited to 100 watts on that band, I figured it would be a lot simpler to get this instead of a lower power and adding an amp.  Their lead time is pretty long and I'm really hoping it arrives in time to test it out.

Mast system:  W4SHG gave me the top section of a tower with a tapered top and large diameter tube.  I'm going to cut this down to 5' and bolt the legs to the steel tool box in the bed of the truck.  The rear leg will be bolted to a cargo divider.  I will install a rotator in the base of it.  Steve also gave me 8' of 2" aluminum pipe that has an inside diameter of just over 1.5".  I'll get a 1.5" OD pipe and make a telescoping mast out of it.  By careful spacing, I should be able to get enough distance between the antennas when the mast is up to prevent any coupling.  The highest will be the 6 meter moxon at roughly 20' off the ground.  

Power:  I'll be adding an inverter for the rotator.  Because my tool box is steel and it houses my auxiliary battery, I'll put it in there.  That should make for a decent Faraday cage and I'll use ferrite cores on the lines as well.  

Omni-directional:  I think I still want to keep the ability to transmit while moving.  I already have the antennas for it.  I'm going to get a hitch mounted mast and put the 144 and 432 stacked loops on it.  A switch in the cab will toggle between these and the beams when stopped.

Miscellaneous:  I'm feeding all of this with runs of LMR400.  I am still working on a cabinet to hold the amps and transverter, as well as a spare radio (746 Pro) and a switch for the hard keying of everything.  I think I'm going to run it all off the IC7000 since it has the ability to remember power settings between bands and its already hard mounted into the truck with a good cooling fan.  

There is a little less than 4 months until the June contest and I think I'm on my way.  I still have a LOT of work to do, but I have the plan and have set it in motion.  I've even put in for the time off at work so I don't need to call in "sick" again.  I can't wait.


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