VA3CDD Rover

After accompanying Tom VA3NFA in the VE3WCC/r during the ARRL June 2006 VHF Contest and experiencing a 6m openning that lasted most of the 1st 8 hours of the contest, I got hooked on roving and decided to field my own entry.

One of the primary design goals should be noted up front. The car used for roving is a leased vehicle -- there are no holes drilled and there should be few scratches resulting from the roving operations.

v1.0: Sept/06

The VA3CDD/r made its maiden voyage for the ARRL September 2006 VHF Contest in the v1.0 form with 3 loop antennas covering 6m, 2m/70cm, and 1.25m attached to a simple wooden dowel on a hatch mounted bicycle rack. A single roof rack provided a guy point for the wooden mast and a mount point for a dual band vertical to for 2m & 70cm FM capabilities. Radios included a TM-V7A dual band FM radio, FT-857 for all mode coverage of 6m, 2m and 70cm, a Kenwood 1296 FM HT, an HTX-100 driving a DEMI 222 transverter and a 10GHz tellurometer.

The actual rove was a Sunday drive through FN15 (my home grid), the NE corner of FN14, the NW corner of FN24, and across FN25. I was following the VE3WCC/r along its route to make spotting easier for fixed stations while I gained an understanding of how to work stations with limited station.

v1.01: Jan/07

There were minimal changes between the September/06 and January/07 contests. The external antenna system did not change. An FT-847 replaced the HTX-100 to drive the DEMI 222 transverter and a Microwave Modules 1296 transverter (using a handheld cheap yagi), and a GTX-900 HT was added for 33cm.

The rove was expanded to cover FN16fc, FN06xe and FN15 on Saturday as a solo expedition. Sunday, I once again followed VE3WCC/r on its path though FN15, FN14, FN24, & FN25 with stops at several local amateur's QTHs to ensure we worked all the bands.

Here is a picture of the VA3CDD/r v1.01 in FN06xe (this was on a logging road that was at least 3 lanes wide)

 

v1.1: June/07

The ARRL June 2007 VHF Contest saw the 1st major changes to the VA3CDD/r. I kept the rear hatch mounted loop array for run-and-gun operation and added beams for stop-and-shoot operation. A wooden rack was mounted on the roof rack to hold a Cushcraft A270-10S dual band beam, a 222 cheap yagi, a 900 FM vertical (on the tail of the 2m/70cm beam), a Directive Systems 1296 looper and a locally made clone of a Directive Systems 903 looper. There were manual coax switches on the 2m/70cm and 222 coax lines to allow switching between the loop and beam for these bands. I also replaced the MMT-1296 transverter with a DEMI 1296 transverter (25W output) and added a DEMI 903 transverter (30W output).

The new antenna rack (front and side view -- the 2m/70cm beam is on top, the 222 beam is in the middle with a 1296 looper on the drivers side and the 903 on the passenger side of the car, note the 6m loop got moved up the mast part way through the contest)

 

The operating position of VA3CDD/r -- FT-857 on the dash, FT-847 (for transverters) on shelf closest to dash, V7A on middle of shelf, transverter stack near seatback, 300Ah of batteries under shelf in front passenger foot well

 
 

v1.2: Sept/07

The September 2007 VHF Contest saw some further refinements to antenna array, with no significant changes to the setup inside the rover vehicle.

The wooden rack was replaced with a larger PVC rack (PVC electrical conduit) with an extra level for the 220 antenna on top. The homebrew 220 antenna was moved to the top of the rack and replaced with a Directive Systems DS222-8R 8el yagi. The dualband 2m/70cm beam is in the middle of the rack vertically and only the 2m portion of the beam is used. A new homebrew 13el 70cm beam built by VE3EFF is now on the lower level between the 903 & 1296 antennas, connected via a diplexor to the 2m beam above it and the FT-857 via a coax switch. The borrowed 903 & 1296 antennas were replaced with Directive Systems 3318LYRMK (903 18el) & 2324LYRMK (1296 24el) loopers.

The 222 loop on the mast at the back of the vehicle was removed since it was not frequently used, allowing the elimination of 1 coax switch from the setup.



  The only change to the inside of the rover was the addition of a dual coax switch to allow the 903 & 1296 transverters to be disconnected from the antennas to protect the front end of the transverters when the PA is added to the 2m setup.

At the start of the contest, I met with VE3OIL/r in FN14 (Numogate -- just north of Smith Falls on Hwy 15). Here is his interior setup:

  And here is the 2 rovers together on a backroad in FN25 near the FN25/FN15/FN14/FN24 grid intersection:

 
 

Future Additions

Here are a few of the future plans for the VA3CDD/r.

DONE: new 222, 903, & 1296 antennas -- the 903 & 1296 were borrowed from the VE3WCC/r and need to be returned, and the 222 antenna did not work as well as was hoped. (completed Sept/07)

DONE: new 70cm antennas -- this will happen as soon as I can find a good cheap diplexor to separate the 2m and 70cm signals. I found the 70cm part of the A270-10S antenna to be a little too low for my liking. (completed Sept/07)

Sept/08: new vehicle -- may happen sooner since the VW Golf does not have enough ground clearance to go where I like to rove.

???: another FT-857 to replace the FT-847 -- will happen as soon as I find a suitable radio, I need to move the batteries and equipment to the back seat to regain use of the passenger seat for a second operator, right now it could get really interesting if there is a good 6m openning while I am mobile.

???: PAs for 2m, 222, & 70cm -- not sure when this will happen, I need to get the diplexor to separate the 2m & 70cm signals and I need to figure out how much RF I can use without causing problems to the car and other radios. I have 120+W bricks for 2m & 222, need to find something for 70cm.

???: more bands -- this will happen as I find equipment to run the other bands

???: computer logging -- this will happen when I find a computer that will work well in the mobile and high RF environments, I am thinking of using an OLPC.