I am trying to gauge the interest of my fellow rally workers and ham radio operators.  I have worked performance rallies in Ontario, and I know as a radio operator that we can sometimes be placed in "less than optimal" positions.  Parked beside a hill, or in a valley, or in other varying terrain which can limit our ability to communicate.  

I am looking at producing some roll-up j-pole antennas, which could be used with either mobile rigs, or even handheld units.  Antennas would be 2m/70cm compliant, and would have the following specifications:
-SWR is in the range of 1.5:1 across 2m, and 2:1 across 70cm
-25ft of RG8X feedline (one of the best coax cables for price vs. signal loss)
-supplied with BNC or SMA male, or PL259 connectors.  

The great advantage of these antennas is how compact they are.  Simply roll them up and store them in the trunk, or in a backpack.  With 25 feet of feed line, you've got more than enough cable to connect to the radio in your car or to your handheld and hang the antenna in a tree.  And we all know rally roads; there are no shortages of trees nearby!  

A test of my first j-pole, hanging on a tree at chest height, had me hitting repeaters 30km away with a 5w Yaesu handheld.  Try that with a duckbill antenna!

The price has not been set because the more supplies I order, the more my cost to manufacture drops.  I'm expecting to sell these in the $35-$40 range, and can deliver for free to rallies I attend.

Also, if anyone would like their existing mobile whip antenna tuned for SWR on the 2m band (assuming your antenna can be tuned), I plan on bringing my antenna analyzer with me to some events.  While I'm offering this as a free service to give back to the rally community, a contibution to the coffee/gas fund is always appreciated.

I do plan on being in the service area at Pines, and can tune antennas during my free time on Saturday.  

Hi Dave,

Most mag-mount antennas that I've come across are adjusted using one or two hex ("allen key") set screws holding the antenna mast to the threaded base.

For minor adjustments, you simply loosen those hex screws and move the antenna mast up or down small amounts to find the optimal length for the given frequency.  If you're antenna is too long, then you may have to cut a piece off the bottom of the mast to allow for proper adjustment.  However, if your antenna is too short, then you're stuck with whatever your "max" adjustment is.  (The point where the hex screws don't hold the mast in anymore).

All you need to do is make sure you have access to the back of your radio.  I'll need to disconnect the antenna from the radio and hook it up to my analyzer.  Everything can be done without removing the antenna from the car.  It would also be helpful if you had the proper hex key for the set screws... but I'll throw mine in the tool box.

Unless more interest is shown soon, I'm going to scrap plans to do this.  

Final price with a bit of markup to cover extra costs is looking like $50.  This makes the antenna nearly double the cost of currently available options (durham radio, radioworld, maple leaf communications), but the difference here is the quality and quantity... 22ft feed line vs. 7ft feed line, low loss RG8X vs. lossy RG58.

Please let me know if you're interested.

Doug.

Hi,

The antennas would be a 1/2 wave on 2m.

One of the big expenses is the RG8X; it's more expensive, and I'm using more than other commercially available antennas.

If I get more interest, I can probably drop the price to $45.  I'm trying to build a bit of buffer into my price incase I end up with a bunch of extra antennas kicking around that nobody wants.

Well, I came home with two of these antennas still in my box;

If anyone is interested in a roll-up j-pole with ~22ft of feed line, and can be rolled up to fit in a backpack or briefcase, I'm selling these at $50/ea.  

The remaining two have PL259 connectors on them; the typical large screw-on VHF connector.

As a testimony to how well this style of antenna works, the Rally HQ radio net control guys were using two roll-up J-poles suspended from ultralight collapsible fiberglass poles (13-16ft tall).  They simply tape the j-pole to the collapsible pole, lift the pole up, and duct-tape it to the railing on the deck outside the rec. center.  From what I understand, those antennas covered the simplex frequencies and had no problems communicating to any of the stages on simplex.  (communicating with the repeater frequencies didn't require antennas to be mounted with any elevation because of the location of the rec. center.)

The collapsible poles came from the "LeBaron" outdoors store.

Hi Eufrades,

I will be home to Norwood (Peterborough-ish) for the Christmas holidays.  Perhaps we can arrange a time to meet up then.  

Thanks,

Doug.