Retuning a Stationmaster

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Back to Home Re-tuning a
Stationmaster-type
antenna
By Jim Barbour WD8CHL
Maintained by Mike Morris WA6ILQ

This modification will LOWER the resonant frequency of these antennas

It is not hard to tune a Stationmaster or SuperStationmaster antenna down in frequency. Take a number of strips of aluminum foil, starting about 2 inches wide and tapering down to about 1 to 1-1/2 inches and long enough to wrap around the fiberglass tube of the antenna. Secure the antenna as far as possible from other metallic objects, at least 4-6 feet. I have heard of people have success with two tall sawhorses or better yet tall fiberglass step ladders to get it high enough off the ground.

Wrap the first piece around the antenna and smooth it out. Start at the bottom with the widest strip and slide the strip up the antenna until you see a dip in reflected power at the desired frequency. Slide it up to about 18 inches above the bottom and then move in 1/2 inch increments until a dip is reached. Fine tune back and forth till you're happy that it's as good as it's going to get, then start the next one about 35-36 inches above that one. Secure each piece with electrical tape, prefer Scotch 33+, then when you're happy with the finished ant., cover all the pieces with more tape, maybe spray everything with clear enamel (not lacquer) or whatever else seems appropriate. Be careful, some spray paints have metallic pigments!! Sitck with clear!! We have used the peel-and-stick foil ground plane kits from Antenna Specialists as well. Don't peel the back off until you have the piece in place. Mark it if you have to remove the foil, so you don't lose your place.

REMEMBER: Don't go near the antenna while taking a measurement! Besides a bit of a safety risk, it will have a HUGE effect on the reading. Also the entire antenna needs to be at least 1 wavelength above ground (about 6 feet). Once you have that dipped, do the same thing again above the first one, then keep going all the way up. On a TRUE Stationmaster or SuperStationmaster antenna the first dip will be about 1/4 wave up from the bottom and the rest will be at 1/2 wave intervals. This is dur to the the construction of the antenna. Myself and others have done this on MANY antennas that were tuned as high as 165 MHz, and it works very well! We are using one now on our 2 meter repeater, and with 60 watts out, it out-talks anything at the site, including the 375 watt paging transmitters on 158 MHz!

The spec'd gain on a Stationmaster is 5.25 dBd, but real world, it is as good as a Hustler G-7 and MUCH better than anything Comet or Diamond or Cushcraft makes, except of course yagi beams. In other words, the Stationmaster is REAL 5.25 dB, the rest are fudging. By the way, this technique has also worked very well on the UHF 7 foot long sticks that we have played with, too.

Jim WD8CHL
wd8chl //at// netscape //dot// net and please put "Repeater Builder / Retuning the Stationmaster" in the subject line