Tech Page

Projects of members and friends.....


Of antennas and things....

Climb a 1786 ft tower? Take a look...


Portable, center-loaded, manual screwdriver, vertical ala Don Johnson. All folds to about 2.5 ft package, including 6 ft mast.

Coil to radials with coil tap.

Coil moves in and out of surrounding metal tube. Small fiberglass rod to right is to move coil up and down. 10 foot telescoping whip above coil.

OK, this is application of above antenna. Notice the radials drooping over front of wings and one of the rear radials on right.

Band fixed by red center coil, with coils for 40m, 20m, 17m. Tuned by bottom coil. This is for use with qrp 40m rig. This one made several qsos back to Shreveport from Dayton Hamvention and packs into a 12 inch bag.

Of tuners for tweaking....


Z-match - tunes a wide range of antennas

This version built with toroid.

This QRP small tuner will tune end-fed half-wave antennas for 40m, 30m, and 20m.

In addition there is a switch to bypass the L-match (toroid and trimmer cap) and output to another BNC. An SWR bridge with LED may be used in all four of the above modes.

Random wire tuner. Inductor is coil around ferrite rod with sliding contact. Tuning LED is to right of SO-239.
    
This is a tuner designed to tune half-wave wires, of which the counterpoise can be only .05 wavelength long. It is designed to handle 100w where the Altoids can tuner will only handle about 30w. A separate half-wave wire for each band must be used, but the 40m wire can also be used on 20m. Since end-fed half-wave antennas have approximately the same reactance, only the capacitor is needed to tune.
* If you have any project pictures to contribute, please contact the webmaster.