QRP Antenna Match was originally designed for the Yaes13FT-817 Transceiver. Such an antenna requires a special coupling network to properly couple my 50 ohm coax to the antenna's high impedance (~5000 ohms). One of my favorite single band portable antennas is the end fed halfwave antenna. QRP 30m through 17m End-Fed Halfwave Antenna Coupler/SWR bridge by AA5TB It uses a parallel circuit for 30 - 80 and a series tuned arrangement for the bands up to 10 metres. This simple aerial tuning unit was described by Doug G4RGN in Sprat 78 and is a useful modification of the Z match. Forward power indicator is omitted because I know the output power of my transceiver anyway. Tuning is done for minimum reflected power. This is a C-L-C type tuner with a reflected power indicator. Homebrew C-L-C QRP Antenna Tuner by 7N3WVM Whenever I would go to a sidewalk sale or hamfest I would pick up any components that might someday come in handy to make a tuner. Your now ready to operate.įor years I've thrown together simple antenna tuners to get me on the air when needed. Remove the Tuner dipper from the tuner and connect the rig to the tuner. Connect the antenna tuner to the jack and power up the Tuner Dipper. This Antenna Tuning Unit also incorporates a 50-ohm QRP dummy load, power meter (1 or 10 Watts full scale), and SWR meter! I have used this ATU for a variety of longwire antennas, including outdoor antennas of various lengths. A compact and light weight system for use in the field by campers and backpackers. Versatile L tuner for end feed wire antennas, fits in an Altoids tin. During these field days, MFJ-945E (above, left) consumed large amount of volume in my backpack.įor this reason, I recently built a compact Z-match tuner (above, right) for field usage with my 7T9521 TX and 7R3357 RX. I made some field operations in May and June, 2005. 250pF polyvaricon capacitors can be used for up to 15 watts, and a T130-2 toroid. This ATU was described by G3WQW in Sprat 84 and being balanced can accomodate balanced line, open wire feeder or 300 ohm slotted. The original of this was found as a lump of militairy surplus at Longleat and cost the pricely sum of 50p! My antenna tuner working perfect with any type of antenna from 80 up to 10 meters and I'm running about 150 Watts on the key without problem for many years. John has modified it by incorporating a balun and would send details of the unit if required.Ī Multi-type (L - PI - T ) "one-box" Antenna Tuner by SV1BSX This tiny tuning unit was descibed in the October 1995 edition of 73 magazine and will match from 80 - 10 metres, unbalanced. Since I enjoy using End-Fed Halfwave antennas so much I built a small coupler to use with my Rock-Mite. I own an Yaesu FT-817 that I wanted to use on 6 meters but none of my antenna tuners could match my antenna setup for that band.Ī 40m through 17m Mini End-Fed Halfwave Antenna Coupler by AA5TBĪ few years ago I built a little Rock-Mite transceiver for 40m. The “Army Loop” tuner is at the bottom of the loop, with the Yaesu FT817 and external battery pack next to it. The photograph on the left shows the mag loop's set up using heavy-duty insulated copper braid in the "Safari" location (aka in my back garden). Using just a few mw of output power, this circuit is used to find the 50 ohm resonance frequency of antennas or can be used to adjust an Antenna Tuning Unit for 50 ohm match, without generating QRM
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