Projects HF / Sat / rptr

Main HF station, 2-meter FM station, satellite station, and 2-meter repeater.

Status Updated 1-3-21


ASUA Grant Push grant with ASUA to fund at a minimum:

HF multiband yagi

Satellite transceiver

Satellite antennas

Preamps: 2m / 70cm preamp

REMOTE OPERATION Configure station for remote SSB operation of KX3 / TS-2000. Casey is coordinating the network issues. (K7CHM)

HF STATION COAX CABLE DISTRIBUTION STRIP Design, procure parts, fabricate, assemble and install 32-inch coax cable distribution strips. One will be installed in the shack, the other on the satellite tower on the roof. Status 1-2-21 : most parts in hand, fabrication in progress. (K7ZOO )

HF station: Remove / sell 15m & 20m yagi's.


Shack Obtain long table to accommodate both satellite station and experimental operation position. Contact Mia second week in January. (K7ZOO)

---low priority ---

HF STATION Guy rope OCF dipole Guy on east is fiberglass strapping; recommend replacing with MASTRANT.

---to be prioritized / assigned / deferred ---

1 HF STATION Incorporate donated Heil headset into Elecraft K3 setup (person TBD)

3 REPEATER Measure current received signal levels across relevant cross section of Tucson metro area, to provide a baseline against which future improvements can be compared. This measurement could use a 1/4 wavelength whip centered on car, mobile rig with s-meter, step attenuator. This measurement need not be absolute, but the same equipment used each time to quantify the effects of change to the repeater system.

4 REPEATER Power output Measure the power output with a Bird wattmeter or similar reliable instrument to ensure it's operating as expected. Consider increasing power output to 50 watts.

5 REPEATER Duplexer cavities Measure and possibly re-tune duplexer cavities. The most instructive method is likely to detach and relocated cavities to ECE building where there is ready access to electronic test gear.

6 REPEATER Antenna Explore options to increase horizontal gain of antenna. Commercially-available antennas could range as much as $200, and provide little educational opportunity. A multi-element vertical colinear is relatively easy to build and tune, and would give insight to the design form, especially phasing coils. One possible option is found at

7 REPEATER Relocation While it's attractive to have the repeater in the shack (providing excellent visibility and potential learning) we will explore relocating the repeater to a higher building on campus. The ECE or Gould-Simpson buildings are likely candidates.

1-19-20 ECE building surveyed and eliminated. Elevation of ECE is no higher than K7UAZ isopole. ECE antenna pad location provides no coverage to NE direction, unless tower of >=15 ft is installed.

--- completed tasks ---

Paddle Feet 11-5-19 COMPLETE! Install new rubber feet on Bencher paddle for Elecraft K3. (N1UW)

2m Rig in Shack 12-20-19 COMPLETE! Donated Yaesu FT-212RH repaired, custom desk mount fabricated, downselect mobile microphone, installed in shack with Astron power supply. Brief instruction/reference card laminated and put on radio. (K7ZOO)

REPEATER Transmission line 1-25-20 COMPLETE! Characterize via TDR and SWR to ensure it's functioning as expected. SWR measurement from duplexer to antenna showed very good performance. TDR not performed. Results published on website. (K7ZOO)

Troubleshoot and repair Remote Coax Switch Control Box (Ameritron) 2-5-20 COMPLETE! Power switch mechanical failure - switch replaced (KG7YTR). Fuses blowing when attached to station HF coax. Relays replaced. Fuses still blow when attached to station HF Coax. Remote coax switch removed and tested good in isolation. (K7ZOO)

HF STATION Replace OCF Dipole Connector 2-8-20 COMPLETE! Loose connector on RG-8/U coax going to OCF dipole - connector freely rotates. Looking at the braid attachment solder holes one can see directly through those holes to the center conductor -- NO DIELECTRIC IS PRESENT AT THIS LOCATION! (KG7YTR & K7ZOO)

HF STATION Sell Henry Amplifier 12-20-20 COMPLETE! (K7ZOO)

HF STATION Sell antenna tuner 12-20-20 COMPLETE! (K7ZOO)

HF STATION Sell 1960's dummy load 12-20-20 COMPLETE! (K7ZOO)

SAT STATION Sell Yaesu FT-736R 12-28-20 COMPLETE! (K7ZOO)