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David Robbins, K1TTT



Radios, Amps, Other Common HW

The Shack

This describes common stuff used on multiple stations so I don't have to repeat it on each one.


  • HF-2500
    • Tuning
      • Use N1MM+ Ctrl-T to tune
      • 50-60w drive for 1500 out
    • 2 different hf-2500’s
      • ‘red line’ ones don’t have grid protection
      • no ‘red line’ means they have grid protection which cuts them out if grid current is >50ma or so. They reset when you unkey so there is no need to cycle power or standby. To re-tune, turn down drive, key up and retune. If its because of a quick QSY or antenna switch to work a multiplier just turn down the drive, make the QSO and go back to where you were.
  • ACOM-2000a
    • Auto tunes on first transmission when changing bands or segments
    • Can set tuning for different antennas, only used on 160m right now
      • Have to manually select antenna before transmitting


  • Yaesu
    • Stops – All my Yaesu rotors have the stops set the same. Counterclockwise they stop at North. Going Clockwise they go 450 degrees and stop at East. When they go past North the ‘Overlap’ light comes on to tell you they are in the 90 degree overlap area.
    • GreenHeron RT-21 control boxes on all rotors
  • TIC Rings
    • Used for lower 10m, 15m, and both 20m Yagis
    • Stops are set South
    • GreenHeron RT-21 control boxes on all rotors
  • K0XG Rings
    • Used for 40m antennas
    • Stops are set South
    • GreenHeron RT-21 control boxes on all rotors

Antenna Switching

  • Custom designed and built pushbutton controllers are on all bands now.
  • They have a TX lockout capability that prevents switching antennas while the radio is keyed.
  • If you poke the buttons too quickly it is possible to get no antenna selected so watch for that. You can also hit two buttons and get both selected. In most cases this will result in a high SWR, but could be interesting for monitoring a band using more than one antenna.

    Sample antenna selector box

The above picture shows a typical antenna selector box. The labels on all the boxes are included in the band by band descriptions. They are basically all set up the same way, the top box contains a short description of the antenna by height or type. Then there is a box for how many elements of if it’s a stack. Then the bottom box is either the rotor type or fixed direction. The band by band breakdown describes each selection for that band.

RX Antenna switching, filtering, and preamps

The switching is designed for two modes of operation. In the M/M 6 station setup the RX antennas are split to feed the 40m, 80m, and 160m tables separately. In the SO2R setup the two radios can each select from any of the RX antennas separately.

RX Antenna Switch Construction




Other Stuff

  • RigBlaster. Shouldn’t have to touch
    • Not using much of the features of this any more
      • Bypassed RS232 keying to use WinKeyUSB instead
      • Added Pyle noise filter because of a ground loop problem not fixed by the RigBlasters
      • Take RX audio from line-out jacks on Yaesu radios direct to line-in on computers.
    • Power should always be OFF
    • Process switch should be UP
    • Level Set should be full clockwise
  • Foot switches. I have several foot switches available, they connect in place of the hand ptt switch.
  • Hand switches. Each station has a hand ptt switch.
  • Paddles. Each station has bencher paddles, if you really want to bring your own they should be wired to a ¼” stereo phone plug.
  • Keyers. Each station has either a WinKeyer USB keyer or uses the WinKeyer built into the YCCC SO2R boxes.
  • Headsets. I have Heil closed ear, boom mic headsets on all stations, and a couple of spare pairs. For listening in I have a couple light weight headsets that can plug into the 1/8” phone jack above the ¼” one on the mp’s.


Some notes on my RTTY setup. The first method for splitting the rx is used on the SO2R setup so you can decode the main VFO on both radios. The second method is used on all the stations for m/m operation to decode both VFO's on the FT-1000mp's.

With mmtty you can set up separate decoders on the left and right channels of a stereo sound card. All you need to do is get a stereo Y cable or connector that plugs into your sound card line-in jack. What I use is a Y cable, I slit the outer jacket of the cable open and expose the inside wires. On one side I clip the wire that goes to the ring, on the other side I cut both wires and connect the one that comes from the tip input to the ring output. So now the tip of one side goes to the tip of the output, and the tip of the other side goes to the ring output... so now one radio is in the left channel and the other is in the right. set up 2 instances of mmtty and point one at each channel and away you go.

The output is even easier, just use the same type of splitter unmodified, run the same audio to both radios. then set up your ptt or tx via cat command to only the selected radio is keyed.

Its even simpler on an mp to use the sub rx, just use a stereo cable from the line-out on the back of the mp straight to the line-in on the sound card, set up 2 mmtty's like above and you can decode both vfo's at once... of course you can't rx while tx in that arrangement since the sub rx is muted.


A multiplier bell


Big toolbox


Coffee and microwave station


Command center


Operator schedule on the command center screen





Wireless lan


Printer and metal and wood signs




WX Station and Skimmer computers