If I had to pick my most favorite amateur radio activity, it would be experimenting with HF antennas, especially on the lower (160, 80, 40 meters) bands. To support this experimentation, I have a number of switches that allow me to select a range of transmitting and receiving antennas. The 756Pro radio helps in that regard by having 3 antenna connectors, two that are transmit/receive, and a third which is receive-only.
The picture shows the four boxes that, in addition to two coax switches, control my antenna selection. The two lower boxes are Ameritron RCS-4 remote antenna switches. Each is a four-way switch. The actual switches are located out in the yard. One is about 130 feet from the house, following an underground feed under the lawn. The second remote switch is closer to the house.
The upper left box is a homebrew box that is a combination three-way antenna switch and direction selector. This box is used for receive-only antennas. The three-way switch is at the end of a run of coax that comes off of one of the four choices on the right RCS-4 switch. The direction selection is accomplished by placing a control voltage on the center conductor of the coax. The three-way receive selection box introduces the voltage on the downstream coax feeds. If a given receive antenna is directional, it will pick up the control voltage from the center conductor (usually to drive one or more relays).
The box was initially constructed to support a K9AY Terminated Loop Array (QST, September, 1997). That array has four selectable directions, which I chose to align with northeast (NE), southeast (SE), southwest (SW), and northwest (NW). The center conductor control voltage is either 0V, +12V, -12V or 12V AC, depending up the direction.
The upper right box is also homebrew. It provides two general purpose switches that can control a +12V device. Currently, one switch is used to add a small base loading coil onto my 160 meter vertical in order to shift from the phone portion of the band to the CW portion. The right side of the box is a matrix of four double throw, center off, switches. Four different antennas (1 - 4) can be placed on the A Bus, the B Bus, or neither. The A and B buses are the main and auxiliary inputs to a MFJ-1026 Deluxe Noise Canceling Signal Enhancer, which is used a a receive antenna phasing box. In practice, I connect a wide range of receive antennas to these four inputs, and pick pairs which are then phase and amplitude combined by the MFJ-1026.
The homebrew boxes are common Radio Shack metal enclosures. The lettering is created by printing onto self-adhesive sheets, which are then applied to the metal case. I have found this to be a quick and easy way to create labeled box that can have color, and are moderately durable. I spray the labeled area with a clear protective spray in order to reduce the chances of smearing or damage.
Please see my Antennas description for more information.
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