Radio W4KAZ

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More Remote Antenna Switches

The current idea to incorporate the SixPak into the antenna switching scheme will also require more remote switching on the down range side of the SixPak. I expect to have two or three 40m antenna choices, and two or three 20m antenna choices. Perhaps even on 15m and 10m. The 20m and 40m antennas will be dipoles at right angles to one another. The goal is to allow all antennas for a given band to plug into the appropriate port on the SixPak.

Currently, the 15m/10m rectangular loop is down. The new 40m dipolewill occupy the support rope previously used for the rectangular loop. There are now brandnew support lines shot into the biologicals that I expect to use for 10m and 15m loops. Right now, a diamond loop fed at the bottom is appealing, but it may be a pair ofdelta loops instead. The nature and locations of the newsupport lines and the surronding foliage will force a dipole to be Vee’d.Pushing the necessary limitations into an advantage indicates loops might be appropriate, or better than Vee’d dipoles. (Engineer the possible!)

Loops on 10m and 15m have appeal. The average height of a delta loop radiator(apex up) will be slightly lower than a Vee’d dipole at the same height, but a loop has a teeny bit of gain over a dipole. Both of the supports are at about 55 feet. Loops favoring EU should be good performers, if those bands ever become more reliable in that direction.

If the band switches are on the antenna side of the SixPak, each radio will be somewhat better isolated, and neither will be on an antenna that is resonant with the other radio’s antenna. For bands with multiple antennas, coaxial stubs could be placed between the SixPak and the antenna switch to provide harmonic filtering across all of the antennas. i.e., One coaxial filter per band. That will save on coax for the stubs.

I will probably choose to run separate control cables for these mono-band antenna switches, but it is possible to use the coax for the control voltages. Personal preference is to keep the apples separate from the oranges. Having a couple of hundred feet of Cat-5e laying around is also a factor. The control cable is already on hand in quantity. Note: The AD5X project linked below uses the coax for control voltages.

Simple one relay switches will allow choosing two antennas. That will fit in a small enclosure, and allow for very short lead lengths between so239 connectors. (??Notes on test…??)

The Ei7BA remote switch.

The AD5X remote switch.

A 6×2 switch project byK5LXP

A list of antenna switching projectlinks at DXzone

Amended 4/13/2009, 6:20pm

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