KK1L 2x6 Antenna Switch and Mods
For this SO2R implementation, a dual-ported antenna switch was needed that would allow the run station antenna access.
The usual solution for this is the popular Six Pack switch. But given the nature of this project (meaning the plan was in flux), I wanted something a bit more easily configurable. The KK1L board was the perfect solution.
KK1L Web Site: http://home.comcast.net/~kk1l/kk1l_2x6switch/
Why the KK1L Switch?
There are a few technical points about the board which set it apart from the other projects I found on the web. First, the advertised port to port isolation was excellent at 60 db. Next, the SWR (return loss) was very low even at higher frequencies.
These two specifications are not often listed in other project's write-up; and they are important for SO2R isolation operation where leakage between antennas can be compounded by leaks in the switching gear like this antenna switch. And finally, Ron had a complete, well documented design - with very importantly an excellent PCB - ready to go.
Ron had a board in stock and a few days later, it arrived in the mail.
One thing that makes this project a real joy is pre-prepared order lists. One click on the web site pulls up a complete parts list from Mouser. Click one time and it loads the parts list into your shopping cart. Very slick, Ron!
While it was not used in my SO2R project, Ron also offers a nice dual-head band-data decoder with lockout logic PCB. And of course, the Mouser parts listing.
Switch Construction
The bare PCB shown here in this stock photo from the KK1L web site:
Assembly was simple and the PCB included good instructions. Builders of the board may want to attend to a couple of details:
A. The photos in the instructions were slightly different from the current revision of the PCB
B. Trim the leads from the cap/diodes close to the PCB. This will allow the relay to sit flush with the PCB.
C. There is some added benefit in increasing the thickness of the trace by flowing a solder bead over the key conductors (not done in my case). But if you want to consider it, it should be done prior to part placement, of course.
