New Antenna Switch
I noticed a swr variation when I switched between my dipole and vertical hf antennas. The swr reading on my Hustler 6btv was 1:6 and I noticed that when I switched back to it sometimes it was up to 2:0. I played around with the switching mechanism and sure enough it was back to 1:6. The next step was a quick inspection of the internal contacts and switch housing. I noticed that the central spindle was worn and this was allowing the switching pole to lean slightly towards the dipole pick up point. The slight movement rectified the closeness but the switch was well worn through years of operation. So I treated my station to a new better quality replacement as seen below.
my old switch has served me well but the new high power Avair switch has better isolation and is much nicer to operate.
I hooked it up and to my pleasure saw the SWR fall to 1:4 which is even better. Let's hope this nice neat upgrade has a good long lifespan as it seems pretty cool on day one of operation. 73 stay healthy!
Comments
Ive made my own antenna relays using a pl259 and two bnc connectors and the contacts from an industrial relay. Find a copper pipe that fits over the threads of the pl259 and solder then together, but first using a strip of brass to mount a double sided contact to the end of the strip of brass to the center of the pl259. The strip should be bent so that it wants to push against the side of the tube. Drill a hole about 1 inch from the end so an insulator can push through the hole against the strip. Shape the double contact so it can be inserted at the other end and centering the strip so the contacts can be operated by the insulated peg through the hole. Two more holes at the very end to mount the bnc Chassis connectors and solder to the contacts.
The insulator can be operated by a relay coil or by a manual means. Using a strip of roughly half the tube diameter will give a good 50 ohm match on Hf.
I used mine on vhf to commutate between two antennas vert and horizontal.mounted up the mast.in a small box to protect from the weather. The tiny amount of heat from the coil actuator was enough to keep it dry through the dampest weather.
Colin f5vhz.