Thanks, Tim! I'd be interested to see the pics and your results with the new relays! I'll have a look at the Struthers-Dunn Data sheet also. Thanks for sharing1
73, Charlie, K4OTV -----Original Message----- From: Topband [mailto:[email protected]] On Behalf Of Tim Shoppa Sent: Sunday, May 17, 2015 10:55 PM To: topBand List Subject: Topband: Antenna relays I think I posted some details here about how I was using Omron G6RN antenna relays (same as used in AC0HB's QEX article) for antenna switching of my coax cables. These are very affordable (circa $3) 8A SPDT relays and they held up OK for me in heavy contest usage - until I got a legal limit amp. Since then I have at first intermittent and then increasing problems especially at higher power levels. To be fair AC0HB never conjectured that these relays could handle legal limit! I had guessed that the failure mode was arcing at the open contact gap, but when I opened up a failing unit I found it was more complex. The relay is a SPDT unit and the "common" current is carried by a super thin flexible springy sheet conductor that also doubles as providing spring tension. Under repeated legal limit usage it appears that heat on this conductor was so high, the tension is no longer high enough to operate the relay reliably. I will be constructing a new 6-way relay switch from far beefier (but still affordable) Struthers-Dunn DPDT T92 relays - will open them up and make pics along the way especially if I figure out how to strap them for common-shorting-bar operation. Tim N3QE _________________ Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband
