Topband: F fitting adaptors

[Tom W8JI]

> Reference to my email, I did  not state I had an Ameritron. In fact I have 
> no remotely switched receiving antennas. All receive antennas are switched 
> in the shack.  Come to my QTH and walk the field and woods and 
> see.....(Watch out for Deer ticks.) The Ameritron reference was to give an 
> idea what was wanted for an adaptor.  Also, the adaptors are for a friend.

Hi Bruce,

That aside, my comments apply to all relays in receive paths. Zero current 
and voltage or near zero current and voltage relays have a very high failure 
rate due to contact resistance.

This "frequently" happens inside amplifiers (even with brand new sealed 
relays) and in higher power antenna switches.

I just thought I'd point out, with the possible exception of vacuum relays, 
higher current relays are much more problematic than low current relays. 
It's an odd case of smaller is better.

While some may think otherwise, this is well documented and is clearly 
reflected in field problem reports of antenna switches. The problem has been 
documented since at least the early 1900's. A "new" problem has appeared in 
enclosed relays, where materials in the relay slowly leech and build a very 
thin film. There is cleaning procedure on my website:

http://www.w8ji.com/relay_cleaning_and_life.htm

Just a bit of trivial information that may someday help someone, because it 
is one of the leading field problems every manufacturer using higher current 
relays to "dry switch" signal circuits has. It even occurs, according to 
relay suppliers, when lower current LED traffic lights replace old 
incandescent lamps.

73 Tom