One thing a person can do to extend relay lifetime is to verify there
is no hot switching going on. Many modern rigs have a built in delay
between amp keying and actual RF output, but many older rig s do not.
A dual trace scope with one input on the keying line and another on
the RF output will give the answer. A typical relay takes about 20 mS
to switch so any delay less than that may be trouble. Remember there
are two relays which have to switch - one in the transceiver and one
in the amp. Be sure to check both key down and key up times.
One method I have heard of but never used myself is to key the
amplifier first and then have the amp key the transceiver. Simple
enough on key down but key up is a little more complicated. You need
some kind of logic box to unkey the transceiver first and then unkey
the amp, just the reverse of key down. Perhaps such boxes are
available on the market? I haven't ever seen one.
73, Bill W6WRT
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