[1000mp] Antenna relays

[Tod -ID]

A follow up to my inquiry on the reflector a few days back.

Several folks responded directly and via the reflector. There were two
alternatives suggested by persons who said they had experienced a similar
problem.

1. The problem is in the FT1000MP and associated with the RX relay system.

2. The problem is external to the FT1000MP and is some fault in the antenna
system.


I decided to check idea #2 first. I found that my RX antennas for 80 meters
[K9AY, Phased active verticals] were receiving just fine even when the main
transmitting antenna was not receiving as expected. Since the RX antennas
enter via the special jack for such antennas rather than the A or B coax
jacks, I decided to check the TX antenna itself for changes.

After five consecutive days of snow, 12 inches in the last day, I decided to
check the TX antenna from the warmth of the shop using my spectrum analyzer.
Sweeping the 80 meter band I could see periodic changes of at least 15 dB
across the band. The changes were abrupt. Maybe related to wind action
outside -- I don't know. 

However, the test was conclusive -- my situation was a type #2 one and the
fix is antenna system repair.

I am putting this on the reflector so as to add to the knowledge base for
this type of failure. My suggestion is to verify that the antenna is not the
cause as a first step -- much easier than trying to check out the relays.



Tod, K0TO