[1000mp] AFSK/SSB Power Drop

[Chris Brougham]

Hi Folks,

I've been noticing a strange problem with my Mark V. Every now and then 
I will get power drops when using afsk RTTY or phone. The SWR is always 
flat so I don't think it's that (I use an external tuner). I never see 
the problem with CW. When the power drops out I often have to power cyle 
the rig to get it working again ... but not always.

I have a couple of different types of antennas at this QTH (an 
apartment). One is a large indoor wire loop fed with 450 ohm ladder 
line. The others are a mag loop, fed with coax, and one is a hamstick 
mounted on my balcony.

I've never seen the issue with the hamstick, but it occurs most 
frequently with the indoor wire loop. I noticed it on 40M phone during 
Field Day with the wire loop for the first time. Yesterday I noticed it 
on 15M phone (running 20 Watts). Today during the SARTG RTTY contest it 
occured for the first time with the mag loop running 75 watts (all the 
other occasions were with the indoor wire loop).

My friend suggested some sort of RF problem in the shack. Why would it 
occur only on phone and AFSK and not CW? It seems to be intermittent too.

Any ideas would be really appreciated!

-- 
Chris VA7CAB