Topband: DX last night and QRM problem

[N1BUG]

Maybe someone can offer some suggestions on this problem.  I 
almost always have some serious QRM between 1813 and 1820, 
sometimes taking out even more of the band.  It has been a 
serious problem in my attempts to work a JA.  It sounds 
like something oscillating, but it is a rough, growling, 
very unstable note that is often 3 or 4 kHz wide.  It also 
moves up and down the band somewhat.  It seems to be weaker, 
narrower, and more stable on VERY cold nights; on warm 
nights it sometimes splits up into several distinct 
"growlers" and they wander the band more.  I have shut off 
everything in my house and it is still there.  I have tried 
a different receiver and power supply and it is still 
there.  Any ideas what this might be???  Last night was very 
warm for this time of year and it nudged up above 1820, at 
times wiping out 6O0CW on 1821 and this morning it covered 
up JA7NI.

6O0CW was just building up nicely when they went QRT at 
0000z last night.  When they came back at 0220z they were 
loud but only for about 5 minutes before dropping off 
sharply.  I suspect the propagation peak was during the 2+ 
hours they were QRT.  Oh well, I'm sure they will be back 
and we can all try again.

It was really nice to work Phil, FR5DN for a new one.  My 
last several QSOs with Phil were on 2 meter EME!  I was the 
first to work him last night, barely squeezing out a QSO at 
0055z.  He peaked 579 at 0210z, which according to my 
program is 10 minutes after his SR.

I was also very pleased to put Jon, OY9JD in the log.  I 
worked OY 20 years ago but it's not confirmed so this was a 
nice one to get.

Last but not least I got a communication from Tom, SU9NC.  
He says work is very busy but he will try to get on top 
band more this season.  He advises having a high local 
noise level so DX / weak signal is difficult.

73
Paul  N1BUG