40m harmonics on 20 / 15 / 10m 6600

DL4RCE

Hi all, following problem:

Two Panadapters, FDX mode, 2 SCUs in use.

Both ANT1/ANT2 are terminated with 50Ohm Dummyload.

PAN1 /SCU1: ANT1/ANT1 40m 
PAN2 /SCU2: ANT2/ANT2 20m (or 15, or 10)

When I am transmitting on 7.100kHz with 100W I do get quite a strong harmonic on 14.200, 21.300 and 28.400. Signal strength gets lower from 20 to 10m. On 20m it is S9+ and I do get strong distortion on the band.

Is this behavior to be expected? I want tom work SO2R on upcoming WAG contest and since this is happens even without antennas ... listening will be **** 20/15/10 when TRX on 40m.

With "real" antennas attached problem stays the same (that was when I first noticed it).

Any help or idea is appreciated.

73, Volker, DL4RCE

Joe N3HEE

DL4RCE

Hi Joe, thanks for the fast reply.

I do not see any phase or wideband noise when connected to dummyloads.

If it is typical to see the harmonic on 20/15/10m then I am Ok. Just wondered if this should happen.

Funny thing is that with 100 or 10W the second harmonic stays at -48dbm, no matter what. When reducing to 1W it slightly drops, so this "leak" must happen before the amplifier stage!?

And to the third part you are right, I am not talking about those influences.

Regards

Volker

Mark NS9N

Hi Volker, just a thought, where do you have your preamp gains set. If not at zero, try that and see what happens. I was seeing all kinds of crazy things until Flex recommend that I put the gain back to zero as stated in the manual. Just a thought.

DL4RCE

Hi Mark, thanks for the reply. I tried this as well. Does not help for the harmonics. But I did see that one antenna had a "+8" which I set back to zero. Thanks for the hint.

Regards

Volker