TS-440S SSB TX noise

[KF7YLC]

To make a long and aggravating story short, here is what I got.

Running my 440 into the dummy load on the bypass side of my 949E:

SWR reads equal and below 1.2 on the 440 and the 949E
No deflection on the ALC
TX on FM at 100 watts forward sounds great
TX on AM at 25 watts forward sounds great
TX on SSB sounds horrible at any setting...  Although the modulation is understandable, It's
buried in white noise.  It almost sounds like the mic gain is way to high, but it's not.

So, if anyone has any insight or advice it would be greatly appreciated.

Robert  KF7YLC

[KA5IPF]

How are you monitoring your transmitted audio?

[KF7YLC]

I ran all tests on 28.650 and monitored on a 10 meter rig I have installed in my truck.

[KA4POL]

No offense meant, You are receiving on the correct sideband?
Perhaps you could try without the mic and insert a piece of wire which you can touch with your fingers to produce hum as modulation. I guess you do not have a sine wave generator.

[KF7YLC]

None taken.  I did use the correct sideband and I do not have a sine wave generator. 

[KA4POL]

So try the hum test to make sure the mic is clean.

[KF7YLC]

I'll need another set of hands to try the wire test.  I hope this isn't a dumb question, but wouldn't
the tests on AM and FM suggest the mic is good?  I have to admit, a new mic would be easier to swing
than the costs of the Kenwood Service Center.....

[KA4POL]

I would try to get a hold of a ham a couple of miles away who can receive your signal in SSB. There is still a chance of the receive chain being the problem.
Is it just by this test or did someone complain about the SSB modulation?

[KA4POL]

You said the mic gain is right. Anyway rotate the button counter clockwise to reduce it even more and check again.

[KF7YLC]

Yeah, this whole fiasco began with bad reports on 80, 40 and 20 meters.  However, these were all
on a home brew 43ft. vertical I wanted to try out.  Naturally, I assumed there was a problem with my design and
switched to a home brew vertical I'd built for 10 meters with less than stellar results.  It turned out to be water in the
feedpoint connector.  After that point I have not attempted any contacts but kept things "in house" so to speak.  I did order up
a factory made antenna and feedline for 10-17 meters.  I'll try to make a local contact and see how things go.  At this point I'll attempt
anything.

Oh, and I did try my "in house" test with minimal mic gain.

[KA5IPF]

Go to http://www.oz1bxm.dk/TS440/TS440S_Repair_FAQ.pdf and look at the second thing. rx bpf fix.

[KA4POL]

As I understood the issue it happens during transmit in SSB: 'TX on SSB sounds horrible at any setting... '
I can not see a fix in the document. What may be helpful though is a visit of the 440 Yahoo group.

[KA5IPF]

As I understood the issue it happens during transmit in SSB: 'TX on SSB sounds horrible at any setting... '
I can not see a fix in the document. What may be helpful though is a visit of the 440 Yahoo group.

Second item. When the rx BPF diodes leak it causes distorted tx audio.

[KF7YLC]

I did check the BPF board before I started this thread and there was indeed a leaky diode on the 500khz filter.  I
cut the lead on the corresponding diode and reassembled the radio.  There was an improvement, but the problem
remains.  I suppose it's possible that the 20 meter filter diode is leaking...  I also sent a request to join the 440 yahoo group but never got a response.

I want to thank everyone for their help.

[W8JI]

I did check the BPF board before I started this thread and there was indeed a leaky diode on the 500khz filter.  I
cut the lead on the corresponding diode and reassembled the radio.  There was an improvement, but the problem
remains.  I suppose it's possible that the 20 meter filter diode is leaking...  I also sent a request to join the 440 yahoo group but never got a response.

I want to thank everyone for their help.

Do you realize when a radio is "tested" with another improperly coupled radio, especially a test receiver with AGC, you get can have all sorts of weird effects that make signals sound bad??

This is the very same reason we should never set a spectrum analyzer near a radio and use an open "probe" antenna to pick up signal for spectral purity tests. I sat through an entire Agilent analyzer demonstration where the Agilent rep coupled the analyzer wrong! Instead of using a wideband sample tap off the transmitter antenna port, he stuck a short whip antenna in the analyzer input connector!!

An improperly coupled test receiver will pick up stray radiation from RF leaks, many of which are modulated by noises, and that garbage sample that comes from power cords and cabinet leakage is not representative of what is on the air.

Making it worse, if the signal is strong and you have AGC on, you will hear "crap" that is -80dBc when mic gain is down.

I'm not saying the KW is OK, but we should all be aware improper test setups can create significant misleading artifacts.