Thanks again...but it seems I'm not done yet
Again everything is totally fine on 20m....
But on 15 meters ....with low power of 5W and on very low speaker volume and very low menu 76 settings I can hear the tones on my other radio coming through fine. But as I slowly edge up the speaker volume and menu 76 settings things start to distort long before my power meter on the 3000 gets anywhere close to indicating 5w. I'd say I get to about 3w output before this 'grating' noise starts and any higher it goes crazy makes horrible noises and HRD shuts down. And it's before the ALC kicks in too.
On 10 meters it's worse....I only get clear tones on the listening station if I have the PC on very very low speaker volume and very low menu 76 settings in the 3000. The PO meter shows zero ( guess milliwatts of output)...any higher on any of the settings and the distortion takes hold.
On either 10 or 15 meters if I try to get the power out up by turning the carrier power up the same thing happens...mega distortion and HRD shut down.
I guess at least I have proved that the soundcard in the radio is working. And given this gets worse at higher frequencies I am starting to think this might be some sort of RF issue....my antenna is just an end fed random wire out the bedroom window, with the balun actually inside the house !
OK, progress is being made.
We have ruled out any further soundcard settings, and can now with reasonable certainty zero in on
high SWR and inadequate common mode choke as causing both power foldback protection in the amp,
as well as stray RF hitting your rig and shack and causing USB disconnect from HRD.
You mentioned an end fed wire antenna with balun. Are you trying to use the internal tuner in
the Yaesu rig, or do you have an external tuner capable of the more than 3:1 mismatch that an
end fed wire can show?
I am no expert in end fed wires and do not use one, but from what I do read, you will frequently
get common mode RF coming back down the coax shield and hitting the rig. And they also can
display greater than 3:1 SWR on certain bands, depending upon the design of the wire antenna
Your remaining symptom has nothing to do with the soundcard. The fact that it works on 20m
and not another band, tells me that your SWR is climbing on the higher bands. If it gets above
an SWR of ~3, your internal tuner can't hack it (are you activating your internal tuner?), and you
would want to be looking at an external LDG or (cringe) MFJ tuner (or any other brand you like).
Have you tried connecting an SWR meter and taking a look at where things stand on each band you
wish to use?
When you say that as you turn up audio out and the menu for data mic gain, you start
getting distortion, yup; The rig does not want to create much power into a high SWR.
[As Bill Murray said in the Movie GhostBusters; "That would be bad".] So if you
adjust the audio input above the top safe limit, it just starts distorting and clipping the signal but not
putting out more RF power. Even though your RF amp can't create more power given the antenna
mismatch (and built in protection circuits), the over drive of the audio and the distortion will be seen
as RF splatter across the band.
Your Yaesu 3000 has a built in SWR meter. Using menu settings, you get to see EITHER the
SWR or the ALC, not both :-)
Take a look (either with the internal SWR meter, or an external meter) at your SWR between
your antenna and your Yaesu. I am guessing you will measure a high SWR on bands other
So again, in summary, we have two remaining problems I suspect are the likely problems you
1. Antenna mismatch causing high SWR on bands other than 20m.
2. Lack of a common mode choke on the antenna line where it comes into your shack/rig.http://palomar-engineers.com/antenna-products/1-1-balun-kits/choosing-a-feedline-choke
Let us know.