> Noise appears at all HF bands, but VHF/UHF not yet tested.
It may help to know if it continues up the spectrum, just
to assist in tracking the source.
I have copied this to a couple of RFI lists for their
informed input.
>> Have you tried just the cable to the rig without the Microham
>> USB II connected at the far end? I am wondering if it is
>> functioning as an antenna of some sort, radiating internal PC
>> noise coming out of the USB connector.
>
> Yes, I did. If the device router software runs, disconnecting the USB
> cable results in disappearing noise; if the device router software
> runs not, there is no noise, so disconnecting the USB cable doesn't
> make any difference (still no noise, of course).
Permit me clarify.
With the USB cable connected to the PC but *not* to the Microham device
AND the CAT cable *not* connected to anything AND the device router
software *not* activated there is *no* noise?
With the USB cable connected to the PC but *not* to the Microham device
AND the CAT cable *not* connected to anything AND the device router
software *is* activated there *is* noise?
With the USB cable *not* connected to the PC AND *not* connected to
the Microham device AND the CAT cable *not* connected to anything AND
the device router software *is* activated there *is* noise?
>> Does the device draw its power from the USB line?
>
> The device draws its power from the CAT jack, I think. The power LED
> on the device lights only when CAT cable is connected.
This is why I have requested the clarification above. I am
trying to isolate the source and/or transmission line.
Same questions as above but now remove the USB cable and try
the CAT cable in the same options.
Is the activation of the router software independent of anything
connected to the USB or CAT ports cause the noise?
Is the activation of the router software with *only* the CAT
cable connected to the PC port but nothing tied to the Microham
cause the noise?
Does the noise begin if *only* the CAT cable is connected to
*both* the PC and Microham but the USB is *not* connected to
anything?
>> Does the noise start when you then power on the device?
>
> Yes, given that the router software is running! Otherwise: no.
>
>> Have you tried coiling up the cable from rig to the device to see
>> if the level of the noise drops?
>
> Yes. Makes no difference.
>> HTH ...
>
> Doc, what means HTH?? I only know QTH :)
"Hope That Helps"
--
Thanks! & 73, doc, KD4E
... in sunny & warm Florida :-)
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