Wouxun Wouxun KG-UV9D+ interference while scanning

[cubemonkey]

Hello all,

I've got a KG-UV9D+, and am noticing that while scanning on both channels, it will sometimes run into what I can only reference as a "collision". I've narrowed down a specific example to show what I'm finding.

Channel A is on 436.76500 MHz
Channel B is on 406.02500 MHz

Channel A simply being on 436.76500 MHz seems to cause enough signal/interference that Channel B breaks squelch. I know this could be cross talk on a circuit, or feedback somewhere, but found it interesting. I'm not recognizing any correlation of resonance between the two frequencies to imply constructive / destructive intererence of some sort. And there's no recognizable audio pattern - just enough signal to break squelch on Channel B, and cause what sounds like FM static.

The "collision" does not go away with the antenna detached. Although, it does seem to change the pattern somewhat from almost a morse code to a steady FM hiss.

This does happen with other frequency combinations, and the radio does seem to be quite sensitive to interference from computers and LEDs.

Is this a known issue of the Baofeng / Wouxun radios (yes, I know they're "bottom barrel")? Or am I running into some sort of an general issue with dual transceiver SDR radios?

This issue doesn't seem to affect my daily use really. So far, simply an curiosity/oddity I've run into.

Thank you,
cubemonkey

 

[nd5y]

If it happens with no antenna then it's probably the local oscillator or some other internal signal.

 

[cubemonkey]

If it happens with no antenna then it's probably the local oscillator or some other internal signal.

Thank you for the input.

Are you experience with this sort of problem? I presume it's something that's "just the way it is" versus something that can be fixed.

Thanks,
CubeMonkey

 

[robertmac]

Some radios have an adjustment to move their "clock" to try and avoid this oscillation especially if it affects frequencies being used. Haven't looked at Wouxun to see if they have this adjustment.

 

[nd5y]

There is probably no way to fix it. I'm only familiar with the KG-UVD1P based radios. Mine doesn't do it on those two frequencies. The older models don't have simultaneous dual receive so that problem is not likely to occur. There is no IF shift, clock shift or similar function. I don't know if the later models share the same guts or LO and IF scheme.

 

[jaspence]

If it is an internal problem, fixing it is probably not possible. I have a radio that has a birdie on the frequency of a local repeater. It is a design flaw with no solution. Due to the modular build using SDR technology in cheaper radios, there are usually few adjustments as in a radio made of individual components. Higher quality radios can sometimes be fixed by a firmware update.

 

[chief21]

If you're finding this behavior annoying, you could likely "fix" this problem by using only one channel display while scanning (rather than both displays).

 

[chief21]

It might also help if you were to reverse the displays... that is to scan on the top display rather than the bottom one (or vice-versa).