[1000mp] Monitor roughness

[Jim Smith]

Hi Pete,

I used to think that my transmitted audio quality was poor because it 
sounded horrible in the monitor.  Many reassurances that it was actually 
nice and crisp caused me to decide that the monitor was a piece of crap 
and not to be trusted.  One day, bored out of my tree while listening to 
my 40th consecutive contest CQ without an answer, my idle fingers 
clicked a ferrite around the earphone line plugged into the front 
panel.  No particular reason, just something to do.  Say what?  The 
monitor audio sounded better.  Hmm . . . wrap a bunch of turns of the 
earphone line around the ferrite.  Monitor audio roughness has pretty 
well disappeared.  Zowie!!

I do have quite a bit of RF in the shack.  I have found that ANYTHING 
plugged into the jacks on the front panel can introduce RF into the 
rig.  So, nothing is.

I have also found that a way of testing for RF getting into the MkV is 
to turn the Moni knob fully CCW so you shouldn't hear anything from the 
monitor.  If you hear weird stuff it's probably due to RF feedback.

Now, I can't think of any mechanism by which RF introduced into the MkV 
is going to cause increasingly severe problems simply due to the passage 
of time since power-up so this may not be relevant to your situation.

IPO button?  Can't make an informed comment.  Can say that if RF is 
running around in there I suppose that it is possible that anything you 
do might make it sound different.

How to find out if it's RF?  Temporarily disconnect everything you can 
from the back and absolutely everything from the front panel.  Wrap all 
remaining lines several times around ferrites.  The monitor should now 
sound nice and clean.  Let some time go by and see if it sounds any 
different.

An easier way of reducing the RF level is, of course, to simply turn the 
RF PWR knob fully CCW.

Hope this is of some help.

73 de Jim Smith   VE7FO

Pete Smith wrote:

> Ever since my MkV was new, I have noticed that after I transmit for a 
> while, the monitor gets rough, whether on CW or voice.  It's been back 
> to Yaesu once, for this and other issues, but they found nothing 
> wrong, and the problem continues.  Voice signals sound rough, and CW 
> signals less than T9.
>
> Today I was operating in the ARRL DX contest, and I noticed that if I 
> was hearing the rough sound in the monitor and switched the IPO button 
> on, the monitor sound cleaned up dramatically.
>
> Have other people noticed the same thing?  And if so, what does this 
> tell you about the possible origin of the problem and how to fix it?
>
> 73, Pete N4ZR
> Check out the World HF Contest Station Database
> Updated 9 Jan 04
> www.pvrc.org/wcsd/wcsdsearch.htm
>
>
>
> _______________________________________________
> List Moderator: Richard Lubash N1VXW
> 1000mp mailing list
> 1000mp@mailman.qth.net
> To Change Options or Unsubscribe:
> http://mailman.qth.net/mailman/listinfo/1000mp
>