[Fox_Tango] Tempo one with a whisssh sound in audio

[Gerald]

On Thu, 2005-06-30 at 08:29 -0700, Kuhns, Arthur G CIV NGCA wrote:
> OK guys.  This is the same tempo with the low output in the higher bands.  I
> had most of the tubes checked and found several dead, most weak.  Replaced
> them and fired it up.  My output is now equal on all bands but I have this
> air tunnel sound in my audio.  I am using a d 104 mic and I checked the
> battery and I tried different variations mic gain etc. both on the radio and
> on the mic.  The air sound did not go away only varied in loudness.  I
> thought it might be RF being picked by the mic so I purchased a Line Audio
> choke the snap on type from Radio Shack.  That puppy made no difference. The
> relays in the radio have never been cleaned, so I thought I would do that
> next.  
> I sure would like your thoughts on what might be the problem.
> Thank you in advance.
> 
> Art
> 
> Arthur Kuhns
> Calif. Army National Guard
> DPW Supply and Services
> Camp Robert, CA. 93451
> Commercial Phone: 805-238-8880
> Fax:  805-238-8473
> Email: arthur.kuhns at ca.ngb.army.mil

This is NOT a CB radio. It doesn't NEED the preamp in the microphone. Go
with an unamplified microphone and you won't have the noise.

After swapping tubes, you need to do an alignment including PA
neutralization to maximize the stable gain and linearity.
-- 
73, Jerry, K0CQ
Dr. Gerald N. Johnson, electrical engineer
All content copyright, Dr. Gerald N. Johnson