[Elecraft] K3/100 crackle on ANT1 transmitted signal

[Scott on GMail]

Hi Don,
Running the TX Gain calibration fixed the problem 
I discovered that the previous owner (and kit builder) did not run the TX Gain calibration at all.
Thanks for the help 
73, Scott

-----Original Message-----
From: Don Wilhelm [mailto:w3fpr at embarqmail.com] 
Sent: 27 October 2013 11:35
To: Scott Larson; elecraft at mailman.qth.net
Subject: Re: [Elecraft] K3/100 crackle on ANT1 transmitted signal

Scott,

You mentioned doing the mW gain calibration, but said nothing about the
5 watt and 50 watt gain calibration.
I suggest you do all 3 TX Gain Calibrations - it is quick and easy using
K3 Utility.

I don;t know if that will correct your problem, but it has a good possibility.

As a side note (which may be relevant), most electret mics can use the "L" mic gain setting.  Using that lower range will give you more control over the mic gain and allow a finer setting.
To set the mic gain properly (you can do it in TX Test mode so you do not put a signal on the air), first set the compression to zero, then bring up the mic gain until you have 5 to 7 bars flickering on the ALC meter.  Then add compression as you desire.

73,
Don W3FPR

On 10/27/2013 6:25 AM, Scott Larson wrote:
> Hi,
> prior to fitting the KXV3A transverter board to my K3 I had always had good tx audio quality reports.
>
> I fitted the KXV3A option 3 weeks ago and carried out the mW gain calibration. I used the auto calibration in the K3 utility. It all went well.
>
> Since I fitted the transverter module my audio reports have mentioned a "crackle" on speech peaks.
> I do not hear the "crackle" on speech peaks on the audio monitor.
> I use an electret mike with the bias on and the H gain setting.
>
> Is it possible that the mW calibration has upset the gain distribution in the ANT1 TX path causing one stage to be overdriven?
>
> Advice on possible causes would be welcome?
> Scott
> GMCLQ
>