Re: K3 Sub RF gain

Posted by Joe Subich, W4TV-4 on Oct 23, 2010; 8:20pm
URL: http://elecraft.85.s1.nabble.com/K3-Sub-RF-gain-tp5659334p5666312.html


> I received a few direct emails from other K3 users and theirs act
> just like mine. Markus' K3 is now the only one I have heard of that
 > is acting like expectations.

Both of mine operate as expected (same RF/AF gain response for main
and KRX3).  Have you performed the RF Gain calibration on both of
the receivers using a calibrated 50 uV signal source (e.g., XG-2)?

73,

    ... Joe, W4TV


On 10/23/2010 3:30 PM, Mike Scott wrote:

> I followed the procedure Markus suggested with no change to my K3 RF gain
> tracking between main and sub Rx.
>
> I have been listening through the 2.7 KHz stock filter in both receivers
> with identical PRE and ATT and both filter gains set to 0 and identical IF
> filter bandwidth settings and both receivers sharing the main antenna.  I
> have SQ MAIN = 0; SQ SUB = 0, SUB AF = nor.  The offsets are matched on both
> filters and set properly.
>
> Still full CCW on the sub is about 12:00 O'clock on the main.
>
> At full RF gain both are about equal. Strong signals are still copyable on
> the sub Rx with full off RF gain, the main is dead when RF gain is minimum.
>
>
>
> So I tried an experiment, set main IF Filter (stock filter) to a maximum of
> +8 dB gain leaving the sub at 0. I still have more gain on the sub Rx than
> the main at low RF gain settings. At high gain settings, now the main is
> louder than the sub. So back to zero on the filter gain and very different
> gain tracking between the receivers.
>
> Audio gain perfectly tracks by the way.
>
> My K3 behavior is as if Wayne were reading every other RF-Sub gain control
> impulse and every one on Main.
>
> I received a few direct emails from other K3 users and theirs act just like
> mine. Markus' K3 is now the only one I have heard of that is acting like
> expectations.
>
>
>
> AE6WA
>
> Mike Scott
>
> Tarzana, CA
>
>
>
>>> Markus said:  Problem solved: At identical settings (PRE, ATT, RF/AF
> Gain), main and
>
> sub signal lelvels are now fully identical.
>
>
>
>
>
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