[Elecraft] S-meter calibration

[O. Johns]

Dear Wayne,

I was also puzzled by this.  After I finished the RX gain calibration  
on the main receiver (no sub-receiver installed), the XG-2 at 50 uV  
showed S8.  Maybe the "finish" page in the K3 Utility RX calibration  
routine should say what the user should do now:  Which CONFIG items to  
adjust and, if any, which ones NOT to adjust.

BTW, what should the CONFIG:SMTR MD be set to during this  
calibration?  NOR or ABS?  Or does it matter?

73,
Oliver Johns
W6ODJ


On 7 Oct 2009, at 1:13 PM, Wayne Burdick wrote:

> Mike,
>
> Now that you've done rf gain cal, you'll still need to adjust SMTR OF
> & SC so that you get S9 with 50 uV and S2-3 with 1 uV. RF gain cal
> linearizes the dsp's internal representation, while SMTR OF & SC set
> the actual meter indication.
>
> Try the factory defaults first.
>
> 73,
> Wayne
>
> ----
> http://www.elecraft.com
>
> On Oct 7, 2009, at 10:59 AM, "Mike Harris" <mike.harris at cwimail.fk>
> wrote:
>
>> G'day,
>>
>> My results are:
>>
>> Source - XG1, RX gain calibration per the utility routine:
>>
>> Subsequently:
>>
>> Main RX only, pre amp OFF  - 50uV (S9), 1uV (S2)
>>
>> Sub-RX ON therefore splitter loss:
>>
>> Main RX S8 & S1
>> Sub-RX  S7 & S0
>>
>> No big deal but not identical.
>>
>> As a matter of interest, the S-meter on the main RX had been set up
>> a year ago or more as above.  When I checked it before doing the RX
>> gain calibration I discovered that the 1uV and 50uV figures were S5
>> & S9.  Little wonder I thought the local noise level had been
>> creeping up!  Maybe after playing with the AGC parameters a re-cal
>> of the S-meter is required, maybe not, but something altered it.  I
>> assume that given the 50uV S9 setting was correct then it isn't
>> associated with the XG1.
>>
>> Regards,
>>
>> Mike VP8NO
>>
>>
>> ----- Original Message -----
>> From: "Ken K3IU" <kenk3iu at cox.net>
>> To: "N1JM" <johnn1jm at gmail.com>
>> Cc: <elecraft at mailman.qth.net>
>> Sent: Wednesday, October 07, 2009 12:22 PM
>> Subject: Re: [Elecraft] [K3] Sub RX S-meter cal
>>
>>
>>> The S-meter Cal procedure in the manual worked up until about
>>> v.3.15 or
>>> so. Now I am pretty sure that it was NOT separately adjusting the
>>> SubRx
>>> S-meter, but I never checked, so I'm not sure. It doesn't really
>>> matter now.
>>>
>>> I have determined that, at least on my K3 (#202) running v3.41 et
>>> al,
>>> after running the RF Gain Calibration procedure and setting the
>>> MAIN Rx
>>> S-meter, the Sub Rx S-meter is spot on. It actually follows the
>>> adjustment for the Main Rx S-meter, i.e., set Main Rx at an
>>> extreme and
>>> the Sub Rx shows the exact same extreme.
>>>
>>> So... it looks to me like there is no reason to have a separate
>>> adjustment for the SubRx S-meter. I'm sure the manual will catch
>>> up.
>>>
>>> 73,
>>> Ken K3IU
>>
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