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K3Utility - Mac RF Calibration

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Grant Youngman

K3Utility - Mac RF Calibration

Did we ever ever get anything final on the "subtle bug" that may have
created a problem with RF Gain calibration in the Mac version of K3
Utility?

I used the new test version sent out a few days ago, calibrated to an
XG2 on 20M. Didn't have to adjust S-Meter cal on the Main receiver,
but did cal the Sub S-Meter, which I'd ignored up until now. All
seemed well, until I powered on the K3 today, and noticed what seemed
to be "scotch" S-Meter readings. A recheck with the XG-2 shows only
about S-7 with the 50uV test signal.

Grant/NQ5T
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Don Wilhelm-4

Re: K3Utility - Mac RF Calibration

Grant,

Re-do the S-meter Cal on the main receiver. There seems to be some
confusion on this topic, but there is only *one* set of S-meter
calibration settings (at least that is the way it is right now). So
when you thought you were calibrating the subRX S-meter, you likely
messed up the settings for both the main RX and the sub - I can't say
for certain but I think it has something to do with the 3 dB pad and
athe variety of ways to connect the subRX antenna..

73,
Don W3FPR

Grant Youngman wrote:

> Did we ever ever get anything final on the "subtle bug" that may have
> created a problem with RF Gain calibration in the Mac version of K3
> Utility?
>
> I used the new test version sent out a few days ago, calibrated to an
> XG2 on 20M. Didn't have to adjust S-Meter cal on the Main receiver,
> but did cal the Sub S-Meter, which I'd ignored up until now. All
> seemed well, until I powered on the K3 today, and noticed what seemed
> to be "scotch" S-Meter readings. A recheck with the XG-2 shows only
> about S-7 with the 50uV test signal.
>
> Grant/NQ5T
>
>

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Grant Youngman

Re: K3Utility - Mac RF Calibration

Don ..

I realized that as I was redoing the adjustments one more time -- no
separate S-meter adjustments for the Sub. I'll start from scratch.

But the results do seem a bit odd. As it now sits on the Main (and
this is after mistakenly tweaking S_meter cal on the Sub), a 50uV
signal yields an S-7 with preamp off and S-9 with preamp on, with the
meter in Nor mode. In Abs mode, I see S-7 with preamp off and S-6
with preamp ON.

It's certainly possible (most likely?) that there's a cockpit problem
here, but the results I'm getting don't look right. Prior to all of
this, there was no change in S-meter reading when activating the
preamp in "abs" mode.

Grant/NQ5T

On Nov 4, 2009, at 3:58 PM, Don Wilhelm wrote:

> Grant,
>
> Re-do the S-meter Cal on the main receiver. There seems to be some
> confusion on this topic, but there is only *one* set of S-meter
> calibration settings (at least that is the way it is right now). So
> when you thought you were calibrating the subRX S-meter, you likely
> messed up the settings for both the main RX and the sub - I can't
> say for certain but I think it has something to do with the 3 dB pad
> and athe variety of ways to connect the subRX antenna..
>
> 73,
> Don W3FPR
>
> Grant Youngman wrote:
>> Did we ever ever get anything final on the "subtle bug" that may
>> have created a problem with RF Gain calibration in the Mac version
>> of K3 Utility?
>>
>> I used the new test version sent out a few days ago, calibrated to
>> an XG2 on 20M. Didn't have to adjust S-Meter cal on the Main
>> receiver, but did cal the Sub S-Meter, which I'd ignored up until
>> now. All seemed well, until I powered on the K3 today, and
>> noticed what seemed to be "scotch" S-Meter readings. A recheck
>> with the XG-2 shows only about S-7 with the 50uV test signal.
>>
>> Grant/NQ5T
>>

Don Wilhelm-4

Re: K3Utility - Mac RF Calibration

Grant,

The compensation between 'nor' and 'abs' is done in software, so it may
be that something you did in the calibrations has thrown it off a bit -
it is not hard to re-do both the RF gain and S-meter calibrations, so I
would do them both (in that order).

73,
Don W3FPR

Grant Youngman wrote:

> Don ..
>
> I realized that as I was redoing the adjustments one more time -- no
> separate S-meter adjustments for the Sub. I'll start from scratch.
>
> But the results do seem a bit odd. As it now sits on the Main (and
> this is after mistakenly tweaking S_meter cal on the Sub), a 50uV
> signal yields an S-7 with preamp off and S-9 with preamp on, with the
> meter in Nor mode. In Abs mode, I see S-7 with preamp off and S-6
> with preamp ON.
>
> It's certainly possible (most likely?) that there's a cockpit problem
> here, but the results I'm getting don't look right. Prior to all of
> this, there was no change in S-meter reading when activating the
> preamp in "abs" mode.
>
> Grant/NQ5T
>
>
> On Nov 4, 2009, at 3:58 PM, Don Wilhelm wrote:
>
>
>> Grant,
>>
>> Re-do the S-meter Cal on the main receiver. There seems to be some
>> confusion on this topic, but there is only *one* set of S-meter
>> calibration settings (at least that is the way it is right now). So
>> when you thought you were calibrating the subRX S-meter, you likely
>> messed up the settings for both the main RX and the sub - I can't
>> say for certain but I think it has something to do with the 3 dB pad
>> and athe variety of ways to connect the subRX antenna..
>>
>> 73,
>> Don W3FPR
>>
>> Grant Youngman wrote:
>>
>>> Did we ever ever get anything final on the "subtle bug" that may
>>> have created a problem with RF Gain calibration in the Mac version
>>> of K3 Utility?
>>>
>>> I used the new test version sent out a few days ago, calibrated to
>>> an XG2 on 20M. Didn't have to adjust S-Meter cal on the Main
>>> receiver, but did cal the Sub S-Meter, which I'd ignored up until
>>> now. All seemed well, until I powered on the K3 today, and
>>> noticed what seemed to be "scotch" S-Meter readings. A recheck
>>> with the XG-2 shows only about S-7 with the 50uV test signal.
>>>
>>> Grant/NQ5T
>>>
>>>
>
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