K2 - Alignment/Test Part II

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K2 - Alignment/Test Part II

JT Croteau
Just completed assembly of the RF Board, Part II.  Getting closer by the day!

I have the counter probe on TP3 and measuring 12099 kHz as I should
according to the manual.  However, it is changing back and forth
somewhat rapidly between 12099.28 and 12099.29 kHz.  Is this normal or
do I have something wrong with the PLL Reference Oscillator?

Thanks

--
JT Croteau, N1ESE - Manchester, NH
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Re: K2 - Alignment/Test Part II

N6TR
On Mon, Aug 27, 2007 at 12:16:17PM -0400, JT Croteau wrote:

> I have the counter probe on TP3 and measuring 12099 kHz as I should
> according to the manual.  However, it is changing back and forth
> somewhat rapidly between 12099.28 and 12099.29 kHz.  Is this normal or
> do I have something wrong with the PLL Reference Oscillator?

This is normal.  The frequency isn't changing - it is just that you
occasionally have one more - or less - count during the gate time of
the frequency counter.  

Tree N6TR
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Re: K2 - Alignment/Test Part II

Don Wilhelm-4
In reply to this post by JT Croteau
JT,

That is the 'last digit indecision' type flicker, and it is not
avoidable in a digital display except for really high end and expensive
equipment.  The actual frequency is in between 12099.28 and 12099.29 and
the gate interval of the counter sometimes picks up one more cycle than
at other times.

Rapid variations in the higher order digits are an indication of a
problem, but no problem when just the last digit is flickering between 2
consecutive digits.

73,
Don W3FPR

JT Croteau wrote:

> Just completed assembly of the RF Board, Part II.  Getting closer by the day!
>
> I have the counter probe on TP3 and measuring 12099 kHz as I should
> according to the manual.  However, it is changing back and forth
> somewhat rapidly between 12099.28 and 12099.29 kHz.  Is this normal or
> do I have something wrong with the PLL Reference Oscillator?
>
> Thanks
>
>  
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Re: K2 - Alignment/Test Part II

JT Croteau
Thanks to N6TR, N0SS, and W3FPR for their explanations and reassurances.

I've just completed all of the Part II test/alignment procedures
except for the Band Pass Filter Alignment.  I'm ordering an N-Gen next
week and may hold off on this alignment until it arrives.  My 40-Meter
dipole is currently coiled up under the bench waiting for helpers to
come over and get it in the air.  The only antenna up at the moment
here is an indoor 6-Meter dipole.

--
JT Croteau, N1ESE - Manchester, NH
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Re: K2 - Alignment/Test Part II

Don Wilhelm-4
JT,

No need to wait for the N-Gen for the Bandpass filter alignment - just
initially peak the BPF in receive using only band noise (connect your 6
meter antenna or just a piece of wire to the antenna jack center
conductor).   Once you have the BPF peaked on receive (this is only an
initial alignment to get things 'into the ballpark' - peak for maximum
antenna noise), then do the Transmit BPF alignment.  It is easier to
observe the peak during the transmit alignment, and when that is done,
it will be correct for both receive and transmit.

The N-Gen will come in handy when you are doing the IF filter alignment
(CAL FIL) using the Spectrogram display - for that process,  a broadband
noise source is best - and the N-Gen is a broadband noise generator.

73,
Don W3FPR

JT Croteau wrote:

> Thanks to N6TR, N0SS, and W3FPR for their explanations and reassurances.
>
> I've just completed all of the Part II test/alignment procedures
> except for the Band Pass Filter Alignment.  I'm ordering an N-Gen next
> week and may hold off on this alignment until it arrives.  My 40-Meter
> dipole is currently coiled up under the bench waiting for helpers to
> come over and get it in the air.  The only antenna up at the moment
> here is an indoor 6-Meter dipole.
>
>  
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