[Elecraft] JT modes alignment

Don Wilhelm w3fpr at embarqmail.com
Tue Feb 11 11:00:59 EST 2014


Jean-Marc,

As I indicated, RTTY FL1 should be set to the OP1 filter and copy the 
BFO setting from the LSB BFO.
Likewise copy the RTTY REV BFO setting from the SSB USB BFO and you 
should have the RTTY FL1 behave just like USB or LSB with the exception 
that there is an independent SSBC setting (look for SSBCr) in the menu - 
it should be set to no compression (1-1) for digital modes.

As far as I know, the ALC will be the same as for SSB, but one usually 
adds compression for SSB use which will make the ALC more aggressive.

As with all digital modes with the K2, adjust the audio level so you can 
see just one bar of ALC indication, then back the audio down until that 
indicator just goes off.  Adjust the desired power level with the POWER 
knob.  Yes, this is different than the 'conventional wisdom' you will 
see in instructions for other rigs that control power differently than 
the K2.

73,
Don W3FPR

On 2/11/2014 9:38 AM, F5LCI wrote:
> Hi Don, and thank you for the fast reply (as usual!)
> I can use the USB mode, decoding is OK, But the ALC is not optimized for
> digital modes.
>
>   My only problem: "R" and reverse "R" behave equally ; I thought that the
> tones would be inverted...
> I seriously wonder : Was I wrong with alignment with the reverse "R" mode
> only ?
> I had carefully aligned my filters ...many years ago, before JT65 appeared.
> So I'll have to RTFM to remind the procedure.
> Back to the book...
>
> 72, Jean-Marc, F5LCI
>
>
> Le Tue, 11 Feb 2014 14:15:27 +0100, Don Wilhelm <w3fpr at embarqmail.com> a
> écrit:
>
>> Jean-Marc,
>>
>> Yes, you will need to align those filters.
>> I normally set the FL1 position to OP1, FL2 to 1.00, FL3 to 0.70 and FL4
>> to 0.40 widths.
>> Then set the BFOs for FL1 to the same values as the SSB filters - RTTY
>> corresponds to LSB and RTTY REV corresponds to USB.  That filter will be
>> used for transmit in all cases and works well with a waterfall display
>> for normal receive.
>> Set the other filters to center on 1000 Hz.  Those can be used if a
>> strong interfering signal appears inside the passband of the OP1
>> filter.  Observe the LSB/USB relationship - the DAC numbers (and also
>> frequency) will be higher for RTTY REV.
>>
>> If you have the KDSP2 option, also set those filters 2, 3, and 4 to
>> center at 1000 Hz to agree with the IF filter centers.
>>
>> The use of Spectrogram is recommended when aligning the IF filters. You
>> can download a copy from my website www.w3fpr.com - look near the bottom
>> of the home page.  Instructions for the use of Spectrogram can be found
>> in the K2 Dial Calibration article.
>>
>> 73,
>> Don W3FPR
>
>
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