[Elecraft] RTTY filter for K3

[Ken K3IU]

OK... thanks Steve. I am familiar with MixW... have used it for years 
and I see what you are talking about. But let me suggest the 
following... Go to AFSK A mode and set the mark frequency to 1445. That 
will give you a center frequency of 1530 which would put you within 30 
Hz of your align frequency of 1500 Hz. If signal is still a l'il off, 
then use mouse to get it on or let the AFC move it on. I just tried it 
on a PSK signal with my filter cranked down as narrow as it would go in 
Data Mode and it hardly missed a beat decoding.

73,
Ken K3IU

n4lq wrote:
> Bear with me on this Ken....It's long but hopefully I can explain.:
>
> By the same token....I can see no reason why the center frequency of 
> DATA A and AFSK A should be different.
> Most advanced digital mode programs such as MixW have something 
> similar to an "Align" macro. You tell the macro what you filter's 
> center frequency is then whenever you click on that macro it instantly 
> tunes your K3 so that the desired trace on your waterfall is exactly 
> centered in the IF passband. You can then choose your most narrow 
> filter and that signal will still be in the IF's center. I have a 
> macro for the filter selection too so everything is really fast and easy.
> Here's how it works for me.
> 1. K3 filter set on very wide....3+ KHZ.
> 2. See signal on waterfall.
> 3. Click on signal.
> 4. Begin to copy data on screen.
> 5. Signal is weak, QRM, need narrow filter.
> 6. Click on "Align" macro. Signal is now centered in passband.
> 7. Click on filter macro, choosing 200Hz filter.
> 8. QRM gone...Signal now easy to copy.
>
> Now this was all in DATA A mode. I use DATA A for PSK31, MFSK and 
> anyother digital mode.
> So what if I want to operate RTTY? Well I can go ahead and do so in 
> DATA A mode however that DUAL FIL feature will not activate. Is this a 
> flaw?
> So I got to AFSK A....Now DUAL FIL works but now my ALIGN macro won't 
> work because my IF Center is different. It should not be....1500 HZ 
> should be the default. If I wanted to use 910 HZ and enjoy that low 
> pitch sound, I would have to either change my Align macro or try to 
> manually tune the RTTY signal which is terribly difficult, especially 
> in a contest when transmissions last for only a few seconds.
>
>
>
>
> Steve Ellington
> N4LQ at insightbb.com
> ----- Original Message ----- From: "Ken K3IU" <kenk3iu at cox.net>
> To: "n4lq" <n4lq at insightbb.com>
> Cc: <elecraft at mailman.qth.net>
> Sent: Sunday, May 18, 2008 3:37 PM
> Subject: Re: [Elecraft] RTTY filter for K3
>
>
>> As far as I know, the reason for having the capability of changing the
>> Mark freq is for personal preference in what you like to listen to. The
>> Dual PB filter works at whatever frequency you select. I can think of no
>> reason why AFSK A and DATA A modes would necessarily have to be the 
>> same.
>>
>> I'm not sure why you want to change the center frequency to specifically
>> 1500 HZ in AFSK A mode. I sure wouldn't... that's too high for my ears.
>> I prefer the lower mark frequency of 915 Hz. The software that is
>> decoding the signal sure doesn't care and it doesn't make any difference
>> to what you are sending.
>>
>> But as they say here ofter.... YMMV.
>>
>> 73,
>> Ken K3IU
>> ~~~~~~~~~~~~~~~~~~~~~
>> n4lq wrote:
>>> Yes but it won't change the center fq. to 1500Hz so it will be like
>>> DATA A. I'm not sure what the purpose of changing the pitch is.
>>>
>>> Steve Ellington
>>> N4LQ at insightbb.com
>>> ----- Original Message ----- From: "Ken K3IU" <kenk3iu at cox.net>
>>> To: "n4lq" <n4lq at insightbb.com>
>>> Cc: <elecraft at mailman.qth.net>
>>> Sent: Sunday, May 18, 2008 2:43 PM
>>> Subject: Re: [Elecraft] RTTY filter for K3
>>>
>>>
>>>> You can change the MARK freq in AFSK A mode to one of four values
>>>> ranging from 915 Hz to 2125 Hz by pressing PITCH and rotating the 
>>>> VFO A
>>>> knob which, of course, will change the center frequency accordingly.
>>>>
>>>> 73,
>>>> Ken K3IU
>>>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>> n4lq wrote:
>>>>> To use the DTF, I changed to AFSK A mode. This allows the DTF to work
>>>>> however the center frequency of the IF changes from 1500Hz to 1356Hz.
>>>>> I will notify Elecraft about these.
>>>
>>>
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>
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