[Elecraft] RTTY filter for K3

[n4lq]

Ok Ken but that's with a BW of 150Hz, not too critical. Soon, I am told, 
Elecraft will activate the 50Hz filter so it can be used in Data mode. I 
suggested to Lyle that they change the default center fq. in AFSK to 1500 so 
it will match Data A then let the user change as desired. Then also allow 
use of the Dual PB feature in Data A. That should perfect things. Then I 
would not even bother using AFSK A.

Steve Ellington
N4LQ at insightbb.com
----- Original Message ----- 
From: "Ken K3IU" <kenk3iu at cox.net>
To: "n4lq" <n4lq at insightbb.com>
Cc: "Elecraft Reflector" <elecraft at mailman.qth.net>
Sent: Sunday, May 18, 2008 5:04 PM
Subject: Re: [Elecraft] RTTY filter for K3


> 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.
>>>>
>>>>
>>>> --------------------------------------------------------------------------------
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> No virus found in this incoming message.
>>>> Checked by AVG.
>>>> Version: 8.0.100 / Virus Database: 269.23.20/1453 - Release Date:
>>>> 5/18/2008 9:31 AM
>>>>
>>>>
>>
>>
>> --------------------------------------------------------------------------------
>>
>>
>>
>>
>> No virus found in this incoming message.
>> Checked by AVG.
>> Version: 8.0.100 / Virus Database: 269.23.20/1453 - Release Date:
>> 5/18/2008 9:31 AM
>>
>>


--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG.
Version: 8.0.100 / Virus Database: 269.23.20/1453 - Release Date: 5/18/2008 
9:31 AM