[Elecraft] K3: The ARRL RTTY Round UP

Mon Jan 5 15:05:16 EST 2009

"Roger that" regarding shift and width granularity!

I had great success (for me) in RU using my 200 Hz 5 pole filter with 
the DSP width set at 200 Hz and moving the filter offset frequency (FLx 
FRQ) about 30 Hz from normal to center up the passband while looking at 
band noise with MMTTY. I used 1275 Hz Mark frequency. DSP LO was 1.3 KHz 
and HI was 1.5 KHz. Moving the filter offset allowed both mark and space 
signals to come through at similar amplitudes. If the DSP resolution 
below a few hundred Hz would switch to 10 Hz resolution, it would be a 
real help and should probably alleviate jockeying the filter offset. In 
my case sensitivity might improve a bit, too since my mark frequency was 
25 Hz outside of the stated DSP passband! With 10 Hz resolution,  the 
DSP could be set something like 1260 through 1460 Hz. (or whatever 
produces the best looking response in the desired audio passband) 
without tweeking FLx FRQ.  At any rate, even with 50 Hz granularity this 
setup allowed me substantially better copy of weak TTY signals in a 
crowded band than did the DUAL PB in the more conventional manner (while 
using MMTTY). The radio performed flawlessly for me in my first RTTY 
Roundup (Single Op, Low power, 530 Q's, 56 Sec,  35 countries, all S&P). 
The radio was run in the FSK D mode with data decoding always running.

Incidentally, my fancy new LCD computer monitor uses a capacitance touch 
power switch which would frequently turn off the monitor when I was 
transmitting on certain bands (40 or 20). But I never lost a Q because 
of this because I could always copy the RTTY on my K3 decoder display 
and would occasionally grab the paddles to send if the stations call had 
not yet been entered in the logging program (N1MM). It always took a few 
seconds for the monitor to reinitialize once I was able to turn it back 
on though it seemed much longer than that in the contest. My next ham 
radio task may be modifying this monitor.

73,
Mike

Guy, K2AV wrote:
> Changing SHIFT and WIDTH granularity to 10 Hz from 50 would improve CW
> useability as well.  
>
> A lot of us have formed contest operating habits and tactics based on analog
> SHIFT and WIDTH functions. Like a combination of a small shift and
> (sometimes) a lesser width change to put someone up or down just a bit
> farther down the passband and keep the same skirt frequency on the opposite
> side of the passband.
>
> 73, Guy
>
>
> wayne burdick wrote:
>   
>> All RTTY issues noted, Dave -- thanks.
>>
>> Congratulations on your excellent showing!
>>
>> Wayne
>> N6KR
>>
>> On Jan 5, 2009, at 9:00 AM, Dave Hachadorian wrote:
>>
>>     
>>> My pair of K3's also worked well in the RTTY Roundup - 1800
>>> qso's. There are only a couple of issues that I saw:
>>>
>>> 1. On each transition between mark/space, there is a brief
>>> upward power excursion. One of my amplifiers has an LED
>>> wattmeter, and one of the LED's was blinking like crazy.
>>> Also, the screen current on that amp was varying
>>> significantly. I've complained about this in the past.
>>> Elecraft is supposed to be working on it.
>>>
>>> 2. When you reduce the DSP bandwidth to 300 Hz, it is not
>>> possible for me to get the audio output exactly centered
>>> between the RTTY modem's mark and space detector. The SHIFT
>>> control is too coarse. One click of the SHIFT control moves
>>> the audio either slightly left of center, or slightly right
>>> of center. It would be nice if there were a "fine mode"
>>> setting for the SHIFT control.
>>>
>>> I can live with both of these issues, but fixing them would
>>> make this rig absolutely perfect for RTTY, at least for me.
>>>
>>> Dave Hachadorian, K6LL
>>> Yuma, AZ
>>>
>>>
>>> ----- Original Message -----
>>> From: "Lee Buller" <k0wa at swbell.net>
>>> To: "Elecraft Reflector" <elecraft at mailman.qth.net>
>>> Sent: Monday, January 05, 2009 2:56 PM
>>> Subject: [Elecraft] K3: The ARRL RTTY Round UP
>>>
>>>
>>>
>>> Ladies and Gents....
>>>
>>> I just about cleared a thousand Qs this weekend in the RU in
>>> only 17 hours of on-the-air time. The K3 was spectacular in
>>> performance. The RX is magnificent and copied signals that I
>>> could not hear out of the speaker but printed on the screen.
>>> This happened many times. From Kansas, I did get to work
>>> some deep Europeans and even Israel called me. I did not
>>> hear any Russian stations at all. The DX was weak but
>>> workable. Magnificent RX. The TX was healthing and robust. I
>>> was running my amp so I was only running about 60 watts or
>>> less. The TX stayed cool and stable.
>>>
>>> The only issue I noticed was that between Dual PB on and
>>> off...the power would drop about 200 watts. No big deal, but
>>> interesting phenomonon. With the Dual PB on...the power
>>> would drop...with it off...the power would return to normal.
>>> Wayne and Eric already know about this issue.
>>>
>>> Thanks to all who worked me. Fun contest.
>>>
>>> Lee - K0WA
>>>
>>>
>>> In our day and age it seems that Common Sense is in short
>>> supply.  If you don't have any Common Sense - get some
>>> Common Sense and use it.  If you can't find any Common
>>> Sense, ask for help from somebody who has some Common Sense.
>>> Is Common Sense divine?
>>>
>>>
>>> ----------------------------------------------------------------------- 
>>> ---------
>>>
>>>
>>>       
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>> ---
>>
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>>     
>
>   
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