[ARDF] My PicCon "script"

Tue Oct 25 16:52:09 PDT 2005

On Tue, Oct 25, 2005 at 04:06:11PM -0700, Marvin Johnston wrote:
> 
> Everything you are doing looks good. I have all of that programmed into
> the Yaesu 470 DTMF memories so I can reprogram all five transmitters in
> a minute or so.
> 
> I am assuming that you started them all at once with a DTMF "1" after
> they were deployed in the field. The only problem with that is some of
> the transmitters might not be able to "hear" from where you are doing
> the start. Setting the A4 start delay allows them to be started before
> they get deployed, and eliminates that problem.

Actually, I held all five of the them in one hand and hit the SW1 on each
in rapid sequence (takes about a half second.)

> FYI, undocumented on the earlier PicCons (not sure about the latest
> revision), DTMF DF while holding the red button down will set the PicCon
> to transmit MO for the finish beacon.

I don't understand this.  I don't have a red button and I don't think 
there's an "F" on my DTMF keypad.

> 30 seconds sounds rather excessive but the drift has nothing to do with
> setup, but rather with the crystal clock frequency for the PicCon. You
> can trim the frequency down by putting some capacitors from each side of
> the crystal to ground. The PicCons I used drifted perhaps 3 or 4 seconds
> at the end of about 6 hours. I need about 22 pF on each side of the
> crystal used in the Microhunt transmitters to get the timing close. I
> would guess that you could probably set the audio to some frequency at a
> *VERY* slow CW rate transmitting Dahs, and use a frequency counter to
> get close to the proper frequency without having to wait several hours
> to find out the drift.

I'll check into this.  I have the current model of PicCons, in the 
translucent green cases.  The ceramic resonator Y1 has three connections
to the PC board (let's call them left, middle, and right.)  Do I put a cap 
in line between left and its pad on the PC board, and then do the same with
right?  Or do I leave the resonator in place and put the cap between left 
and ground and between right and ground?  (I'm not really an engineer, if
you couldn't tell :-)  Aside from painful experimentation, how would I know 
what value cap to use?

Does temperature have anything to do with it?  Between the time I set out the 
transmitters and when we picked them up, the air temperature had gone 
up like 20 degrees Fahrenheit.

Some of the PicCons had drifted well over 60 seconds off their cycle over 
a period of 7 hours.

> Marvin, KE6HTS
> 
> 
> 
> "Kenneth E. Harker" wrote:
> > 
> >      This is the script I used to program each of the PicCons at the Texas
> > ARDF Championship last weekend (where several of the transmitters gradually
> > drifted in time during the course of the event, leading to significant
> > overlaps.)  This specific example is for MOH.  I'd appreciate feedback from
> > the more savvy PicCon users if there is anything I'm doing wrong:
> > 
> > C123133518#  Set Morse code ID to WM5R
> > A10100       Set a transmission delay of one minute duration
> > A20056       Morse code sequence is 56 seconds long (leaving 4 seconds for ID)
> > A30500       Transmission loop time is 5 minutes
> > A40000       No initial delay time
> > A50000       Run until commanded to stop
> > B188         Set Morse code sequence to default code speed
> > B220         Set Morse code ID to 20 WPM
> > B371         Set Morse code tone to ~700 Hz
> > D4           While holding down button, set IARU transmitter ID to MOH
> > C411123#     Set transmission sequence order beginning with three delays
> > 
> > Start with SW1
> > 
> >      Anything obvious that I was doing wrong?  For at least the first several
> > cycles, everything sounded like it was in proper timing and sequence, but
> > by the time of the first start three hours later, some of the transmitters
> > had drifted by as much as 30 seconds.
> > 
> > --
> > Kenneth E. Harker WM5R
> > kenharker at kenharker.com
> > http://www.kenharker.com/
> > 
> > _______________________________________________
> > ARDF mailing list
> > ARDF at kkn.net
> > http://www.kkn.net/mailman/listinfo/ardf

-- 
Kenneth E. Harker WM5R
kenharker at kenharker.com
http://www.kenharker.com/