[FoxHunt] IARU Transmitter question

[Marvin Johnston]

Okay, I have a question then; how far can the local oscillator be picked
up if it is left running? I also am using the ATX-80 80M transmitter,
and tied the oscillator low so it is always running. On the bench, I
could pick up the signal for a foot or so, but I haven't tested it with
a full antenna on it. If it can only be picked up for 10 or 15 feet, I
would think it is a "who cares" issue since the flag should be visible
within that distance!

While we are on the question of questions :), what kind of an antenna
was used on the 80M transmitters in both Georgia and Albuquerque? We
have typically been throwing some 20 feet or so of wire up over a tree
limb with a radial of about the same length laying on the ground. Has
anyone done any work on a quicker-to-set-up type of antenna? I was
thinking about an 80M mobile whip, but haven't done any research into
finding out if that would work for championship events.

Marvin, KE6HTS

Gerald Boyd wrote:
> 
> Sam has brought up a very good point.
> 
> We are using the ATX-80 80 meter transmitters.
> Our controllers have been modified to assert the OSC enable line before CW
> keying starts. This prevents a high current condition that occurs if the PA
> is keyed before the OSC is enabled.
> 
> At the end of the cycle the reverse occurs, that it keying stops then the
> OSC enable line is de asserted.
> 
> When we had the original MFC code in our controllers we could observe a
> large current spike at the start of the cycle. With the modified code that
> does not occur.
> 
> Our code is also modified to prevent the "smoke effect" when the led is
> blinking in delayed start mode (original MFC controller).
> 
> The controllers also have been modified to flash the MO code (with out
> keying the TX)during delayed start to see that the transmitters are still in
> sync. At the end of the cycle the led goes back to the blinking state. This
> lets you know what is going on during delayed start.
> 
> Mike K5ATM can give the details on how he modified the code.
> 
> Jerry WB8WFK
> 
> ----- Original Message -----
> From: "Sam Smith" <sam.smith@ece.gatech.edu>
> To: <foxhunt@mailman.qth.net>
> Sent: Tuesday, May 13, 2003 5:33 AM
> Subject: Re: [FoxHunt] IARU Transmitter question
> 
> Byon Garrabrant wrote:
> > I'm making a change to PicCon's IARU mode, and have a question I need
> > answered ASAP.
> >
> 
> I can't answer that question, but I do have another suggestion. Last
> year for the US Champs I had to kludge a sort of VOX circuit for the 80
> meter transmitters. What is needed is a seperate key line and
> "transmitter on" line. The "transmitter on" signal would stay active for
> the whole minute, while the key line does it's thing. This would assist
> those of us using 80 meter crystal oscillators. If we let the oscillator
> run all the time, you can DF to the very low level signal from close
> range even when it's not transmitting.
> 
> What I did last year was use an RC circuit with a few seconds of time
> delay so that whenever the key line became active it would keep the
> oscillator on.
> 
> Sam N4MAP
> 
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