[usa2003ardf] What's next for this e-mail reflector?

[Kuon & Dale Hunt]

Matthew wrote:
>One topic I'd like to propose is Club Equipment for ARDF.  Or maybe "Meet
>Equipment".  At Oxford, someone I spoke to wanted to put on events, but was
>having trouble figuring out what pieces to get and how to put them together.
>  On a budget.


   There are several different options.  I use the Montreal Controllers
   since they cost around $15 each for parts, and that makes a big
   difference in the budget for a set of 5 or more.  If you can
   find the ICS525 chip then the "Montreal 525 Fox" is a self-
   contained controller and transmitter with over half a watt
   output.  (The IARU Region 1 rules specify 0.25 to 1.5 watts
   on 2m.  It is nice if all of your transmitters are about the
   same, but, especially for practice, the exact power output is
   not that important.)  Otherwise my collection includes a couple
   Hamtronics synthesized transmitters, and old Wilson crystal
   HT, a couple IC2A's and/or clones thereof, and a TR-2500.
   Whatever I can find cheap at hamfests!  (At Dayton I saw a whole
   tub of old VHF HT boards for $5 each - and you probably could
   have gotten them all for much less.)  If you have some old crystal
   HTs you can get computer crystals in the 8, 12, 16, or 18 MHz range
   that will multiply up to 147.456 MHz.

   On the other hand, if you have a couple friends who are interested,
   each of you can make a box with plugs to fit your own HT.

   I know Gerry Boyd is planning an ARDF transmitter/controller board in
   the upcoming months.

   For 80m I've had good luck with the "Pippen" transmitter circuit
   that I found on the G3PTO web site - easy to build from the
   junkbox and puts out about a watt.  Colorburst crystals on
   3579.545 kHz are standard, but B.G. Micro has crystals for
   3542 kHz in stock for a buck or so if you want a second
   choice.

   The controller doesn't have to be fancy to be usable:  check
   the one on W7TDC's web site using an analog voice recorder
   chip.  You can record the appropriate MOE/MOI in morse code,
   a voice description of ARDF, or a rooster crowing - any will
   give you a chance to practice taking bearings.


   I find it easier to carry several of the thinner .30 calibre
   ammo cans in one hand than the wider .50 calibre ones.  I put
   a BNC connector and ON/OFF switch on the top of each one.
   (The switch disables the transmitter, but leaves the controller
   on for synchronization.)  The folks in Victoria BC painted their
   transmitter boxes orange and white so they don't need a separate
   orienteering flag.  I started with the 7Ah gel cells, but switched
   to surplus 2Ah batteries which have plenty of power for a practice
   session but weigh a LOT less - especially if you are carrying
   several of them at once.


   So what you will find is that most folks improvise with what
   they have on hand, or what is conveniently available.  When
   someone comes up with a good solution it is quickly adopted.
   I started with wires thrown over tree branches, which works
   fine when you have cooperative trees. The same toroid matching
   network is used on the fishing pole antennas, and is adaptable
   for any reasonable wire length.  Ground radials help a lot.

   For 2m I build a set of turnstyle antennas for the first
   Region II Championships, but usually just use a bent wire
   dipole built on a piece of wood lath and attached to the
   transmitter box with a big rubber band (probably cut from
   an old inner tube for a wheelbarrow tire.)  This makes a
   self-contained unit that can just be set down and turned
   on.  Not perfectly unidirectional, but quite adequate
   for practice.

   Even getting one transmitter on the air will provide practice
   for people - and that can be someone sitting there keying it
   by hand.  Two or three is better - they don't all have to be
   the same, though standardizing connectors is useful so you
   can swap parts around if something breaks.  I use BNC for the
   antenna, 2-pin snappable headers for the power, and a 5-pin
   dip header for the controller (because that was what was on
   my PK-232 packet controller and I had cables made up for my
   HTs.)  Not that these are the best choices, I used what I
   had handy or could find at the local surplus store.

   Oh, yes...  ALWAYS put a fuse in the battery lead.  The ammo
   boxes may be water tight, but they sure can let out smoke
   in a hurry!  Even better are the PolySwitch self-resetting
   electronic circuit breakers - looks like a large disk ceramic
   capacitor but is actually a thermister that goes to a high
   resistance state when the rated current is exceeded.  When
   the fault is cleared and it cools down it resets itself.
   Saves having to replace a fuse in the field following
   an intermittent short, and they are less than $1 each.


   Enough for now - I'm sure others have ideas that they want
   to add as well.

   Good luck!

        - Dale WB6BYU


---
[This E-mail Scanned for viruses by Onlinemac.com]