As I mentioned before, Chris, you may want to consider
a less populated and less RF-populated area....Payson
area, or Prescott....there's plenty of nice little
peaks up here that would allow a cute li'l QRP signal
to emanate 360 nicely.....
And thanks, Fred, for your interesting post!
73,
Trisha "Lightning"
N7TMY
On Thu, 18 April 2002, "Fred Coe" wrote
>
> Howdy,
>
> I've been on the road to Douglas and Sierra Vista
this week, and just
> getting caught up on the mail.
>
> It sounds interesting, especially since I found out
(today!) that I might
> end up being the custodian of some rather
sophisticated doppler RDF
> equipment. It's purpose is to track down
interference from Mexico, but I'll
> have to calibrate, test, and learn how to use it
sometime....
>
> If I read and understand some of the posts on this
topic correctly (and as I
> type this, I'm tired, dirty, and mildly
sunburned--hmmm, if its fun
> geocaching, why isn't it fun at work?, but my mind
wanders...). The
> coordinates given will lead to a jumping off spot,
where you will RDF to the
> location of the cache.
>
> Potential locations will be your challenge. Most
mountain tops with
> relatively easy access are already littered with
various RF emitters which
> will make zeroing in on the TX in question a
challenge. Mt. Lemmon, and
> Heliograph have enough intermod to wipe out my
Bendix-King XCVRs about 1/4
> mile from the respective summits. I imagine South
Mountain in PHX is worse.
> 150 mW will have trouble competing with even the 5th
order intermod at those
> sites, particularly if a consumer scanner or typical
compact amateur radio
> HT is used for RX. Since this maybe some our
geocacher's first experience
> with T-Hunting I recommend you put it in a relatively
RF quiet area so it
> can be found using a handheld scanner and the body
shielding technique.
>
> I also recommend that you include some simple
T-Hunting techniques (or at
> least references) on the cache page. And/or consider
holding a geocache
> get-together before the cache is actually deployed to
demonstrate some of
> the techniques to help some of the folks not familiar
with T-Hunting get the
> hang of things.
>
> I'd be interested in hearing about charge control,
power, and battery
> management for a solar power system on this small a
scale--then again it's
> so small it may not matter.
>
> This cache sounds like a great way to combine
interests, and maybe encourage
> some geocachers to consider amateur radio as another
hobby, and hams to
> consider geocaching.
>
> --Fred
> WA0RTO
> Team Boulder Creek
>
> Glossary
> (added after I re-read the message an noticed the
techno-babble):
>
> doppler RDF: Radio Direction Finding using doppler
shift between antennas
> RF emitters: Radio Frequency transmitters
> TX: Transmitter or transmit (depends on context)
> Intermod: short for intermodulation distortion, what
happens in a RX when
> you mix different TX frequencies together
> XCVR: the morse code abbrevation for transceiver
> mW: milliwatt
> HT: handitalkie-handheld xcvr
> RX: Receiver or receive (depends on context)
> T-Hunting: Transmitter Hunting
>
> es 73 de WA0RTO sk
>
> ----- Original Message -----
> From: "C. Sullivan" <feedle@feedle.net>
> To: <listserv@azgeocaching.com>
> Sent: Tuesday, April 16, 2002 6:09 PM
> Subject: [Az-Geocaching] Amateur Beacon / GeoCache..
>
>
> > It's about to happen: a GeoCache that can be found
not only by GPS, but by
> > radio direction-finding.
> >
> > I recently constructed a small QRP 2 meter CW
beacon inside the bottom of
> > a quart-size paint can. It has a small solar panel
and two AA NiCd cells
> > for power. It is capable of transmitting a
100-character message every
> > five minutes. My initial tests show it has about a
45mW output.. but
> > beefing that up to around 150mW should be trivial
(one good transistor can
> > do wonders).
> >
> > I've given it a lot of thought, and I've decided
that I want this little
> > "rabbit" to be my first GeoCache. The only problem
is, I can't think of a
> > really good place to put it. So, here's my
challenge.
> >
> > If somebody out there who is a ham (or other radio
hobbyist) can find me a
> > good mountaintop site to hide a GeoCache,
preferably somewhere where a
> > 100mW signal can be heard for enough of a distance
to be
> > challenging / interesting to RDF enthusiasts, and
also an interesting
> > destination for the GPS-equipped.
> >
> > Anyone have any thoughts?
> >
> > Feedle (aka Chris KD6COS)
> >
> >
> > _______________________________________________
> > Az-Geocaching mailing list
> > listserv@azgeocaching.com
> >
http://listserv.azgeocaching.com/mailman/listinfo/az-geocaching
> >
> > Arizona's Geocaching Resource
> > http://www.azgeocaching.com
> >
> _______________________________________________
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>
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>
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