[FoxHunt] ELT Training

[sdonnell]

Hi, Have  been reading the ELT thread w/ great interest. Much of which we can
directly relate to; When we were first licensed as a Ham 25 yrs ago, we did a
bit of "fun" foxhunting w/ some  friends, using just a "ZL Special" antenna. For
over 15 yrs now weve been an active member of CAP, doing mostly Comm and LOTs of
Ground DF. We typically average 6 - 10 missions per yr.While(fortunately) we
have only been involved w/ a few "actual" search missions, we always try to keep
in mind what COULD be the result whenever we are called out to DF a signal. In
truth, this is part of the "hook" that makes DFing such a challenge and
interesting: You absolutly never know where you are going to end up or what you
are going to find as the source of the signal. Weve tracked beacons in all typs
of weather, and at all times of day and night, and while always keeping in mind
the VERY serious nature of of activity, I can also say that its the most fun
that you can have w/ a radio and antenna,,.But I suspect that many of the list
members already know that part,.

I living near the coast as we do, a good many of the false alarms that we see
are from boat EPIRBs, whch also operate on 121.500. While (thankfully) seems to
be dropping back, in recent yrs as much as 3 out of 5 DF searchs that we went
out on, ended up being an EPIRB. Most of which were improperly disposed of older
beacons that were thought to not be of any use,,,,. While the newer generation
"406" beacons should help reduce this issue, weve already had 2 close encounters
w/ these type as well.

While CAP has many dedicated members, and provides very good training programs,
I think that one of their primary limitations(as far as DFing goes) is that they
only have one tool in their bag of tricks, that being the Ltronics ELPer. While
an ELPer can be very effective, Ive seen many instances where that is not the
case. It also helps be familiar w/ the readings that you get from it, and how to
properly deploy it, which can be hard of you only use it once or twice a
yr...Ive also think that (more)CAP Ground  DF training should focus on DFing w/o
assistance from aircraft. All too often, Ive seen training scenarios where
Ground teams are brought in(directed from the aircrew) simply to "finish off"
locating the target which has already been IDd by the aircrew. As this does very
little to hone the skills of the ground team... In all of my experience to doing
Ground DF, Ill say that having an aircraft avaible for DF, can be an EXTREMELY
useful asset, and save countless hours in searching. And that there are many
aircrews that are VERY good at narrowing down the location of a signal. However
in reality, there are also many instances where using an aircraft for DF is
simply not an option, and the job falls entriely on the Ground team. Or that by
the time an aircraft  takes off, the approximate location of the signal has
already been determined.

One recent addition to my Dfing "tool kit" is an Arrow Antenna yagi. In speaking
w/ the Co owner at Dayton, I heard that they already had made antenans for
beacon DFing. But I ordered one that had 3 elements cut for 121.5, AND 4
elements for 243 on the same boom, similiar to their OSCAR antenna, but w/o the
phasing harnass. I havent(yet) tried placing both sets of elements on the boon
at the same time, I simply wanted the versatility of being able to have a 121 or
243 antenan available. I also figured that using a 4 el 243 yagi could,be useful
in geting a tighter bearing plot, and would be a bit easier(lighter) to use. It
could also be used to track a 243-only beacon, however unlikely. Besides the
additional signal gain of the 3 el yagi, one distinct dividend that Ive  gotten
from using it, is from being able to easily swap from vertical to horizontal
polarization. In two search mssions over the past yr, this has enabled us to get
a bearing on a very weak signal that our standard ELPer would not hear at
all...I highly recomend that anyone who does 121.50 DFing, to give the Arrow
Antenna a try.

Another part of our bag of tricks has been in tracking the beacon signal from
one of its harmonics; I keep 486.00 Mhz in one memory channel of my vehnicle's
IC-R100, right next to the channels where 121.50 and 243.00 are kept. I have
found that by simply switching from 121, to 243, and then 486, and using the
Attenuator as well, we can usually get to within one hundred feet of a beacon,
w/o ever getting out of the car. Which can be kind of handy  when its raining or
have 30 below zero wind chill... But our secret zinger, is with the use of a 5
element yagi designed for 800 MHz. fom using this, w/ an HT or scanner set for
850.500(121.5 x7), we can easily pinpoint a specific house, or vehicle(or
airplane or boat). Then for the final "kill", some variety of Field Strength
meter, either one of those new consumer "bug detectors" or a modified VE2. In
many situations, its one thing to "know" where a beacon is, its another to
actually get your hands on it, such can be the case in finding out where it is
stored on a large boat. This can also be helpful in verifying which specific
boat or plane, or car the beacon is in. We once tracked a beacon signal to a
house. The owers, who lived on the first floor had no idea as to what an ELT
was. When we placed a handheld frequecny counter to the downstairs ceiling and
got a "121.500" reading, we knew we had it nailed. The beacon was found on the
floor of a recently vacacted appartment. One word of caution though, from what
Ive seen in the new "406" beacons, besides the much lower power 121.5 signal,
they have almost NO harmonic content, even on 243.0.

Id be quite interested in hearing form other CAP members about these ideas or
what DFing techniques they find useful.

Steve Donnell
WA1YKL/Abenaki 102

"J. Craswell" wrote:

> Well sounds like that would be a good scheme.  Any Hams who can outdo us
> will of course have to be "drafted."  <grin>  Of course a lot of our crew
> are Hams also and were previously drafted <grin>  Per the comment about high
> percentages of false alarms we have had a good number of non distress
> missions as well.  I think the percentages are 90+%  We worked on one really
> nasty crash a while back and my fervent hope is that it will be the last.
> But, we will continue to work as if all are real.  A very bad idea is (I
> think) to go out on a ELT Mission-Foxhunt and assume it is another in a
> series of false alarms.  What is it they say about assume?  It makes and ASS
> or U and ME? <grin>