Is there some other equipment can be improvised (homemade) to find ELTs?? I already know about using a VHF radio, are there any others??
http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=DDF1
http://captalk.net/index.php?topic=5048.0
http://www.radioshack.com/product/index.jsp?productId=3704415&retainProdsInSession=1
Edit: I misunderstood. This isn't homemade, but it's one of the cheapest options I can find besides EvilBay.
The FoxHunt i think is called that was posted by CAPT Tomasone is amazing, I want to see if I can get one for my unit!
Quote from: GTCommando on July 02, 2011, 01:48:58 AM
http://www.radioshack.com/product/index.jsp?productId=3704415&retainProdsInSession=1
Edit: I misunderstood. This isn't homemade, but it's one of the cheapest options I can find besides EvilBay.
This might work BUT I don't think there's a signal level indicator on it, so it would be by sound alone and body blocking. I'm not sure how well this would work at a longer distance from the ELT transmitter source. IF an aircraft can fly and box in the area that would be best. For a general area search, with no aircraft available (due to weather) I would think a magnetic mount antenna (e.g. http://www.grove-ent.com/procomm.html $19.95) would allow picking up the signal sooner. For the most part CAP depends upon the LTronics L'pers DF equipment and there's really no formal training course for using other device like just plain scanners. I'm not sure an IC would be willing to deploy a UDF team with just a radio scanner and no actual DF specific equipment.
RM
I have tested, designed and and built numerous radio direction finding receivers, and although I love the old L-Per, the MK 4 from Australia is definitely the product that will give you the most bang for your buck. You will still need a directional antenna (usually a 2 or 3 element or "tape Measure" Yagi) but its an awesome little unit. Don't throw away your money on a scanner or cheapie aircraft radio unless you just plan on running SAREX'S and other games.
Major Lord
. . a small loop antenna works well if u r in close. u provide the radio. listen for the null as the antenna is broadside to the signal.
. . a beam antenna works very well if u r not close. u provide the radio. listen for the peak in strength as the beam is directed at the signal.
. . i too will not part with my lper, but they r not cheap and simply unavailable now.
. . i too have a mk4 sniffer, aka vk3yng, df receiver and if ur looking for a synthesized unit that will cover the aviation band and 143-149 mhz cap/ham band, its hard to beat. u provide the beam antenna. bob makes a fine one if u have a few bucks.
. . but if ur looking for something cheap, that will work, and u can put together urself, i would try the doppler antenna switching unit. this guy is no more than a multivibrator driving two antenna switching diodes. u provide an fm radio and a couple of vertically mounted dipoles. we used the circuit designed by van field, w2oqi. build it in a shielded box.
. . when the antennas are equidistant from the signal source, they have no doppler shift in the receiver. as they are turned perpendicular to the signal, u will be able to hear the switching tone in the receiver audio, due to the doppler shift that occurs as the antennas are switched. i have had excellent results with this unit, known locally as the electronic pitchfork. this unit can not tell if the signal is in front or behind u, so some shoe leather may have to be sacrificed.
. . i can provide the circuit if its ok with van.
bill
In my ground team days, I actually had more luck with a Jetstream than an LPer.
The biggest advantage of the L-per is that it's pretuned, and allows you to acquire a signal sooner. My Jetstreams won't hold a tune well enough when not in use, or they are still tuned to 121.775 from the last training evolution, and require tuning prior to use.
I have about equal success with either radio.
Quote from: ol'fido on September 15, 2011, 12:29:24 AM
In my ground team days, I actually had more luck with a Jetstream than an LPer.
I love those things... Anybody got an extra one around, I'll pay you a lot more than $20 or whatever you got it for. ;)
Quote from: md on September 16, 2011, 07:33:19 PM
Quote from: ol'fido on September 15, 2011, 12:29:24 AM
In my ground team days, I actually had more luck with a Jetstream than an LPer.
I love those things... Anybody got an extra one around, I'll pay you a lot more than $20 or whatever you got it for. ;)
http://www.ebay.com/itm/RADIO-SHACK-JETSTREAM-WORKING-TRANSISTOR-RADIO-YES-WORKS-/270818547607?pt=LH_DefaultDomain_0&hash=item3f0e0b1797
. . i too have several jetstreams, lmao. radio shack had a sale on them when the older model was discontinued. i have had very good results from them. i couldn't part with any of them, though. i remember one night at hunter aaf, finding two elts with one before the lper team found either.
. . i also remember the odd stares i would get as i held the unit upside down, antenna against my tummy, turning slowly in a circle. the old, and i do mean old, backbone attenuator method found more than a few elts.
bill