---------------------------------------------------------- RV-List Digest Archive --- Total Messages Posted Mon 11/17/08: 11 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:41 AM - Re: ARTEX 406 ELT in a 7A () 2. 05:18 AM - Re: Re: ARTEX 406 ELT in a 7A (Kelly McMullen) 3. 05:43 AM - Re orig question from Bob C (Charles Heathco) 4. 05:47 AM - Re: Trio Auto Pilot FS (PaulR) 5. 06:35 AM - Re: ARTEX 406 ELT in a 7A (bcollinsmn) 6. 01:06 PM - RV : [ Rob Ray ] : New Email List PhotoShare Available! (Email List PhotoShares) 7. 01:07 PM - RV : [ Al Herron ] : New Email List PhotoShare Available! (Email List PhotoShares) 8. 07:45 PM - 406 MHz ELT (DEAN PSIROPOULOS) 9. 09:02 PM - Re: 406 MHz ELT (Jerry Springer) 10. 09:37 PM - Re: 406 MHz ELT (Skylor Piper) 11. 11:34 PM - Re: 406 MHz ELT and RV8 (=?iso-8859-1?Q?Mich=E8le_W?=) ________________________________ Message 1 _____________________________________ Time: 01:41:23 AM PST US From: Subject: RV-List: Re: ARTEX 406 ELT in a 7A John as a fellow HAM, you know the answer, external, vertical polarization with a good ground plane. No one has tested these creative internal ELT antenna installations. It may be fine in a Lancair or Glasair but a all metal RV is not a good canadate for internal antennas. I can tell you the VHF wing tip com antenna's are really piss poor. Any one who has one and is honest will tell you. Some say the wing tip VHF com antenna works. The definition of work is flying 1000' agl towards the airport tower 5 miles infront of you. Forget long distance omni directional communications at max theoretical range of an airborne 5-10 watt VHF transmitter. One popular hidden ELT antenna location on RV's is laying the antenna horizontal in the vertical/horz stab intersection fairing area, under the vertical stabilizer. It is pretty popular and makes no sense to me from a technical stand point. I DON'T KNOW OF ANY ONE WHO HAS TESTED IT FORMALLY or INFORMALLY. I personally think its a bad idea. Hidden use but affective range limited. The other idea is in the wing but that is a LONG coax run unless you put the ELT in the wing tip as well. The wing tip is also really terrible for propagation and practical reasons, like the wing tip rips off. Also access is not great unless you install an access panel. The Artex 406 has one antenna for both 406/121.5Mhz about the same dimensions as current ELT antennas. The EBC has two antennas, one short 406Mhz antenna and a seperate 121.5 Mhz antenna. Of course the 406Mhz is very short. HERE IS SOME FOOD FOR THOUGHT. The DRAG from one typical (20") ELT antenna is 1/8th mph, 0.125 mph penalty (at 200 mph). Is it worth it to hide antennas? If you are talking about a 406 Mhz only antenna that is a short antenna with negligible drag. When I raced my RV-4 I took off the Com, VOR antennas for about 1/2 mph to 2/3rds mpg gain. I did put the ELT antenna under the bubble canopy. Some hide antenna for eye appeal. I think it's not worth it but that is a hard sale with many builders I consult with. I think the best NON standard is mounting the antenna or antennas inside the canopy/cockpit area. The down side is getting a proper ground plane. The old EBC elts had an internal antenna and the unit was always mounted in the cabin. The new EBC uses two remote antennas as I mentioned above. I did a informal survey of RV accidents that where off field and survivable; many end up on their back, so the belly is not totally a horrible area. That does not follow the common ELT instructions for mounting the ELT on top of the aircraft. Of course any thing that does not follow the ELT's instructions violates the FAR / STC approved instructions. Almost all approved ELT installations call for the following: - Mount ELT as far aft as possible - Antenna'(s) be mounted close by, no excessive long coaxial run - Mount the antenna externally. - Provide maintence access & access after accident So the approved ideal location is ELT in the tail cone far aft with the antenna'(s) mounted directly above on the back top, just forward of Vert stabilizer. The old transmitter was only 100mw and now the new 406 ELT's have 5 watt burst, so that is better regardless of antenna. Still of the antenna is shielded from the satellites than you are invisible even with 5 watts. We also still need 121.5 Mhz and 100mw for local DF steer to find us. How far can can 100mw get out with an antenna buried inside of metal structure? I think you are talking feet not miles in range. I just can't stand to see such a violation of good antenna installation practices for the sake of looks and a tenth of a mph. Cheers George ************************************************************************************************* Subject: RE: RV-List: Re: ARTEX 406 ELT in a 7A From: "John Cox" Bob, I am hoping that this thread actually expands and becomes a Big Deal, or at least bigger. I have felt for some time that the location, mount orientation, ground plane and attempt at concealing the antenna actually leads to an ineffective or nearly worthless electronic device. That premise was based on the 121.5 variant not the 406 however, because one build might have mounted it incorrectly, scores follow suit and then the masses drink the Kool-Aid. I have always concluded the function might not be important, only its presence for the DAR signoff. I have remained curious how many rescues rather than recoveries "after the fact" are attributed to a properly functioning signal and a responsible response by the parties that monitor the frequency (either 121.5 or 406. As a ham (amateur) radio license holder this pursuit of concealing the antenna has always been fascinating. Do any of the readers have signal propagation graphs on signal strength radiating from inside the tin can? John Cox Aurora, OR ________________________________ Message 2 _____________________________________ Time: 05:18:26 AM PST US From: Kelly McMullen Subject: Re: RV-List: Re: ARTEX 406 ELT in a 7A Well just some random musings. I know of TC aircraft with the ELT antenna bent back under fiberglass ventral fin in otherwise all metal aircraft..but don't know whether any feds cared about it. I know that my 121 ELT activated on its own in my all metal hangar, and was satellite detected. Only the weird propagation pattern made it a little difficult to ascertain it was coming from my hangar and not an ajacent row. So, not so sure how critical this is, especially at 406 where your radiating element is approx 1/4 the length of 121 element. Ever look at a police supervisor car? They often have 5 or 6 UHF antennas around the roof and trunk, not very far apart. Wonder what issues they have. gmcjetpilot@yahoo.com wrote: > John as a fellow HAM, you know the answer, external, vertical > polarization with a good ground plane. No one has tested these > creative internal ELT antenna installations. It may be fine in a > Lancair or Glasair but a all metal RV is not a good canadate for > internal antennas. I can tell you the VHF wing tip com antenna's are > really piss poor. Any one who has one and is honest will tell you. > Some say the wing tip VHF com antenna works. The definition of work is > flying 1000' agl towards the airport tower 5 miles infront of you. > Forget long distance omni directional communications at max > theoretical range of an airborne 5-10 watt VHF transmitter. > > One popular hidden ELT antenna location on RV's is laying the antenna > horizontal in the vertical/horz stab intersection fairing area, under > the vertical stabilizer. It is pretty popular and makes no sense to me > from a technical stand point. I DON'T KNOW OF ANY ONE WHO HAS TESTED > IT FORMALLY or INFORMALLY. I personally think its a bad idea. Hidden > use but affective range limited. > > The other idea is in the wing but that is a LONG coax run unless you > put the ELT in the wing tip as well. The wing tip is also really > terrible for propagation and practical reasons, like the wing tip rips > off. Also access is not great unless you install an access panel. > > The Artex 406 has one antenna for both 406/121.5Mhz about the same > dimensions as current ELT antennas. > > The EBC has two antennas, one short 406Mhz antenna and a > seperate 121.5 Mhz antenna. Of course the 406Mhz is very short. > > HERE IS SOME FOOD FOR THOUGHT. The DRAG from one typical (20") ELT > antenna is 1/8th mph, 0.125 mph penalty (at 200 mph). Is it worth it > to hide antennas? > > If you are talking about a 406 Mhz only antenna that is a short > antenna with negligible drag. When I raced my RV-4 I took off the Com, > VOR antennas for about 1/2 mph to 2/3rds mpg gain. I did put the ELT > antenna under the bubble canopy. > > Some hide antenna for eye appeal. I think it's not worth it but that > is a hard sale with many builders I consult with. > > I think the best NON standard is mounting the antenna or antennas > inside the canopy/cockpit area. The down side is getting a proper > ground plane. The old EBC elts had an internal antenna and the unit > was always mounted in the cabin. The new EBC uses two remote antennas > as I mentioned above. > > I did a informal survey of RV accidents that where off field and > survivable; many end up on their back, so the belly is not totally a > horrible area. That does not follow the common ELT instructions for > mounting the ELT on top of the aircraft. > > Of course any thing that does not follow the ELT's > instructions violates the FAR / STC approved instructions. > > Almost all approved ELT installations call for the following: > > - Mount ELT as far aft as possible > - Antenna'(s) be mounted close by, no excessive long coaxial run > - Mount the antenna externally. > - Provide maintence access & access after accident > > So the approved ideal location is ELT in the tail cone far aft with > the antenna'(s) mounted directly above on the back top, just forward > of Vert stabilizer. > > The old transmitter was only 100mw and now the new 406 ELT's have 5 > watt burst, so that is better regardless of antenna. Still of the > antenna is shielded from the satellites than you are invisible even > with 5 watts. We also still need 121.5 Mhz and 100mw for local DF > steer to find us. How far can can 100mw get out with an antenna buried > inside of metal structure? I think you are talking feet not miles in > range. > > I just can't stand to see such a violation of good antenna > installation practices for the sake of looks and a tenth of a mph. > > Cheers George > > > > ************************************************************************************************* > Subject: RE: RV-List: Re: ARTEX 406 ELT in a 7A > From: "John Cox" > > > > Bob, I am hoping that this thread actually expands and becomes a Big > Deal, or at least bigger. > > I have felt for some time that the location, mount orientation, ground > plane and attempt at concealing the antenna actually leads to an > ineffective or nearly worthless electronic device. That premise was > based on the 121.5 variant not the 406 however, because one build might > have mounted it incorrectly, scores follow suit and then the masses > drink the Kool-Aid. I have always concluded the function might not be > important, only its presence for the DAR signoff. > > I have remained curious how many rescues rather than recoveries "after > the fact" are attributed to a properly functioning signal and a > responsible response by the parties that monitor the frequency (either > 121.5 or 406. > > As a ham (amateur) radio license holder this pursuit of concealing the > antenna has always been fascinating. Do any of the readers have signal > propagation graphs on signal strength radiating from inside the tin > can? > > John Cox > Aurora, OR > > * > > * ________________________________ Message 3 _____________________________________ Time: 05:43:10 AM PST US From: "Charles Heathco" Subject: RV-List: Re orig question from Bob C I didnt build my plane, but the ELT instal does work well (I have tested it accidently couple times) Unit is mounted on side of Fusl midway in baggage far enuf forward to give clearance to remove bulkhead. Thin flex whip ant mounted just aft of where open canopy rests. Charles H ________________________________ Message 4 _____________________________________ Time: 05:47:21 AM PST US Subject: RV-List: Re: Trio Auto Pilot FS From: "PaulR" > Would like to know what is the name of the unit etc. never heard of > golden trio." I am looking for the Altitude Holder.... > thanks for any info > Robert, The "Gold" servo is the ONLY one Trio has. It will work with either axis. The Trio unit will also work with the old Navaid servos if I'm not mistaken. I have only the servo and the install kit for sale. -------- Paul Rose N417PR (res) RV-9A Read this topic online here: http://forums.matronics.com/viewtopic.php?p=214659#214659 ________________________________ Message 5 _____________________________________ Time: 06:35:52 AM PST US Subject: RV-List: Re: ARTEX 406 ELT in a 7A From: "bcollinsmn" [quote="stein(at)steinair.com"]The do not archive was because this was to settle my personal curiosity more than anything else. I didn't have anything to add to the technical part of the discussion, so I guess I just didn't want my weird question filling up the already bloated archives do not archive (just to make Bob shake his fist at me) !!! > -- Your personal curiosity is our enlightenment, fella! (g) When you ask a question.... it makes me think it's an answer I NEED! Do not archive -------- Bob Collins St. Paul, Minn. RV-7A (#&^ fiberglass!) http://rvbuildershotline.com Day job: http://minnesota.publicradio.org/collections/special/columns/news_cut/ Read this topic online here: http://forums.matronics.com/viewtopic.php?p=214665#214665 ________________________________ Message 6 _____________________________________ Time: 01:06:19 PM PST US Subject: RV-List: RV : [ Rob Ray ] : New Email List PhotoShare Available! From: Email List PhotoShares A new Email List PhotoShare is available: Poster: Rob Ray Lists: RV-List,Rocket-List,RV4-List,RV8-List Subject: Vets Day Fly-By... http://www.matronics.com/photoshare/smokyray@rocketmail.com.11.17.2008 ---------------------------------------------------------- o Main PhotoShare Index http://www.matronics.com/photoshare o Submitting a PhotoShare If you wish to submit a PhotoShare of your own, please include the following information along with your email message and files: 1) Email List or Lists that they are related to: 2) Your Full Name: 3) Your Email Address: 4) One line Subject description: 5) Multi-line, multi-paragraph description of topic: 6) One-line Description of each photo or file: Email the information above and your files and photos to: pictures@matronics.com ---------------------------------------------------------- ________________________________ Message 7 _____________________________________ Time: 01:07:53 PM PST US Subject: RV-List: RV : [ Al Herron ] : New Email List PhotoShare Available! From: Email List PhotoShares A new Email List PhotoShare is available: Poster: Al Herron Lists: RV-List Subject: Canopy Slide Seal Lanyard http://www.matronics.com/photoshare/herronpvf@sbcglobal.net.11.17.2008 ---------------------------------------------------------- o Main PhotoShare Index http://www.matronics.com/photoshare o Submitting a PhotoShare If you wish to submit a PhotoShare of your own, please include the following information along with your email message and files: 1) Email List or Lists that they are related to: 2) Your Full Name: 3) Your Email Address: 4) One line Subject description: 5) Multi-line, multi-paragraph description of topic: 6) One-line Description of each photo or file: Email the information above and your files and photos to: pictures@matronics.com ---------------------------------------------------------- ________________________________ Message 8 _____________________________________ Time: 07:45:03 PM PST US From: "DEAN PSIROPOULOS" Subject: RV-List: 406 MHz ELT When I was flying missions with Civil Air Patrol in the State of Oregon we had far more 121.5 ELT false alarms than real activations but...we responded to every one of them and learned some lessons along the way. Most of the missions I was associated with were production spam cans who had their antennas mounted on top of the fuselage behind the cockpit. Yes it's ugly but they put them there for a reason. When the ELT IS activated in a crash, these installations have the BEST chance of being located by search and rescue (SAR). Scott's waveguide premise is correct, the cockpit does make a great one and NO that is not helpful in getting one located and rescued in a timely manner. If you land (crash) right side up that waveguide will direct the ELT signal upward where the satellites will receive it. But, once the 121.5 ELT is heard by the satellite and a SAR aircraft dispatched, the area to be searched is still quite large. The SAR aircraft has to be able to "hear" the ELT in order to pinpoint you. If your installation is in the cockpit then this waveguide effect means that the SAR aircraft's direction finding (DF) equipment needs to be A LOT closer to you to pick up the signal. That takes more time in the grid and eats up precious time getting help to a stricken pilot who may be badly injured. This waveguide effect was brought home to me quite vividly on one CAP practice mission where our incident commander placed the ELT inside a metal garbage can and then tipped the can on its side with the open end facing a mountain peak. We spent hours with the direction finder pointed at the mountain listening to the reflected signal from the garbage can waveguide and searched all over that mountain but never located the "stricken" aircraft. A frustrating exercise but very eye opening. John is correct, the practical value of "hiding" the ELT antenna along the roll bar or under the tail fairing is ZILCH!!! I just finished my RV-6A and mounted the ELT antenna on the top of the fuselage behind the sliding canopy. Yup it's ugly sticking up there but...if I do go down and the unit is activated, that location gives me the best chance of being found as fast as possible. Yes I know the activation rate is not that great but...you spent good money on and are installing a tool that could save your life in an emergency so why not give yourself the best chance of having it do some good. Since 406 MHz ELTs still use radio waves to perform their magic, everything I just mentioned applies. There will be a lot fewer false alarms on the 406 ELTs IF AND ONLY IF all you aviators out there fill out your registration cards and mail them in. Then, when the USAF search and rescue center gets your signal they can phone you right away and find out whether it's just a false alarm or a real emergency. The good news is, if it's a real emergency the satellites will pick up your 406 MHz signal quicker and locate you within a smaller radius of area. The only down side is for the SAR team, the 406 ELTs send out a burst of data every so often as opposed to the continuous transmission of the 121.5 units. This makes DF tracking a little more difficult but you should still be found much more quickly than before. Recommendation: read the instructions that come with your unit and mount the antenna where they say to do so. If no instruction, mount on top of the wing or fuselage in an open area with the least potential for reflections. And PLEASE PLEASE register your unit. I live in Florida now where boaters have had 406 MHz EPIRBs for a long time. Problem is, there are still lots of false alarms because boaters have a dismal record of registering their units!! Fill out that card and send it in. Dean Psiropoulos RV-6A N197DM First flight scheduled for this Saturday. ________________________________ Message 9 _____________________________________ Time: 09:02:38 PM PST US From: Jerry Springer Subject: Re: RV-List: 406 MHz ELT DEAN PSIROPOULOS wrote: > > >I just finished my RV-6A and >mounted the ELT antenna on the top of the fuselage behind the sliding >canopy. Yup it's ugly sticking up there but...if I do go down and the unit >is activated, that location gives me the best chance of being found as fast >as possible. > >Dean Psiropoulos >RV-6A N197DM >First flight scheduled for this Saturday. > > > > Of course it well not do much good if you are inverted and the antenna is bent over against the fuselage or is broken off. I am one of those people that mounted mine inside under the roll over frame on a tip up, it has just as much chance of working there as anywhere else. Jerry do not archive ________________________________ Message 10 ____________________________________ Time: 09:37:22 PM PST US From: Skylor Piper Subject: Re: RV-List: 406 MHz ELT All of this discussion regarding mounting of the ELT antenna is very intere sting and eye opening, but we -8 builders have one issue:- There is simpl y no place on top of the fuselage to mount the antenna because the canopy o n the -8 slides all they way back to the vertical stabilizer when it's open !- As far as I can tell, this leaves only the options of mounting the ant enna in the cockpit, or underneath the empennage fairing as others have don e.- Anyone have any other suggestions? Skylor RV-8 under construction (getting close) --- On Mon, 11/17/08, DEAN PSIROPOULOS wrote : From: DEAN PSIROPOULOS Subject: RV-List: 406 MHz ELT When I was flying missions with Civil Air Patrol in the State of Oregon we had far more 121.5 ELT false alarms than real activations but...we responde d to every one of them and learned some lessons along the way. Most of the missions I was associated with were production spam cans who had their antennas mounted on top of the fuselage behind the cockpit. Yes it's ugly but they put them there for a reason. When the ELT IS activated in a crash, these installations have the BEST chance of being located by search and rescue (SAR). Scott's waveguide premise is correct, the cockpit does make a great one and NO that is not helpful in getting one located and rescued in a timely manner. If you land (crash) right side up that waveguide will direct the EL T signal upward where the satellites will receive it. But, once the 121.5 ELT is heard by the satellite and a SAR aircraft dispatched, the area to be searched is still quite large. The SAR aircraft has to be able to "hear" the ELT in order to pinpoint you. If your installation is in the cockpit then this waveguide effect means that the SAR aircraft's direction finding (DF) equipment needs to be A LOT closer to you to pick up the signal. That take s more time in the grid and eats up precious time getting help to a stricken pilot who may be badly injured. This waveguide effect was brought home to me quite vividly on one CAP practice mission where our incident commander placed the ELT inside a metal garbage can and then tipped the can on its side with the open end facing a mountain peak. We spent hours with the direction finder pointed at the mountain listening to the reflected signal from the garbage can waveguide and searched all over that mountain but never located the "stricken" aircraft. A frustrating exercise but very eye opening. John is correct, the practical value of "hiding" the ELT antenna along the roll bar or under the tail fairing is ZILCH!!! I just finished my RV-6A an d mounted the ELT antenna on the top of the fuselage behind the sliding canopy. Yup it's ugly sticking up there but...if I do go down and the unit is activated, that location gives me the best chance of being found as fast as possible. Yes I know the activation rate is not that great but...you spent good money on and are installing a tool that could save your life in an emergency so why not give yourself the best chance of having it do some good. Since 406 MHz ELTs still use radio waves to perform their magic, everything I just mentioned applies. There will be a lot fewer false alarms on the 40 6 ELTs IF AND ONLY IF all you aviators out there fill out your registration cards and mail them in. Then, when the USAF search and rescue center gets your signal they can phone you right away and find out whether it's just a false alarm or a real emergency. The good news is, if it's a real emergency the satellites will pick up your 406 MHz signal quicker and locate you within a smaller radius of area. The only down side is for the SAR team, the 406 ELTs send out a burst of data every so often as opposed to the continuous transmission of the 121.5 units. This makes DF tracking a littl e more difficult but you should still be found much more quickly than before. Recommendation: read the instructions that come with your unit and mount th e antenna where they say to do so. If no instruction, mount on top of the win g or fuselage in an open area with the least potential for reflections. And PLEASE PLEASE register your unit. I live in Florida now where boaters have had 406 MHz EPIRBs for a long time. Problem is, there are still lots of false alarms because boaters have a dismal record of registering their units!! Fill out that card and send it in. Dean Psiropoulos RV-6A N197DM First flight scheduled for this Saturday. =0A=0A=0A ________________________________ Message 11 ____________________________________ Time: 11:34:10 PM PST US From: =?iso-8859-1?Q?Mich=E8le_W?= Subject: RE: RV-List: 406 MHz ELT and RV8 I changed the subject because I feel that there is a definite issue as to ELT mounting on RV8s as Skylor mentioned. The canopy slides back all the way against the vertical stabilizer fairing ' so that leaves no room on the back deck. On the premise that the antenna must be vertical, this leaves the following areas on the outside: =B7 On top of the vertical stabilizer =B7 Forward of the wind shield =B7 On top of one of the wings ' certainly feasible but so ugly!!! =B7 On the rear of the canopy fairing ' ground plane issue ? Furthermore would require that the antenna cable move back and forth with the canopy. Inside of the cockpit would seem to be a bad compromise as it would not be vertical and would be close to metal, hence serious concerns as to its transmission capabilities. As to mounting it under the vertical stabilizer, horizontally, probably a bad compromise as the antenna is horizontal and masked by a fair amount of metal. Then there is another issue. If the plane tips over during the crash, then all the topside locations are rendered useless. Question : Is it OK to place two antennas on one line via a splitter or are splitters good only for receiving antennas such as VOR + ILS. If that were the case, then it would be possible to have two ELT antennas, one on top and one on the belly. The down side would be that if the belly antenna were zapped during the crash, it might ground the cable and render the top antenna useless. Any thoughts ? Mich=E8le RV8 De : owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] De la part de Skylor Piper Envoy=E9 : mardi 18 novembre 2008 06:32 =C0 : rv-list@matronics.com Objet : Re: RV-List: 406 MHz ELT All of this discussion regarding mounting of the ELT antenna is very interesting and eye opening, but we -8 builders have one issue: There is simply no place on top of the fuselage to mount the antenna because the canopy on the -8 slides all they way back to the vertical stabilizer when it's open! As far as I can tell, this leaves only the options of mounting the antenna in the cockpit, or underneath the empennage fairing as others have done. Anyone have any other suggestions? Skylor RV-8 under construction (getting close) --- On Mon, 11/17/08, DEAN PSIROPOULOS wrote: From: DEAN PSIROPOULOS Subject: RV-List: 406 MHz ELT When I was flying missions with Civil Air Patrol in the State of Oregon we had far more 121.5 ELT false alarms than real activations but...we responded to every one of them and learned some lessons along the way. Most of the missions I was associated with were production spam cans who had their antennas mounted on top of the fuselage behind the cockpit. Yes it's ugly but they put them there for a reason. When the ELT IS activated in a crash, these installations have the BEST chance of being located by search and rescue (SAR). Scott's waveguide premise is correct, the cockpit does make a great one and NO that is not helpful in getting one located and rescued in a timely manner. If you land (crash) right side up that waveguide will direct the ELT signal upward where the satellites will receive it. But, once the 121.5 ELT is heard by the satellite and a SAR aircraft dispatched, the area to be searched is still quite large. The SAR aircraft has to be able to "hear" the ELT in order to pinpoint you. If your installation is in the cockpit then this waveguide effect means that the SAR aircraft's direction finding (DF) equipment needs to be A LOT closer to you to pick up the signal. That takes more time in the grid and eats up precious time getting help to a stricken pilot who may be badly injured. This waveguide effect was brought home to me quite vividly on one CAP practice mission where our incident commander placed the ELT inside a metal garbage can and then tipped the can on its side with the open end facing a mountain peak. We spent hours with the direction finder pointed at the mountain listening to the reflected signal from the garbage can waveguide and searched all over that mountain but never located the "stricken" aircraft. A frustrating exercise but very eye opening. John is correct, the practical value of "hiding" the ELT antenna along the roll bar or under the tail fairing is ZILCH!!! I just finished my RV-6A and mounted the ELT antenna on the top of the fuselage behind the sliding canopy. Yup it's ugly sticking up there but...if I do go down and the unit is activated, that location gives me the best chance of being found as fast as possible. Yes I know the activation rate is not that great but...you spent good money on and are installing a tool that could save your life in an emergency so why not give yourself the best chance of having it do some good. Since 406 MHz ELTs still use radio waves to perform their magic, everything I just mentioned applies. There will be a lot fewer false alarms on the 406 ELTs IF AND ONLY IF all you aviators out there fill out your registration cards and mail them in. Then, when the USAF search and rescue center gets your signal they can phone you right away and find out whether it's just a false alarm or a real emergency. The good news is, if it's a real emergency the satellites will pick up your 406 MHz signal quicker and locate you within a smaller radius of area. The only down side is for the SAR team, the 406 ELTs send out a burst of data every so often as opposed to the continuous transmission of the 121.5 units. This makes DF tracking a little more difficult but you should still be found much more quickly than before. Recommendation: read the instructions that come with your unit and mount the antenna where they say to do so. If no instruction, mount on top of the wing or fuselage in an open area with the least potential for reflections. And PLEASE PLEASE register your unit. I live 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rv-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RV-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rv-list Browse Digests http://www.matronics.com/digest/rv-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.