---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Wed 02/13/08: 18 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:33 AM - Re: Crowbar Application - off topic (Robert L. Nuckolls, III) 2. 04:46 AM - Fusible Link Question (Robert L. Nuckolls, III) 3. 05:47 AM - Re: Crowbar Application - off topic (Ken) 4. 07:15 AM - External antennas on composite plane (was Alternator article) () 5. 07:58 AM - Re: External antennas on composite plane (was Alternator article) (Bruce Gray) 6. 08:12 AM - Re: External antennas on composite plane (was Alternator article) () 7. 08:14 AM - Re: External antennas on composite plane (was Alternator article) (Matt Prather) 8. 08:16 AM - bus bars (John Tvedte) 9. 08:43 AM - Re: bus bars (Fiveonepw@aol.com) 10. 08:45 AM - Re: bus bars (JOHN TIPTON) 11. 08:52 AM - Re: bus bars (JOHN TIPTON) 12. 11:14 AM - Re: bus bars (Greg Young) 13. 11:40 AM - Links to Appendix Z ? (Gilles Thesee) 14. 12:56 PM - Re: bus bars (Robert L. Nuckolls, III) 15. 04:51 PM - Why can't the tower hear me? (Steve Ruse) 16. 05:38 PM - Re: Why can't the tower hear me? (H. M. Haught Jr.) 17. 05:55 PM - Re: Why can't the tower hear me? (S. Ramirez) 18. 07:36 PM - Re: Why can't the tower hear me? (Robert Feldtman) ________________________________ Message 1 _____________________________________ Time: 04:33:08 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Crowbar Application - off topic At 12:37 AM 2/13/2008 -0500, you wrote: > > >Frank > >Why not use a DPDT or DPST-N/C relay instead, and wire the contacts in >series with the compressor supply instead of shorting it to ground? That way >when the pressure drops low enough the compressor simply shuts off rather >than shorting out. When you are using large quantities of air of course you >have to defeat this system however just as you would with your scheme. >Sounds very inconvenient. Shorting the hydro line to ground isn't a >particularly good idea and is asking for trouble, probably sooner than >later. An alternative is to wire your DPST relay such that the compressor >supply is through this relay and then wire the relay coil to the lighting >circuit in your shop. You turn out the lights when you leave and the >compressor is automatically shut down. While you're in the shop working, the >compressor runs as intended, no dangerous shorts or other complications >involved and no extra circuits to arm or disarm as required. My shop in Medicine Lodge has an outlet driven through a wind-up two-hour timer, not unlike the cooking timers of yesteryear. I give 'er a good crank when I need air but if I forget to turn the compressor off before leaving, the timer does it for me. I use a small contactor to relieve the timer's contacts from having to carry the motor current. If I'm in the shop long enough for the timer to run out, I'll generally hear it drop out unless I'm making a lot of noise. Once could also consider adding an indicator light that goes out when the compressor power goes away. The crowbar thing on AC mains breakers involves a much higher energy event than for tripping a 5A breaker in an airplane. It would probably function as advertised but it's not the elegant solution. Bob's idea is probably the best. Lowest parts count yet. Bob . . . ________________________________ Message 2 _____________________________________ Time: 04:46:54 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Fusible Link Question (response to query sent privately. writer identity filtered to comply with the writer's perceived wishes). Bob . . . I believe I'm going with Z 13 diagram. While studing this diagram and comparing to Z 12, I see that in Z13 the 5 Amp ALT FLD CB coming off the Main Bus has a fuseable link before it. In Z-12 the ALT FLD CB comes right off the Main Bus and no fuseable link. Does it make a difference which way I go? I would perfer NOT to use fuseable link, but come off the Main Bus as depicted in Z-12. Z-13 features fuseblock mounted remotely from the panel . . . so the bus must be extended to the panel to accommodate the lonely 5A breaker. The upstream protection for the bus extension to the panel needs to be MUCH more robust than the breaker. I.e, the I-squared * T constant for the upstream protection needs to be bigger. Crowbaring the 5A breaker does not pose a nuisance trip risk to a fusible link. What's your heartburn with a fusible link? They're an exceedingly mature technology with wide application and in this particular case, makes for the most elegant solution. Another point- I am using fuse blocks instead of bus bars, so if I take the 5 amp CB off the Main Bus as in Z-12, would I install a 15 or 20 amp fuse, then run 18g to the CB ? Make it a 30A fuse and then I suppose one would also up-size the fuse-to-breaker feeder to say 12AWG. You can see which way this is going. My advice is to stay with the fusible link. It was a long considered feature of this architecture. Lastly, in the Z-13, the SD-8 comes off the Battery Contactor, once again an 18g fuseable link. Is there any way around that ? "like" starting at the Battery Fuse block instead of the Battery Contactor (use 7 or 10 amp fuse), then run 18 g to shunt, etc, etc.? Leave the wire sizes as depicted. Put a 15A in-line fuse in there if it makes you feel better. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 3 _____________________________________ Time: 05:47:06 AM PST US From: Ken Subject: Re: AeroElectric-List: Crowbar Application - off topic Yes and a similar scheme for water may be even more useful. Water leaks are frequent and can be very expensive as insurance companies well know. There are commercial valve units with leak detectors available for those on city water. However for well water, I wired in such a relay that pulls in to kill power to the pump when the burglar alarm is armed. (BTW the relay consumes far less power than any one of numerous household electronic items do when they are turned OFF!) If concerned about my compressor, I'd wire a relay to pull in and power the compressor when shop lights were turned on or when Bob's wind up timer was activated. Some guys do simply use a 230 volt switch box to kill lights and shop power simultaneously when they leave the shop. For my electronics bench, turning off the lights also kills power to the soldering iron plug. Ken Robert McCallum wrote: > > Frank > > Why not use a DPDT or DPST-N/C relay instead, and wire the contacts in > series with the compressor supply instead of shorting it to ground? That way > when the pressure drops low enough the compressor simply shuts off rather > than shorting out. When you are using large quantities of air of course you > have to defeat this system however just as you would with your scheme. > Sounds very inconvenient. Shorting the hydro line to ground isn't a > particularly good idea and is asking for trouble, probably sooner than > later. An alternative is to wire your DPST relay such that the compressor > supply is through this relay and then wire the relay coil to the lighting > circuit in your shop. You turn out the lights when you leave and the > compressor is automatically shut down. While you're in the shop working, the > compressor runs as intended, no dangerous shorts or other complications > involved and no extra circuits to arm or disarm as required. > > Bob McC > > ________________________________ Message 4 _____________________________________ Time: 07:15:03 AM PST US From: Subject: AeroElectric-List: External antennas on composite plane (was Alternator article) Walter three or four things: External antennas are better performing in general, even on a fiberglass plane. Cost to bond in antennas is more than off the shelf antennas that bolt on (externally). All they have to do is put a metal ground plane (the size of a large round or square serving plate) under the antenna. Done. Last, some one told me (I don't know this for sure) the Columbia has some kind of lighting protection in the layup, to route a lightning strike through and out the plane. I have not confirmed this, but this would make internal antennas as impractical as they are in metal planes. In the area of pure gussing, it might also be a certification issue, meaning its easier and cheaper to use exisiting products. It is a fact that the DRAG from an antenna or two is small. Why bother? George >On an unrelated matter, I notice that most of the type >certified composite aircraft (columbia, cirrus and diamond) >have external antennas. Do you know if this is a requirement >for certification? Is there any reason that blind antennas >cannot be just as effective as external antennas? >Best Regards >Walter Fellows --------------------------------- ________________________________ Message 5 _____________________________________ Time: 07:58:36 AM PST US From: "Bruce Gray" Subject: RE: AeroElectric-List: External antennas on composite plane (was Alternator article) Antennas reside quite well internally in composite, fiberglass airplanes, as long as the structure is fiberglass. As soon as you move to carbon based cloth, external antennas are needed. Some carbon cloth kits (Lancair) have specific areas of fiberglass cloth instead of carbon to allow internal antennas. Lightning protection is another issue. The accepted way of protecting a fiberglass (Glasair) or carbon (Lancair) or certified composite (Columbia, Cirus) airframe is to place a layer of copper mesh in the last few (outer) laminates of the structure. This means that all antenna have to be external. Bruce www.Glasair.org -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of gmcjetpilot@yahoo.com Sent: Wednesday, February 13, 2008 10:08 AM Subject: AeroElectric-List: External antennas on composite plane (was Alternator article) Walter three or four things: External antennas are better performing in general, even on a fiberglass plane. Cost to bond in antennas is more than off the shelf antennas that bolt on (externally). All they have to do is put a metal ground plane (the size of a large round or square serving plate) under the antenna. Done. Last, some one told me (I don't know this for sure) the Columbia has some kind of lighting protection in the layup, to route a lightning strike through and out the plane. I have not confirmed this, but this would make internal antennas as impractical as they are in metal planes. In the area of pure gussing, it might also be a certification issue, meaning its easier and cheaper to use exisiting products. It is a fact that the DRAG from an antenna or two is small. Why bother? George >On an unrelated matter, I notice that most of the type >certified composite aircraft (columbia, cirrus and diamond) >have external antennas. Do you know if this is a requirement >for certification? Is there any reason that blind antennas >cannot be just as effective as external antennas? >Best Regards >Walter Fellows ________________________________ Message 6 _____________________________________ Time: 08:12:31 AM PST US Subject: RE: AeroElectric-List: External antennas on composite plane (was Alternator article) From: Internal antennas are for esthetics and the micro speed conscious. I have love washing my airplane and not having to go around everything in the process. One clean sweep on the belly. They do not necessarily work better or worse. I have noticed little difference having everything inside. If you crash your ELT antenna will be outside after you land, so problem solved. Yes, Columbia (Cessna) and Lancair have a lightning kit which routes energy out the tail. It requires a new paint job when added as it must be bonded to the skin. It is basically uses thin copper material bonded to the skin with whips on the tail or elevator. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of gmcjetpilot@yahoo.com Sent: Wednesday, February 13, 2008 10:08 AM To: walter.fellows@gmail.com; aeroelectric-list@matronics.com Subject: AeroElectric-List: External antennas on composite plane (was Alternator article) Walter three or four things: External antennas are better performing in general, even on a fiberglass plane. Cost to bond in antennas is more than off the shelf antennas that bolt on (externally). All they have to do is put a metal ground plane (the size of a large round or square serving plate) under the antenna. Done. Last, some one told me (I don't know this for sure) the Columbia has some kind of lighting protection in the layup, to route a lightning strike through and out the plane. I have not confirmed this, but this would make internal antennas as impractical as they are in metal planes. In the area of pure gussing, it might also be a certification issue, meaning its easier and cheaper to use exisiting products. It is a fact that the DRAG from an antenna or two is small. Why bother? George >On an unrelated matter, I notice that most of the type >certified composite aircraft (columbia, cirrus and diamond) >have external antennas. Do you know if this is a requirement >for certification? Is there any reason that blind antennas >cannot be just as effective as external antennas? >Best Regards >Walter Fellows ________________________________ Message 7 _____________________________________ Time: 08:14:30 AM PST US Subject: Re: AeroElectric-List: External antennas on composite plane (was Alternator article) From: "Matt Prather" > Walter three or four things: > > External antennas are better performing in general, even > on a fiberglass plane. snip > products. It is a fact that the DRAG from an antenna or > two is small. Why bother? George > snip Drag is a relative thing. One or two antennas on a big 4 seater that won't go 200kts down low is one thing. As the airframe gets smaller (lower airframe flat-plate area) and the speed goes up, antenna drag becomes less trivial.. Plus, antennas are ugly. But, I agree that for most airplanes external antennas make sense unless you're looking to be experimental. Regards, Matt- ________________________________ Message 8 _____________________________________ Time: 08:16:06 AM PST US From: John Tvedte Subject: AeroElectric-List: bus bars Hi, I know I have seen suggested material thickness - for creating circuit breaker bus bars, and the suggested material is brass. I am wondering how one calculates the width, thickness required? Also can someone explain the benefits of brass? John ________________________________ Message 9 _____________________________________ Time: 08:43:44 AM PST US From: Fiveonepw@aol.com Subject: Re: AeroElectric-List: bus bars In a message dated 02/13/2008 10:19:06 AM Central Standard Time, johnt@comp-sol.com writes: Also can someone explain the benefits of brass? Also- thoughts on using aluminum for bus bars? Thanks! Mark do not archive **************The year's hottest artists on the red carpet at the Grammy Awards. Go to AOL Music. (http://music.aol.com/grammys?NCID=aolcmp00300000002565) ________________________________ Message 10 ____________________________________ Time: 08:45:53 AM PST US From: "JOHN TIPTON" Subject: Re: AeroElectric-List: bus bars Buy them from 'Aircraft Spruce' already made up: and move on http://www.aircraftspruce.com/catalog/elpages/bussbars.php John ----- Original Message ----- From: "John Tvedte" Sent: Wednesday, February 13, 2008 3:56 PM Subject: AeroElectric-List: bus bars > > Hi, > > I know I have seen suggested material thickness - for creating circuit > breaker bus bars, and the suggested material is brass. I am wondering how > one calculates the width, thickness required? Also can someone explain > the benefits of brass? > > John > > > ________________________________ Message 11 ____________________________________ Time: 08:52:09 AM PST US From: "JOHN TIPTON" Subject: Re: AeroElectric-List: bus bars Hi conductivity, and of course corrosion resistant John ----- Original Message ----- From: Fiveonepw@aol.com To: aeroelectric-list@matronics.com Sent: Wednesday, February 13, 2008 4:39 PM Subject: Re: AeroElectric-List: bus bars In a message dated 02/13/2008 10:19:06 AM Central Standard Time, johnt@comp-sol.com writes: Also can someone explain the benefits of brass? Also- thoughts on using aluminum for bus bars? Thanks! Mark do not archive ------------------------------------------------------------------------- ----- The year's hottest artists on the red carpet at the Grammy Awards. AOL Music takes you there. ________________________________ Message 12 ____________________________________ Time: 11:14:55 AM PST US From: "Greg Young" Subject: RE: AeroElectric-List: bus bars You can get brass bars from your local hobby/craft store that has one of those K&D hobby metal displays. I got .062x.5x12 brass bars for ~$1.90 each. Regards, Greg Young > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On > Behalf Of JOHN TIPTON > Sent: Wednesday, February 13, 2008 10:43 AM > To: aeroelectric-list@matronics.com > Subject: Re: AeroElectric-List: bus bars > > --> > > Buy them from 'Aircraft Spruce' already made up: and move on > > http://www.aircraftspruce.com/catalog/elpages/bussbars.php > > John > > > ----- Original Message ----- > From: "John Tvedte" > To: > Sent: Wednesday, February 13, 2008 3:56 PM > Subject: AeroElectric-List: bus bars > > > > > > > Hi, > > > > I know I have seen suggested material thickness - for > creating circuit > > breaker bus bars, and the suggested material is brass. I > am wondering how > > one calculates the width, thickness required? Also can > someone explain > > the benefits of brass? > > > > John ________________________________ Message 13 ____________________________________ Time: 11:40:36 AM PST US From: Gilles Thesee Subject: AeroElectric-List: Links to Appendix Z ? Bob and all, I was about to post a link to your site on a Jabiru List, when I noticed that your links to the Appendix Z seem to be out of order. Or did I miss the obvious ? Best regards, -- Gilles http://contrails.free.fr ________________________________ Message 14 ____________________________________ Time: 12:56:47 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: bus bars At 01:05 PM 2/13/2008 -0600, you wrote: > >You can get brass bars from your local hobby/craft store that has one of >those K&D hobby metal displays. I got .062x.5x12 brass bars for ~$1.90 each. This would have been my suggestion. Brass is preferable to copper for machinability . . . it's much easier to drill clean, round holes in brass than copper. Aluminum is electrically and mechanically attractive but less friendly in terms of creating high quality, corrosion free, gas tight, long lived connections under the small fasteners (6-32). Thickness is not critical. A flat sheet of material has excellent heat rejection qualities compared to round wires under insulation. A bus fabricated from .025" brass will be just fine . . . especially if you bring the bus feeder into the center of the bus. Use internal tooth lockwashers under the screws and torque to 80% of rated limits at final assembly. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 15 ____________________________________ Time: 04:51:19 PM PST US From: Steve Ruse Subject: AeroElectric-List: Why can't the tower hear me? I fly an open cockpit experimental (Pietenpol). My radio is a Vertex Standard VXA-150 (handheld), powered by an external 8AH/12v battery. I have an antenna mounted on a ground plane on the belly, in front of the gear. I have no problems communicating air to air with other planes, I have actually maintained contact air-air with friends at distances over 125NM. My calls were reported as loud and clear. I was based at a class D airport (KFTW) for about one year, and never had trouble with the tower there. Two years ago, I moved to a new area, near a class D airport that I occasionally go to (KOUN in Norman, OK). I often have trouble being understood by the tower, even though all pilots indicate that my transmissions are loud and clear. Last weekend I tried to enter the class D, but both times I called, the tower responded saying that my transmissions were "scratchy and unintelligable". I was about 6NM away and could actually see the tower. I immediately switched to another frequency, and heard traffic on the CTAF at KGYI, about 95NM away. I called them and asked for a radio check. That pilot replied that I was loud and clear. Not wanting to bother the tower or cause trouble in their airspace, I turned away before entering. I am baffled by this. What would cause me to be unintelligable to the KOUN tower repeatedly, when no one else has trouble understanding me, even at long distances? I was on a heading for the tower, and I know my transmission strength in that direction (forward) is good. AND it was only six miles away. My only theory is that the tower doesn't like the wind noise in my mic...but I have a noise cancelling mic, with a leather wind-blocking mic cover, AND other pilots report my transmissions as clear. Any thoughts on what might cause this would be appreciated. It is difficult to trouble shoot because I have to bother the tower to replicate the problem. Steve Ruse ________________________________ Message 16 ____________________________________ Time: 05:38:15 PM PST US From: "H. M. Haught Jr. " Subject: Re: AeroElectric-List: Why can't the tower hear me? Steve - This is strange! I fly into KOUN regularly. When I fly in, I'm communicating with flight following with no problems, and transfer off to KOUN okay. The next day, sitting on the ramp, radio cold, they tell me that my radio is unreadable. I've had the radio checked out throughly by two different radio shops now 4 times. Now it is starting to happen at another airport KSAG. Yet, I taxi across the field at KASG, the radio shop does a check, call up tower, and everything is normal. Makes no sense and I think something is wrong with THEIR radios. And no, it isn't wind noise. I've tried everything, even my handheld, and at KOUN, they say they cannot understand it either, although at KASG, the handheld usually works. I keep telling them that they have something wrong with their system, which has now made me almost persona non grata at their facility. I'm using an ICOM radio and have had absolutely no problems with anyone else reading me other than those two places, and was all over California, Texas, New Mexico, and Arizona with it last December and January, with no problems whatsoever. I use flight following on every flight, and occasionally someone will tell me my radio has some background noise, but I've gotten in the habit of asking for radio checks and always get a good report. The only places I have problems is KOUN and KASG, and usually only on initial call up. Once I'm airborne, they can generally hear me fine. I'd say we have a similar problem - let's stay in touch until we find some way to resolve it. M. Haught Steve Ruse wrote: > > > I fly an open cockpit experimental (Pietenpol). My radio is a Vertex > Standard VXA-150 (handheld), powered by an external 8AH/12v battery. > I have an antenna mounted on a ground plane on the belly, in front of > the gear. I have no problems communicating air to air with other > planes, I have actually maintained contact air-air with friends at > distances over 125NM. My calls were reported as loud and clear. I > was based at a class D airport (KFTW) for about one year, and never > had trouble with the tower there. > > Two years ago, I moved to a new area, near a class D airport that I > occasionally go to (KOUN in Norman, OK). I often have trouble being > understood by the tower, even though all pilots indicate that my > transmissions are loud and clear. Last weekend I tried to enter the > class D, but both times I called, the tower responded saying that my > transmissions were "scratchy and unintelligable". I was about 6NM > away and could actually see the tower. I immediately switched to > another frequency, and heard traffic on the CTAF at KGYI, about 95NM > away. I called them and asked for a radio check. That pilot replied > that I was loud and clear. Not wanting to bother the tower or cause > trouble in their airspace, I turned away before entering. > > I am baffled by this. What would cause me to be unintelligable to the > KOUN tower repeatedly, when no one else has trouble understanding me, > even at long distances? I was on a heading for the tower, and I know > my transmission strength in that direction (forward) is good. AND it > was only six miles away. > > My only theory is that the tower doesn't like the wind noise in my > mic...but I have a noise cancelling mic, with a leather wind-blocking > mic cover, AND other pilots report my transmissions as clear. > > Any thoughts on what might cause this would be appreciated. It is > difficult to trouble shoot because I have to bother the tower to > replicate the problem. > > Steve Ruse > > ________________________________ Message 17 ____________________________________ Time: 05:55:58 PM PST US From: "S. Ramirez" Subject: RE: AeroElectric-List: Why can't the tower hear me? -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Steve Ruse Sent: Wednesday, February 13, 2008 7:39 PM Subject: AeroElectric-List: Why can't the tower hear me? I fly an open cockpit experimental (Pietenpol). My radio is a Vertex Standard VXA-150 (handheld), powered by an external 8AH/12v battery. I have an antenna mounted on a ground plane on the belly, in front of the gear. I have no problems communicating air to air with other planes, I have actually maintained contact air-air with friends at distances over 125NM. My calls were reported as loud and clear. I was based at a class D airport (KFTW) for about one year, and never had trouble with the tower there. Two years ago, I moved to a new area, near a class D airport that I occasionally go to (KOUN in Norman, OK). I often have trouble being understood by the tower, even though all pilots indicate that my transmissions are loud and clear. Last weekend I tried to enter the class D, but both times I called, the tower responded saying that my transmissions were "scratchy and unintelligable". I was about 6NM away and could actually see the tower. I immediately switched to another frequency, and heard traffic on the CTAF at KGYI, about 95NM away. I called them and asked for a radio check. That pilot replied that I was loud and clear. Not wanting to bother the tower or cause trouble in their airspace, I turned away before entering. I am baffled by this. What would cause me to be unintelligable to the KOUN tower repeatedly, when no one else has trouble understanding me, even at long distances? I was on a heading for the tower, and I know my transmission strength in that direction (forward) is good. AND it was only six miles away. My only theory is that the tower doesn't like the wind noise in my mic...but I have a noise cancelling mic, with a leather wind-blocking mic cover, AND other pilots report my transmissions as clear. Any thoughts on what might cause this would be appreciated. It is difficult to trouble shoot because I have to bother the tower to replicate the problem. Steve Ruse Very interesting, Steve. Can you please identify the frequencies you were using? Thanks. Simon Copyright C 2008 ________________________________ Message 18 ____________________________________ Time: 07:36:28 PM PST US From: "Robert Feldtman" Subject: Re: AeroElectric-List: Why can't the tower hear me? I suspect it is the tower radios. I believe that many still use vaccum tubes - Jurassic radios I used to play with in the 60s as a ham! Anyway, I suspect the govt is wasting out precious airport tax monies (yes they collect taxes on every airline flight we make).... on programs other than aviation safety and upgrades. That's what will happen if the put further tax on GA as well. I frequently have problems with ARTCC in my glastar and a GX65 radio.. not them hearing me - but me hearing them. their transmission are so weak and unreadable bobf On 2/13/08, Steve Ruse wrote: > > steve@wotelectronics.com> > > I fly an open cockpit experimental (Pietenpol). My radio is a Vertex > Standard VXA-150 (handheld), powered by an external 8AH/12v battery. > I have an antenna mounted on a ground plane on the belly, in front of > the gear. I have no problems communicating air to air with other > planes, I have actually maintained contact air-air with friends at > distances over 125NM. My calls were reported as loud and clear. I > was based at a class D airport (KFTW) for about one year, and never > had trouble with the tower there. > > Two years ago, I moved to a new area, near a class D airport that I > occasionally go to (KOUN in Norman, OK). I often have trouble being > understood by the tower, even though all pilots indicate that my > transmissions are loud and clear. Last weekend I tried to enter the > class D, but both times I called, the tower responded saying that my > transmissions were "scratchy and unintelligable". I was about 6NM > away and could actually see the tower. I immediately switched to > another frequency, and heard traffic on the CTAF at KGYI, about 95NM > away. I called them and asked for a radio check. That pilot replied > that I was loud and clear. Not wanting to bother the tower or cause > trouble in their airspace, I turned away before entering. > > I am baffled by this. What would cause me to be unintelligable to the > KOUN tower repeatedly, when no one else has trouble understanding me, > even at long distances? I was on a heading for the tower, and I know > my transmission strength in that direction (forward) is good. AND it > was only six miles away. > > My only theory is that the tower doesn't like the wind noise in my > mic...but I have a noise cancelling mic, with a leather wind-blocking > mic cover, AND other pilots report my transmissions as clear. > > Any thoughts on what might cause this would be appreciated. It is > difficult to trouble shoot because I have to bother the tower to > replicate the problem. > > Steve Ruse > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-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/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-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.