---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 05/20/18: 19 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:45 AM - Re: VHF antenna in the tail (GTH) 2. 06:19 AM - Re: VHF antenna in the tail (FLYaDIVE) 3. 06:45 AM - Re: VHF antenna in the tail (Timothy Meyer) 4. 07:26 AM - Re: VHF antenna in the tail (user9253) 5. 08:33 AM - Radio or Television Tower Buzz (mike>bentley) 6. 08:53 AM - Re: VHF antenna in the tail (Robert Borger) 7. 09:04 AM - Radio or Television Tower Buzz (Kelly McMullen) 8. 09:16 AM - Re: Radio or Television Tower Buzz (mike>bentley) 9. 09:26 AM - Re: Radio or Television Tower Buzz (Charlie England) 10. 09:35 AM - Re: Radio or Television Tower Buzz (mike>bentley) 11. 09:43 AM - Re: Radio or Television Tower Buzz (FLYaDIVE) 12. 09:47 AM - Re: Re: Radio or Television Tower Buzz (Kelly McMullen) 13. 10:48 AM - New toy . . . (Robert L. Nuckolls, III) 14. 12:09 PM - Re: VHF antenna in the tail (Robert L. Nuckolls, III) 15. 01:31 PM - Re: VHF antenna in the tail (user9253) 16. 02:58 PM - Re: Re: VHF antenna in the tail (Robert L. Nuckolls, III) 17. 02:59 PM - Re: VHF antenna in the tail (Peter Pengilly) 18. 04:32 PM - Re: VHF antenna in the tail (Robert L. Nuckolls, III) 19. 04:43 PM - Re: Radio or Television Tower Buzz (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 04:45:55 AM PST US Subject: Re: AeroElectric-List: VHF antenna in the tail From: GTH /Le 23/12/2017 01:26, Robert L. Nuckolls, III a crit: / > / > Can you describe the physical configuration of > the vertical fin vis-a-vis the empennage? Is > the vertical fin detachable? > > I presume the antenna, once installed, will > forever more be inaccessible for tweeking? / Hi Bob and all, Reviving the antenna-in-tail subject, as the project fuselage is now assembled. Bob mentionned a promising "bazooka" configuration for the antenna, as the tail is too narrow to allow for a regular ground plane. Here are some answers to your questions : The entire fuselage is carbon. The vertical fin is integral with the fuselage but is made of glass for the installation of the antenna. The fin height is ~ 0.9 m (35") while the carbon tail at the base is only 0.18 m (7") wide. The base of the antenna will be accessible via the tail cone aperture, and crawling into the fuselage will permit limited access. I was considering installing the radiating element in a plastic tube in the fin, so that the antenna may be easily inserted and removed. Any suggestions as to how to devise a reasonably efficient comm antenna in the tail ? Thanks in advance, -- Best regards, Gilles http://contrails.free.fr http://lapierre.skunkworks.free.fr ________________________________ Message 2 _____________________________________ Time: 06:19:40 AM PST US From: FLYaDIVE Subject: Re: AeroElectric-List: VHF antenna in the tail Giles: You solved half of the antenna issue by making the vertical stab out of fiberglass. The second issue is: What is the Torque Tube of the rudder made out of? If it is aluminum then you have a Blanketing issue as it will mess up the radiation pattern of the antenna. The third issue is you will need at least a 1/4 wave length Ground-plane made out of a conductive material... Aluminum or copper. >From the looks of the empennage you do not have enough area to have a ground-plane. So, what are your options: The most logical will also probably be the easiest - Install two home-brew antennas in the tips of the Horizontal Sab or the tips of the Elevator and co-phase them. Of course they will be horizontally phased as compared to most other antennas out there but, that is a minor inconvenience. Consider ALL those bent 1/4 wave belly mounted antennas that are bent over - - - they still work. Here is a simple co-phased feed line: http://www.jonfinley.com/hobbies/harness.html I would use BNC connectors as apposed to PL & SO connectors. I also totally dislike CRIMP connectors. The solder ones work better and do not cut into the COAX - - EVER! Just work out the math for the frequency you wish to use. Barry On Sun, May 20, 2018 at 7:43 AM, GTH wrote: > > *Le 23/12/2017 =C3- 01:26, Robert L. Nuckolls, III a =C3=A9crit : * > > > * Can you describe the physical configuration of the vertical fin > vis-a-vis the empennage? Is the vertical fin detachable? I presume th e > antenna, once installed, will forever more be inaccessible for tweeking ? > * > > > Hi Bob and all, > > Reviving the antenna-in-tail subject, as the project fuselage is now > assembled. > > Bob mentionned a promising "bazooka" configuration for the antenna, as th e > tail is too narrow to allow for a regular ground plane. > > Here are some answers to your questions : > The entire fuselage is carbon. The vertical fin is integral with the > fuselage but is made of glass for the installation of the antenna. > The fin height is ~ 0.9 m (35") while the carbon tail at the base is only > 0.18 m (7") wide. > > > The base of the antenna will be accessible via the tail cone aperture, an d > crawling into the fuselage will permit limited access. > I was considering installing the radiating element in a plastic tube in > the fin, so that the antenna may be easily inserted and removed. > > Any suggestions as to how to devise a reasonably efficient comm antenna i n > the tail ? > > Thanks in advance, > > > -- > Best regards, > Gilles > http://contrails.free.fr > http://lapierre.skunkworks.free.fr > ________________________________ Message 3 _____________________________________ Time: 06:45:14 AM PST US From: Timothy Meyer Subject: Re: AeroElectric-List: VHF antenna in the tail Here is a link to Jim Wier of RST Engineering information of aircraft antennas in fiberglass airplanes and fiberglass airplane components. http://www.rstengineering.com/rst/products/plasticplaneantenna/plasticplane antenna.htm I've heard Jim talk st Oshkosh numerous times. Tim Meyer On Sun, May 20, 2018 at 6:55 AM GTH wrote: > > *Le 23/12/2017 =C3- 01:26, Robert L. Nuckolls, III a =C3=A9crit : * > > > * Can you describe the physical configuration of the vertical fin > vis-a-vis the empennage? Is the vertical fin detachable? I presume th e > antenna, once installed, will forever more be inaccessible for tweeking ? > * > > > Hi Bob and all, > > Reviving the antenna-in-tail subject, as the project fuselage is now > assembled. > > Bob mentionned a promising "bazooka" configuration for the antenna, as th e > tail is too narrow to allow for a regular ground plane. > > Here are some answers to your questions : > The entire fuselage is carbon. The vertical fin is integral with the > fuselage but is made of glass for the installation of the antenna. > The fin height is ~ 0.9 m (35") while the carbon tail at the base is only > 0.18 m (7") wide. > > > The base of the antenna will be accessible via the tail cone aperture, an d > crawling into the fuselage will permit limited access. > I was considering installing the radiating element in a plastic tube in > the fin, so that the antenna may be easily inserted and removed. > > Any suggestions as to how to devise a reasonably efficient comm antenna i n > the tail ? > > Thanks in advance, > > > -- > Best regards, > Gilles > http://contrails.free.fr > http://lapierre.skunkworks.free.fr > ________________________________ Message 4 _____________________________________ Time: 07:26:58 AM PST US Subject: AeroElectric-List: Re: VHF antenna in the tail From: "user9253" I would try a 1/4 wave antenna with ground plane. Of course the small diameter tail is not the ideal shape and size for a ground plane. But it might be good enough. Use 4 or 6 copper tape radials (or aluminum strips) glued to the inside of the tail cone. Or it might be easier to install a thin sheet of aluminum glued to the inside surface of the tail cone. If that does not work out, then try the bazooka antenna. No antenna is perfect. Be satisfied with good enough. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=480242#480242 ________________________________ Message 5 _____________________________________ Time: 08:33:54 AM PST US Subject: AeroElectric-List: Radio or Television Tower Buzz From: "mike>bentley" When flying in the vicinity of radio or TV towers, I get a constant buzz or static over the radio. Sometimes I can hear the conversation or music from the station, but just barely. It seems to start when I'm within a 1/2 to 1/4 mile from a tower. Anyone else have this type of issue or resolved this type of issue? -------- Mike Bentley Joplin, MO N5498B Kitfox Model 4-1200 Jabiru 2200 #438 Rotec Aerosport LCH Heads Prince Prop (64 x 34) Ellison EFS-2 Throttle Body Read this topic online here: http://forums.matronics.com/viewtopic.php?p=480244#480244 ________________________________ Message 6 _____________________________________ Time: 08:53:31 AM PST US From: Robert Borger Subject: Re: AeroElectric-List: VHF antenna in the tail Giles, There are a number of comm antenna solution that do not require a ground plane. They are produced by Archer and by Advanced Aircraft Electronics. These are center-tap, full-wave antennas of various styles, shapes and prices. See =94 http://www.aircraftspruce.com/search/search.php?cache=75660d9834ea34b12f c9146878e6443b&filter=&perpage=all&pageno=1 They are hidden amongst the various other antennas on the page. In addition there are plans available on the net to craft your own copper tape/strip full wave antennas that could be used on the stern post. I have used both the AAE and Archer antennas in composite aircraft and I have built a copper strip antenna for use with a base radio all with excellent results. Blue skies & tailwinds, Bob Borger Europa XS Tri, Rotax 914, Airmaster C/S Prop (100 hrs). Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP, Hercules Prop. 3705 Lynchburg Dr. Corinth, TX 76208-5331 Cel: 817-992-1117 rlborger@mac.com On May 20, 2018, at 6:43 AM, GTH wrote: Le 23/12/2017 =C3- 01:26, Robert L. Nuckolls, III a =C3=A9crit : > > Can you describe the physical configuration of > the vertical fin vis-a-vis the empennage? Is > the vertical fin detachable? > > I presume the antenna, once installed, will > forever more be inaccessible for tweeking? Hi Bob and all, Reviving the antenna-in-tail subject, as the project fuselage is now assembled. Bob mentionned a promising "bazooka" configuration for the antenna, as the tail is too narrow to allow for a regular ground plane. Here are some answers to your questions : The entire fuselage is carbon. The vertical fin is integral with the fuselage but is made of glass for the installation of the antenna. The fin height is ~ 0.9 m (35") while the carbon tail at the base is only 0.18 m (7") wide. The base of the antenna will be accessible via the tail cone aperture, and crawling into the fuselage will permit limited access. I was considering installing the radiating element in a plastic tube in the fin, so that the antenna may be easily inserted and removed. Any suggestions as to how to devise a reasonably efficient comm antenna in the tail ? Thanks in advance, -- Best regards, Gilles http://contrails.free.fr http://lapierre.skunkworks.free.fr ________________________________ Message 7 _____________________________________ Time: 09:04:40 AM PST US Subject: AeroElectric-List: Radio or Television Tower Buzz From: Kelly McMullen What is happening is that the high power from the towers is exciting one of the oscillators in one of your radios. What is most common, especially with older 121.5 ELTs is for their transmit oscillator to be activated by the high power RF from the towers, generating a weak white noise signal that breaks squelch on your com radio. I used to have that problem with a previous aircraft, where there are about 15 high power towers on a mountain a few miles south of the Phoenix Class B and in line with the VFR transition through the Class B. Communications with approach control while flying that transition would become very difficult. Newer 121.5 ELTs and 406 ELTs are better shielded for that. Also, moving a com antenna from top of fuselage to belly can help isolate the ELT from the com antenna. On 5/20/2018 8:38 AM, mike>bentley wrote: > --> Avionics-List message posted by: "mike>bentley" > > When flying in the vicinity of radio or TV towers, I get a constant buzz or static over the radio. Sometimes I can hear the conversation or music from the station, but just barely. It seems to start when I'm within a 1/2 to 1/4 mile from a tower. > > Anyone else have this type of issue or resolved this type of issue? > > -------- > Mike Bentley > Joplin, MO > N5498B > Kitfox Model 4-1200 > Jabiru 2200 #438 > Rotec Aerosport LCH Heads > Prince Prop (64 x 34) > Ellison EFS-2 Throttle Body > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=480245#480245 > > > > > > > > > ________________________________ Message 8 _____________________________________ Time: 09:16:24 AM PST US Subject: AeroElectric-List: Re: Radio or Television Tower Buzz From: "mike>bentley" Thanks Kelli, I have a 406mhz elt with the antenna mounted inside the fuselage and comm antenna mounted on top of the fuselage. The elt antenna is approximately 18" below and 12" forward of the comm antenna. The elt antenna is much easier to relocate than the comm. Would moving the elt antenna farther away help? -------- Mike Bentley Joplin, MO N5498B Kitfox Model 4-1200 Jabiru 2200 #438 Rotec Aerosport LCH Heads Prince Prop (64 x 34) Ellison EFS-2 Throttle Body Read this topic online here: http://forums.matronics.com/viewtopic.php?p=480249#480249 ________________________________ Message 9 _____________________________________ Time: 09:26:39 AM PST US Subject: Re: AeroElectric-List: Radio or Television Tower Buzz From: Charlie England On 5/20/2018 10:33 AM, mike>bentley wrote: > > When flying in the vicinity of radio or TV towers, I get a constant buzz or static over the radio. Sometimes I can hear the conversation or music from the station, but just barely. It seems to start when I'm within a 1/2 to 1/4 mile from a tower. > > Anyone else have this type of issue or resolved this type of issue? > > -------- > Mike Bentley > Joplin, MO > N5498B > Kitfox Model 4-1200 > Jabiru 2200 #438 > Rotec Aerosport LCH Heads > Prince Prop (64 x 34) > Ellison EFS-2 Throttle Body Flying within 1/4 mile of a tower? My solution would be the He Haw (TV show, for uninitiated) solution: 'If it hurts when you do that, don't do that!' Especially in the case of towers, just don't do that. Charlie (Your issue is not an uncommon problem within a few miles of high power transmitters, as someone else has said.) --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 10 ____________________________________ Time: 09:35:40 AM PST US Subject: AeroElectric-List: Re: Radio or Television Tower Buzz From: "mike>bentley" We have several towers in the vicinity of our airport. It can be occasionally annoying depending on the direction you're going to or coming from. -------- Mike Bentley Joplin, MO N5498B Kitfox Model 4-1200 Jabiru 2200 #438 Rotec Aerosport LCH Heads Prince Prop (64 x 34) Ellison EFS-2 Throttle Body Read this topic online here: http://forums.matronics.com/viewtopic.php?p=480251#480251 ________________________________ Message 11 ____________________________________ Time: 09:43:01 AM PST US From: FLYaDIVE Subject: Re: AeroElectric-List: Radio or Television Tower Buzz Mike: Very Interesting.... Our plane radios transmit and receive in AM. TV video is AM while their audio is FM. AM land based radio shows are at a frequency well, well below our aviation frequencies. So... Something else must be happening if you are receiving and Hearing Voices. I can understand static and buzzing, just not the voices? Start Simple and work up from their. Simple: Check the GROUNDS on your radios and antennas. You CANNOT check Grounds by LQQKing at them. You MUST open the connection, Clean the connection and replace or ADD (if missing) an Internal Star Washer, then Tighten the connection. Getting a bit more complicated you can build a Band Pass Filter. This would work if the interference was a few harmonics away from from our frequencies. If you can: Drive to the radio/TV stations and bring a Hand Held aviation radio and see if you can hear them when right next to them. You - May even talk to the station engineer. And as a last resort, report the station to the FCC. BUT Only if your test with the Hand Held proves true. Barry On Sun, May 20, 2018 at 11:33 AM, mike>bentley wrote: > mikeeeb@gmail.com> > > When flying in the vicinity of radio or TV towers, I get a constant buzz > or static over the radio. Sometimes I can hear the conversation or music > from the station, but just barely. It seems to start when I'm within a 1/2 > to 1/4 mile from a tower. > > Anyone else have this type of issue or resolved this type of issue? > > -------- > Mike Bentley > Joplin, MO > N5498B > Kitfox Model 4-1200 > Jabiru 2200 #438 > Rotec Aerosport LCH Heads > Prince Prop (64 x 34) > Ellison EFS-2 Throttle Body > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=480244#480244 > > ________________________________ Message 12 ____________________________________ Time: 09:47:58 AM PST US Subject: Re: AeroElectric-List: Re: Radio or Television Tower Buzz From: Kelly McMullen I don't know if you would gain improvement or not, but generally I like to have at least 2 ft between com antennas, more if I can get it. The ELT is in same frequency spectrum as com, so interaction is mostly a function of distance. Before doing anything, the easy test is to simply disconnect the antenna cable from the ELT and go fly near the offending towers. You will know right away if the problem is reduced or not. Your com radio(s) may be interfered with independent of the ELT. Most broadcast towers are close in frequency, either below or above the com frequency band. On 5/20/2018 9:15 AM, mike>bentley wrote: > > Thanks Kelly, > > I have a 406mhz elt with the antenna mounted inside the fuselage and comm antenna mounted on top of the fuselage. The elt antenna is approximately 18" below and 12" forward of the comm antenna. The elt antenna is much easier to relocate than the comm. Would moving the elt antenna farther away help? > > -------- > Mike Bentley > Joplin, MO > N5498B > Kitfox Model 4-1200 > Jabiru 2200 #438 > Rotec Aerosport LCH Heads > Prince Prop (64 x 34) > Ellison EFS-2 Throttle Body > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=480249#480249 > > > > > > > > > ________________________________ Message 13 ____________________________________ Time: 10:48:58 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: New toy . . . For those of you who suffer from quantitative OCD like I do, there is a class of measurement tool that has trickled down in price to where us po' folk can afford them. GPS disciplined signal sources can exploit the extra-ordinary time-keeping features of the GPS system to produce accurate reference signals with accuracies/stabilities out to a buckets-full-of-zeros. https://goo.gl/B4hqTm I've been eyeing these for several years but finally yielded to temptation with this puppy on eBay https://goo.gl/zVviDZ With this device driving the 10MHz reference port on my 40 year old HP signal generator, proving legality of the radios on our emergency services hand-helds and trucks is a no-brainer. You may have to mount an antenna outside your facility with good sky view . . . beyond that, these things are plug-n-play. Bob . . . ________________________________ Message 14 ____________________________________ Time: 12:09:50 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: VHF antenna in the tail A >The base of the antenna will be accessible via the tail cone >aperture, and crawling into the fuselage will permit limited access. >I was considering installing the radiating element in a plastic tube >in the fin, so that the antenna may be easily inserted and removed. > >Any suggestions as to how to devise a reasonably efficient comm >antenna in the tail ? Assuming my mental image of your configuration is accurate, consider the following. Terminating the antenna coax in a BNC cable connector. Then use a BNC chassis connector to make the mechanical transition to the antenna and "ground planes". The radiating portion of the antenna obviously needs to extend up the tube. I'd go for a chunk of RG400 with the outer jacket and removed from about 2" of the 'antenna' segment. http://www.aeroelectric.com/articles/Antennas/TailCone_Antenna/ Push shields back hard exposing center conductor http://www.aeroelectric.com/articles/Antennas/TailCone_Antenna/ Cut off center conductor http://www.aeroelectric.com/articles/Antennas/TailCone_Antenna/ Stretch the braids out and 'tin' the last 1/4" or so with solder. http://www.aeroelectric.com/articles/Antennas/TailCone_Antenna/ Mount chassis BNC connector to 'ground plane'. Suggest copper sheet, 1/2" minimum to as wide as you can fit into the tail cone. The chassis connector can be spot-soldered to copper sheet. http://www.aeroelectric.com/articles/Antennas/TailCone_Antenna/ Repeat on opposite side . . . http://www.aeroelectric.com/articles/Antennas/TailCone_Antenna/ If copper sheet is not readily available, aluminum can be used. If the aluminum option is selected, use the star-washer supplied with the connector to improve electrical interface with the ground-plane. The 'radials' are 1/4-wave (24") extending forward on each side of tailcone. http://www.aeroelectric.com/articles/Antennas/TailCone_Antenna/ If you have access to an antenna analyzer (MFJ259 or similar), you can survey the installed antenna for resonance. I suspect you'll find that it resonates a bit low in frequency due to proximity effects of the rudder post. Trim antenna 1/4" at a time until SWR minimizes at 126.5 MHz. If post installation evaluation is impractical or impossible, then shorten the antenna by about 5% . . . make it 23 inches. Does this look 'doable' on your project? The photos above have been posted at . . . https://goo.gl/9NaAK1 Bob . . . ________________________________ Message 15 ____________________________________ Time: 01:31:32 PM PST US Subject: AeroElectric-List: Re: VHF antenna in the tail From: "user9253" Bob, it is not clear from the photo, but is the 23" antenna braid soldered to the center pin on the BNC chassis connector? I assume coax is used for the radiating element instead of a wire because the coax is fatter and will give a wider bandwidth than, say, a 14 awg wire. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=480260#480260 ________________________________ Message 16 ____________________________________ Time: 02:58:51 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: VHF antenna in the tail At 03:30 PM 5/20/2018, you wrote: > >Bob, it is not clear from the photo, but is the 23" antenna braid >soldered to the center pin on the BNC chassis connector? Yes. The center conductor in the radiator is not a participant in the design. > I assume coax is used for the radiating element instead of a wire > because the coax is fatter and will give a wider bandwidth than, > say, a 14 awg wire. The design goal is to make a flexure-resistant connection between the connector and the radiator. The dual-shield configuration on RG400 offers an attractive solution for achieving this goal . . . leaving it 1/4-wave long finishes out the radiator with a single soldered joint. Bob . . . ________________________________ Message 17 ____________________________________ Time: 02:59:20 PM PST US From: "Peter Pengilly" Subject: RE: AeroElectric-List: VHF antenna in the tail Have you considered one of these? http://www.dolba.de/antennenloesungen/funk-antenne-bd5/ Fitted to many German gliders, bonded to the fin structure, most how have glass fiber fins to allow VHF, txpdr & flarm antennas all to be hidden inside. Peter From: owner-aeroelectric-list-server@matronics.com On Behalf Of GTH Sent: 20 May 2018 12:43 Subject: Re: AeroElectric-List: VHF antenna in the tail Le 23/12/2017 =E0 01:26, Robert L. Nuckolls, III a =E9crit : Can you describe the physical configuration of the vertical fin vis-a-vis the empennage? Is the vertical fin detachable? I presume the antenna, once installed, will forever more be inaccessible for tweeking? Hi Bob and all, Reviving the antenna-in-tail subject, as the project fuselage is now assembled. Bob mentionned a promising "bazooka" configuration for the antenna, as the tail is too narrow to allow for a regular ground plane. Here are some answers to your questions : The entire fuselage is carbon. The vertical fin is integral with the fuselage but is made of glass for the installation of the antenna. The fin height is ~ 0.9 m (35") while the carbon tail at the base is only 0.18 m (7") wide. The base of the antenna will be accessible via the tail cone aperture, and crawling into the fuselage will permit limited access. I was considering installing the radiating element in a plastic tube in the fin, so that the antenna may be easily inserted and removed. Any suggestions as to how to devise a reasonably efficient comm antenna in the tail ? Thanks in advance, -- Best regards, Gilles http://contrails.free.fr http://lapierre.skunkworks.free.fr ________________________________ Message 18 ____________________________________ Time: 04:32:22 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: VHF antenna in the tail At 04:57 PM 5/20/2018, you wrote: >Have you considered one of these? > >http://www.dolba.de/antennenloesungen/funk-antenne-bd5/ > >Fitted to many German gliders, bonded to the fin structure, most how >have glass fiber fins to allow VHF, txpdr & flarm antennas all to be >hidden inside. > >Peter Do you know anyone who has installed this antenna on an OBAM aircraft? It's not clear from the image just how it installs. The website had no links to installation manuals that I could find. The SWR plot is impressive . . . but SWR and efficiency are two separate things. I've dropped them an email requesting more details. Bob . . . ________________________________ Message 19 ____________________________________ Time: 04:43:32 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Radio or Television Tower Buzz At 10:33 AM 5/20/2018, you wrote: > >When flying in the vicinity of radio or TV towers, I get a constant >buzz or static over the radio. Sometimes I can hear the conversation >or music from the station, but just barely. It seems to start when >I'm within a 1/2 to 1/4 mile from a tower. > >Anyone else have this type of issue or resolved this type of issue? Seen this and similar situations many times in the past. Powerful transmitters are strong potential interference sources. Effects are many and varied. Used to rent a Beech B77 at Mid Continent that would treat me to a 'buzz' in the headsets while awaiting clearance at the south end of 1R. The hold pad was about 100 yards from the ATC antenna dish. Every time the antenna swept around, you'd hear a buzz-burst at the PRF for the radar transmitter. Sometimes you hear a similar buzz-burst from a transponder reply when the antenna coax shield is broken and the leakage is radiating the cabin. Another rental a/p would drift off track if my LOC intercept path took me past the television stations antenna farm NW of KICT. After passage, the a/p would recover and correctly nail the intercept. Those transmitters have really BIG radiated power numbers . . . sometimes 200,000 watts. Since the effects are inversely proportional to square of distance from the source, they usually go away if you're more than a couple miles from the antenna. Best fix . . . fly around it . . . or simply be aware of it and turn the volume down until you are past it. Bob . . . ------------------------------------------------------------------------------------- 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.