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
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| Subject: | Re: VHF antenna in the tail |
/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
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| Subject: | Re: 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 <gilles.thesee@free.fr> 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
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| Subject: | Re: 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 <gilles.thesee@free.fr> 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
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| Subject: | Re: VHF antenna in the tail |
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
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| Subject: | Radio or Television Tower Buzz |
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
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| Subject: | Re: 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
<http://www.aircraftspruce.com/search/search.php?cache=75660d9834ea34b12
fc9146878e6443b&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 <gilles.thesee@free.fr> 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.
<gljgacbhkillonjj.png>
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.
<jnklmjhabmdjcpkm.png><ckbakhooanognjlj.png>
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://contrails.free.fr/>
http://lapierre.skunkworks.free.fr <http://lapierre.skunkworks.free.fr/>
Message 7
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| Subject: | Radio or Television Tower Buzz |
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" <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=480245#480245
>
>
>
>
>
>
>
>
>
Message 8
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| Subject: | Re: Radio or Television Tower Buzz |
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
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| Subject: | Re: Radio or Television Tower Buzz |
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
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| Subject: | Re: Radio or Television Tower Buzz |
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
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| Subject: | Re: 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 <mikeeeb@gmail.com> 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
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| Subject: | Re: Radio or Television Tower Buzz |
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
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|
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
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| Subject: | Re: 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
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| Subject: | Re: VHF antenna in the tail |
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
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| Subject: | 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
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| Subject: | 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
<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
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| Subject: | 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/>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
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| Subject: | Re: 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 . . .
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