Our club repeater also ended up interfering with the local tower.

It seems that the transmitter PLL was unstable, and "hopping" between that
frequency, and ours.
We were clearly audible in their recordings.

Ouch. That'd be categorized as a "double-plus ungood" for certain!

Lest any "experts" step in and claim that you can't receive FM on an AM
receiver, I'd ask them to consider what effect the passband filter of the AM
receiver's IF might have on the FM signal as it deviates from side to
side....

I believe the magic words are "slope detection". The resulting audio
on the AM receiver isn't great (it's often distorted) but it's
certainly there.

I hit the magic codes and took the repeater down, once we determined that
this was indeed the source.

A re-tweak of the transmit PLL, and a stub filter cut to pass 146.730 and
reject the tower frequency, cured the problem, and insured that if it ever
happens again, they probably won't hear us. The tower now has our phone
numbers in their books, in case there is ever another problem. The tower
complimented our rapid and assertive handling of the problem in their
closing letter to the FCC.

Well done!

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Dave Bushong wrote:

[Dramatic generalization mode on]
Nearly all aircraft accidents are caused by a series of unlikely
events all happening together, none of which by itself would be
a problem.
[Dramatic generalization mode off]

Nice sweeping piece of dis-information there buddy.

How about this: Nearly all aircraft accidents are caused by a single
failure in a single component or a single failure to do something.
Pitot tubes that are taped over. Fuel tanks that explode. Structural
failure that causes entire pieces of fuselage to peel off while in
flight. Fuel leaks that turn large jets into gliders. Cabin fires
caused by the overload of a single wire powering the entertainment
system. Air pressure equalization valves that bleed cabin air
rendering the occupants unconscious and results in a ghost plane
flying thousands of miles before crashing. Failure to de-ice.
Overloading resulting in stalling upon take-off. Failure to secure
cargo upon takeoff. Being struck in the fuel tank by a piece of
debris on the runway kicked up by the tires. An engine ingesting a
flock of birds. A shipment of improperly-disarmed oxygen generators
placed in the cargo hold. Lack of proper lubrication of tail
jack-screws. Tail fins that are not as strongly connected to the
fuselage as they should be. Need I continue?

A series of events will surely happen AFTER any of those incidents,
none of which are either unlikely or unexpected, and by and large
would have no effect on the outcome.

Will the in-flight use of an FM radio EVER cause a plane to run out of
fuel? Or cause a sudden ice build-up on the wings? Or blow out a
tire upon landing? Or an overload of the electrical system leading to
a fire? Will the feeble RF emitted by the LO even be detectable
OUTSIDE the plane, where the plane's antennas are located?

If you read the various documents on the web relating to issues of
in-flight use of PED's (personal electronic devices) it's clear that

1) The FAA and NTSB are either negligent or a bunch of cowards for not
forcing the AIRCRAFT MANUFACTURERS to determine the level of
susceptibility of their planes to PED's. Instead the issue is pawned
off to the aircraft operators when logically it should be the airplane
makers!

2) The use of cell phones (analog and perhaps more frequently GSM)
seems to have the most influence of any PED. The next most frequent
culprit seems to be laptop computers.

3) No incidence of communication failure or disruption seems to have
ever been documented by a passenger's FM radio receiver.

4) MANY MANY incidences of navigation equipment errors caused by
improper installation / connection of the equipment, or interference
caused by one of the plane's other systems where these were first
attributed to a PED.

5) Planes have to fly near high-power commercial radio and TV
transmission towers. They fly through the beams of powerful radar
signals. They get struck by lightning. There are those that say that
for a (commercial jet) to be certified there is no way that a
certified plane could be susceptible to the stray RF given off by
PED's (at least PED's that are non-intentional radiators).

6) The authorities would probably not admit it, but the ban or
restrictions on PED use in planes probably has more to do with
insurance/liability reasons, or passenger distraction reasons, than it
does for technical (interference) reasons.

PED's are here to stay. There will be more of them, and people will
use them wherever they are. It makes just as much sense to ban them
or perform half-ass on-board supervision on a plane for these devices
as it is to ban them from cars. PED's used cars cause injury and
death each year (due to driver in-attention). Instead of banning
radios, phones, and entertainment systems in cars, they instead come
from the factory with them installed! Where's your crusade against
that situation? Where are your dire warnings here?

Would you want to add one more "unlikely event" to your next
flight?

Nothing caused by or brought on board by a passenger (short of
alcohol, a gun, a bomb, or otherwise a strong intent to do harm) will
or has ever caused anything bad to happen on a plane or to a plane.
No gun ever brought on board (and there have been MANY!) has ever
discharged. No can of hairspray has ever exploded in the cargo hold.

There is relatively little variety in the types, makes or models of
commercial airplanes flying today. There is a high degree of
uniformity in construction of these vehicles. There have been
millions of flights over the past, say 20 years. There have been many
hundred million passengers carried by these planes. There surely has
been ample opportunity for all sorts of PED's to be used on these
planes (surreptitiously or with consent). If any particular plane
model (or even specific plane) had a systemic or inherent
susceptibility to a PED, it would have been recognized by now.

Amen!
"Some Guy" wrote in message ...
Dave Bushong wrote:

[Dramatic generalization mode on]
Nearly all aircraft accidents are caused by a series of unlikely
events all happening together, none of which by itself would be
a problem.
[Dramatic generalization mode off]

Nice sweeping piece of dis-information there buddy.

How about this: Nearly all aircraft accidents are caused by a single
failure in a single component or a single failure to do something.
Pitot tubes that are taped over. Fuel tanks that explode. Structural
failure that causes entire pieces of fuselage to peel off while in
flight. Fuel leaks that turn large jets into gliders. Cabin fires
caused by the overload of a single wire powering the entertainment
system. Air pressure equalization valves that bleed cabin air
rendering the occupants unconscious and results in a ghost plane
flying thousands of miles before crashing. Failure to de-ice.
Overloading resulting in stalling upon take-off. Failure to secure
cargo upon takeoff. Being struck in the fuel tank by a piece of
debris on the runway kicked up by the tires. An engine ingesting a
flock of birds. A shipment of improperly-disarmed oxygen generators
placed in the cargo hold. Lack of proper lubrication of tail
jack-screws. Tail fins that are not as strongly connected to the
fuselage as they should be. Need I continue?

A series of events will surely happen AFTER any of those incidents,
none of which are either unlikely or unexpected, and by and large
would have no effect on the outcome.

Will the in-flight use of an FM radio EVER cause a plane to run out of
fuel? Or cause a sudden ice build-up on the wings? Or blow out a
tire upon landing? Or an overload of the electrical system leading to
a fire? Will the feeble RF emitted by the LO even be detectable
OUTSIDE the plane, where the plane's antennas are located?

If you read the various documents on the web relating to issues of
in-flight use of PED's (personal electronic devices) it's clear that

1) The FAA and NTSB are either negligent or a bunch of cowards for not
forcing the AIRCRAFT MANUFACTURERS to determine the level of
susceptibility of their planes to PED's. Instead the issue is pawned
off to the aircraft operators when logically it should be the airplane
makers!

2) The use of cell phones (analog and perhaps more frequently GSM)
seems to have the most influence of any PED. The next most frequent
culprit seems to be laptop computers.

3) No incidence of communication failure or disruption seems to have
ever been documented by a passenger's FM radio receiver.

4) MANY MANY incidences of navigation equipment errors caused by
improper installation / connection of the equipment, or interference
caused by one of the plane's other systems where these were first
attributed to a PED.

5) Planes have to fly near high-power commercial radio and TV
transmission towers. They fly through the beams of powerful radar
signals. They get struck by lightning. There are those that say that
for a (commercial jet) to be certified there is no way that a
certified plane could be susceptible to the stray RF given off by
PED's (at least PED's that are non-intentional radiators).

6) The authorities would probably not admit it, but the ban or
restrictions on PED use in planes probably has more to do with
insurance/liability reasons, or passenger distraction reasons, than it
does for technical (interference) reasons.

PED's are here to stay. There will be more of them, and people will
use them wherever they are. It makes just as much sense to ban them
or perform half-ass on-board supervision on a plane for these devices
as it is to ban them from cars. PED's used cars cause injury and
death each year (due to driver in-attention). Instead of banning
radios, phones, and entertainment systems in cars, they instead come
from the factory with them installed! Where's your crusade against
that situation? Where are your dire warnings here?

Would you want to add one more "unlikely event" to your next
flight?

Nothing caused by or brought on board by a passenger (short of
alcohol, a gun, a bomb, or otherwise a strong intent to do harm) will
or has ever caused anything bad to happen on a plane or to a plane.
No gun ever brought on board (and there have been MANY!) has ever
discharged. No can of hairspray has ever exploded in the cargo hold.

There is relatively little variety in the types, makes or models of
commercial airplanes flying today. There is a high degree of
uniformity in construction of these vehicles. There have been
millions of flights over the past, say 20 years. There have been many
hundred million passengers carried by these planes. There surely has
been ample opportunity for all sorts of PED's to be used on these
planes (surreptitiously or with consent). If any particular plane
model (or even specific plane) had a systemic or inherent
susceptibility to a PED, it would have been recognized by now.

"Some Guy" wrote in message ...
Dave Bushong wrote:

[Dramatic generalization mode on]
Nearly all aircraft accidents are caused by a series of unlikely
events all happening together, none of which by itself would be
a problem.
[Dramatic generalization mode off]

Nice sweeping piece of dis-information there buddy.

How about this: Nearly all aircraft accidents are caused by a single
failure in a single component or a single failure to do something.
Pitot tubes that are taped over. Fuel tanks that explode. Structural

What is a Pitot tube anyway? I have seen a switch for most aircraft
in Flight Simulator marked "Pitot Heat", what is that?

Lots of data, not much information. No cites given.

Angry crap.

Some Guy wrote:
Dave Bushong wrote:

[Dramatic generalization mode on]

Nearly all aircraft accidents are caused by a series of unlikely
events all happening together, none of which by itself would be
a problem.

[Dramatic generalization mode off]

Nice sweeping piece of dis-information there buddy.

How about this: Nearly all aircraft accidents are caused by a single
failure in a single component or a single failure to do something.
Pitot tubes that are taped over. Fuel tanks that explode. Structural
failure that causes entire pieces of fuselage to peel off while in
flight. Fuel leaks that turn large jets into gliders. Cabin fires
caused by the overload of a single wire powering the entertainment
system. Air pressure equalization valves that bleed cabin air
rendering the occupants unconscious and results in a ghost plane
flying thousands of miles before crashing. Failure to de-ice.
Overloading resulting in stalling upon take-off. Failure to secure
cargo upon takeoff. Being struck in the fuel tank by a piece of
debris on the runway kicked up by the tires. An engine ingesting a
flock of birds. A shipment of improperly-disarmed oxygen generators
placed in the cargo hold. Lack of proper lubrication of tail
jack-screws. Tail fins that are not as strongly connected to the
fuselage as they should be. Need I continue?

A series of events will surely happen AFTER any of those incidents,
none of which are either unlikely or unexpected, and by and large
would have no effect on the outcome.

Will the in-flight use of an FM radio EVER cause a plane to run out of
fuel? Or cause a sudden ice build-up on the wings? Or blow out a
tire upon landing? Or an overload of the electrical system leading to
a fire? Will the feeble RF emitted by the LO even be detectable
OUTSIDE the plane, where the plane's antennas are located?

If you read the various documents on the web relating to issues of
in-flight use of PED's (personal electronic devices) it's clear that

1) The FAA and NTSB are either negligent or a bunch of cowards for not
forcing the AIRCRAFT MANUFACTURERS to determine the level of
susceptibility of their planes to PED's. Instead the issue is pawned
off to the aircraft operators when logically it should be the airplane
makers!

2) The use of cell phones (analog and perhaps more frequently GSM)
seems to have the most influence of any PED. The next most frequent
culprit seems to be laptop computers.

3) No incidence of communication failure or disruption seems to have
ever been documented by a passenger's FM radio receiver.

4) MANY MANY incidences of navigation equipment errors caused by
improper installation / connection of the equipment, or interference
caused by one of the plane's other systems where these were first
attributed to a PED.

5) Planes have to fly near high-power commercial radio and TV
transmission towers. They fly through the beams of powerful radar
signals. They get struck by lightning. There are those that say that
for a (commercial jet) to be certified there is no way that a
certified plane could be susceptible to the stray RF given off by
PED's (at least PED's that are non-intentional radiators).

6) The authorities would probably not admit it, but the ban or
restrictions on PED use in planes probably has more to do with
insurance/liability reasons, or passenger distraction reasons, than it
does for technical (interference) reasons.

PED's are here to stay. There will be more of them, and people will
use them wherever they are. It makes just as much sense to ban them
or perform half-ass on-board supervision on a plane for these devices
as it is to ban them from cars. PED's used cars cause injury and
death each year (due to driver in-attention). Instead of banning
radios, phones, and entertainment systems in cars, they instead come
from the factory with them installed! Where's your crusade against
that situation? Where are your dire warnings here?


Would you want to add one more "unlikely event" to your next
flight?


Nothing caused by or brought on board by a passenger (short of
alcohol, a gun, a bomb, or otherwise a strong intent to do harm) will
or has ever caused anything bad to happen on a plane or to a plane.
No gun ever brought on board (and there have been MANY!) has ever
discharged. No can of hairspray has ever exploded in the cargo hold.

There is relatively little variety in the types, makes or models of
commercial airplanes flying today. There is a high degree of
uniformity in construction of these vehicles. There have been
millions of flights over the past, say 20 years. There have been many
hundred million passengers carried by these planes. There surely has
been ample opportunity for all sorts of PED's to be used on these
planes (surreptitiously or with consent). If any particular plane
model (or even specific plane) had a systemic or inherent
susceptibility to a PED, it would have been recognized by now.

Pitot tube at URL;
http://www.grc.nasa.gov/WWW/K-12/airplane/pitot.html

Re Pitot Heat -- see URL:
http://www.allstar.fiu.edu/aero/PSSI.htm


Sez
The system shown employs a heated pitot tube to prevent ice formation, a
necessary feature for flight in instrument conditions.
--
ID with held to protect the innocent



What is a Pitot tube anyway? I have seen a switch for most aircraft
in Flight Simulator marked "Pitot Heat", what is that?

"Dave Bushong" wrote:

Nearly all aircraft accidents are caused by a series of unlikely
events
all happening together, none of which by itself would be a problem.

I'll bet there's no record of a U.S. airline accident caused by faulty
navigation equipment for any reason, or at least excluding maybe the
early years. General aviation, yes.

Would you want to add one more "unlikely event" to your next
flight?

I have no problem with any airline with a flat "no" policy on this,
because things do happen even if rarely. NASA gathers the PED
incident data, and over a 14-year period, there have been less than
100 events, mostly in cruise, most not classed as potentially serious.
The reason they were reported is because the equipment told the pilot
about it, and often ATC did so too. Also, NASA has to take the
pilot's word for it that the anomaly was caused by a PED.

Fred F.

Dave, try these:

Boeing has investigated alleged interference from portable electronic
devices (PEDs) and concluded:

"As a result of these and other investigations, Boeing has not been able
to find a definite correlation between PEDs and the associated reported
airplane anomalies."

You can look this up at:

http://www.boeing.com/commercial/aer..._textonly.html
Aero 10 - Interference from Electronic Devices

Here's another one:

http://www.rvs.uni-bielefeld.de/publ...ticle/EMI.html
Electromagnetic interference with aircraft systems


Dave Bushong wrote:
Lots of data, not much information. No cites given.

Angry crap.

Some Guy wrote:

Dave Bushong wrote:

[Dramatic generalization mode on]

Nearly all aircraft accidents are caused by a series of unlikely
events all happening together, none of which by itself would be
a problem.


[Dramatic generalization mode off]

Nice sweeping piece of dis-information there buddy.

How about this: Nearly all aircraft accidents are caused by a single
failure in a single component or a single failure to do something.
Pitot tubes that are taped over. Fuel tanks that explode. Structural
failure that causes entire pieces of fuselage to peel off while in
flight. Fuel leaks that turn large jets into gliders. Cabin fires
caused by the overload of a single wire powering the entertainment
system. Air pressure equalization valves that bleed cabin air
rendering the occupants unconscious and results in a ghost plane
flying thousands of miles before crashing. Failure to de-ice.
Overloading resulting in stalling upon take-off. Failure to secure
cargo upon takeoff. Being struck in the fuel tank by a piece of
debris on the runway kicked up by the tires. An engine ingesting a
flock of birds. A shipment of improperly-disarmed oxygen generators
placed in the cargo hold. Lack of proper lubrication of tail
jack-screws. Tail fins that are not as strongly connected to the
fuselage as they should be. Need I continue?

A series of events will surely happen AFTER any of those incidents,
none of which are either unlikely or unexpected, and by and large
would have no effect on the outcome.

Will the in-flight use of an FM radio EVER cause a plane to run out of
fuel? Or cause a sudden ice build-up on the wings? Or blow out a
tire upon landing? Or an overload of the electrical system leading to
a fire? Will the feeble RF emitted by the LO even be detectable
OUTSIDE the plane, where the plane's antennas are located?

If you read the various documents on the web relating to issues of
in-flight use of PED's (personal electronic devices) it's clear that

1) The FAA and NTSB are either negligent or a bunch of cowards for not
forcing the AIRCRAFT MANUFACTURERS to determine the level of
susceptibility of their planes to PED's. Instead the issue is pawned
off to the aircraft operators when logically it should be the airplane
makers!

2) The use of cell phones (analog and perhaps more frequently GSM)
seems to have the most influence of any PED. The next most frequent
culprit seems to be laptop computers.

3) No incidence of communication failure or disruption seems to have
ever been documented by a passenger's FM radio receiver.

4) MANY MANY incidences of navigation equipment errors caused by
improper installation / connection of the equipment, or interference
caused by one of the plane's other systems where these were first
attributed to a PED.

5) Planes have to fly near high-power commercial radio and TV
transmission towers. They fly through the beams of powerful radar
signals. They get struck by lightning. There are those that say that
for a (commercial jet) to be certified there is no way that a
certified plane could be susceptible to the stray RF given off by
PED's (at least PED's that are non-intentional radiators).

6) The authorities would probably not admit it, but the ban or
restrictions on PED use in planes probably has more to do with
insurance/liability reasons, or passenger distraction reasons, than it
does for technical (interference) reasons.

PED's are here to stay. There will be more of them, and people will
use them wherever they are. It makes just as much sense to ban them
or perform half-ass on-board supervision on a plane for these devices
as it is to ban them from cars. PED's used cars cause injury and
death each year (due to driver in-attention). Instead of banning
radios, phones, and entertainment systems in cars, they instead come
from the factory with them installed! Where's your crusade against
that situation? Where are your dire warnings here?


Would you want to add one more "unlikely event" to your next
flight?



Nothing caused by or brought on board by a passenger (short of
alcohol, a gun, a bomb, or otherwise a strong intent to do harm) will
or has ever caused anything bad to happen on a plane or to a plane. No
gun ever brought on board (and there have been MANY!) has ever
discharged. No can of hairspray has ever exploded in the cargo hold.

There is relatively little variety in the types, makes or models of
commercial airplanes flying today. There is a high degree of
uniformity in construction of these vehicles. There have been
millions of flights over the past, say 20 years. There have been many
hundred million passengers carried by these planes. There surely has
been ample opportunity for all sorts of PED's to be used on these
planes (surreptitiously or with consent). If any particular plane
model (or even specific plane) had a systemic or inherent
susceptibility to a PED, it would have been recognized by now.

Well, I'll be flying to philly again tuesday.
My dualband HT goes in my breifcase, but with the battery detached during
flight.

TaxSrv wrote:
cabin. But has anybody ever heard a cabin announcement during flight
to turn off any devices?

Fred F.

YES.

I was on a flight from Toronto to Tampa a few years ago and somewhere
over the Carolinas the pilot came on the PA and calmly informed us they
have spent the last 45 mins trying to find the source of a buzzing noise
on their radios. (He also reinforced the fact that they were all still
working, but there was a buzzing noise on the audio.) He politely told
everyone to turn off any electronic devices they may be using. The
flight attendants quickly verified passenger compliance a few minutes
later. About 10 mins after that, he came on the PA to say it was gone
and instructed everyone to leave them off for the duration of the
flight, not that there was any danger, but it was distracting to have a
constant buzzing coming over the radio.

I did notice a couple of laptops had been fired up, but sitting in your
seat is not exactly an ideal vantage point to see what everyone else was
doing.

Do I think someone's radio is going to make the plane fall from the sky?
Of course not. Is there a remote possibility it could cause birdies or
other RF anomalies that 'could' affect things? Sure.

On one flight, a few years earlier still, WITH the ok from the flight
deck (you know, in those friendlier years when you could say 'hi'
through the open cockpit door when you were coming out of the bathroom)
I used my FT-470 handie for a few mins. The pilot knew what ham radio
was, knew I was going to be on UHF (because I told him that's where I
would try for a quick QSO) and he very politely said "Sure, but only for
5 minutes, then turn it off. What seat are you in?" I thanked him
kindly, returned to my window seat, and did manage to get into some
repeater in Maine for about a minute or two. The funny thing was he was
in the galley as we were getting off the plane, I thanked him again, and
he asked if I had any luck, I said 'yep' and asked him if I came over
anything up front. He smiled and said "Nope, and we were up there
looking to see if you would."

The purpose of my sharing this snippet from many years ago is not to
illustrate there's no danger in using a receiver (or in this case, a low
power transmitter) while on a plane, but using one does not
automatically imply you're going to write off the comm/nav systems.

My $.02