Picking up ATC from 300 NM away? Frequency bleed?

Last night while flying from Teterboro, New Jersey up to Ithaca, NY, I was
talking to Bingamton approach (located in south central NY state) and
cruising at 8,000 ft.

On the frequency there were several calls from aircraft but not one was
answered by ATC. At first I thought the controller was missing the calls,
but then I heard one of the calls quite clearly: "Akron-Canton Approach,
this is ..." Akron-Canton is located in Ohio, about 300 NM away from my
position and sure enough, they share the same frequency as Binghamton
approach.

After mentioning the call to the controller, he responded that there had
been some complaints of what he called "frequency bleed" the last few days.

Is this pretty common? What causes it?

--
Peter

"Peter R." wrote in message
s.com...

Last night while flying from Teterboro, New Jersey up to Ithaca, NY, I was
talking to Bingamton approach (located in south central NY state) and
cruising at 8,000 ft.

On the frequency there were several calls from aircraft but not one was
answered by ATC. At first I thought the controller was missing the calls,
but then I heard one of the calls quite clearly: "Akron-Canton Approach,
this is ..." Akron-Canton is located in Ohio, about 300 NM away from my
position and sure enough, they share the same frequency as Binghamton
approach.

After mentioning the call to the controller, he responded that there had
been some complaints of what he called "frequency bleed" the last few
days.

Is this pretty common? What causes it?


Frequency lacerations.

Peter

I used to know the proper description for this, but I'm a bit rusty on
amateur radio now. Basically what happens is that in mid summer, under the
influence if intense solar radiation the MUF (maximum upper frequency) which
can be reflected of the ionosphere increases. It can reach such high levels
that signals at the 120-160Mhz level can be reflected back down to earth
(normally they would go straight out into space) and can then be heard by
people a considerable distance away.

You can imagine a signal leaving an antenna and heading out towards the
horizon at a small angle of attack. At some point it strikes the ionised
layer in the upper atmosphere and is reflected back down to earth. By the
time it gets down low, it is a considerable distance from the transmitter.
This process can be repeated several times, with the signal alternatively
being reflected off the ground/surface (particularly over water) and the
upper atmosphere and the records (with appropriate equipment and dedication)
go into thousands of miles.

Keith

"Peter R." schrieb im Newsbeitrag
s.com...
Last night while flying from Teterboro, New Jersey up to Ithaca, NY, I was
talking to Bingamton approach (located in south central NY state) and
cruising at 8,000 ft.

On the frequency there were several calls from aircraft but not one was
answered by ATC. At first I thought the controller was missing the calls,
but then I heard one of the calls quite clearly: "Akron-Canton Approach,
this is ..." Akron-Canton is located in Ohio, about 300 NM away from my
position and sure enough, they share the same frequency as Binghamton
approach.

After mentioning the call to the controller, he responded that there had
been some complaints of what he called "frequency bleed" the last few
days.

Is this pretty common? What causes it?

--
Peter

I believe it is called ducting. It is caused by a temperature inversion and typically affects VHF frequencies.

Mike Z


"Peter R." wrote in message s.com...
Last night while flying from Teterboro, New Jersey up to Ithaca, NY, I was
talking to Bingamton approach (located in south central NY state) and
cruising at 8,000 ft.

On the frequency there were several calls from aircraft but not one was
answered by ATC. At first I thought the controller was missing the calls,
but then I heard one of the calls quite clearly: "Akron-Canton Approach,
this is ..." Akron-Canton is located in Ohio, about 300 NM away from my
position and sure enough, they share the same frequency as Binghamton
approach.

After mentioning the call to the controller, he responded that there had
been some complaints of what he called "frequency bleed" the last few days.

Is this pretty common? What causes it?

--
Peter

"Peter R." wrote:
Is this pretty common? What causes it?

Around Mobile we can frequently hear aircraft calling Tampa approach
on our Downtown Airport tower frequency, 118.8. When atmospheric
conditons are right, VHF signals can "skip" a long way. TPA is over
300nm from BFM.
--
Dan
C172RG at BFM

"Peter R." wrote in message
s.com...
Last night while flying from Teterboro, New Jersey up to Ithaca, NY, I was
talking to Bingamton approach (located in south central NY state) and
cruising at 8,000 ft.

On the frequency there were several calls from aircraft but not one was
answered by ATC. At first I thought the controller was missing the calls,
but then I heard one of the calls quite clearly: "Akron-Canton Approach,
this is ..." Akron-Canton is located in Ohio, about 300 NM away from my
position and sure enough, they share the same frequency as Binghamton
approach.

After mentioning the call to the controller, he responded that there had
been some complaints of what he called "frequency bleed" the last few
days.

Is this pretty common? What causes it?

--
Peter



This is most likely troposphere ducting. This summer has been very good for
VHF propagation. I have in the ham radio bands (144MHz) made contacts from
my home in Illinois all the way out to Vancouver and east to New Hampshire.
Granted the Vancouver contact was not through the ducting mode as I
mentioned before but through meteor scatter. In that mode we actually bounce
radio waves off the ion trail of meteor entering the atmosphere. On some of
the lower frequencies (50MHz close to TV channel 2) it has been possible to
make very long haul comms with small amounts of power on an almost daily
basis.

'Frequency bleed' is a non-sensical term and has no real meaning other than
something laymen would use to describe an observation they do not understand

Hope that helps without getting to technical.
--
-------------------------------------
Scott F. Migaldi, K9PO
MI-150972
PP-ASEL
-----------------------------------
Catch the wave!
www.hamwave.com

http://groups.yahoo.com/group/PADI-Instructors/join

**"A long time ago being crazy meant something, nowadays everyone is
crazy" -- Charles Manson**
-------------------------------------

On Wed, 20 Aug 2003 22:09:58 +0200, "Keith Olivier"
wrote:

Peter

I used to know the proper description for this, but I'm a bit rusty on
amateur radio now. Basically what happens is that in mid summer, under the
influence if intense solar radiation the MUF (maximum upper frequency) which
can be reflected of the ionosphere increases. It can reach such high levels
that signals at the 120-160Mhz level can be reflected back down to earth
(normally they would go straight out into space) and can then be heard by
people a considerable distance away.

Back in the CB radio craze days of the 1970's this phenominon was
called "skip" from the signal "skipping" off the ionosphere and
travelling in a reflected angle path instead of line-of-sight.

Peter....
Consider..... Could have been simple line of sight. Just how close to
Binghamton were you? If you were anywhere close, southeast, then you were
about 260 or 270NM from the A/C airport. You were at 8000, so roughly 105
to the horizon. Another aircraft at 8 or 10,000, located southeast of
Meadville PA and trying to call Akron could have been in a position such
that you and Akron could BOTH have heard him. Unusual coincidence, but
possible.

JG

"Peter R." wrote in message
s.com...
Last night while flying from Teterboro, New Jersey up to Ithaca, NY, I was
talking to Bingamton approach (located in south central NY state) and
cruising at 8,000 ft.

I did CB from a mountain top in NH to a guy in the FL keys doing that one
day.. either that or he was pulling more than my leg...

very rare.. in the CB band

BT

"Neal" wrote in message
...
On Wed, 20 Aug 2003 22:09:58 +0200, "Keith Olivier"
wrote:

Peter

I used to know the proper description for this, but I'm a bit rusty on
amateur radio now. Basically what happens is that in mid summer, under
the
influence if intense solar radiation the MUF (maximum upper frequency)
which
can be reflected of the ionosphere increases. It can reach such high
levels
that signals at the 120-160Mhz level can be reflected back down to earth
(normally they would go straight out into space) and can then be heard by
people a considerable distance away.

Back in the CB radio craze days of the 1970's this phenominon was
called "skip" from the signal "skipping" off the ionosphere and
travelling in a reflected angle path instead of line-of-sight.

Howdy!

In article T5U0b.5844$Qy4.2599@fed1read05,
BTIZ wrote:
it's called "ducting" or "skip".. ducting is more prevalent with radars..
especially over water.. and skip is more prevalent with lower frequencies..
not normally VHF ATC frequency bands..

Yep. Two meter HAM stuff (144 MhZ) can also be ducted by certain meterological
conditions (IIRC something about a trough).

Not common, but certainly possible.

yours,
Michael


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| White Wolf and the Phoenix
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