Is it 100% impossible to work a satellite below the horizon?
I was giving a presentation at our club meeting called Working DX on the Satellites and afterwards someone had a good question: is it at all possible that tropo, skip, or other form of enhanced propagation can enable a contact via a satellite below the horizon?
It has never happened to me. Has it ever happened?
73, Bill NZ5N
I work in radar and have seen radar go over the horizon
Sent from my iPhone Andrew Rich
On 13/03/2011, at 10:25, Bill Dzurilla [email protected] wrote:
I was giving a presentation at our club meeting called Working DX on the Satellites and afterwards someone had a good question: is it at all possible that tropo, skip, or other form of enhanced propagation can enable a contact via a satellite below the horizon?
It has never happened to me. Has it ever happened?
73, Bill NZ5N
Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
It might have happened before on some of the Mode K satellites, due to F2, but not sure if the other modes would work below the horizon, as getting the conditions right on both bands would be pretty tough. Tropo wouldn't get high enough into the air to get into the satellite. Has anyone heard AO7 in mode A when it is below your horizon due to F2 skip extending your range of the satelllite?
73s John AA5JG ----- Original Message ----- From: "Bill Dzurilla" [email protected] To: [email protected] Sent: Sunday, March 13, 2011 12:25 AM Subject: [amsat-bb] Is it 100% impossible to work a satellite below thehorizon?
I was giving a presentation at our club meeting called Working DX on the Satellites and afterwards someone had a good question: is it at all possible that tropo, skip, or other form of enhanced propagation can enable a contact via a satellite below the horizon?
It has never happened to me. Has it ever happened?
73, Bill NZ5N
Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
When the RF signal leaves the duct, it doesn't disappear. It keeps radiating in the direction that it was going, and can successfully reach any altitude appropriate for that line of propagation. The hard part, is then getting the return path (the downlink freq) to propagate with the same characteristics so that you can actually hear it. But, it is not impossible at all...
Gregg Wonderly W5GGW
On 3/12/2011 6:53 PM, John Geiger wrote:
It might have happened before on some of the Mode K satellites, due to F2, but not sure if the other modes would work below the horizon, as getting the conditions right on both bands would be pretty tough. Tropo wouldn't get high enough into the air to get into the satellite. Has anyone heard AO7 in mode A when it is below your horizon due to F2 skip extending your range of the satelllite?
73s John AA5JG ----- Original Message ----- From: "Bill Dzurilla"[email protected] To:[email protected] Sent: Sunday, March 13, 2011 12:25 AM Subject: [amsat-bb] Is it 100% impossible to work a satellite below thehorizon?
I was giving a presentation at our club meeting called Working DX on the Satellites and afterwards someone had a good question: is it at all possible that tropo, skip, or other form of enhanced propagation can enable a contact via a satellite below the horizon?
It has never happened to me. Has it ever happened?
73, Bill NZ5N
Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
It's quite common.
On 13-Mar-11 00:25, Bill Dzurilla wrote:
I was giving a presentation at our club meeting called Working DX on the Satellites and afterwards someone had a good question: is it at all possible that tropo, skip, or other form of enhanced propagation can enable a contact via a satellite below the horizon?
It has never happened to me. Has it ever happened?
73, Bill NZ5N
Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Hello Bill,
Simple answer is YES. The RS series were good examples. I am sure I have done it on FMsats.
Enhanced propagation can extend your range both before normal AOS and beyond LOS.
Most programs seem to only use "line of sight" (LOS) Az/El settings.
One difficulty is that satellite programs may not give you info on where you could talk to, for negative elevations. Only positive elevations. I would like to see tracking programs that could give me info for -10 degrees, not to track in elevation, but to track in azimuth.
One way to make that "elusive DX" QSO.
Stan, W1LE Cape Cod FN41sr
On 3/12/2011 7:25 PM, Bill Dzurilla wrote:
I was giving a presentation at our club meeting called Working DX on the Satellites and afterwards someone had a good question: is it at all possible that tropo, skip, or other form of enhanced propagation can enable a contact via a satellite below the horizon?
It has never happened to me. Has it ever happened?
73, Bill NZ5N
Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
On 3/12/2011 7:25 PM, Bill Dzurilla wrote:
I was giving a presentation at our club meeting called Working DX on the Satellites and afterwards someone had a good question: is it at all possible that tropo, skip, or other form of enhanced propagation can enable a contact via a satellite below the horizon?
It has never happened to me. Has it ever happened?
It was relatively commonplace with RS-12 on Mode K, 15m up, 10m down. There was one guy in North Carolina I think that worked dxcc on RS-12/13. He was my first satellite QSO in 1992 or so, and was always on. I can't remember the call, but it was a 1x2 I think.
I imagine it would be at least possible on other birds and higher bands with strong tropo. Jerry, KK5YY told me about doing that on AO-27 or UO-14 from Alaska over the ocean. I've not experienced it though.
73, Drew KO4MA
Hi Bill, NZ5N
When AO40 was alive and well I experimented many QSO's with several stations in USA when the elevation of AO40 for me in JN70ES was already -2 or -3 degrees belove my free horizon using InstantTrack for tracking
The AO40 downlinh was obviously in 2401.300 MHz but my uplink was in 70 cm or 23 cm and my negative elevation was monitored by those stations in USA using all the same set of keplerian elements but with different tracking programs and all gives the same results that the elevation for me was negative.
To explain this uncommon below the horizon propagation anomaly I believe that is my QTH location that play an important rule because my building is located only 100 meters from the beach and the antennas are 50 meters above the sea level and so it is possible that propably in presence of particular temperature and humidity and pressure conditions a duct similar to a wave guide is developed over the sea so that my signals and the satellite signals are traveling into the duct for many miles allowing the QSO to be made with AO40 belove my horizon.
Another station i8KCL in my QTH wich home is many undred meters behind my back and more high them me over the sea level he was never able to receive AO40 with -2 or -3 degrees belove the horizon or made a two way QSO with the above negative elevation because probably owing of his home altitude he was not in condition to enter his signals into the suspected duct.
I do not remember the call letter of the many stations in USA experimenting with me the above propagation anomaly but if some of them are reading this AMSAT-BB please drop a line in responce.
Best 73" de
i8CVS Domenico
----- Original Message ----- From: "Bill Dzurilla" [email protected] To: [email protected] Sent: Sunday, March 13, 2011 1:25 AM Subject: [amsat-bb] Is it 100% impossible to work a satellite below thehorizon?
I was giving a presentation at our club meeting called Working DX on the
Satellites and afterwards someone had a good question: is it at all possible that tropo, skip, or other form of enhanced propagation can enable a contact via a satellite below the horizon?
It has never happened to me. Has it ever happened?
73, Bill NZ5N
Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
participants (8)
-
Andrew Glasbrenner -
Andrew Rich -
Bill Dzurilla -
Gregg Wonderly -
i8cvs -
John Geiger -
Nigel Gunn G8IFF/W8IFF -
Stan, W1LE