Trying to receive RCAG sites 40 to 50 miles away

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xms3200

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I have been trying to receive RCAG sites in Cleveland that have their transmitters 50 miles or more away. My setup is an Icom A25C handheld with the Sirio Yagi antenna, which is excellent. The antenna is about 20 feet up in the air and have not had any luck. Is it possible to receive ground stations so far away. Any replies would be appreciated.
Thanks in advance.
 

mmckenna

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Unless the site is very high up, you probably are not going to receive it.
These frequencies are ~usually~ line of sight. Not an issue for aircraft since they are all well above the horizon.
For your installation, 20 feet above ground level gets you about 5 or 6 miles to the horizon. You may be able to hear the aircraft just fine, since they are well above the horizon, but the radio site is w-a-y below from your antennas point of view.
The RCAG site would need to be about 1400 feet up for you to be able to reliably receive it.

You can use online "distance to horizon" calculators to check this. Keep in mind, that the calculators will not take into account topographical variations. If there is a lot of dirt between you and the site, it's going to block the signal.
 

alcahuete

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Not going to happen, unfortunately, as mmckenna mentioned. You have a very good setup for airband monitoring, but you're just not going to be able to overcome the laws of physics, which are line of sight on that band. Here in Southern California, you can get lucky sometimes, as the RCAGs are often up on mountaintops, co-located with RADAR sites, for coverage with the terrain. But in Ohio, you're pretty much out of luck. Going to be on flat land likely on 50' towers or less.
 

chief21

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I have been trying to receive RCAG sites in Cleveland that have their transmitters 50 miles or more away.
Unlike land mobile and amateur stations, most air band installations are engineered and optimized to communicate with aircraft, not ground stations. My local airport has their comm site on a small ridge near the airport and I can barely receive them at my house, just 10 miles away.
 

dlwtrunked

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I have been trying to receive RCAG sites in Cleveland that have their transmitters 50 miles or more away. My setup is an Icom A25C handheld with the Sirio Yagi antenna, which is excellent. The antenna is about 20 feet up in the air and have not had any luck. Is it possible to receive ground stations so far away. Any replies would be appreciated.
Thanks in advance.
As others have already said, you will not be successful. Normally (unless ducting is happening ), here in VA, I only receive RCAG sites on top 2000 ft mountains at roughly that distance and not closer ones not on top the mountains. This is with a 40 tower, good antennas, filtering, and pre-amps.
 

nr2d

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As previously stated both the RCAG and your antennas need to much higher. If your antenna is at 20' and let's say that the RCAG site is at 40' your Radio Line of site (RLOS) is 13.28 NM. And this calculation does not take into account the difference in elevation of you location and the RCAG location.

85390
 

dlwtrunked

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As previously stated both the RCAG and your antennas need to much higher. If your antenna is at 20' and let's say that the RCAG site is at 40' your Radio Line of site (RLOS) is 13.28 NM. And this calculation does not take into account the difference in elevation of you location and the RCAG location.

View attachment 85390
Technically, it is not the "difference in height" but the two heights that count. The very simple formula that can be done on a calculator based on a spherical earth (ignoring hills and other obstructions) is (no need to use a web site to do this (in statute miles and not nautical miles):
Range (statute miles) is:
1.22*square_root(height receive antenna)+1.22*square_root (height transmit antenna)
If using kilometers for range and meters for antenna heights instead, change both the 1.22 to 3.57.
 

ATCTech

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ATCTech. yes sir.
Wow, memories. Those were the UHF radios I first started working on here in 1982 (they had already been in service for 2 or 3 years at the time) and many were still in service when I retired in 2016, although I had moved on to much wider responsibilities than just voice communications years earlier. Thanks for the flashback!

Cheers!
 

nr2d

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Wow, memories. Those were the UHF radios I first started working on here in 1982 (they had already been in service for 2 or 3 years at the time) and many were still in service when I retired in 2016, although I had moved on to much wider responsibilities than just voice communications years earlier. Thanks for the flashback!

Cheers!
We had them at the Air Force RBS sites in the US when I was in the Air Force and that was 1975 - 1980. We had ground radio troops that took care of them at most site but at some of the Mobile and remote site we radar technicians work take of them.
 

dlwtrunked

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Technically, it is not the "difference in height" but the two heights that count. The very simple formula that can be done on a calculator based on a spherical earth (ignoring hills and other obstructions) is (no need to use a web site to do this (in statute miles and not nautical miles):
Range (statute miles) is:
1.22*square_root(height receive antenna)+1.22*square_root (height transmit antenna)
If using kilometers for range and meters for antenna heights instead, change both the 1.22 to 3.57.
I should have noted in the above formula that the height of the antenna is in feet (with the range in statute miles).
 
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