412.9750 mhz.

[W4UVV]

Recently I programmed the newer P25 Coast Guard frequencies in my Uniden 536. I was quite surprised today when I received a strong P25 signal on 412.9750 mhz., NAC 293. I had it listed as CG Sector Hampton Roads, Portsmouth "channel"? 409. Comms were infrequent i.e., every 15 minutes and appeared to be confined to contacting CG aircraft currently flying in its' control area for periodic position reports. I could not hear the CG aircraft(s) responses.

The CG Sector Hampton Roads transmitter appears to be using a high powered uhf transmitter for the Uniden 536 scanner's' Q5+/S 5 bar strength indicator..

I was unable to locate a graphic map for Sector HR's area of responsibility but the below link states it includes the lower half of the Chesapeake Bay to the Va. Capes 200 nautical miles out.

Coast Guard Sector Hampton Roads

John
W4UVV

 

[ecps92]

Try this
http://www.navcen.uscg.gov/images/marcomms/cgcomms/Rescue21/SECHR.jpg

Recently I programmed the newer P25 Coast Guard frequencies in my Uniden 536. I was quite surprised today when I received a strong P25 signal on 412.9750 mhz., NAC 293. I had it listed as CG Sector Hampton Roads, Portsmouth "channel"? 409. Comms were infrequent i.e., every 15 minutes and appeared to be confined to contacting CG aircraft currently flying in its' control area for periodic position reports. I could not hear the CG aircraft(s) responses.

The CG Sector Hampton Roads transmitter appears to be using a high powered uhf transmitter for the Uniden 536 scanner's' Q5+/S 5 bar strength indicator..

I was unable to locate a graphic map for Sector HR's area of responsibility but the below link states it includes the lower half of the Chesapeake Bay to the Va. Capes 200 nautical miles out.

Coast Guard Sector Hampton Roads

John
W4UVV

 

[W4UVV]

Tnx. That helps.

John

 

[KG4INW]

The Richmond RFF is located in southeastern Henrico Co. near the James River and would explain why you were hearing such a strong signal. Although there's no one there physically, everything in there is wirelined back to HR.

 

[W4UVV]

CG Richmond RFF

The Richmond RFF is located in southeastern Henrico Co. near the James River and would explain why you were hearing such a strong signal. Although there's no one there physically, everything in there is wirelined back to HR.

Tnx. I had forgotten about the CG Richmond RFF. That would explain the strong signal. However, my past CG reception experience shows the Richmond RFF appears to be only for selected, not all CG/marine vhf/uhf frequencies. For example, yesterday also the CG Auxillary frequency 157.1250 mhz. was active with a small private plane out of Chesapeake patrolling along the eastern shore giving periodic position reports. The plane's reception was good and Sector HR reception was ok but significantly lower in signal strength because I was receiving Sector HR transmissions direct. If the Sector HR transmissions had been via the Richmond RFF, those transmissions would have been as strong as the 412.4750 mhz.signal.

Conversely, I hear the Sector HR 165.3125 mhz. comms strong via the Richmond RFF.

John
W4UVV.

 

[ecps92]

Each Sector can select any/all of the sites to transmit at the same time
Conversely it's sometimes better to only use the needed tower

Tnx. I had forgotten about the CG Richmond RFF. That would explain the strong signal. However, my past CG reception experience shows the Richmond RFF appears to be only for selected, not all CG/marine vhf/uhf frequencies. For example, yesterday also the CG Auxillary frequency 157.1250 mhz. was active with a small private plane out of Chesapeake patrolling along the eastern shore giving periodic position reports. The plane's reception was good and Sector HR reception was ok but significantly lower in signal strength because I was receiving Sector HR transmissions direct. If the Sector HR transmissions had been via the Richmond RFF, those transmissions would have been as strong as the 412.4750 mhz.signal.

Conversely, I hear the Sector HR 165.3125 mhz. comms strong via the Richmond RFF.

John
W4UVV.

 

[LeSueurC]

Each Sector can select any/all of the sites to transmit at the same time
Conversely it's sometimes better to only use the needed tower

I'm maybe 2-2.5 miles from Station Portsmouth and all my comms are broken and I miss a lot of traffic, probably has to do with my antenna, RS 800, but the helos I can normally pick up.