MIAMI ZMA SECTORS

[captkel]

THE RCAG FOR 135.600 IS WHAT I'M TRYING TO TRACK DOWN. I KNOW IT'S SOUTH OF FT.LAUDERDALE. WHEN THE CONDITIONS ARE RIGHT I CAN PICK IT UP. MY ANTENNA IS MOSTLY DIRECTIONAL.

[cipher66]

135.6 is transmitted from Bimini, BAH, with a backup in Miami.

[captkel]

that's what I heard. When I visited the Miami RCAG site I could barley hear it. When the conditions are right I can hear it and again when I would aim my antenna at Bimini I would lose the signal. Bimini is about 50 miles from my location, the Miami RCAG is about 35 miles. Current conclusion: Great conditions-pickup signal from Miami location.
This brings up another question; how can they transmit from two locations and not interfere with each other.

[cipher66]

The short answer is "they can't".   The controllers can receive aircraft from multiple receive sites, but have to select the site they wish to key up for transmitt.   In controller speak, when you have more than 1 transmit primary RCAG site, they are considered SELKEY'd...  In other words, the controller can select the transmitter to key up.   Normally, controllers will keep one site "Bimini" as the main transmitter, and only use Miami when aircraft are closer to MIA and having difficulty hearing them.

Interestingly, the UK I believe uses multiple transmitters on the same freqs but slightly offsets the actual transmit frequency so that all sites can transmit at the same time without harmful interference or multipath signal images... 

[captkel]

makes sense...i pretty much assumed that. THANKS

KEL

[captkel]

As of Saturday Dec. 18, 2010 the transmitter for 135.600 located on Bimini is out of service...HURRAH!! Good for us but the pilots flying low out in the Atlantic are having trouble hearing the controller... just increase the transmitter power...that too works for me.
They are currently using the backup transmitter at the Miami RCAG.
I can receive it, so as of Saturday, I put that frequency on the 126.325 Bimini ZMA feed too. I may add 133.850 since they seem to be using it during the day when they get busy. It is also transmitted from the Miami RCAG.

Enjoy

KEL

[captkel]

133.850 has been added

KEL