FCARC Jan 11,2016

Repeaters FCARC January 11, 2016 Al Woodhull N1AW FCARC operates two repeaters..., one on 2 meters, located at Frizzell Hill in Leyden, and one on 70 cm, located on Rocky Mountain in Greenfield. The 2 meter repeater is on with a PL, with a minus offset of 600 KHz. The 440 MHz repeater is on with a PL, with a minus offset of 5 MHz.

WPVQ Tower on Frizzell Hill

First some repeater basics...

SPLAT map shows our coverage out to about a 50 mile radius.

We have talked so far about the transmitter, receiver, and control unit (incorporating the COR, the CTCSS detector, the ID generator, and the timers that limit transmission times and ensure that the repeater is operated and identified according to FCC rules). We have also mentioned some other controls, some available to all users and some limited to control operators. We still need to talk about antennas...

A powerful transmitter and a sensitive receiver operating on frequencies separated by only about 0.4% is a difficult combination. One possibility is to separate the receiving and transmitting antennas. One way is to put the receiver and transmitter in entirely different locations, linked by wire or by radio in a different frequency band...

It's easier to stack the antennas one above the other on a tall antenna. Since the desired pattern of the antennas maximizes radiation in the horizontal plane and minimizes vertical radiation this can be effective....

… but... the antenna on top will be much more effective than the one lower on the tower.

You may end up with an alligator repeater (big mouth, no ears)

Or a rabbit repeater (big ears, no mouth)

The usual solution is to use a single antenna with a duplexer, which is an extremely effective pair of filters that can separate two signals of slightly different frequencies travelling on the same cable.

The requirements for a duplexer are quite strict. The sensitivity of our new Yaesu repeater's receiver is specified as 0.2 microvolts for 12 dB signal to noise ratio. At 50 watts output the transmitter voltage on the cable leading to the antenna is 50 volts.

Things You Can Do on the 2m KB1BSS Repeater With an HT TouchTone pad you can: Check the time: enter 400 Temperature report: enter 476 You can record your signal and play it back to hear how you sound. Key up and enter 725*. The repeater will say “Start test now.” Key up again and say something like “This is YOURCALL testing from YOURTOWN” and unkey. The repeater will play back the recording.

More user commands 470 disables the time-out timer. 471 re-enables it. Why do this? Not usual, but possibly needed if you want to do CW practice or somebody really has a lot to say. 472 disables the requirement for a CTCSS tone. 473 enables it. Normally CTCSS should be enabled, but in an emergency net with volunteers who don't have their radios configured for our repeater it may be useful to disable it. See: twww.fcarc.org/Files/

That's all folks...