[SMCARA] 64 repeater info

[Frederic Clarke]

The K3HKI repeater consists of a Bridgecom repeater (the receiver and 
transmitter plus power supply) which works in conjunction with the 
CAT-250 controller. The Bridgecom RF feeds a duplexer that permits the 
transmitter and receiver to share one antenna/feedline. The antenna is a 
Super Stationmaster at about 140 feet on a Navy tower.  Thanks to the 
Atlantic Test Range for hosting us. There is a 70cm link transceiver 
that also is controlled by the CAT-250 for control operators to manage 
the repeater functions.

In the normal configuration the repeater requires a CTCSS of 146.2Hz 
(that's the annoying hum you hear on the repeater.) to repeat the signal 
from the input of 146.04. When the Bridgecom hears a signal on the input 
with the correct CTCSS, it exerts a "low" (i.e., ground) signal called 
COS to the controller. Since the controller is looking for either a 
CTCSS and/or a COS signal to operate, we configured the controller to 
repeat when only the COS signal is there, since the Bridgecom only 
exerts COS when a valid CTCSS is present. You will hear the terms COS 
(Carrier Operated Squelch) and COR (Carrier Operated Relay) used 
interchangeably. COR is somewhat dated, as there was an actual relay 
controlled by the receiver. Today it is all digital. At the moment we 
have no way of disabling the CTCSS, but a fix is in work.

The Bridgecom is capable of functioning as a standalone repeater with 
the control and ID functions done internally.  This is a fallback mode 
for K3HKI if the CAT-250 ever takes a powder. Currently it takes a trip 
to the site to effect that changeover. Eventually the control operator 
will be able to do this remotely. In this mode there will be no voice 
announcements, only a CW ID and courtesy beep.

At present the repeater is set with a 3 minute timer (alligator) that 
will disable the transmitter if you get long winded. It automatically 
resets after you release your PTT.  The courtesy beep that you hear 
after the end of a transmision indicates that the timer has reset. 
During the Tuesday night net, the timer is disabled, so if you are 
reading a bulletin or have a long transmission, it is not necessary to 
drop PTT to "get another nickel". The control operator can also disable 
the alligator.

Here's a question for old timers: the phrase "Getting another nickle" 
came from where? Two theories I have heard: a. Back in the day of pay 
telephones, you had to drop another nickel in the phone to keep talking, 
or b. Back in the day of trolleys and buses, the coin collector for the 
fare was called a "nickel snatcher", as it actually snatched the coin 
from you when you put it in the slot.

Have fun every day!

73 Tom/W4OKW


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