Programmers Corner
Information about the repeater
July 2006
Some of the inner workings of a repeater are managed by a computer
called a controller. Often when people speak of a repeater they really
mean the controller. Over the past 2 years 146.91 has sustained the
largest down time due to the old computer controller. The 146.91 radio
in fact has been with out failure for quiet some time. In April 2006
the computer managing the 146.91 radio was upgraded to one made by
SCOM. It is designed to handle two repeaters at the same time and has
the ability to have a third receiver often used to control the SCOM
computer. In summary, Controller = Computer. So now that we know that a
computer is running our repeater we know what to blame for all our
problems!
Why do we need a computer to run the repeater? To solve problems.
Number one is the ID required by the FCC. In addition the FCC requires
us to keep the repeater free from spurious and unwanted emissions. Some
of the biggest complaints with our old controller was some inability to
listen to the repeater. What inability? Most of our club would not scan
or listen to the repeater because it was always making noises and
making transmissions from unlicensed sources. I could not monitor it at
work because it was always making noises. NoBarc has added PL (another
topic) and we added a feature called "Anti Kerchunking". These
two features have improved the usage of the repeater and IMHO we have
gained back some of our former users.
The Anti Kerchunk feature allows us to control what noises we will
allow to use the radio. If a noise is too short the computer can just
ignore that transmission. This means that only the longer and more
useful transmissions will be transmitted. We are using a computer so we
can make it less inconveniant. In 146.91's case the repeater will only
ignore short transmissions if the repeater has been idle for two
minutes. So short transmissions during a normal conversation will still
be repeated. The specifics are; if the repeater has been idle for more
than 2 minutes it requires at least a half second transmission to wake
it up. This means the repeater noises are GONE! A side effect is that
is if you are the first one to use the repeater after a period of two
minutes may loose the first word spoken. Often this is the callsign of
the person you are calling. Even before this was implemented there were
those of us that sometimes key up and talk at the same time and loose
the first syllable of their transmission. Others just plain old talk to
fast. Kinda like they are excited. Even without the Anti Kerchunker
some of us have been hard to copy when making a call. I have noticed
some of the more regular repeater users have the tendency to start
talking before they have keyed their radio. I have found that even I
have done this. How long is a half a second? Try saying "ONE ONE
THOUSAND". Half of the
time it takes to say that is about 0.5 seconds. What can you do? Well
it is simple, if you key up, RELAX and do not talk so fast!
If you have questions or suggestions for next months issue feel free to
email me. ke3ht@nobarc.org
Tim KE3HT
146.91 & 147.03 repeater manager