Before reading any
make sure that you have fully read the Repeater
If you are here, it is safe to say that you are at least curious
obtaining the repeater monitoring software.
In the interest of full disclosure and to let you know exactly
what you are getting yourself into, here are a few things about the
Most importantly, it was written for one-off use.
I never really intended for anyone else to use it and thus, I haven't
much impetus to go back and "improve" it.
- This means that I threw it together and put enough effort into it
so that it would work. It isn't pretty, user-friendly, or even
guaranteed to be bug-free.
- The code is hashed together and must be run under a DOS or a DOS
in W95 or W98/SE: It will not work under W2k or XP!
Why? The serial interface routine talks directly to the serial
hardware (UART.) This also means that if your computer doesn't
a serial port, then you are out of luck.
- It was compiled under Borland C Ver. 3.1. This
supported Windows 3.1 (not that I used any of that capability...) and
are consequently a few functions that are not ANSI standard that
under BCC - but likely nowhere else. Specifically, a few display
functions and, most certainly, the serial interface routines. It
shouldn't be too hard for a semi-experienced programmer to modify it to
use a GNU compiler, though.
- This is true "Franken-Code." Like Frankenstein's monster,
up of bits of code from other projects - some of which was badly
to make it work properly. There are even functions present that
- The radio-specific calibration constants are set at compile time
code. Ideally, these parameters would be in a separate file that
could be modified by the user - but that wasn't done as I didn't expect
it to be used by anyone else at the time. More on these
- Important note: This program produces copious
quantities of text for its data
output - it does not produce a graphical output at all.
The picture that you see on the web page was a result of manually going
through the data and extracting the calculated antenna gain and then
creating an antenna pattern file for input to the RadioMobile
program. This process took an hour or so to do and wasn't too
painful for just one use, but one would certainly want to write
something to help automate the process a bit if one were to do this
more often. The source code
contains info on how the generated text is formatted and what it
means: If you still have questions, feel free to ask.
Even after saying all of this, if you are still brave enough
to be interested in the code, here is what you will need:
Conditions of usage:
- A compiler and the skill to decipher and modify the code.
that I commented some of the more important parts, so it shouldn't be
terrible to figure out what is going on. You'll need to run this
under DOS or a DOS window as mentioned above. (You'll also need a
- A service monitor or well-calibrated signal generator.
is absolutely useless unless the radio to be used with
has been adjusted and characterized. As mentioned on the Repeater
Monitoring page you will need to readjust several important
- The "FM-S1" and "FM-FS" parameters in the hidden menu.
These parameters will need to be adjusted to increase the
dynamic range of the FT-817's S-meter to make it more usable.
- Charactarize the S-meter readings: After
is done you will need to characterize your '817 in terms of
signal versus the S-meter reading.
- Determine the "RXG" parameters to provide approximately 10,
and 30 db of attenuation. In addition to this, you will need
to determine the precise amount of
that those RXG settings provide. Once this is done, you'll have
insert that data into the program and recompile it. (Unless, of
you've modified the program to be able to read this data from an
- A GPS receiver with a serial port that can produce NMEA data.
- A simple switching circuit that will allow multiplexing of the
the GPS receiver. For my setup this is just a relay that is
by one of the serial port's handshake lines. If you have two
ports that can be used, then you could handily avoid this requirement.
If/when you get this software, here are a few things to keep in
- If you improve it, please pass the improved version back to me so
I can make it available to others who may wish to use it.
- Give credit where credit is due!
- Your mileage may vary!
If, after all of this, you are still seriously interested, please
send an email!
Things like "W98", "W95" "W2K", "XP", "BCC",
C","DOS", "NMEA", "817" and other things are tradmarks of their
This page maintained by Clint Turner,
and was last updated on 20070220. (Copyright 2001-2007 by Clint