Add some smarts
to your FM900 with AFI900!
AFI900 is replacement control
software (firmware) for
FM900 radios in amateur use, providing many
enhanced features and functions.
The Philips FM900s
are commercial two way radios built in Australia during the 1980’s.
Many of them have reached the end of their commercial life and have
become available to amateur radio operators.
The AFI900 software is a
replacement version of the control program for the Philips FM92R
written by David Griffiths, VK2AFI. I will
not go into a lot of detail about the FM900s here as there are already
several
good pages covering them. See the links
at the
bottom of this page.
The FM92 with Remote Control Head
is the model which comprises
most of the units now in amateur service. This head has a volume
control,
a mute adjustment, three LEDs, a two digit 7 segment display and four
push
buttons (the power button doesn't count!). These controls were quite
adequate
for normal commercial use, where only very limited scanning and channel
selection
options were required, however for amateur use they prove to be
somewhat
limited.
The AFI900 software
retains the original functions of:
- 99 programmable channels
- two predefined scan groups
of ten channels each
- priority channel
and adds the following functions:
- Single button Anti Repeater mode without
using any of the 99 possible channels
- user
configurable scan group of ten channels (in
addition to the 2 existing predefined scan groups)
- a ‘scan
all channels’
scan group - scans 1-69, 70-99 reserved for packet etc
- temporary channel barring within a scan group so
that a channel can be locked out of the scan group temporarily if there
is interference or excessive waffle on the channel. Temporary barring
is also available in the Scan All group.
- a 'step
on' button when stopped on a scan channel to
check if there is other activity in the scan group
- a user
configurable priority channel which is
checked regularly while stopped on another channel
or scanning
- dual
watch mode (main
and priority channels) - operate on one channel but keep
watch on
another
- a ‘scan’ mode that does not
stop indefinitely on a
channel - for keeping an ear on a group of channels
- display of channels in each
scan group - so
you don't have to remember what channels are being scanned
- a signal strength (S Meter) display
- low
power option on any channel - preprogrammed or user
selectable
- diagnostic display of
internal ADC readings
- Other enhancements include
less objectionable alarm
beeps, fast stepping when selecting channels, improved display usage
and
less flashing displays!
The Scan Group and Priority Channel
referred to as 'User Configurable' can be configured by the user from
the buttons on the radio
and are stored while-ever the radio has power applied to it, which is
always
in a normal mobile situation. The items described as predefined or
preprogrammed
are configured in the EPROM.
CHANGE
AN EPROM - NO HARDWARE
MODIFICATIONS
The AFI900 software requires no
hardware modifications, however it does
require that the I/O Expansion option be fitted. All that is required
to install the AFI900 software is the installation of the
new EPROM supplied.
Operation
Operation of the radio using AFI900 software is straightforward.
Pressing
the AUX key changes into function mode and the display shows F1 to F9.
The
channel up and down keys change function number, then pressing SEND
sets
the function or pressing AUX cancels the function. For example to start
scanning
Scan Group 1 would require the following actions: Press AUX, select F1
using
up and down keys (normally defaults to F1), then press SEND. To cancel
scanning
press AUX twice.
Function mode display examples: 
F1=Scan Group
1, 
F9 enables the S Meter, which is displayed as 
after two seconds of channel display.
A full explanation of the operation is supplied with the software.
I/O
Expansion Kit
The FM900 radios have an I/O Expansion Kit option that
is fitted when any of the signalling options (CTCSS, Selcall
etc) are required. Even though this software does not use any of the
signalling
options, it does require the extra RAM that the I/O Expansion kit
provides.
I have a limited supply of I/O Expansion kits available.
Channel
Allocations
The standard AFI900 software comes with a Channel Allocation plan
that includes all channels in the 2M
144-148MHz band that are intended for FM use.It
also includes the two standard scan groups and a priority channel.
Customised allocation plans are available if required for a small fee.
Please contact
me.
The programming software for configuring AFI900 is called DGFM900,
which replaces the FPP program from Philips.
Acknowledgements
My thanks to Chris Minahan VK2EJ for his invaluable support and input
during the development of this software, and also to Steve Leatheam
VK2BGL for beta
testing the software.
How do I order it?
The AFI900 software is available for $25 (AUD) for the first copy,
which includes the software in an EPROM, six page User Notes and
laminated Channel Allocation card. Please read the licencing
conditions. Please check if you
also need the I/O Expansion Kit.
I have obtained
a small quantity of the scarce NSC810AN chips (see ordering page).
You've read all
about it - now find out how to get it!
Go to pricing
and ordering information
and read the Licencing
Conditions.
For further info, please send me an email: vk2afi@digitalgraphics.com.au
Back to David's Home Page
Copyright David
Griffiths VK2AFI 1998-2007
