Firstly thank you for trying this software. PC-ALE is a Windows 95+ program
that emulates the FED-STD 1045A or MIL-STD 188-141A
Automatic Link Establishment Protocol (ALE). It does not claim to be a replacement for a standard ALE controller, however it is able
to inter operate with any network based on this protocol. Therefore it is ideal for users that require inter operability in an emergency situation but
cannot afford the outlay of a traditional ALE controller/Radio.
With this software, a multimedia Laptop and an inexpensive HAM radio transceiver, it is possible to successfully enter an ALE network.
This manual assumes familiarity with HF ALE operations and is simply a get you going manual.
This ALE software requires the following.
133 Mhz Pentium processor or better.
32 Mb of dynamic RAM
Windows 95 operating system or better.
Sound Card (Most cards should work)
Supported HF Transceiver or Receiver.
Automatic Antenna Tuner (Optional)
DTM MODE (BASIC and EXTENDED)
DBM MODE (BASIC and EXTENDED)
100 Other addresses
20 Own addresses
20 Net addresses
SINGLE CHANNEL OPERATION
Installing the Software
The software comes as a zipped file called pcale.zip. this file contains all
the components required to install the PC-ALE system.
After unzipping the file simply run the setup program and the software will instal onto your P.C. The instal program will add an ALE
Icon to the desktop. The program is updated by copying the new executable over the old one, a re-install is not required.
Setting up a station
This section assumes the user is familiar with the use and operation of an HF radio system.
After installing the radio, automatic ATU, antenna and ground system it is
necessary to connect the radio to the PC. Two leads
will be required for this, firstly an audio lead will be required. This connect the audio out from the transceiver to the microphone
input on the P.C. it also connects the speaker or line output to the line/microphone input of the transceiver. The second lead is
the remote control connection to the radio. The remote control connects a spare serial port from the computer to the radios remote control
When making this lead please take care as most Amateur radio transceivers do
not use RS232 levels but TTL levels instead. This means that
a convertor board will be required. Two of the handshaking lines from the P.C are also used to control the radio, the RTS line is used to operate
the radios PTT and the DTR line is used to control muting and unmuting of the radio, it is advisable to do this using a relay or optocoupler. If using a relay it
will be necessary to use a transistor to drive it as the RS232 control line is not capable of sourcing enough current to power a normal relay.
The actual serial port used for remote control is determined by the options
menu. After changing the serial port it is necessary to restart the program
for the new option to take effect. It is also necessary whilst doing this to select the correct radio interface from the same menu.
Using the PC-ALE Software
Before the software can be used it must be configured, the menu items on the
main window are fairly self evident. Channels can be added using the
CHANNEL ADD menu item. OWN and OTHER addresses maybe added in a similar fashion. Once all these parameters have been entered it is
advisable to insert a pre formatted disk into the A: drive and then select the dump command from the menu. This writes the database to a file that is human
readable. This file allows NET information to be distributed to other users. On another system the parameters maybe loaded by selected using the
fill menu option. The file name has to be changed from dump to fill, this is a security precaution. Also you should manually alter the own address
lines in the file, otherwise you will end up with all your controllers thinking they are the same address!
Making a Call
A call may be made by selecting the call option from the main menu, then
using the pull down, select an address to call, then click on O.K. This system
over. If the call must be terminated before completion select the kill menu item or the AXE Icon on the toolbar. This terminates the call immediately.
Once a call has been established, data maybe passed, this is done by
selecting the DATA menu item and following the dialogue boxes.
There is a choice of AMD, DTM or DBM data. Data may also be sent before a call is made, however the controller simply sets up a call first then sends the data.
There are two modes available ARQ and Broadcast, ARQ mode requires the far end to acknowledge the transmission.
Clearing a Call
This maybe done by selecting the clear menu item and following the instructions.
Menu Items and Usage
File Menu item
This only allows the program to be terminated.
Configuration Menu item
The recording facility, records received audio to disk,
it is triggered by hearing a complete ALE three way exchange. For this facility
to be operational
it has to be enabled in the Recorder dialogue box AND the listen calls must also be activated ( Options menu ). The Listen time also affects the operation of
the recording facility.
Recording is completed when either the Listen timer
expires, the max sound file period has been exceeded or one of the stations
being received sends a
This option enables and disables the recording facility.
Max period in seconds
This determines the maximum size of the recorded file, 1 minute equates to slightly less than 1Mb of data.
The Path to the directory where files are saved.
This set of radio buttons sets the group of frequencies being scanned. A channel may be a member of more than one group, see the channel dialogue for more details.
This set of radio buttons selects the rate at which the channels are being scanned, the system may scan at 1, 2 or 5 channels per second.
This combo box determines the type of radio equipment being used
Enable Disable Group
Enable/disable sounding. This is only required for transmitting and should be disabled for monitoring purposes.
If a station has not been heard for a period of time the software will actively try to exchange LQA information.
It is better not to enable this as it causes congestion and has not been fully tested.
Enable LQA requests in call attempts. When making a call the controller will request LQA information from the remote end.
Allow reception of Allcalls. Many networks ban the use of all calls.
Allow reception of Anycalls.
Allow reception of calls using wild card addresses. On outgoing calls only one character in a wild card address is accepted at the moment.
Use frames terminated in this is when sounding, after a sound the controller listens on the channel before
returning to scan when operating in this mode.
Display received sounds on the operator console, it is probably better to leave this disabled, unless you want
pages of sounds, which can be very boring. Even with this disabled the controller is saving the information away for later use.
Listen to calls between other stations. If this is disabled the controller immediately it discovers a call is not to it
should return to scanning.
This is a simple protocol trace function, it produces large quantities of output on both transmit and receive and
should be left off. It also can cause some problems with the DSP functions in the software and causes the occasional loss of
This option allows command strings to be decoded, it is a good way of seeing
AMD and DTM ASCII messages when receiving.
Also LQA and some other cmds will de displayed. The controller can identify all the 141B command messages but can only decode a
subset of them.
Bad data frames
When enabled this displays frames whose CRCs are incorrect. This was designed to be used for receiving unacknowledged
data frames either DTM or DBM. At the moment this is not completely implemented.
When a call is received if this option is enabled an AMD message will be sent in the response. You can use it to inform callers
of the status of the station.
This provides AL1/AL2 linking protection. Linking protection has been disabled and is missing time server code anyway.
This maybe added to the professional version of the software if there is enough demand.
At present this is not functional.
This option when enabled will display the frequency on the screen rather than the channel number
Period in minutes between sounds.
Period after which an attempt will be made to sound on a channel if a scheduled sound failed. This period is in minutes.
This determines the DCD detect sensitivity when scanning, a suitable value is between 3 and 5. If it is set too low the controller stops on every channel
and if it is set too high is never stops.
This is the number of times the ALE controller will try all the available channels when making a call.
Inactivity period in seconds. If no PTT activity has occurred for this period the controller goes back into scanning.
Time allowed in milliseconds for the transmitter to ramp up to full power after keydown.
Maximum number of no unanimous votes allowed when searching for word sync.
Maximum number of non unanimous votes allowed when receiving a frame.
Period of scanning call when in single channel operation. This is required when a station operating in single
channel operation is trying to call a station operating in scanning operation, where they both share a channel.
Timout period in minutes before LQA is considered un-reliable.
Number of errors allowed when hunting for word sync.
Number of errors allowed when receiving a frame.
Transmit audio level. This controls the sound cards output level.
Audio input level. This controls the sound cards input level both for mic input and line input.
Serial port being used to control the radio. After this has been changed it is necessary to close the program and restart it
for the change to take effect.
AMD Message to send after being called. (Sent in the response frame).
Number of retransmission attempts in DTM mode before link is terminated.
Length in seconds allowed for DTM frame. This is required because of frequency inaccuracies (and hence timing) in the sound card.
Number of retransmission attempts in DBM mode before the link is terminated.
Length in seconds allowed for DBM frame. This is required because of frequency inaccuracies (and hence timing) in the sound card.
Keys Menu item
Encryption keys and application level. This is not active at the moment. All keys are 56 bits.
This outputs to the screen the link state when selected. It is for my own use.
Channels Menu item
The use of the items in the menu are fairly obvious, Linked addresses are
the addresses of the stations you are currently linked to.
Reset deletes are the addresses the ALE controller has picked up off air, ones I call dynamic addresses, static addresses are addresses that
have been entered by the operator or net manager.
Allows you to add a channel
Allows you to delete a channel.
Allows you to modify a channel
Allows you to list all available channels.
Forces the controller to go to a given channel when stopped.
Addresses Menu items
Other addresses are addresses of
other stations, i.e not you own.
Own addresses are address that you are known by.
NET addresses are addresses of the NETs you are a member of.
Scan Menu item
Allows you to start or stop scanning, these are mimicked on the tool bar.
Call menu item
For an explanation of the call menu please read the ALE standard. Kill, kills any call that is in progress.
Data Menu item
This allows you to send one of
three types of data messages, again please refer to the ALE spec for a
description of these.
Only ASCII modes are supported.
Clear Menu item
This allows you to clear down a call.
Fill Menu item
This provides a way to save the
controllers parameters in a semi man readable format, it is mainly intended for
channel information across a net using the floppy net protocol.
Help Menu item
Ha Ha Ha Ha! I managed to disable the help facility and am having some trouble getting it back.
You will find two files in the applications home directory, these are
owlog.txt and dalog.txt these files contain a record of any ALE
activity detected by the controller.
This ALE software uses a standard sound card interface. It is not advisable to
connect the sound card directly to an HF transceiver.
This is because the output of the card will probably be at too high a level and not the correct impedance. Originally we tried using the
mixer controls to set the output level. This however proved to be unreliable. A better method is to set the output level to a maximum
then use a 10k multiturn resister to set the correct level for the transceiver. The correct level is when no ALC shows on the transceiver.
Although because the 8ary wave form is an FSK wave form it is permissible to run the system with a little ALC.
Amateur radio equipment is built to a price and therefore is not as good as
military grade equipment. This causes a number of problems,
one of which is that for a given drive level the output will be different on each frequency. As a rule the lower the frequency the less drive
that is required. Therefore to be on the safe side and to protect other users of the H.F spectrum it is advisable to set the transceivers
drive up on the lowest frequency that will be used. This means however that the radio will be under driven on the higher frequencies.
However this is more acceptable than overdrive.
A number problem with amateur radio equipment is that it does not have such
good filters as commercial/miltary equipment. Inevitably
this will mean that the BER will be slightly worse using Amateur equipment than would be the case if military equipment was used. Amateur
Radio equipment filters tend to be a bit narrower than their commercial counterparts and do not have such good GROUP DELAY characteristics.