K1 based Keyer
This microcontroller-based beacon controller board was originally developed during March - September 1996 to become part of the
then replacement P29 beacon (the previous P29BPL was QRT for some time prior due to irreparable salt water corrosion damage).
The recipient and beacon keeper was to be my friend Pete Linden VK3AMX/P29CW/WA6VDF. Sadly, Pete is now a SK as of 27/9/96.
The controller never ended up in P29.
The information is presented here to encourage others to design something similar that may suit their individual needs.
More recently other microcontrollers such as the PIC have become available and are extremely easy to program using
BASIC type instructions.
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The C8 Beacon Keyer PBA size: 102 x 139mm
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A typical programmed sequence might be;
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<DE> P29BPL <P29BP>L QI30 <V> <H> <LORF> (LBAT) (TA) carrier <beeps>
where:
<Optional>
(under Alarm conditions)
Having a 8k of ROM to play with there is plenty of space for longer (additional) strings if required.
Some key features of the keyer include:
- Microprocessor controlled (Motorola 68HC705C8) with 8k ROM
- Low cost 3.58MHz clock Xtal
- Most parameters are DIP Switch configurable
- Selectable send speed 7/11WPM.
- Enable/disable sending “DE”
- Send callsign once/twice.
- Select Callsign1/Grid 1 or Callsign2/Grid 2
- Inter-ID either continuous carrier or beeps
- Inter-ID duration 4 seconds or 8 seconds
- Low Battery volts alarm monitor
- High Temperature alarm monitor (ie; monitor PA transistor etc)
- Both alarms modify beacon behaviour to suit fault condition(s)
- Enable/disable antenna switching. Coax relay port (toggles every cycle) ie; switch between a vertical & yagi
- On-board auxiliary SPDT relay. Primarily intended for changing TX O/P power. (Additional SPDT auxiliary relay on voice module)
- Optional voice module announces beacon status. (Intended for use on separate control link)
- DTMF remote controllable with 3-digit PIN security. (Intended for use on separate control link)
- Antenna rotator control port. (future option - not yet developed)
- Screw terminal blocks for convenient interface connection
- LEDs to indicate “Power”, “Key down”, “DTMF received”, “Battery Alarm”, and “Temperature Alarm”
- Spare DIP switches for further customisation
- PTT keying output to control the transmitter (NPN switching to ground with open collector)
- All ICs socketed for easy on-site replacement, if ever necessary
- PCB size: 102mm x 139mm (voice module 56mm x 80mm)
- Power requirements: 8 - 30V @ 100mA. (On board 5V regulator)
Add on Voice module board
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Voice module
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The Voice Module Board is based on an ISD-2560 voice recorder and stores 60 seconds of real speech.
It is loaded with all the possible verbal announcements and the microcontroller addresses the correct message fragments in
the correct order in order to construct a meaningful sentence.
It is intended to interface to either a 2m or 70cm FM transceiver, and allows the sys op to send DTMF commands and also be
able to receive a complete status run-down.
The voice module simply piggy backs onto the main board.
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Voice Module board fitted to Main Board
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The smaller brother - based on a 68HC705K1 microcontroller
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Features;
- Microprocessor controlled (Motorola 68HC705K1) with 504 bytes ROM
- Low cost 3.58MHz clock Xtal
- Most parameters are DIP Switch configurable
- Selectable send speed 7/11WPM
- Enable/disable sending “DE”
- Send callsign once/twice
- Inter-ID either continuous carrier or beeps
- Inter-ID duration 4 seconds or 8 seconds
- Low Battery volts alarm monitor
- High Temperature alarm monitor (ie; monitor PA transistor etc)
- Both alarms modify beacon behaviour to suit fault condition(s)
- Enable/disable antenna switching. Coax relay port (toggles every cycle) ie; switch between a vertical & yagi
- Output keying either; NPN switching to ground, keyed +12V, or + adjustable suit Mitsubishi module
- All ICs socketed for easy on-site replacement, if ever necessary
- PCB size: 70 x 102mm
- Power requirements: 8 - 30V @ 100mA. (On board 5V regulator)