General operation:

The controller enables a conventional duplex repeater to be controlled by a COS line from a receiver(s). The various timers and tones for operator information are provided. It uses DTMF tones for remote control (password protected) and has facility for CTCSS control. In addition it provides either a gateway or linking port (software determined). When configured as a gateway the secondary port has identification and a tail with telltail beeps if required. The controller has a beacon function for club information. There is a choice of five identification modes to match European and some local Australian requirements.

Features a minimum of components and cost to achieve the following features:

• Two carrier-operated switch inputs (i.e. a receiver A and receiver B) either +ve or –ve going and programmable at ‘burn’ time.
• Two PTT outputs (any combination of low or high active programmed at ‘burn’ time.)
• Programmable delay for mute opening to overcome transient interference.
• Onboard DTMF decoder (jumpered to either receiver - may use an external receiver with no COS facility)
• Onboard CTCSS decoder (to meet licensing conditions or remove interference on main TX or link)
• Timeout timer
• Callsign generator with timer
• Short message morse beacon if required.
• Two adjustable tails - one before the beep and one after.
• Tail with mode pips (high pitch and low pitch depending on receiver)
• Remote inhibit of timer (two methods)
• Remote inhibit of primary repeater
• Remote inhibit of gateway (or link)
• Remote control of CTCSS requirement on primary or secondary
• Remote control of 'roger' beeps (inhibit or allow)
• Remote callsign change
• Remote adjustment of callsign delay (1 to 75 minutes in 1 minute increments)
• Remote adjustment of timeout period (0 to 75 minutes in 1 min increments)
• Remote adjustment of extended CTCSS operation
• Remote adjustment to support either a link or a gateway
• Remote adjustment of morse code speed (very slow to approx 35 wpm) and tone
• Remote adjustment of COS trigger (delay opening up to 255msecs)
• Remote adjustment of tail length (tail adjustable in 0.1sec increments from 0 - 15 seconds).
• Remote adjustment of secondary tail length (after the beep) from 0-15 seconds.
• Remote enable and timing of a regular CW message (never, or 1-75 minutes in 1 minute increments).
• Remote change of the morse message
• Remote decision on whether to pass DTMF tones through and DTMF may be received from any of three receivers (external, rptr, link)
• By retuning the CTCSS decoder the controller can be programmed to use 1750 tone "beep" access.
• AC Fail indication if a small board modification is made.
• LEDs to indicate power on, DTMF decoded, CTCSS decoded, PTT main, PTT secondary
• All components are readily available in Australia including commercial boards.

PCBs with plated through holes and component mask are available from the author for AUS$15 each and the sometimes hard to get MC145436 DTMF chips are available for $7-50 each.

On the supply of a 16F628 the author will burn the program into the PIC for Australian amateurs at no cost . P/P of $2 would be appreciated.

PIC16F648A is an acceptable subsitute for the 16F628 as the former has twice the memory and if later versions of the software no longer fit (I currently have about 20 bytes of program memory free) I will switch to the 16F648A.