Amateur Radio Repeater Controller

meridian

Member
Has anyone built one of these? Can't find it with search...

I am part of a small group that wants to put up a VHF/UHF repeater. The specs I have been given:

On startup send Morse code ID then start a 10 minute timer. If no activity send Morse Id again.

Waiting for carrier detect. On carrier from receiver, key transmitter and connect audio.

On carrier, start a 3 minute timer which resets on carrier drop. If 3 minutes is up and carrier still active, wait for carrier drop then transmit raspberry tone.

If 10 minute timer up, send Morse on carrier drop.

I have the Morse routine from another repeater setup, but not the timing bits.

I have started but these new-fangled M2 devices are a bit of a challenge. I am looking at interrupts and 'parallel' processing.

meridian
 

premelec

Senior Member
I haven't built one but it sounds like it could be done with a 14M2 - the programming of the M2 chips is not much different than earlier - just more memory and features. You probably want to send your audio Morse ID even when there is an incoming signal being repeated... just run fast Morse... may not even need the speed of interrupt if you do a pretty speedy polling loop which updates timers and checks for incoming activity... how accurate does the timing have to be - I recall something about ID at least every 10 or less minutes [it's been a while since I've been operating as a ham...]. 73...
 

RexLan

Senior Member
Your plan is a little short actually and I would not consider this in our area. The entire purpose of the repeater is to "reach out" and one needs to take care that it does not create issues for other nearby users.

A carrier only system will routinely false and if you key-up you may tie the channel up for possibly no reason. You also need a time-out timer that will start when the carrier drops to shut the system down. To activate the repeater I would require carrier and at a minimum one DTMF character, typically the *, and/or either a CTCSS of DCS tone. Typically the DTMF character is a sub signal used to activate an auto-patch but it can also be used as an enable for the repeater function as well.

The CTCSS or DCS signal may be available in the radio itself and could be used in the background so when that radio breaks squelch or is keyed it has already validated the receiver signal and the transmit radio can encode the necessary tone. Short of that, the functions will need to be performed within the controller - not simple.

I also am not sure the 14M chip can even handle the CWID function and maintain timers too. My hunch is that you will need a lot more chip but not speed so it will essentially come down to coding.

You can buy a good club repeater controller for $60 or so ... has it all and ready to go. Not the same as as a roll-your-own but you may quickly discover it isn't as easy as it may seem when the CWID is mixed in.
 

premelec

Senior Member
I agree with RexLan that there are a lot more considerations to build a successful repeater - unless perhaps you are a long way from other signals - as you may be in NSW ;-0
 

meridian

Member
Thanks to all for your input. Many repeaters don't have tone access, others have 91.5 or 123Hz. There aren't that many amateurs in the area, ACMA lists about 40 but not very many active. So I don't anticipate many ker-chunkers.

I have a beacon running the CWID on an '08 when triggered with carrier. The code came from another repeater and is quite clever and compact. I'm in Bathurst NSW with one repeater at Mt Bindo, south of Lithgow, the other NE of Orange so both about 80km distant. Both are accessible but not always around town. RexLan, I'd be interested to know what sort of repeater is available for USD60

The time-out timer is a good point, that could be the function of the 3 minute timer, to drop carrier. Times aren't critical, I doubt that anyone would care.

meridian VK2AHB
 

RexLan

Senior Member
Thanks to all for your input. Many repeaters don't have tone access, others have 91.5 or 123Hz. There aren't that many amateurs in the area, ACMA lists about 40 but not very many active. So I don't anticipate many ker-chunkers.

I have a beacon running the CWID on an '08 when triggered with carrier. The code came from another repeater and is quite clever and compact. I'm in Bathurst NSW with one repeater at Mt Bindo, south of Lithgow, the other NE of Orange so both about 80km distant. Both are accessible but not always around town. RexLan, I'd be interested to know what sort of repeater is available for USD60

The time-out timer is a good point, that could be the function of the 3 minute timer, to drop carrier. Times aren't critical, I doubt that anyone would care.

meridian VK2AHB
I guess we look at it different ways. For me, times are quite an important function. For example: so it won't tie up the frequencies with a hung transmitter or with false starts. Or, it will shut down a user with a stuck mic which is not uncommon. I believe most regulations also suggest that there needs to be some form of control signal to activate the repeater function. Carrier alone certainly does not meet the intent this condition.

JimPerry gave you one link and there are many more on eBay.
 
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