Multitone Paging transmitter - UK Vintage Radio Repair and Restoration Discussion Forum

G8BBZ · 13th Jul 2016, 5:40 pm

Hi All,
I have been given a very nice 25w FM paging transmitter, currently crystalled for 147.80MHz. The label says Multitone and the model number appears to be TA666 but there is a label saying "Made in Quincy, Illinois" and the style of assembly is certainly american, probably 70's or early 80's.
I would like to try and convert this for use on 2m. as it is so close already, and wonder if anybody out there might have any info on the equipment - a circuit diagram would be ideal!
cheers
Peter G8BBZ

Bazz4CQJ · 13th Jul 2016, 8:59 pm

Interesting. The early Multitones worked on about 27MHz, the Tx running a 6146 PA and the receivers had an AF114 receiver sending AF in to a few OC71's. Sounds as though at some later stage, they went to VHF FM using badged equipment from the US.

B

AC/HL · 13th Jul 2016, 10:55 pm

Multitone is a UK company, set up by a Russian immigrant in the late 50s. They do have a Canadian distributor, and presumably also source internationally.

Malcolm G6ANZ · 14th Jul 2016, 11:36 am

Peter, you could try asking Multitone directly for information. If the Tx is obsolete , by their standards, then they might send you circuit details or even a manual. I have done this direct approach several times and if you are polite and honest then usually the company will help.

Malcolm

Biggles · 14th Jul 2016, 9:17 pm

I used to work on these things back in the eighties for the Fire Service. The frequency sounds about right so you may have an ex Fire unit, or maybe RNLI. From memory they were very reliable so I can't remember much about the units we had apart from they ran off a 24VDC battery supply and were triggered by a telephone line. I doubt whether they would be synthesised, probably just crystals, so it may not be too difficult to convert. It may be you have a different version to the ones I maintained as I imagine the units would be marketed to a variety of users.

G8BBZ · 15th Jul 2016, 12:53 pm

I thought that there was something familiar about the frequency - it's the one used for Fireman's Alerters isn't it? I had a Pye unit on the same frequency some time ago.
The transmitter is crystal controlled and the RF side seems quite straightforward, but the modulator card has a phase locked oscillator on it which I don't understand and the control arrangements are difficult to backtrace - I haven't managed to get the unit to Transmit yet, despite there being an input marked Keying Line. Also, there appears to be inputs for Tone, Voice and Digital, with lots of pots for adjusting levels and modulation etc. I am still trying to work out what the Digital input does.
I may try contacting Multitone, as suggested.
cheers
Peter G8BBZ

G6Tanuki · 16th Jul 2016, 10:44 am

Alas it's *just* outside the new extended up-to-147MHz 2M-band, so shouldn't be too hard to move it.

I wonder if there'd be much in the way of opportunities for POCSAG pager-protocol QSOs if you do get it working? Could be an interesting 'classic digital' mode in the same spirit as RTTY.

13th Jul 2016, 5:40 pm	#1
G8BBZ Pentode Join Date: Oct 2005 Location: Hebden Bridge, West Yorkshire, UK. Posts: 200	Multitone Paging transmitter Hi All, I have been given a very nice 25w FM paging transmitter, currently crystalled for 147.80MHz. The label says Multitone and the model number appears to be TA666 but there is a label saying "Made in Quincy, Illinois" and the style of assembly is certainly american, probably 70's or early 80's. I would like to try and convert this for use on 2m. as it is so close already, and wonder if anybody out there might have any info on the equipment - a circuit diagram would be ideal! cheers Peter G8BBZ __________________ Peter G8BBZ

13th Jul 2016, 8:59 pm	#2
Bazz4CQJ Dekatron Join Date: Apr 2009 Location: Oxfordshire, UK. Posts: 4,935	Re: Multitone Paging transmitter Interesting. The early Multitones worked on about 27MHz, the Tx running a 6146 PA and the receivers had an AF114 receiver sending AF in to a few OC71's. Sounds as though at some later stage, they went to VHF FM using badged equipment from the US. B

13th Jul 2016, 10:55 pm	#3
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: Multitone Paging transmitter Multitone is a UK company, set up by a Russian immigrant in the late 50s. They do have a Canadian distributor, and presumably also source internationally.

14th Jul 2016, 11:36 am	#4
Malcolm G6ANZ Octode Join Date: Feb 2006 Location: Bristol, UK. Posts: 1,042	Re: Multitone Paging transmitter Peter, you could try asking Multitone directly for information. If the Tx is obsolete , by their standards, then they might send you circuit details or even a manual. I have done this direct approach several times and if you are polite and honest then usually the company will help. Malcolm

14th Jul 2016, 9:17 pm	#5
Biggles Rest in Peace Join Date: Feb 2004 Location: Hexham, Northumberland, UK. Posts: 2,234	Re: Multitone Paging transmitter I used to work on these things back in the eighties for the Fire Service. The frequency sounds about right so you may have an ex Fire unit, or maybe RNLI. From memory they were very reliable so I can't remember much about the units we had apart from they ran off a 24VDC battery supply and were triggered by a telephone line. I doubt whether they would be synthesised, probably just crystals, so it may not be too difficult to convert. It may be you have a different version to the ones I maintained as I imagine the units would be marketed to a variety of users.

15th Jul 2016, 12:53 pm	#6
G8BBZ Pentode Join Date: Oct 2005 Location: Hebden Bridge, West Yorkshire, UK. Posts: 200	Re: Multitone Paging transmitter I thought that there was something familiar about the frequency - it's the one used for Fireman's Alerters isn't it? I had a Pye unit on the same frequency some time ago. The transmitter is crystal controlled and the RF side seems quite straightforward, but the modulator card has a phase locked oscillator on it which I don't understand and the control arrangements are difficult to backtrace - I haven't managed to get the unit to Transmit yet, despite there being an input marked Keying Line. Also, there appears to be inputs for Tone, Voice and Digital, with lots of pots for adjusting levels and modulation etc. I am still trying to work out what the Digital input does. I may try contacting Multitone, as suggested. cheers Peter G8BBZ __________________ Peter G8BBZ

16th Jul 2016, 10:44 am	#7
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 14,007	Re: Multitone Paging transmitter Alas it's just outside the new extended up-to-147MHz 2M-band, so shouldn't be too hard to move it. I wonder if there'd be much in the way of opportunities for POCSAG pager-protocol QSOs if you do get it working? Could be an interesting 'classic digital' mode in the same spirit as RTTY.