Cleartone/Tait 2way radios (any uses?) - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

SiriusHardware · 4th Sep 2018, 9:35 pm

Quote:

Originally Posted by Jon_G4MDC

There is some hack fix under the HEF4750 to make 12.5k spacing 10k - but I can quite understand if you don't want to do that!!

Why not? But I'm afraid it is well and truly (20+ years of accumulation) mothballed at the moment. Could take some finding as I have a large cache of MX290 series radios buried in the loft and they all look very much the same on the outside.

electronicskip · 5th Sep 2018, 12:46 pm

Quote:

Originally Posted by SiriusHardware

Good pictures, can we see the insides now?

Your wish is my command

Cleartone 150 PIC 1
Crystals 172t.000 NKD R TX
172T.000 26W 80H TX

Cleartone 235 PIC 2
Crystals TX172t00 TX
RX 172.000

Tait T198 PIC3/4
Crystal TX 28.59375
Crystal Filter QMF 10758

'Ive copied everything I can from the crystals which are in the sets, but some are obviously missing.

SiriusHardware · 5th Sep 2018, 1:42 pm

Just looking quickly. It seems the crystals in the first two may be marked with the actual operating frequency for which they were made, rather than their own frequency. Do you have a scanner? Fire the 150 up into a dummy load and listen on 172.000Mhz?

Although this seems like a suspicious round-number frequency the only previous Cleartone radios I've ever come across - as-new in the box handhelds in my case - came with crystals for a 'Test Frequency' already installed. I'm wondering if this was the case with the mobiles as well?

unixmanuk · 5th Sep 2018, 3:44 pm

172.000 MHz was a short term hire frequency back in the day - may still be...

Common to find handhelds on that spot.

unixmanuk · 5th Sep 2018, 3:55 pm

Looking at the available data, the T198 is a high band (138-174) FM transceiver, 25W output. The one I mentioned earlier may have been a T162c on lowband AM (memory none too good these days....)

The crystal frequency for the transmitter is given as 1/6 carrier, which puts your transmitter on 171.5625MHz with the figure you gave for that one. Seems to be possibly on similar channels to the Cleartone(s)?

SiriusHardware · 5th Sep 2018, 4:27 pm

In two of those radios I'm seeing what looks to be an FM I.F. / discriminator IC. In the first image the IC number is only just not readable but I would say it is likely to be a CA3089. In the second image the likely FM I.F. discriminator IC is half hidden in the shadow of wiring.

In the third image it's not so clear cut, as the unreadable IC upper-left is not surrounded by RF components, and the one lower-right appears to be a 4011 (logic IC). Ah, silly me, it's on the other board, the fourth image: Another CA3089 IC by the look of it.

5th Sep 2018, 1:42 pm	#23
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,557	Re: Cleartone/Tait 2way radios (any uses?) Just looking quickly. It seems the crystals in the first two may be marked with the actual operating frequency for which they were made, rather than their own frequency. Do you have a scanner? Fire the 150 up into a dummy load and listen on 172.000Mhz? Although this seems like a suspicious round-number frequency the only previous Cleartone radios I've ever come across - as-new in the box handhelds in my case - came with crystals for a 'Test Frequency' already installed. I'm wondering if this was the case with the mobiles as well?

5th Sep 2018, 3:44 pm	#24
unixmanuk Pentode Join Date: Jan 2012 Location: Worcester, Worcs. UK. Posts: 112	Re: Cleartone/Tait 2way radios (any uses?) 172.000 MHz was a short term hire frequency back in the day - may still be... Common to find handhelds on that spot. __________________ John

5th Sep 2018, 3:55 pm	#25
unixmanuk Pentode Join Date: Jan 2012 Location: Worcester, Worcs. UK. Posts: 112	Re: Cleartone/Tait 2way radios (any uses?) Looking at the available data, the T198 is a high band (138-174) FM transceiver, 25W output. The one I mentioned earlier may have been a T162c on lowband AM (memory none too good these days....) The crystal frequency for the transmitter is given as 1/6 carrier, which puts your transmitter on 171.5625MHz with the figure you gave for that one. Seems to be possibly on similar channels to the Cleartone(s)? __________________ John Last edited by unixmanuk; 5th Sep 2018 at 4:17 pm. Reason: update

5th Sep 2018, 4:27 pm	#26
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,557	Re: Cleartone/Tait 2way radios (any uses?) In two of those radios I'm seeing what looks to be an FM I.F. / discriminator IC. In the first image the IC number is only just not readable but I would say it is likely to be a CA3089. In the second image the likely FM I.F. discriminator IC is half hidden in the shadow of wiring. In the third image it's not so clear cut, as the unreadable IC upper-left is not surrounded by RF components, and the one lower-right appears to be a 4011 (logic IC). Ah, silly me, it's on the other board, the fourth image: Another CA3089 IC by the look of it. Last edited by SiriusHardware; 5th Sep 2018 at 4:34 pm.