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Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment.

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Old 6th Sep 2018, 10:32 pm   #21
Sparky67
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Default Re: Tait 2015 programming

If you would like to let me have your email address via a PM I will send you a PDF of the service manual.

Martin
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Old 6th Sep 2018, 10:43 pm   #22
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Default Re: Tait 2015 programming

I think I'm going to need it after all, thanks Martin ... sending you a PM shortly.
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Old 7th Sep 2018, 8:44 am   #23
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Default Re: Tait 2015 programming

Dropbox link emailed...


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Old 7th Sep 2018, 9:47 am   #24
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Default Re: Tait 2015 programming

Martin, thanks for that. Some of the files in the archive are actually broken and will not open in either Adobe Reader or Chrome Browser, but the files I needed to work are OK. The RXD and TXD lines from the microphone socket eventually go to the serial transmit and receive pins on the internal UART of the 68HC705 processor, and if they went there directly then a standard MAX232 level converter (as I have built) would work fine.

But in this wider view of the control head circuit (attached), we can see that the RXD and TXD lines pass through internal inverters on the way through the control head. The TXD output is via a simple logic inverter gate and therefore not exactly RS232 compliant - the RXD input is via a transistor inverter clearly designed to be RS232 voltage tolerant.

However, this internal inversion means that the inversion already performed by my one stage MAX232 level converter leaves the data the 'wrong way up'. Your interface deals with that by using elements 3 and 4 of the MAX232 to perform a second inversion within the interface, turning the data the right way up again and also converting it back to RS232 levels which the Tait's RXD input stage can tolerate.

I think I can fix mine either by modifying it to include the extra two elements of the MAX232, currently unused, or I can insert TTL level inverters in the RXD and TXD lines between the MAX232 and the radio.
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Old 7th Sep 2018, 6:58 pm   #25
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Default Re: Tait 2015 programming

Quote:
Originally Posted by SiriusHardware View Post
But in this wider view of the control head circuit (attached), we can see that the RXD and TXD lines pass through internal inverters on the way through the control head. The TXD output is via a simple logic inverter gate and therefore not exactly RS232 compliant - the RXD input is via a transistor inverter clearly designed to be RS232 voltage tolerant.
In the common (IBM pc) serial port, 1488 and 1489 chips were used. The MC1489 receiver chip internally is just the same sort of circuit as your RXD input i.e. transistor with 4k resistor and diode to eliminate the negative swing. A lot of later "RS232" style device ports did not bother with the negative rail at all - and with the normal shortish cables everyone was happy.
I would just connect direct - making sure not to let the PC TX line meet your TX output transistor while experimenting.
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Old 7th Sep 2018, 7:50 pm   #26
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I would just connect direct -
It may yet come to that - I had some time spare at work today so I rejigged my cable to be like Sparky's and very briefly tried it tonight.

Now, whenever the software tries to open a dialogue with the radio the radio is going 'beep beep', which suggests that the radio may be seeing the PC trying to talk to it. However, the software still is not seeing the response, if any, from the radio.

Unfortunately I've run out of time on this for now and will have to get on with other things for a week or so but when I get back on it I'll look to see if any data is coming back out of the radio and if so, how far through the interface it is getting.

On the face of it what the interface does is absurd - it takes in RS232, converts it to TTL level, and then converts it back to RS232. So as you say, might as well not bother with the interface and just connect direct.

I think the reason for the interface is to cover those cases where the PC will NOT accept the radio's 0V to +5V output swing as a valid RS232 input swing, but presumably the MAX232 does, and so the main job of the interface is to convert the radio's feeble 0V to 5V output swing into a -9V to +9V swing which will drive PC RS232 inputs of all flavours. That's my guess anyway.
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Old 13th Sep 2018, 7:50 pm   #27
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Default Re: Tait 2015 programming

Out of interest, which software / version is being used?

Martin
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Old 13th Sep 2018, 8:10 pm   #28
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I can't really say just now as the PC etc have been put away for now. I'll be back on this in a few days and then I will be able to be a bit more informative.
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Old 17th Sep 2018, 9:38 pm   #29
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I'm now 100% sure that my programming lead is correct after I configured it to be like Sparky's with RS232 in and RS232 out. I've tried the following versions of software

PGM201X V1.24 (DOS)
PGM201X V1.30 (DOS)
T2000 Conventional programming application V3.00 (Windows)

All three of these make the radio beep and flash when trying to establish contact with it, but none of them prompt a data response from the radio, that is, no response can be seen on the data output terminal of the microphone socket even though the radio appears to be reacting to the software query.

It might just be that the Windows version only works with series II radios and the two DOS versions are too early to communicate with the firmware in this radio. It would be helpful to know what the final / latest DOS version was.

Otherwise, I'm going to have to dismantle the radio to scope the TX data from the microprocessor's TX data pin. It's possible that someone may have damaged the output inverter in the control head during previous efforts to connect to this radio.

Sparky, several of the files you kindly pointed me to were corrupt including, I believe, the one containing the disassembly instructions for the series 1 T2000 radios. The covers look like a very strong spring clip fit but I don't want to apply the amount of force which will obviously be needed without knowing that is actually what is required.
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Old 17th Sep 2018, 10:01 pm   #30
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Default Re: Tait 2015 programming

..add to the above T210X V1.40 (DOS) which, like the above, makes the radio beep / flash but prompts no data output from it.
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Old 17th Sep 2018, 10:24 pm   #31
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Default Re: Tait 2015 programming

I found the following interesting software-agnostic test snippet over in a discussion on the Austech forums:

"Use a Terminal program such as Hyperterminal. Set it to 4800 baud N,8,1 if you understand how to do this. Then send Shift-6 (^) to try a radio reset, if this works the path in to the radio is tested. You should then see a return from the radio the character v, proving path out from the radio is tested. If these both are OK, then it looks like a Software and PC Hardware problem"

I tried this test and sending Shift-6 from Hyperterminal at 4800-N-8-1 does make the radio flash / beep just as it does when queried by the software. But unlike in the case stated above, the radio is not transmitting a 'v' response.
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Old 18th Sep 2018, 9:21 pm   #32
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Default Re: Tait 2015 programming

Finally.

I took the radio apart and found that there was data coming out of the microprocessor TX pin and followed it across the logic board and into the control head, where I found probably the most obvious thing it could ever be, a crack around the relevant solder joint on the microphone socket itself. For anyone else troubleshooting the programming connection in future it's worth knowing that the radio squirts out a lower case 'v' (4800-N-8-1) on TXD at power-on.

With that repaired, I find that the latest DOS software I have (V1.40) recognises the radio and works with it, but the Windows (V3.0) software, although it sees the radio and recognises the type, declares itself unable to work with this specific model. It does however identify the radio uP firmware as V2.05.

the DOS software (V1.40) shows the model to be a T201516, or in other words a 16 channel (maximum) variant.

It's actually already programmed for what would have been a perfectly sensible set of 2m frequencies 20 years ago,

CH1 - CH7 = R1 to R7
CH8 = R0, displaced here because there is no channel 0 on the radio

CH9 - CH15 are programmed with S17 to S23 in 25Khz steps. CH16 is 144.525 simplex, possibly SSTV or ATV spot frequency back in those days?

Last edited by SiriusHardware; 18th Sep 2018 at 9:45 pm.
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Old 18th Sep 2018, 9:32 pm   #33
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Default Re: Tait 2015 programming

Great stuff. Pleased you got it working in the end. There is still T2000 stuff on my old PC I haven’t sent you so let me know if there is anything else you need.

Martin
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Old 18th Sep 2018, 9:43 pm   #34
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Thanks for all your help Martin, the diagrams were especially valuable.
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