We intend to use the telecar 9 for an APRS Digipeater project and have obtained two pieces.
I have programmed the eprom 27C256 with the tc9 firmware (the tc2m-v15-doublebin version) on my Willem programmer and it looks like all the functions are working, except I almost hear no audio really very very low level. The audio amp is ok, because the Morse code comes out loud and clear.
Could it be that there is some remnant left in the GR881 EEprom from previous programming (sub audible tone filter ?) and can I still programme this firmware with the software by Jan, Triple1nl (http://www.triple1.nl/index.php/page/6.html)
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Hi Erik, I hope you already solved your audio problem. I see your problem only in these days while searching doc about the Telecar9 160/25. In order to “destroy” a couple of them I tried the DL1FAC firmware and I found the same problem.
I solved it shorting pins 3 and 4 (using a common PC jumper) on the ST652 connector, removing first the CTCSS (Mopil?) module, of course.
After this, as the Telecar was still working and as I found very noisy to receive also the 12,5KHz adjacent channels I changed the CFU455D ceramic filter with a CFU455HT; now I can receive only one channel within a 8,6KHz bandwith and an adjacent channel rejection more than 40dB. Not sensational but satisfactory.
The Telecar is still working, do you have any other idea in order to stop it? Joking aside, it’s the first time I play with this radio and every advice or suggestion will be well accepted.
Giorgio IW4ANU
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Hi Erik, nice to see that someone more is interested in the tc9 project!
I remember having a problem with the audio in some devices, but I don't remember if it was on TX or RX. One IC pad was deliberately cut almost at the IC casing. The chip was located near the "back" of the radio (near the heatsink side). It might be IS401 if I remember well, but this is some years old now. Have a close look at ALL the DIL pins to see if one of them is cut. I could re-solder the pin and everything went fine.
Another hint is that you may have a bridge between pin 16 (GAKO=Gabel Kontakt) and ground (Pin 22 for example) in the microphone connector (DB25). It has to be removed for tc9 firmware, but be in place for the original one.
I don't thinks that tc9 do support sub audio squelch, so I doubt that this is your problem, although Wulf-Gerd could answer more precisely than me!
Have fun and 73
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Stupid idea that poped to me today, isn't it simply the squelch that is blocking your audio? It can be set by pressing the "squelch" key (the one with a small wave pictogram) and then the down arrow several times.
Regarding the EEPROM content it's good practice to erase the full EEPROM. We had a bad behavior on some tigs with the setting of the TX power, because the firmware didn't like the old content of one particular byte in the EEPROM. If you clear the whole memory, then you're safe.
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We intend to use the telecar 9 for an APRS Digipeater project and have obtained two pieces.
I have programmed the eprom 27C256 with the tc9 firmware (the tc2m-v15-doublebin version) on my Willem programmer and it looks like all the functions are working, except I almost hear no audio really very very low level. The audio amp is ok, because the Morse code comes out loud and clear.
Could it be that there is some remnant left in the GR881 EEprom from previous programming (sub audible tone filter ?) and can I still programme this firmware with the software by Jan, Triple1nl (http://www.triple1.nl/index.php/page/6.html)
Hi Erik, I hope you already solved your audio problem. I see your problem only in these days while searching doc about the Telecar9 160/25. In order to “destroy” a couple of them I tried the DL1FAC firmware and I found the same problem.
I solved it shorting pins 3 and 4 (using a common PC jumper) on the ST652 connector, removing first the CTCSS (Mopil?) module, of course.
After this, as the Telecar was still working and as I found very noisy to receive also the 12,5KHz adjacent channels I changed the CFU455D ceramic filter with a CFU455HT; now I can receive only one channel within a 8,6KHz bandwith and an adjacent channel rejection more than 40dB. Not sensational but satisfactory.
The Telecar is still working, do you have any other idea in order to stop it? Joking aside, it’s the first time I play with this radio and every advice or suggestion will be well accepted.
Giorgio IW4ANU
Hi Erik, nice to see that someone more is interested in the tc9 project!
I remember having a problem with the audio in some devices, but I don't remember if it was on TX or RX. One IC pad was deliberately cut almost at the IC casing. The chip was located near the "back" of the radio (near the heatsink side). It might be IS401 if I remember well, but this is some years old now. Have a close look at ALL the DIL pins to see if one of them is cut. I could re-solder the pin and everything went fine.
This schematics may help you (even if you don't have the exact model, it's a source of inspiration). Just follow the audio path:
http://www.yvesoesch.ch/radio/trxmod/aeg/schema/rt-61_scheme.pdf
Layout of the controler board is here:
http://www.yvesoesch.ch/radio/trxmod/aeg/schema/layout/layout_ctrl.jpg
Another hint is that you may have a bridge between pin 16 (GAKO=Gabel Kontakt) and ground (Pin 22 for example) in the microphone connector (DB25). It has to be removed for tc9 firmware, but be in place for the original one.
I don't thinks that tc9 do support sub audio squelch, so I doubt that this is your problem, although Wulf-Gerd could answer more precisely than me!
Have fun and 73
Stupid idea that poped to me today, isn't it simply the squelch that is blocking your audio? It can be set by pressing the "squelch" key (the one with a small wave pictogram) and then the down arrow several times.
Regarding the EEPROM content it's good practice to erase the full EEPROM. We had a bad behavior on some tigs with the setting of the TX power, because the firmware didn't like the old content of one particular byte in the EEPROM. If you clear the whole memory, then you're safe.