Morton Jim@LLL-MFE.ARPA (05/01/85)
I ordered a Heath TNC as soon as the catalog came out and it was an "official" product. Recieved my kit Thurs the 25th. (i picked mine up at my local store) The kit is nice. Uses a taped roll of resistors, diodes and caps to speed assembly. I took about six hours to glue the thing together and make cables for my terminal and radio. The kit comes with a connector and cable for the connection to the radio but none for the terminal. I had some bad parts - most were locally replaceable. The first was a bad 7912 -12V regulator that liked 18 volts better than 12 . The second was a MC1458 op amp in the output to my transmitter. This was pretty easy to find as the last step in calibration (audio level and tone null) would not work right. the idea of this cal step was to hook a scope onto the audio output and adjust the level with ptt on. then turn off ptt and adjust a null control for minimum level. then set the proper audio level key down to make sure. Well my op-amp was a better oscilator than amplifier so no matter how i adjusted things, the level stayed the same. Being curious, i looked at the input of the op-amp and saw evrything o.k. so i swapped the chip and viola ! i am on the air. My last problem regards the Non - volatle ram. I can not seem to program it. I will consult heath and probably get a new chip or some such. anyway... i have had a contact with the thing... seems to work although i need a better antenna and more power ( i am running a whopping 3 W) I can hear a lot of stations that can not hear me. Heath did provide good instructions for hooking the unit to various radios including my ICOM IC02AT which required a transformer on the XMIT side of things. All in all i am happy and satisfied with what i got. Jim Morton WA6FWW 415-423-2374 days