De : EA5XE A : MODS @EA Tipo/status : BX Fecha/hora : 05-Dic 06:26z Bid : 9801_EA5BU Mensaje # : 76638 Titulo : 9600 BAUDIOS - tnc220.9K6 Path: !EA7UH!EA4PO!EA8AOP!EA8JF!EA7RSM!EA7PW!EA5EDU!EA5VDR!EA5BU! From: EA5XE@EA5BU.EACS.ESP.EU To : MODS@EA PAC-COMM TNC-220 9600 baud Fullduplex by G4WFQ ---------------------------------------------- For those of you owning a 220 and would like to be able to operate at 9600 fullduplex the following information will save you an awful lot of hassle and bother. If you thought it did work at 9600 fullduplex think again it doesnt. The manual does say it can, but dont believe a word in the manual its all a load of rubbish. Same goes for what it says about the Watch dog Timer. Carry out this simple mod, should take you all of 5 minutes. It took me 3 days to figure out why I could not Digi-peat via UOSAT3 at 9600 bauds. Its because when you turn Fullduplex on the TX Radio baud rate returns to 1200 buads whilst the rx baud rate remains at 9600. Most strange isnt it. Pac-comm told me it does work. Cant see how myself. Locate 74HC4020 (Baud rate generator chip) and remove from SKT Bend pin 12 up and replace. Solder flying lead onto pin 12. (DONT FORGET THE HEAT SINKS) Solder flying lead onto pin 1. ( " " " " " ) Terminate these two leads onto a SPDT switch. Solder lead from output of switch to pin 12 (rtxca) of 8530 sio chip. Throw the switch for 9600 fullduplex. Restore for 1200 operation. Thats it job done. Pac-Comm were there usual selves in support of this problem. NILLLLL. 73 de Dave G4WFQ @ GB7HXA 5 NOV 90 2330UTC EOF ============ FIN MSG# 76638 ============ De : EA5XE A : MODS @EA Tipo/status : BX Fecha/hora : 05-Dic 06:22z Bid : 9800_EA5BU Mensaje # : 76637 Titulo : 9600 BAUDIOS - tnc220-2.9K6 Path: !EA7UH!EA4PO!EA8AOP!EA8JF!EA7RSM!EA7PW!EA5EDU!EA5VDR!EA5BU! From: EA5XE@EA5BU.EACS.ESP.EU To : MODS@EA Hello All @ AMSAT The following modification to the 220 will allow your Tnc to operate at 9600 bauds in Fullduplex. For those of you who thought you already could I suggest you try it. It must be mentioned at this stage that the version of my 220 is 1.3. If yours is a different version then the story may be different, but I doubt it. The reason for this mod is to allow my station to operate on UOSAT3 FULLDUPLEX Previous to this mod I have been ripping my hair out as to why I could not digipeat via UOSAT3. When one day I discovered that when I changed the baud speed to 9600 and then put Fullduplex on the txbaud rate changed back to 1200 whilst the rx rate remained at 9600. Most perculiar I thought. So, I got in communications with the main Agent in the UK for Pac-comm to see if anyone else had this same problem. No came the reply, obviously no one else has tried it yet I thought. So here I am stuck with a TNC that is no use to me for UO3. Can you help me then please I asked Agent. Yes we'll see what we can do. In the meantime Rep has been to Paccomm across the pond and I am told that they work alright over there. Cant be I said! So anyway he suggests I try changing the thirmware which I did but still no good. Ok we'll send them another Fax they said. Fine! Another phone call to Agent 2 weeks later, no info or reply. So I put pen to paper and addressed the same question to the Gentleman concerned at Pac-comm. To date Ive no reply, letter sent some 4 months ago. Not impressed! With UO3 software now on release, and uploading and testing of UO3 bulletin software imminent I figured I had better do something. The result is a crued cure. 9600 FULLDUPLEX on the Pac-Comm TNC-220 by D. Hulatt G4WFQ 19th Aug 90 ------------------------------ Locate 74HC4020 and remove from IC socket CAREFULLY bend pins 1 and 12 up Solder flying leads to pins 1 and 12 on 74HC4020 Solder flying lead to pin 12 on SIO 8530 chip Use a SPDT switch to switch to 2 signals from 4020 to SIO Replace 4020 Drill 1/4 inch hole in rear plate above RS232 slot Insert switch and secure. Thats it. Throw switch for 9600 FULLDUPLEX operation, revert for normal. NB: You still have to change buad rate in s/w. I hope this information will be of use to some. I would like to thank Uk Agent for trying to get info from Pac-Comm. It must be like trying to get blood out of a stone. Thanks Pac-Comm, no need to bother now I've done it myself! 73 de Dave G4WFQ @ GB7PET AUK.2404 19 Aug 90 ============ FIN MSG# 76637 ============