Modifications for the ICOM - RogerK

Das spart einen mords Haufen Arbeit, weil man am 475H nur sehr beschwerlich an die Buchse in der Rückwand hinkommt.Um diese Leitung umzumünzen muß man am Connector J13 den Pin 4 abklemmen, das ist eben diese Leitung zu Pin5 derErweiterugsbuchse, und sie an PIN9/IC 6 anlöten. FERTIG. Dazu braucht man nur den unteren Deckel des Gerätes zu öffnen.J13 sitzt nur ca. 3 cm vom IC6 entfernt, und wenn man die Leitung an PIN 4 (schwarz isoliert) knapp am Stecker abzwickt oderaus dem Stecker herausbastelt reicht es problemlos bis zum IC hinüber.Die dazugehörige Abschirmung auf Pin5 / J13 läßt man natürlich dran. Das RX-Signal liegt jetzt logischerweise an PIN 5 der AQS-Buchse am Gerät, nicht an PIN 11, wie von DG5EM ursprünglich beschrieben.Fragen bitte an DH1SAJ @ DB0RBS, MYBBS DB0SAO ist z.Zt. ohne LINK73 de Jochen, DH1SAJ @ DB0RBSThis modification is read 507 times.top of page19-07-1998(IC-490) Modifikation af IC-490 for 9K61. The back section is fixed by four screws through the side plates. Remove those screws and bend the back section as far asthe wiring allows. You will see the screw heads when the top and bottom cover of IC490 have been removed.2. 470 nF = 0.47 µF The capacitance could be higher, but there are space limitations inside the rig underneath the IC490 MainUnit print.For the time being you will not need the connection with varactor D3 for any satellite, but you may need it for a 9600 baudterrestrial net. It will, however, be feasible to prepare that connection as well when the AF/FM and AF/SSB connections arebeing built.3.+12V -------+ 4.7 k¦ X850 k X ¦ 0.47 µF¦ +--¦--> SSB out to 9-pin connector#3/IC3 ¦ /SSB in ->--¦-----*cable-----+--¦ BC337 or similar NPN transistor0.47 µF ¦150 k X ¦- -*cable from 0.47 µF condenser on the Main Unit to the amplifier located at an empty spot within the rigYou will need the above amplifier only when SSB signal level at #3/IC3 will not be sufficient for your TNC. I am not familarwith TAPR 1200 baud psk modem.4. As you know doppler shifts UO-14 frequency downwards only from rise to set. Often 435.077 ---> 435.058 MHz.Consequently IC490 needs down commands only. It will get such a command each time the calculated frequency drops by1 kHz. My program calculates the current frequency, not doppler shift only. I initally tune my Rx to the frequency I knowUO-14 has, when rising above horizon. I dont need to hear UO-14 at that moment. In fact I know UO-14 frequency anytime without listening, just by looking at the monitor. When I tune my Rx at that frequency I know that UO-14 is there. Thecontrol system then steps the frequency down as frequency calculation tells it to do.I think you will not need the diagram for the circuitry since your tracking program apparently does not tell the above things.You would find Finnish speaking fellows at the subsidiaries of Finnish companies, like EPL-Kone Pty, in your country. That wouldunfortunately not solve the program problem.Pate OH2SN @ OH2RBIThis modification is read 551 times.top of page