Hi all, I know this is not directly related to Elecraft, but I think it is an acceptable OT topic per the admins, and I think I remember Wayne even talking about this subject long ago, so here goes.
I have a radio (FT8100) that I want to use with a TNC-X PIC modem. However, the tnc will not put the FT8100 into transmit. The tnc uses a simple 2n2222a switch with a 10K resistor in series with the PIC output and the base of the 2n2222a. 1) If I disconnect the radio cable from the tnc and ground the PKS (ground to transmit) wire, the FT8100 goes into transmit. 2) If I connect the same cable to a new Icom IC-208H, the TNC-X works fine and keys the radio. John Hansen the designer of the TNC-X says that there are many hams using the FT8100 with the TNC-X and there are no currently known problems with using the TNC-X and FT-8100. I am thinking that the 2n2222a might be a little weak or have too much on resistance. I will be checking the 2n2222a with my analyzer. I think I remember Wayne, N6KR, saying how great the 2n7000 was over a bipolar transistor for use as a switch. Can anyone recommend a circuit change using a 2n7000 or perhaps some other simple mod to the tnc other than using a reed relay to let the FT8100 do its thing? I relize that I should probably go into the FT8100, but I am not looking forward to that. Thanks, Steve Pituch, W2MY Corpus Christi -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.409 / Virus Database: 268.14.3/531 - Release Date: 11/12/2006 _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
