"dmartin" <[EMAIL PROTECTED]> made an utterance to the drakelist gang ---------------------------------------------------------------------- Curious to me why the calibrator signal in my R-4C is consistently and immediately 20 dB greater when the Drake-supplied antenna jumper cable connecting it to the T-4XC is pulled from the receiver RCA jack? This occurs on any frequency and band and when the T- 4XC is off and in "separate" mode, i.e., the T-4XC is a completely passive player. The transmitter SO-239 jack is connected to a short length of coax cable terminating in a coax switch with the switch in a position that effectively opens the cable at that point, i.e., no antenna connected. If I remove the coax from the T-4XC SO-239 and attach it directly to the R-4C RCA jack using a suitable adapter, the R-4C calibrator remains at its plus-20 dB signal level, indicating it really is just the loading effect of the T-4XC that drags the calibrator signal down. As you know, the transmitter SO-239 goes directly to the RCA antenna out jack through the relay. My DMM shows the SO-239 in to RCA out on the transmitter to be a direct DC connection and open to ground, but I guess the mere connection of the T-4XC somehow loads down the R-4C calibrator level or detunes the receiver ant/rf circuits.
I suppose there is some kind of fundamental electrical precept I'm missing here. Is this observed condition common to other C-Lines? I could understand "a little bump" one way or another in the receiver calibrator strength when removing connecting cables but 20 dB is a lot! Dan WB4GRA -- Open WebMail Project (http://openwebmail.org) ---------------------------------------------------------------------- Submissions: [email protected] Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net ----------------------------------------------------------------------
