Re: [Drakelist] T4XC drive
Rick - Check the DC voltage on the shielded wire at T14 (center pin on side closest to CAR BAL pot). In CW mode, this voltage should be 0.0 with the GAIN at MIN, rising to about a volt as the GAIN is turned up. IF the voltage does NOT go to 0 at MIN, there is a problem with R105/R15, switch, etc. In AM mode this voltage should be about a volt regardless of GAIN position. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com Richard Tucker wrote: My T4XC began providing full output on cw regardless of where the drive control was set--even all the way CCW. Normally on CW you have to advance it beyond 12 o'clock for full output. I consulted with Garey, K4OAH, and at his suggestion, checked R-105, the xmit gain control for continuity and value and it checked out. I also checked R106 and it checked out okay. His CD was a great help in locating R-106. I am going to trace and check the associated wiring. Another other thoughts or ideas to check out would be appreciated. Thank you Rick ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T4XC drive
Rick, Is this on any particular band? Does the power out vary with position of the TUNE and LOAD controls? Does this happen into a dummy load? If the PA goes into parasitic oscillation power out will go full bore with the slightest advancement of the GAIN control. Also if there is an issue with the carrier null this will also cause full or nearly full output when the mic is keyed. 73, Gary http://home.roadrunner.com/~w8pu/___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T4XC drive
Hi Rick, Sounds to me like your finals are ...taking off somehow, i.e. oscillating... What does the monitored signal sound like...? Is it exactly as displayed on the frequency dial...? Is it raspy-sounding / unstable...? Those are all sure-fire indicators that you have an instability issue with your rig there! ~73~ de Eddy VE3CUI - VE3XZ *** - Original Message - From: Rick Tucker To: drakelist@zerobeat.net Sent: Thursday, January 07, 2010 9:10 AM Subject: [Drakelist] T4XC drive Last night, my T4XC was providing full output on cw regardless of where the drive control was set -- even all the way CCW. Normally, on cw you have to advance it beyond 12 o'clock for full drive. I checked and double checked all switch settings, etc. Any suggestions? Thanks Rick W0RT ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T4XC drive
Rick - Check R105 and R106 and associated wiring for continuity and value. If R105 opens at the bottom (ground) end, R106 or its wiring open up, full drive regardless of GAIN control setting. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Rick Tucker wrote: Last night, my T4XC was providing full output on cw regardless of where the drive control was set -- even all the way CCW. Normally, on cw you have to advance it beyond 12 o'clock for full drive. I checked and double checked all switch settings, etc. Any suggestions? Thanks Rick W0RT ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
