Re: [Drakelist] Possible problem with T-4XC xmtr
Thanks to all who offerred help. I let the transmitter sit over the weekend and on Monday it was OK again. Back to normal. I don't understand, but since it don't seem broke I think I won't open it up. 73, DE WA9RYF - Original Message - From: Richard Knoppow 1oldle...@ix.netcom.com To: Howard Traxler htraxl...@earthlink.net Sent: Monday, February 22, 2010 9:55 AM Subject: Re: [Drakelist] Possible problem with T-4XC xmtr - Original Message - From: Howard Traxler htraxl...@earthlink.net To: drakelist@zerobeat.net Cc: Howard K Traxler htrax...@earthlink.net Sent: Sunday, February 21, 2010 3:58 PM Subject: [Drakelist] Possible problem with T-4XC xmtr Hi all, don't know that this question went out on the list: Friday I was tuning up my T-4XC on 80M. Heard a very loud POP came from somewhere behind the front panel. No smell of smoke or oazone. Never tune for more than 4 or 5 seconds at a time and never off-resonance more than 1 or 2 seconds. Before this incident, the xmtr tuned up to 120 to 140 watts (according to my TW-1 talking watt meter); after, it now peaks at about 80W. I had a QSO afterwords, so I know it's working some. Antenna match is about 1.3/1. Do you think I did something real bad or maybe it's just a tube or a plate choke or something? Where should I start to diagnose? Thanks, anybody. 73, Howard, WA9RYF This is sort of generalized trouble shooting advice. First make a careful visual inspection. Sometimes parts fail without producing much smoke or odor, however, there may be visible residue. Also wiggle the resistors a bit to see if any are cracked. The next step is to make socket resistance and voltage readings and compare them to the values in the handbook charts. Keep in mind that in equipment as old as this that the resistors will have drifted so the values may not be exact without indicating a problem. However, if any are more than perhaps 20% off its a pretty good sign of something wrong. Of course check power supply values first and open up the power supply and inspect it also. Even if the noise did not seem to come from the PS it may have. -- Richard Knoppow Los Angeles WB6KBL dickb...@ix.netcom.com ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Possible problem with T-4XC xmtr
Howard, Hmmm. Give the loud pop and subsequent drop of output power, I'm wondering if you had a brief internal arc within one of your final tubes. A violent arc that involves the cathode could easily destroy a region of the cathode coating and thus reduce peak emission, yet allow the tube to continue to operate. But maybe you lost one of the tubes completely? Is your resting plate current normal? Dennis AE6C On Sun, Feb 21, 2010 at 3:58 PM, Howard Traxler htraxl...@earthlink.netwrote: Hi all, don't know that this question went out on the list: Friday I was tuning up my T-4XC on 80M. Heard a very loud POP came from somewhere behind the front panel. No smell of smoke or oazone. Never tune for more than 4 or 5 seconds at a time and never off-resonance more than 1 or 2 seconds. Before this incident, the xmtr tuned up to 120 to 140 watts (according to my TW-1 talking watt meter); after, it now peaks at about 80W. I had a QSO afterwords, so I know it's working some. Antenna match is about 1.3/1. Do you think I did something real bad or maybe it's just a tube or a plate choke or something? Where should I start to diagnose? Thanks, anybody. 73, Howard, WA9RYF ___ 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
[Drakelist] Possible problem with T-4XC xmtr
Hi all, don't know that this question went out on the list: Friday I was tuning up my T-4XC on 80M. Heard a very loud POP came from somewhere behind the front panel. No smell of smoke or oazone. Never tune for more than 4 or 5 seconds at a time and never off-resonance more than 1 or 2 seconds. Before this incident, the xmtr tuned up to 120 to 140 watts (according to my TW-1 talking watt meter); after, it now peaks at about 80W. I had a QSO afterwords, so I know it's working some. Antenna match is about 1.3/1. Do you think I did something real bad or maybe it's just a tube or a plate choke or something? Where should I start to diagnose? Thanks, anybody. 73, Howard, WA9RYF ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
