Re: [Drakelist] T4XB No +250V AND blown Filament Fuse
OK T4XB is working now. Finally (with lots of help) and Thanks to the group found a shorted Cathode to Filament in V1 which was causing the 'Tranmit Line' to turn on when it was supposed to be in Standby/Rcvr. Just made a contact with it and got a good report. Still have RF output a bit low but I think will leave it alone this time... THANKS!!! Paul K3PG some rig pix and snow at: http://pgerhardt.blogspot.com On Tue, Feb 9, 2010 at 12:00 PM, drakelist-requ...@zerobeat.net wrote: Send Drakelist mailing list submissions to drakelist@zerobeat.net To subscribe or unsubscribe via the World Wide Web, visit http://mailman.zerobeat.net/mailman/listinfo/drakelist or, via email, send a message with subject or body 'help' to drakelist-requ...@zerobeat.net You can reach the person managing the list at drakelist-ow...@zerobeat.net When replying, please edit your Subject line so it is more specific than Re: Contents of Drakelist digest... Today's Topics: 1. Re: Cleaned the TR-4 (Garey Barrell) 2. Re: Cleaned the TR-4 (Richard Palmer) 3. Re: T4XB No +250V AND blown Filament Fuse (Paul Gerhardt) 4. Re: T4XB No +250V AND blown Filament Fuse (Garey Barrell) 5. ECL counter IC source? (Curt Nixon) 6. Re: MC10138 ECL counter IC source? (Gary Poland) -- Message: 1 Date: Mon, 08 Feb 2010 15:56:42 -0500 From: Garey Barrell k4...@mindspring.com Subject: Re: [Drakelist] Cleaned the TR-4 To: drakelist@zerobeat.net Message-ID: 4b707a8a.6080...@mindspring.com Content-Type: text/plain; charset=ISO-8859-1; format=flowed Richard - The S-Meter is Zero'd with the cleverly disguised ZERO control on the right side of the chassis.!! :-) Disconnect antenna, detune RF TUNE control, and adjust ZERO control for S1 on the meter. There is no S0 on Drake meters! 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Richard Palmer wrote: There is on thing that is not spelled out. Zeroing the meter. I cleaned all the pots and when I went to zero the meter I found nothing to help me determine the proper setting. So any help there is appreciated. -- Message: 2 Date: Mon, 08 Feb 2010 18:06:42 -0500 From: Richard Palmer burnto...@toast.net Subject: Re: [Drakelist] Cleaned the TR-4 To: k4...@mindspring.com Cc: drakelist@zerobeat.net Message-ID: 4b709902.8000...@toast.net Content-Type: text/plain; charset=ISO-8859-1; format=flowed Gary, Since I cleaned it I knew where it was. I noticed that the zero adjust affected the meter's reading of the bias also ... so I wanted to get it set correctly. Thanks for your help, Richard Palmer Garey Barrell wrote: Richard - The S-Meter is Zero'd with the cleverly disguised ZERO control on the right side of the chassis.!! :-) Disconnect antenna, detune RF TUNE control, and adjust ZERO control for S1 on the meter. There is no S0 on Drake meters! 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Richard Palmer wrote: There is on thing that is not spelled out. Zeroing the meter. I cleaned all the pots and when I went to zero the meter I found nothing to help me determine the proper setting. So any help there is appreciated. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist -- The law, in its majestic equality, forbids the rich as well as the poor to sleep under bridges, to beg in the streets, and to steal bread. - Anatole France -- Message: 3 Date: Mon, 8 Feb 2010 18:30:25 -0500 From: Paul Gerhardt phgerha...@gmail.com Subject: Re: [Drakelist] T4XB No +250V AND blown Filament Fuse To: drakelist@zerobeat.net Message-ID: bf7299be1002081530r31c5a92du31bf76176f263...@mail.gmail.com Content-Type: text/plain; charset=iso-8859-1 OK still troubleshooting but found 2 more clues I pulled all the tubes and the AC4 power resistor R3 in the 250V line is now cool to touch and V is 260V with NO tubes in. When OA2 is in place (only OA2) R3 is too hot to touch and V drops about 12V. 2nd Clue I finally found what smoked in the chassis. It was hiding under a switch shaft in the RF compartment. The 'smoker' was R30 the 68 ohm 1/2 watt resistor on V5 (final) So I think maybe the tube had a grid to fil short and took out both circuits. I am still not getting a spot signal. R3 is still too hot when OA2 is 'IN' OA2 is blue not shure otherwise if it is good? Problem may be on the 150 V line as that powers the VFO (I think). Still have the tubes out. Paul K3PG in 'snowy' MD pix on http://pgerhardt.blogspot.com On Thu, Feb 4, 2010 at 11:31 AM, Paul Gerhardt phgerha...@gmail.com
Re: [Drakelist] T4XB No +250V AND blown Filament Fuse
Paul, Congrats to you on several accountsfirst for fixing your radio. Second, for taking the time to document your struggle and sharing it with us. It's really useful to virtually look over your shoulder during hunts like this. We all learn something from it. Thanks for sharing your journey John K5MO At 03:10 PM 2/12/2010, Paul Gerhardt wrote: OK T4XB is working now. Finally (with lots of help) and Thanks to the group found a shorted Cathode to Filament in V1 which was causing the 'Tranmit Line' to turn on when it was supposed to be in Standby/Rcvr. Just made a contact with it and got a good report. Still have RF output a bit low but I think will leave it alone this time... THANKS!!! Paul K3PG some rig pix and snow at: http://pgerhardt.blogspot.comhttp://pgerhardt.blogspot.com On Tue, Feb 9, 2010 at 12:00 PM, mailto:drakelist-requ...@zerobeat.netdrakelist-requ...@zerobeat.net wrote: Send Drakelist mailing list submissions to mailto:drakelist@zerobeat.netdrakelist@zerobeat.net To subscribe or unsubscribe via the World Wide Web, visit http://mailman.zerobeat.net/mailman/listinfo/drakelisthttp://mailman.zerobeat.net/mailman/listinfo/drakelist or, via email, send a message with subject or body 'help' to mailto:drakelist-requ...@zerobeat.netdrakelist-requ...@zerobeat.net You can reach the person managing the list at mailto:drakelist-ow...@zerobeat.netdrakelist-ow...@zerobeat.net When replying, please edit your Subject line so it is more specific than Re: Contents of Drakelist digest... Today's Topics: 1. Re: Cleaned the TR-4 (Garey Barrell) 2. Re: Cleaned the TR-4 (Richard Palmer) 3. Re: T4XB No +250V AND blown Filament Fuse (Paul Gerhardt) 4. Re: T4XB No +250V AND blown Filament Fuse (Garey Barrell) 5. ECL counter IC source? (Curt Nixon) 6. Re: MC10138 ECL counter IC source? (Gary Poland) -- Message: 1 Date: Mon, 08 Feb 2010 15:56:42 -0500 From: Garey Barrell mailto:k4...@mindspring.comk4...@mindspring.com Subject: Re: [Drakelist] Cleaned the TR-4 To: mailto:drakelist@zerobeat.netdrakelist@zerobeat.net Message-ID: mailto:4b707a8a.6080...@mindspring.com4b707a8a.6080...@mindspring.com Content-Type: text/plain; charset=ISO-8859-1; format=flowed Richard - The S-Meter is Zero'd with the cleverly disguised ZERO control on the right side of the chassis.!! :-) Disconnect antenna, detune RF TUNE control, and adjust ZERO control for S1 on the meter. There is no S0 on Drake meters! 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs http://www.k4oah.comwww.k4oah.com Richard Palmer wrote: There is on thing that is not spelled out. Zeroing the meter. I cleaned all the pots and when I went to zero the meter I found nothing to help me determine the proper setting. So any help there is appreciated. -- Message: 2 Date: Mon, 08 Feb 2010 18:06:42 -0500 From: Richard Palmer mailto:burnto...@toast.netburnto...@toast.net Subject: Re: [Drakelist] Cleaned the TR-4 To: mailto:k4...@mindspring.comk4...@mindspring.com Cc: mailto:drakelist@zerobeat.netdrakelist@zerobeat.net Message-ID: mailto:4b709902.8000...@toast.net4b709902.8000...@toast.net Content-Type: text/plain; charset=ISO-8859-1; format=flowed Gary, Since I cleaned it I knew where it was. I noticed that the zero adjust affected the meter's reading of the bias also ... so I wanted to get it set correctly. Thanks for your help, Richard Palmer Garey Barrell wrote: Richard - The S-Meter is Zero'd with the cleverly disguised ZERO control on the right side of the chassis.!! :-) Disconnect antenna, detune RF TUNE control, and adjust ZERO control for S1 on the meter. There is no S0 on Drake meters! 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs http://www.k4oah.comwww.k4oah.com Richard Palmer wrote: There is on thing that is not spelled out. Zeroing the meter. I cleaned all the pots and when I went to zero the meter I found nothing to help me determine the proper setting. So any help there is appreciated. ___ Drakelist mailing list mailto:Drakelist@zerobeat.netDrakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist -- The law, in its majestic equality, forbids the rich as well as the poor to sleep under bridges, to beg in the streets, and to steal bread. - Anatole France -- Message: 3 Date: Mon, 8 Feb 2010 18:30:25 -0500 From: Paul Gerhardt mailto:phgerha...@gmail.comphgerha...@gmail.com Subject: Re: [Drakelist] T4XB No +250V AND blown Filament Fuse To: mailto:drakelist@zerobeat.netdrakelist@zerobeat.net Message-ID: mailto:bf7299be1002081530r31c5a92du31bf76176f263...@mail.gmail.combf7299be1002081530r31c5a92du31bf76176f263...@mail.gmail.com Content-Type: text/plain; charset=iso-8859
Re: [Drakelist] T4XB No +250V AND blown Filament Fuse
Paul - Make sure that the TRANSCEIVE switch is in SEPARATE and the MODE switch is in SSB. Are you SURE the relay is dropping out? If these are correct, pull V11 out of the socket. A heater-cathode short in this tube will keep the transmitter keyed. Check the relay carefully. It is possible for the Normally Closed contacts to be pressed down far enough to trap the Arm contact between the NC and Normally Open contacts, keeping the receiver On even though the relay is not energized. A 150 ohm resistor at R3 will dissipate about 1.5 - 2W, which will make the resistor quite warm. 2W of heat is 2W of heat, regardless of how big the resistor is! A maximum of 18 VDC ACROSS R3 is within the normal range. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Paul Gerhardt wrote: 100+ watts out but T4 not going fully to standby mode. Idle current is ok same as before but it is still 'idling' with the TR relay in Receive. I can hear 'noise' in the receiver especially with the INJ cable plugged in. Not all the damage has been discovered. Today I did find a short in one of the 'flea bay' tubes between Cathode and the 'middle' screen on pin 7. The R30 68 ohm 1/2 watt resistor is on pin 7 and it opened. The 100 5 Watt resistor in the AC4 opened this has been replaced with an on-hand 150 ohm 5 watt which is still running hot with the tubes in Filament fuse opened and has been replaced with proper fuse Will ck some more voltages tomorrow. -- Paul Gerhardt K3PG http://pgerhardt.blogspot.com QRP ARCI 6674 FP 274 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T4XB No +250V AND blown Filament Fuse
OK I did some more checks today and this is what I see. With the Transceive in Separate and INJ cable hooked up I can hear the Transmiter VFO in the Receiver and I can still adj the Idle current (although the idle goes up another needle width when the relay closes) I turned it over and tried poking the relay while in receive mode and it did not change. I can hear it switching and seems to be working but in Separate the xmit VFO is 'ON' and I can adj the level in the receiver with the bias adj. I pulled V11 and it did not change. Will check the T/R relay again and make shure someting is not stuck in the contacts. I feel it is almost working but not yet... In Separate should both neon vfo lights be on all the time? I can't remember but now I have the transmitter neon on ALL the time and the rcvr neon goes OFF when I key the mic. In Rcvr AND Xmit Mode either light stays on all the time. Should Both Neons alternate in Separate? Paul - -- Content-Type: text/plain; charset=iso-8859-1 100+ watts out but T4 not going fully to standby mode. Idle current is ok same as before but it is still 'idling' with the TR relay in Receive. I can hear 'noise' in the receiver especially with the INJ cable plugged in. Not all the damage has been discovered. Today I did find a short in one of the 'flea bay' tubes between Cathode and the 'middle' screen on pin 7. The R30 68 ohm 1/2 watt resistor is on pin 7 and it opened. The 100 5 Watt resistor in the AC4 opened this has been replaced with an on-hand 150 ohm 5 watt which is still running hot with the tubes in Filament fuse opened and has been replaced with proper fuse Will ck some more voltages tomorrow. -- Paul Gerhardt K3PG http://pgerhardt.blogspot.com QRP ARCI 6674 FP 274 -- next part -- An HTML attachment was scrubbed... URL: http://mailman.zerobeat.net/pipermail/drakelist/attachments/20100210/e2cb9576/attachment-0001.html Paul - Make sure that the TRANSCEIVE switch is in SEPARATE and the MODE switch is in SSB. Are you SURE the relay is dropping out? If these are correct, pull V11 out of the socket. A heater-cathode short in this tube will keep the transmitter keyed. Check the relay carefully. It is possible for the Normally Closed contacts to be pressed down far enough to trap the Arm contact between the NC and Normally Open contacts, keeping the receiver On even though the relay is not energized. A 150 ohm resistor at R3 will dissipate about 1.5 - 2W, which will make the resistor quite warm. 2W of heat is 2W of heat, regardless of how big the resistor is! A maximum of 18 VDC ACROSS R3 is within the normal range. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Paul Gerhardt wrote: 100+ watts out but T4 not going fully to standby mode. Idle current is ok same as before but it is still 'idling' with the TR relay in Receive. I can hear 'noise' in the receiver especially with the INJ cable plugged in. Not all the damage has been discovered. Today I did find a short in one of the 'flea bay' tubes between Cathode and the 'middle' screen on pin 7. The R30 68 ohm 1/2 watt resistor is on pin 7 and it opened. The 100 5 Watt resistor in the AC4 opened this has been replaced with an on-hand 150 ohm 5 watt which is still running hot with the tubes in Filament fuse opened and has been replaced with proper fuse Will ck some more voltages tomorrow. -- Paul Gerhardt K3PG http://pgerhardt.blogspot.com -- Paul Gerhardt K3PG http://pgerhardt.blogspot.com QRP ARCI 6674 FP 274 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T4XB No +250V AND blown Filament Fuse
100+ watts out but T4 not going fully to standby mode. Idle current is ok same as before but it is still 'idling' with the TR relay in Receive. I can hear 'noise' in the receiver especially with the INJ cable plugged in. Not all the damage has been discovered. Today I did find a short in one of the 'flea bay' tubes between Cathode and the 'middle' screen on pin 7. The R30 68 ohm 1/2 watt resistor is on pin 7 and it opened. The 100 5 Watt resistor in the AC4 opened this has been replaced with an on-hand 150 ohm 5 watt which is still running hot with the tubes in Filament fuse opened and has been replaced with proper fuse Will ck some more voltages tomorrow. -- Paul Gerhardt K3PG http://pgerhardt.blogspot.com QRP ARCI 6674 FP 274 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T4XB No +250V AND blown Filament Fuse
OK still troubleshooting but found 2 more clues I pulled all the tubes and the AC4 power resistor R3 in the 250V line is now cool to touch and V is 260V with NO tubes in. When OA2 is in place (only OA2) R3 is too hot to touch and V drops about 12V. 2nd Clue I finally found what smoked in the chassis. It was hiding under a switch shaft in the RF compartment. The 'smoker' was R30 the 68 ohm 1/2 watt resistor on V5 (final) So I think maybe the tube had a grid to fil short and took out both circuits. I am still not getting a spot signal. R3 is still too hot when OA2 is 'IN' OA2 is blue not shure otherwise if it is good? Problem may be on the 150 V line as that powers the VFO (I think). Still have the tubes out. Paul K3PG in 'snowy' MD pix on http://pgerhardt.blogspot.com On Thu, Feb 4, 2010 at 11:31 AM, Paul Gerhardt phgerha...@gmail.com wrote: Turned on my Working T4Xb and smoke came out the bottom of the rig which I can't see for some reason. The filimant fuse (8A pigtail lead fuse near the 3 big power resistors) is open so replaced that, then no 250 V B+ and found R3 1K 5 watt resistor to be open. Both of these were 'effect' and not cause (I suspect). I changed R3 and got 150V and R3 is hot. Unhooked the yellow 250V wire to the rig and V is good about 270V. Turned power OFF and measured Resistance on yellow wire and it is low only about 150 ohms. Last thing is always suspect and for this the last thing I did a few days ago was install some used FleaBay finals which worked ok it seemed but were very weak only about 60-70 watts out (maybe one was not working?) Put the bright light on the bottom and compared to photo I took before and fail to 'see' any burned parts on the bottom but there was smoke and I think it was from a hot wire and not a componet. Will probably change the finals back to the 'other' weak ones that were at least putting out 120W into the Cantenna and see what is pulling the 250V B+ line down. Any ideas on this one? 73 Paul -- Paul Gerhardt K3PG http://pgerhardt.blogspot.com QRP ARCI 6674 FP 274 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T4XB No +250V AND blown Filament Fuse
Paul - OK. See below. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Paul Gerhardt wrote: OK still troubleshooting but found 2 more clues I pulled all the tubes and the AC4 power resistor R3 in the 250V line is now cool to touch and V is 260V with NO tubes in. When OA2 is in place (only OA2) R3 is too hot to touch and V drops about 12V. The 0A2 will glow blue when it is working, and will have +150V across it. 12V drop across R3 is a little high, but is about 1.5W dissipation, assuming it is 100 ohms. 2nd Clue I finally found what smoked in the chassis. It was hiding under a switch shaft in the RF compartment. The 'smoker' was R30 the 68 ohm 1/2 watt resistor on V5 (final) So I think maybe the tube had a grid to fil short and took out both circuits. I think that's where we started! :-) I am still not getting a spot signal. R3 is still too hot when OA2 is 'IN' SPOT will not be present with V8 out of the socket. Again, 12 V drop across R3 is ok, only 1.5W, and if the 0A2 is blue, it's regulating. The +150 bus drives the PTO, BAND OSC and the screen of the PreMixer, along with V1, V2 Screen and V3 screen. The PTO supply should have about 11 V on it, at the low end of R64, 6k @ 5W. OA2 is blue not shure otherwise if it is good? Problem may be on the 150 V line as that powers the VFO (I think). Still have the tubes out. Paul K3PG in 'snowy' MD pix on http://pgerhardt.blogspot.com http://pgerhardt.blogspot.com/ On Thu, Feb 4, 2010 at 11:31 AM, Paul Gerhardt phgerha...@gmail.com mailto:phgerha...@gmail.com wrote: Turned on my Working T4Xb and smoke came out the bottom of the rig which I can't see for some reason. The filimant fuse (8A pigtail lead fuse near the 3 big power resistors) is open so replaced that, then no 250 V B+ and found R3 1K 5 watt resistor to be open. Both of these were 'effect' and not cause (I suspect). I changed R3 and got 150V and R3 is hot. Unhooked the yellow 250V wire to the rig and V is good about 270V. Turned power OFF and measured Resistance on yellow wire and it is low only about 150 ohms. Last thing is always suspect and for this the last thing I did a few days ago was install some used FleaBay finals which worked ok it seemed but were very weak only about 60-70 watts out (maybe one was not working?) Put the bright light on the bottom and compared to photo I took before and fail to 'see' any burned parts on the bottom but there was smoke and I think it was from a hot wire and not a componet. Will probably change the finals back to the 'other' weak ones that were at least putting out 120W into the Cantenna and see what is pulling the 250V B+ line down. Any ideas on this one? 73 Paul ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T4XB No +250V AND blown Filament Fuse
I checked the schematic and R3 in AC4 IS 100 ohm at 5 Watts not shure where I got 1000 so will look for that but in any case 250V B+ is still shorted and filimants are 'on' and nothis is smoking with wire in place. Am not leaving it on though and I did get some 10A glass fuses at the auto parts store OR will use the single strand of wire from the zip cord. Then will pull tubes and try the 250 v line again. Paul Message: 5 Date: Fri, 05 Feb 2010 18:09:34 -0500 From: Garey Barrell k4...@mindspring.com Subject: Re: [Drakelist] T4XB No +250V AND blown Filament Fuse To: drakelist@zerobeat.net Message-ID: 4b6ca52e.8080...@mindspring.com Content-Type: text/plain; charset=ISO-8859-1; format=flowed Paul - I realized I used the wrong number for the fuse wire. I actually use a single strand of 18-2 ZIP cord, which I think is #33. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Paul Gerhardt wrote: OK and thanks to all. I just got back home and am going to try the T4Xb troubleshooting again this weekend. Will pull the finals and see if that is what is pulling the 250 B+ down. The R3 was in the AC4 sorry for not noting this before. I looked at the old one and the schematic and was reading it as 1k but will look again and make sure it I have the value correct. Auto parts store had some 10amp glass buss fuses in packs of 5 so I got one for the fil fuse 8A and will at least replace the #22 wire I put in there before I do any more. The filaments are lighting ok with the wire in at this point. 73, Paul -- Paul Gerhardt K3PG http://pgerhardt.blogspot.com QRP ARCI 6674 FP 274 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T4XB No +250V AND blown Filament Fuse
OK and thanks to all. I just got back home and am going to try the T4Xb troubleshooting again this weekend. Will pull the finals and see if that is what is pulling the 250 B+ down. The R3 was in the AC4 sorry for not noting this before. I looked at the old one and the schematic and was reading it as 1k but will look again and make sure it I have the value correct. Auto parts store had some 10amp glass buss fuses in packs of 5 so I got one for the fil fuse 8A and will at least replace the #22 wire I put in there before I do any more. The filaments are lighting ok with the wire in at this point. 73, Paul -- Paul Gerhardt K3PG http://pgerhardt.blogspot.com QRP ARCI 6674 FP 274 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T4XB No +250V AND blown Filament Fuse
Paul - Couple of things. One, be careful using a larger fuse than the 8 Amp original. That fuse is to protect the wiring harness in case of a filament short. Melted harness = parts radio. The early units used a piece of #30 wire instead of a fuse. There aren't many places in the transmitter where enough current can be drawn from the +250 bus to heat up R3 in the AC-4 without smoking something IN the radio itself. I believe I'd start with V7, as a short here would put R35 across the +250 bus for approximately a 4.5 W load. Of course a short anywhere along the +150 bus would give a similar result, but all but the PTO/BAND OSC resistor paths are small, high value resistors So... Guessing shorted VR tube, V7 socket wiring shorted, shorted lead to PTO. Let us know! 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Paul Gerhardt wrote: OK and thanks to all. I just got back home and am going to try the T4Xb troubleshooting again this weekend. Will pull the finals and see if that is what is pulling the 250 B+ down. The R3 was in the AC4 sorry for not noting this before. I looked at the old one and the schematic and was reading it as 1k but will look again and make sure it I have the value correct. Auto parts store had some 10amp glass buss fuses in packs of 5 so I got one for the fil fuse 8A and will at least replace the #22 wire I put in there before I do any more. The filaments are lighting ok with the wire in at this point. 73, Paul ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T4XB No +250V AND blown Filament Fuse
Paul - I realized I used the wrong number for the fuse wire. I actually use a single strand of 18-2 ZIP cord, which I think is #33. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Paul Gerhardt wrote: OK and thanks to all. I just got back home and am going to try the T4Xb troubleshooting again this weekend. Will pull the finals and see if that is what is pulling the 250 B+ down. The R3 was in the AC4 sorry for not noting this before. I looked at the old one and the schematic and was reading it as 1k but will look again and make sure it I have the value correct. Auto parts store had some 10amp glass buss fuses in packs of 5 so I got one for the fil fuse 8A and will at least replace the #22 wire I put in there before I do any more. The filaments are lighting ok with the wire in at this point. 73, Paul ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] T4XB No +250V AND blown Filament Fuse
Turned on my Working T4Xb and smoke came out the bottom of the rig which I can't see for some reason. The filimant fuse (8A pigtail lead fuse near the 3 big power resistors) is open so replaced that, then no 250 V B+ and found R3 1K 5 watt resistor to be open. Both of these were 'effect' and not cause (I suspect). I changed R3 and got 150V and R3 is hot. Unhooked the yellow 250V wire to the rig and V is good about 270V. Turned power OFF and measured Resistance on yellow wire and it is low only about 150 ohms. Last thing is always suspect and for this the last thing I did a few days ago was install some used FleaBay finals which worked ok it seemed but were very weak only about 60-70 watts out (maybe one was not working?) Put the bright light on the bottom and compared to photo I took before and fail to 'see' any burned parts on the bottom but there was smoke and I think it was from a hot wire and not a componet. Will probably change the finals back to the 'other' weak ones that were at least putting out 120W into the Cantenna and see what is pulling the 250V B+ line down. Any ideas on this one? 73 Paul some new pix on the port op for the 160M CQ CW contest last weekend on www.pgerhardt.blogspot.com -- Paul Gerhardt K3PG http://pgerhardt.blogspot.com QRP ARCI 6674 FP 274 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T4XB No +250V AND blown Filament Fuse
Paul - Finals are certainly suspect. Pull both Final tubes and see what happens to your resistance measurement. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Paul Gerhardt wrote: Turned on my Working T4Xb and smoke came out the bottom of the rig which I can't see for some reason. The filimant fuse (8A pigtail lead fuse near the 3 big power resistors) is open so replaced that, then no 250 V B+ and found R3 1K 5 watt resistor to be open. Both of these were 'effect' and not cause (I suspect). I changed R3 and got 150V and R3 is hot. Unhooked the yellow 250V wire to the rig and V is good about 270V. Turned power OFF and measured Resistance on yellow wire and it is low only about 150 ohms. Last thing is always suspect and for this the last thing I did a few days ago was install some used FleaBay finals which worked ok it seemed but were very weak only about 60-70 watts out (maybe one was not working?) Put the bright light on the bottom and compared to photo I took before and fail to 'see' any burned parts on the bottom but there was smoke and I think it was from a hot wire and not a componet. Will probably change the finals back to the 'other' weak ones that were at least putting out 120W into the Cantenna and see what is pulling the 250V B+ line down. Any ideas on this one? 73 Paul some new pix on the port op for the 160M CQ CW contest last weekend on www.pgerhardt.blogspot.com http://www.pgerhardt.blogspot.com/ -- Paul Gerhardt K3PG http://pgerhardt.blogspot.com QRP ARCI 6674 FP 274 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T4XB No +250V AND blown Filament Fuse
Paul - I just got a chance to look at the T-4XB schematic. R3 is NOT a 1k 5W resistor, at least on my schematics! Where is this resistor in your unit? Physically and on the schematic. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Paul Gerhardt wrote: Turned on my Working T4Xb and smoke came out the bottom of the rig which I can't see for some reason. The filimant fuse (8A pigtail lead fuse near the 3 big power resistors) is open so replaced that, then no 250 V B+ and found R3 1K 5 watt resistor to be open. Both of these were 'effect' and not cause (I suspect). I changed R3 and got 150V and R3 is hot. Unhooked the yellow 250V wire to the rig and V is good about 270V. Turned power OFF and measured Resistance on yellow wire and it is low only about 150 ohms. Last thing is always suspect and for this the last thing I did a few days ago was install some used FleaBay finals which worked ok it seemed but were very weak only about 60-70 watts out (maybe one was not working?) Put the bright light on the bottom and compared to photo I took before and fail to 'see' any burned parts on the bottom but there was smoke and I think it was from a hot wire and not a componet. Will probably change the finals back to the 'other' weak ones that were at least putting out 120W into the Cantenna and see what is pulling the 250V B+ line down. Any ideas on this one? 73 Paul some new pix on the port op for the 160M CQ CW contest last weekend on www.pgerhardt.blogspot.com http://www.pgerhardt.blogspot.com/ -- Paul Gerhardt K3PG http://pgerhardt.blogspot.com QRP ARCI 6674 FP 274 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T4XB No +250V AND blown Filament Fuse
Tim - Thanks. R3 in the power supply is 100 ohms, but I believe you're right. In this case, I'd immediately suspect C4b, but that would not cause smoke out of the transmitter. I'm still going with a shorted 6JB6. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Bolbach, Timothy wrote: I think he is referring to R3 in the power supply. -Original Message- From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of Garey Barrell Sent: Thursday, February 04, 2010 1:04 PM To: drakelist@zerobeat.net Subject: Re: [Drakelist] T4XB No +250V AND blown Filament Fuse Paul - I just got a chance to look at the T-4XB schematic. R3 is NOT a 1k 5W resistor, at least on my schematics! Where is this resistor in your unit? Physically and on the schematic. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Paul Gerhardt wrote: Turned on my Working T4Xb and smoke came out the bottom of the rig which I can't see for some reason. The filimant fuse (8A pigtail lead fuse near the 3 big power resistors) is open so replaced that, then no 250 V B+ and found R3 1K 5 watt resistor to be open. Both of these were 'effect' and not cause (I suspect). I changed R3 and got 150V and R3 is hot. Unhooked the yellow 250V wire to the rig and V is good about 270V. Turned power OFF and measured Resistance on yellow wire and it is low only about 150 ohms. Last thing is always suspect and for this the last thing I did a few days ago was install some used FleaBay finals which worked ok it seemed but were very weak only about 60-70 watts out (maybe one was not working?) Put the bright light on the bottom and compared to photo I took before and fail to 'see' any burned parts on the bottom but there was smoke and I think it was from a hot wire and not a componet. Will probably change the finals back to the 'other' weak ones that were at least putting out 120W into the Cantenna and see what is pulling the 250V B+ line down. Any ideas on this one? 73 Paul some new pix on the port op for the 160M CQ CW contest last weekend on www.pgerhardt.blogspot.comhttp://www.pgerhardt.blogspot.com/ -- Paul Gerhardt K3PG http://pgerhardt.blogspot.com QRP ARCI 6674 FP 274 ___ 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
