Re: [Drakelist] What have I done now?
Thinking about it a little more, since it may or may not have transitioned to TX, the driver or any of the other tubes that are bias controlled can do the same at reduced voltages. Hope there was no long term damage. I once worked on a FT101E that had a defective socket on the grid of one of the finals. As soon as HV came on, with that grid floating, it began cooking. Bias measured OK, all voltages lookedOK, but no bias was getting to the actual tube--duh! I finally figured out what was going on after the tube got so hot, the vacuum sucked a hole thru the side of the tube. Still have that tube BTW...reminder.. Curt KU8L On 3/12/2014 12:18 PM, Damien Mannix wrote: Hi all, Still waiting for better weather to put up an antenna but then ready to go with my TR4/AC4 which are fine into a dummy load, or at least they were! Bought a, supposedly good, AC4 as a spare. Decided to power it up gradually with the TR4 as a load. Two hours at 50v, two at 80v, two at 110v, two at 140v. No problems and a fan on the rear behind the PA begins to run at this voltage. Then, ten minutes at 170v and 'wow' what is that smell? I thought it was my shack heater. No it was the TR4. The top, above the forward most PA tube, was unbelievably hot. Switched off immediately of course. Can't spot anything untoward in the PA compartment so after a complete cool down I took it slowly up to 230v with my usual AC4. Not done a full test but it seems perfectly happy again, heat and smell wise, after 30 minutes at 230v. Might I have ruined anything and, presumably, the fault is in the AC4. Thanks in advance for any thoughts. 73 Damien G3XER ___ 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] What have I done now?
Hi Damien: Doesn't change my thoughts really. Even tho the relay for Tx would not be engaged, and this keeps the cathodes floating and not grounded, with bias very low or removed from the grids, the tubes will conduct enough to get hot for sure. I think the worst is that the current comes thru the grids so can physically damage the tube internals. Which tubes, finals or driver, or others, is a guess only--perhaps all to some degree. I would just power it up again with a full on AC4 and monitor it closely to be sure nothing has gotten burned or out of tolerance enough to do damage. Especially, confirm that the bias control does what it is supposed to do with adjustment range, verify that the current reading of plate current is close (be careful!) and do an operational check-out. These are very robust rigs but the finals are especially intolerant of unloaded or excessive plate current being that they are TV sweep tubes. Let us know how it goes. Kind of surprised we haven't heard from anyone else on the list. Curt KU8L On 3/13/2014 10:31 AM, Damien Mannix wrote: Hi Curt, Thank you for your two replies. I am most grateful for your input. How one can be misled. I certainly thought I was doing the right thing! No sure if it makes any difference to your conclusions but I never switched to transmit I just left the TR4 in Receive mode. 73 Damien Date: Thu, 13 Mar 2014 08:25:26 -0500 From: cptc...@flash.net To: drakelist@zerobeat.net Subject: Re: [Drakelist] What have I done now? Thinking about it a little more, since it may or may not have transitioned to TX, the driver or any of the other tubes that are bias controlled can do the same at reduced voltages. Hope there was no long term damage. I once worked on a FT101E that had a defective socket on the grid of one of the finals. As soon as HV came on, with that grid floating, it began cooking. Bias measured OK, all voltages lookedOK, but no bias was getting to the actual tube--duh! I finally figured out what was going on after the tube got so hot, the vacuum sucked a hole thru the side of the tube. Still have that tube BTW...reminder.. Curt KU8L On 3/12/2014 12:18 PM, Damien Mannix wrote: Hi all, Still waiting for better weather to put up an antenna but then ready to go with my TR4/AC4 which are fine into a dummy load, or at least they were! Bought a, supposedly good, AC4 as a spare. Decided to power it up gradually with the TR4 as a load. Two hours at 50v, two at 80v, two at 110v, two at 140v. No problems and a fan on the rear behind the PA begins to run at this voltage. Then, ten minutes at 170v and 'wow' what is that smell? I thought it was my shack heater. No it was the TR4. The top, above the forward most PA tube, was unbelievably hot. Switched off immediately of course. Can't spot anything untoward in the PA compartment so after a complete cool down I took it slowly up to 230v with my usual AC4. Not done a full test but it seems perfectly happy again, heat and smell wise, after 30 minutes at 230v. Might I have ruined anything and, presumably, the fault is in the AC4. Thanks in advance for any thoughts. 73 Damien G3XER ___ Drakelist mailing list Drakelist@zerobeat.net mailto:Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ 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] What have I done now?
Hi Damien: Yes, especially when replying to posts, be sure to note where the reply is directed address-wise. Always good to copy the list as well as any direct message so others can follow along with the discussion responses. The scenario Garey outlined is very likely indeed. It kind of was an extension of my comment about it is sometimes hard to tell exactly what was going to happen in all stages of the rig. He went into the schematic a little deeper than I did--All of those guys are very knowledgeable in the Drake line-up. If you plan to do much work at all on these rigs, Garey's CD with annotated pictures and notes is the best available as far as I know. Hopefully, you caught it before the finals or other parts got damaged. BTW, a fan pulling air out of the back of the cage is a great benefit to these rigs to shed some of the heat. That being said, these things will run 24/7 at rated output in tough modes like RTTY and just keep going--they are very robust as long as properly loaded. Cheers Curt On 3/13/2014 11:20 AM, Damien Mannix wrote: Hi Curt, Thanks again. I will do everything you suggest. Actually I am puzzled myself as to how the list works nowadays! I did in fact also hear from Mike Bryce (no call sign given), Evan K9SQG and Gary K4OAH who also kindly invited me to join the DrakeRadio group. Never knew it existed but I will certainly join. Regards, Damien G3XER Date: Thu, 13 Mar 2014 11:07:11 -0500 From: cptc...@flash.net To: damienman...@hotmail.com; drakelist@zerobeat.net Subject: Re: [Drakelist] What have I done now? Hi Damien: Doesn't change my thoughts really. Even tho the relay for Tx would not be engaged, and this keeps the cathodes floating and not grounded, with bias very low or removed from the grids, the tubes will conduct enough to get hot for sure. I think the worst is that the current comes thru the grids so can physically damage the tube internals. Which tubes, finals or driver, or others, is a guess only--perhaps all to some degree. I would just power it up again with a full on AC4 and monitor it closely to be sure nothing has gotten burned or out of tolerance enough to do damage. Especially, confirm that the bias control does what it is supposed to do with adjustment range, verify that the current reading of plate current is close (be careful!) and do an operational check-out. These are very robust rigs but the finals are especially intolerant of unloaded or excessive plate current being that they are TV sweep tubes. Let us know how it goes. Kind of surprised we haven't heard from anyone else on the list. Curt KU8L On 3/13/2014 10:31 AM, Damien Mannix wrote: Hi Curt, Thank you for your two replies. I am most grateful for your input. How one can be misled. I certainly thought I was doing the right thing! No sure if it makes any difference to your conclusions but I never switched to transmit I just left the TR4 in Receive mode. 73 Damien Date: Thu, 13 Mar 2014 08:25:26 -0500 From: cptc...@flash.net mailto:cptc...@flash.net To: drakelist@zerobeat.net mailto:drakelist@zerobeat.net Subject: Re: [Drakelist] What have I done now? Thinking about it a little more, since it may or may not have transitioned to TX, the driver or any of the other tubes that are bias controlled can do the same at reduced voltages. Hope there was no long term damage. I once worked on a FT101E that had a defective socket on the grid of one of the finals. As soon as HV came on, with that grid floating, it began cooking. Bias measured OK, all voltages lookedOK, but no bias was getting to the actual tube--duh! I finally figured out what was going on after the tube got so hot, the vacuum sucked a hole thru the side of the tube. Still have that tube BTW...reminder.. Curt KU8L On 3/12/2014 12:18 PM, Damien Mannix wrote: Hi all, Still waiting for better weather to put up an antenna but then ready to go with my TR4/AC4 which are fine into a dummy load, or at least they were! Bought a, supposedly good, AC4 as a spare. Decided to power it up gradually with the TR4 as a load. Two hours at 50v, two at 80v, two at 110v, two at 140v. No problems and a fan on the rear behind the PA begins to run at this voltage. Then, ten minutes at 170v and 'wow' what is that smell? I thought it was my shack heater. No it was the TR4. The top, above the forward most PA tube, was unbelievably hot. Switched off immediately of course. Can't spot anything untoward in the PA compartment so after a complete cool down I took it slowly up to 230v with my usual AC4. Not done a full
Re: [Drakelist] What have I done now?
I may get disagreement on this but I would NEVER bring up a PS like this attached to a transmitter. When you do that, the bias is minimal, and ven at low plate voltage, the finals are going to be conducting I suspect. Really hard to tell what is going to be happening. If you want to bring the supply itself up slowly, thats fine...THEN attached the rig and power it up normally. Curt KU8L A line, B line, TR4 TR3, TR7 On 3/12/2014 12:18 PM, Damien Mannix wrote: Hi all, Still waiting for better weather to put up an antenna but then ready to go with my TR4/AC4 which are fine into a dummy load, or at least they were! Bought a, supposedly good, AC4 as a spare. Decided to power it up gradually with the TR4 as a load. Two hours at 50v, two at 80v, two at 110v, two at 140v. No problems and a fan on the rear behind the PA begins to run at this voltage. Then, ten minutes at 170v and 'wow' what is that smell? I thought it was my shack heater. No it was the TR4. The top, above the forward most PA tube, was unbelievably hot. Switched off immediately of course. Can't spot anything untoward in the PA compartment so after a complete cool down I took it slowly up to 230v with my usual AC4. Not done a full test but it seems perfectly happy again, heat and smell wise, after 30 minutes at 230v. Might I have ruined anything and, presumably, the fault is in the AC4. Thanks in advance for any thoughts. 73 Damien G3XER ___ 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] Drake R4B calibrator
THe only problem with the captive freeware from the places like Express is that you cannot do anything else with the result. Not even print out the board layouts--only send them in to have them made. There are several free packages...some good, others not so much, that do the same and are under the GNU free software environmnet. I have used freePCB and the free version of viewmate from Pentalogix to generate standard gerber or plotting files for small boards--multi-layer are ok as well. Learning the full automated process from schematic capture thru net list, etc to final art is an interesting passtime. Starting with a fully documented schematic with bill of material makes the capture process work very well--but it is sometimes contrary to the way us older guys develop stuff! Cheers Curt KU8L On 1/23/2014 7:27 AM, Rick Lutzinger wrote: Have you looked at ExpressPCB/ExpressSCH? Great for what you are describing and the software is free. Rick KD6ZR On 1/22/2014 8:42 PM, Doug Smith wrote: Thanks Mike. Good info. I took a look at circad --- whew! Pricey.. I've got a couple of projects that I've been wanting to have a board or two made up but not at that level of professionalism! 73, Doug, W7KF On Jan 20, 2014, at 10:04 PM, Mike Bryce proso...@sssnet.com mailto:proso...@sssnet.com wrote: Gang The purple pcbs are made by a company called osh park. He ( they) have a thing for purple. Even the mailing envelopes are purple. All the prototypes are purple. Go figure. I use circad for the pcb layout software. I am currently teaching myself eagle. That's been slow. Mike wb8vge Sent from my iPad */Knowledge is knowing a tomato is a fruit; Wisdom is not putting it in a fruit salad./**//* ___ 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 mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] 4-line Dials
I might have a dial from a T4X.. same same I think although if I recal there were some version differences between A B and C twins. But the Tx looks just like the Rx. I will check when I get home. On 12/17/2013 1:34 PM, Bob Loving wrote: Hi, Lee: Have you seen the February 2005 QST article in Hints Kinks (pp 72-73) about a replacement for the R-4B dial? If not and you are an ARRL member, you can find it in the archives at the ARRL website. 73, Bob K9JU (Snowy and cold) Streamwood, IL ___ 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
