Re: [Drakelist] Cooling fan
- Original Message - From: Henry Foglesong hwfogles...@gmail.com To: drakelist@zerobeat.net Sent: Monday, August 22, 2011 8:45 PM Subject: [Drakelist] Cooling fan I hear conflicting opinions about the advisability of using a cooling fan (eg: muffin fan) on top of the finals of T-4XB and XC transmitters. Any opinions in this group? Also on the TR-4 finals and R4B receiver over the power transformer. The latter can be quite a small fan but makes all the difference, the transformer goes from being too hot to touch to cool to the touch. -- Richard Knoppow Los Angeles WB6KBL dickb...@ix.netcom.com ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Cooling fan
Hi Henry, I was surprised some time ago after a session of CW operating with my T-4X at the amount of heat that was being radiated upward from the cage containing the final PA tubes! (if you look inside that enclosure, you'll see that those RF amplifiers share some very close quarters)... On the suggestion of a subscriber to this Reflector I mounted a small 12 VDC muffin fan to the outside of the main enclosure (i.e. the top), by happy coincidence oriented it to draw the hot air up out of the rig...it's powered by a wall wart that I happened to have on hand here. It's amazing how much cooler that area of the transmitter is now. I think it is definitely worth whatever slight trouble the incorporation of a fan might pose for you. ~73~ de Eddy VE3CUI - VE3XZ * On 2011-08-22, at 11:45 PM, Henry Foglesong wrote: I hear conflicting opinions about the advisability of using a cooling fan (eg: muffin fan) on top of the finals of T-4XB and XC transmitters. Any opinions in this group? ___ 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] Cooling fan
Hank - Any opinions in this group?!?!?!! :-) You have received excellent advice, as usual, from the members of this group. One comment I did not see mentioned is that while the top mount of a fan is certainly easiest, there's not always clearance under a shelf. Yeah, I know you're supposed to leave 'several inches' of space above these units, but esthetics often win over 'best practices'. What all this is leading up to is that it is just as effective if mounted on the back of the PA cage, most certainly blowing _OUT_. Especially in the case where there IS a shelf above the transmitter! I have yet to find a fan that didn't have at least two appropriate holes in the PA cage, so no 'extra' holes are necessary. Power can either be from a switched power strip (another subject, but with the 'unobtainium' rotary control switches used on much of our vintage gear, it's a good idea to switch power externally), either AC directly to a (220V?) fan, or DC from a wall wart or accessory 13.6 VDC supply. As others have said, it does NOT have to be a blast of air. A small computer 'silent' type fan is plenty of air. We're not looking for 'forced air cooling', merely an assist to get the heated air moved AWAY from the area. 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 Henry Foglesong wrote: I hear conflicting opinions about the advisability of using a cooling fan (eg: muffin fan) on top of the finals of T-4XB and XC transmitters. Any opinions in this group? ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Cooling fan
Use one on top of the final cage pulling the air UP and out. Suggest a surplus 220V fan operated on 120. Quiet and easy. A 24V DC fan on 12V works as well It will extend your final life especially under heavy duty cycle modes (RTTY) etc. 73 Gene K1NR On Tue, 23 Aug 2011 03:45:42 - Henry Foglesong hwfogles...@gmail.com wrote: I hear conflicting opinions about the advisability of using a cooling fan (eg: muffin fan) on top of the finals of T-4XB and XC transmitters. Any opinions in this group? - Web mail provided by NuNet, Inc. The Premier National provider. http://www.nni.com/ ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] cooling fans
Sent this earlier but it bounced as a fwd. Yes..one of the better reasons for having the fan on the back is so it WILL stay cool under a shelf. Fans are excellent idea...even on the rx. They dont have to be on top to work well. m mounted on the rear of the finals cage pulling air out works just as well. Its not really like forced air cooling, all you are doing is removing the warm stagnant air from the cage reducing the temp of the ambient air around the tube envelopes. This allows the tube to shed heat as it was designed to do more effectively. My R4x fan install is in the space between the bandpass box and the transformer and uses a small cardstock duct to pull air from the audio amp area out past the transformer. all runs cool to touch now. t4x top over the finals cage is also always cool. I use the silenx fans..exteremely quiet. See install pics here: https://picasaweb.google.com/captcurt08/DrakeFanInstall Cheers, Curt KU8L ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Cooling Fans
In the for what it's worth department - I used to hold a muffin fan ATOP my SB-220 and SB-200, with a pair of toothpicks. It made NO permanent holes, held the fan where it did some good, AND I had it sucking out, as opposed to blowing in. Any physics or fluid-mechanics guy will tell you that when you compress a fluid (like air), it heats up (albiet, in this case - very slightly), a negative pressure [sic] tends to lower the temp - whatever works for you, but my fans PULL - they don't PUSH. Tom - W0EAJ ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Cooling Fans
- Original Message - From: TC Dailey daileyservi...@qwest.net To: drakelist@zerobeat.net Sent: Tuesday, August 23, 2011 11:38 AM Subject: [Drakelist] Cooling Fans In the for what it's worth department - I used to hold a muffin fan ATOP my SB-220 and SB-200, with a pair of toothpicks. It made NO permanent holes, held the fan where it did some good, AND I had it sucking out, as opposed to blowing in. Any physics or fluid-mechanics guy will tell you that when you compress a fluid (like air), it heats up (albiet, in this case - very slightly), a negative pressure [sic] tends to lower the temp - whatever works for you, but my fans PULL - they don't PUSH. Tom - W0EAJ Having a sucking fan on top takes advantage of the normal flow of the heated air due to convection. It also does not blow heated air over the rest of the chassis. Since the amount of air to be moved is not great a low speed fan works fine. Mounting on the back of the final cage works fine despite the theoretical advantage of top mounting (I've tried it). The size of the fan and design of the blades and its speed determine the volume of air it moves and also the amount of back pressure it can work against. Both are not critical at all here. However, the _noise_ a fan makes also depends on size, speed, and blade shape. For the same volume of air a small fan must run faster. Some miniature fans are nearly sirens, they are necessary for some applications but not for cooling fairly large vacuum tube gear so a much quieter fan can be used. I suppose one could devise a physics lab problem of determining both compressional heating and the heating due to frictional forces on the flowing air. That would require measuring a _lot_ of parameters. While this is silly here there are engineering applications where such things _do_ need to be calculated. -- Richard Knoppow Los Angeles WB6KBL dickb...@ix.netcom.com ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Cooling fans
Wow, the score is about 15 to 0 in favor of cooling fans. I guess the guys that gave me the negatives a number of years ago when I owned a T-4XB aren't a part of this list!! Thanks for all the comments, and yes, I have a cooling fan and will be installing it on my newly purchased T-4XC. Hank___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Cooling Fans
Hi Richard: It is nice now that a lot of the gamers and power PC users want to run silent cooling systems in their machines. Many of the PC fan mfgs rate airflow as well as noise in dB. Silenx utilizes the same blade modeling algorithms previously used for SSBN Boomer propellors. Quietest fans I've ever seen. Curt Richard Knoppow wrote: - Original Message - From: TC Dailey daileyservi...@qwest.net To: drakelist@zerobeat.net Sent: Tuesday, August 23, 2011 11:38 AM Subject: [Drakelist] Cooling Fans In the for what it's worth department - I used to hold a muffin fan ATOP my SB-220 and SB-200, with a pair of toothpicks. It made NO permanent holes, held the fan where it did some good, AND I had it sucking out, as opposed to blowing in. Any physics or fluid-mechanics guy will tell you that when you compress a fluid (like air), it heats up (albiet, in this case - very slightly), a negative pressure [sic] tends to lower the temp - whatever works for you, but my fans PULL - they don't PUSH. Tom - W0EAJ Having a sucking fan on top takes advantage of the normal flow of the heated air due to convection. It also does not blow heated air over the rest of the chassis. Since the amount of air to be moved is not great a low speed fan works fine. Mounting on the back of the final cage works fine despite the theoretical advantage of top mounting (I've tried it). The size of the fan and design of the blades and its speed determine the volume of air it moves and also the amount of back pressure it can work against. Both are not critical at all here. However, the _noise_ a fan makes also depends on size, speed, and blade shape. For the same volume of air a small fan must run faster. Some miniature fans are nearly sirens, they are necessary for some applications but not for cooling fairly large vacuum tube gear so a much quieter fan can be used. I suppose one could devise a physics lab problem of determining both compressional heating and the heating due to frictional forces on the flowing air. That would require measuring a _lot_ of parameters. While this is silly here there are engineering applications where such things _do_ need to be calculated. -- Richard Knoppow Los Angeles WB6KBL dickb...@ix.netcom.com ___ 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] Cooling fans
I really can't think of a single negative to a cooling fan other than the noise from whatever fan you use. I suppose some could say they are needed since these rigs lasted dozens of years without them, but heat is the enemy of tubes and all the rest of the works. Really quiet, inexpensive low voltage fans were not as readily available in the 60's and 70's as they are today. FWIW Curt KU8L Henry Foglesong wrote: Wow, the score is about 15 to 0 in favor of cooling fans. I guess the guys that gave me the negatives a number of years ago when I owned a T-4XB aren't a part of this list!! Thanks for all the comments, and yes, I have a cooling fan and will be installing it on my newly purchased T-4XC. Hank ___ 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] I feel like a buzzard...
...circling around and around... Moved the (new) filter caps up out of the way and grounded them to the grounding stud on the rear panel. Chirp, chirp, chirp! Up - down - up - down, chirp! Monitored Lo @ 18.1 MHz on my K3 - solid signal even while the R-4A was happily chirping away... Monitored PTO on the K3 - chirp, chirp, etc... Disconnected everything from the PTO... Chirp, chirp on the K3... Put in a 10V zener to get voltage to solid 10.2V. Chirp! When it wobbles and chirps, I see the trace of the 10V line on the scope change. It doesn't drop or increase - it's just a change in the ripple, apparently. If I tap the chassis under the PTO, I can make it wobble and chirp. I'm not really understanding this in that this PTO is the one that was working great in the T-4XB. Could the power supply be starving even though the xtal oscillator is not changing at all? 73, Steve Wedge, W1ES/4 I can't complain, but sometimes I still do. - Joe Walsh If the above message appears, it came from Steve's Son of Laptop!___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] I feel like a buzzard...
Steve, Is the chirping clocked or more free running in nature? Ron --- On Tue, 8/23/11, Steve Wedge w1es1...@earthlink.net wrote: From: Steve Wedge w1es1...@earthlink.net Subject: [Drakelist] I feel like a buzzard... To: drakelist@zerobeat.net Date: Tuesday, August 23, 2011, 7:20 PM ...circling around and around... Moved the (new) filter caps up out of the way and grounded them to the grounding stud on the rear panel. Chirp, chirp, chirp! Up - down - up - down, chirp! Monitored Lo @ 18.1 MHz on my K3 - solid signal even while the R-4A was happily chirping away... Monitored PTO on the K3 - chirp, chirp, etc... Disconnected everything from the PTO... Chirp, chirp on the K3... Put in a 10V zener to get voltage to solid 10.2V. Chirp! When it wobbles and chirps, I see the trace of the 10V line on the scope change. It doesn't drop or increase - it's just a change in the ripple, apparently. If I tap the chassis under the PTO, I can make it wobble and chirp. I'm not really understanding this in that this PTO is the one that was working great in the T-4XB. Could the power supply be starving even though the xtal oscillator is not changing at all? 73, Steve Wedge, W1ES/4 I can't complain, but sometimes I still do. - Joe Walsh If the above message appears, it came from Steve's Son of Laptop! -Inline Attachment Follows- ___ 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] Scammer
I advertised for a T-4XC front panel on the Australian VKHam classified website and immediately received an Email response from somebody supposedly located at: 46 medomak mobile home park waldoboro,me 04572 offering either the T-4XC or just the front panel, claiming he has tried to sell the transmitter but hasn't as yet and would just sell the panel. Seems very odd indeed. I am aware there are some scammers responding to Hams placing wanted ads on online classified sites claiming to have exactly what was advertised. Anybody have any insight into this activity in the USA , or is this address familiar, or am I being a bit too cautious? Regards John ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] I feel like a buzzard...
At 07:20 PM 8/23/2011, you wrote: . Could the power supply be starving even though the xtal oscillator is not changing at all? 73, Steve Wedge, W1ES/4 I dunno Steve, but THANK YOU for taking the time to post all this... it's like watching Hercule Poirot on the trail. I'm really anxious to find out whodunnit...and I'll learn stuff to boot! John K5MO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] I feel like a buzzard...
completely random. Gets worse if I tap on it, but then again, I'd expect some reaction when tapping it. Now, I've got to find some test leads. I'm going to turn my station supply down to 11V so I can still run the K3 and will power each PTO off this very stiff supply. It's now obvious to me that it's either the PTO (yeah, both of 'em) or the regulated supply has issues. Steve Wedge, W1ES/4 I can't complain, but sometimes I still do. - Joe Walsh If the above message appears, it came from Steve's Son of Laptop! - Original Message - From: Ron To: Steve Wedge Cc: drakelist@zerobeat.net Sent: Tuesday, August 23, 2011 7:29 PM Subject: Re: [Drakelist] I feel like a buzzard... Steve, Is the chirping clocked or more free running in nature? Ron --- On Tue, 8/23/11, Steve Wedge w1es1...@earthlink.net wrote: From: Steve Wedge w1es1...@earthlink.net Subject: [Drakelist] I feel like a buzzard... To: drakelist@zerobeat.net Date: Tuesday, August 23, 2011, 7:20 PM ...circling around and around... Moved the (new) filter caps up out of the way and grounded them to the grounding stud on the rear panel. Chirp, chirp, chirp! Up - down - up - down, chirp! Monitored Lo @ 18.1 MHz on my K3 - solid signal even while the R-4A was happily chirping away... Monitored PTO on the K3 - chirp, chirp, etc... Disconnected everything from the PTO... Chirp, chirp on the K3... Put in a 10V zener to get voltage to solid 10.2V. Chirp! When it wobbles and chirps, I see the trace of the 10V line on the scope change. It doesn't drop or increase - it's just a change in the ripple, apparently. If I tap the chassis under the PTO, I can make it wobble and chirp. I'm not really understanding this in that this PTO is the one that was working great in the T-4XB. Could the power supply be starving even though the xtal oscillator is not changing at all? 73, Steve Wedge, W1ES/4 I can't complain, but sometimes I still do. - Joe Walsh If the above message appears, it came from Steve's Son of Laptop! -Inline Attachment Follows- ___ 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] I feel like a buzzard...
This has certainly been a challenge, complete with a couple of false climaxes. Don't think I'll get much more time tonight to play with this, as my XYL will be home soon and we'll have to eat. Next is to try running an external 11V supply to the PTO. If it still warbles, I'll have to figure out how a good PTO went bad just from moving it. I'll not jump to conclusions until I've done the experiment. Steve Wedge, W1ES/4 I can't complain, but sometimes I still do. - Joe Walsh If the above message appears, it came from Steve's Son of Laptop! - Original Message - From: john joh...@nc.rr.com To: Steve Wedge w1es1...@earthlink.net; drakelist@zerobeat.net Sent: Tuesday, August 23, 2011 7:38 PM Subject: Re: [Drakelist] I feel like a buzzard... At 07:20 PM 8/23/2011, you wrote: . Could the power supply be starving even though the xtal oscillator is not changing at all? 73, Steve Wedge, W1ES/4 I dunno Steve, but THANK YOU for taking the time to post all this... it's like watching Hercule Poirot on the trail. I'm really anxious to find out whodunnit...and I'll learn stuff to boot! John K5MO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Scammer
John, There are 26 amateurs in Waldoboro, ME. None at that address (not that it means anything). His residence was assessed for USD13,ooo. Personally, I wouldn't take the chance even though I could drive up there and put the fear of God in him if he chose to deal me out of the money. de WA1ISA - Original Message - From: John Brown brown...@optusnet.com.au To: Drake List drakelist@zerobeat.net Sent: Tuesday, August 23, 2011 7:36:12 PM Subject: [Drakelist] Scammer I advertised for a T-4XC front panel on the Australian VKHam classified website and immediately received an Email response from somebody supposedly located at: 46 medomak mobile home park waldoboro,me 04572 offering either the T-4XC or just the front panel, claiming he has tried to sell the transmitter but hasn’t as yet and would just sell the panel. Seems very odd indeed . I am aware there are some scammers responding to Hams placing “wanted” ads on online classified sites claiming to have exactly what was advertised. Anybody have any insight into this activity in the USA , or is this address familiar, or am I being a bit too cautious? Regards John ___ 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] Cooling fan
I hear conflicting opinions about the advisability of using a cooling fan (eg: muffin fan) on top of the finals of T-4XB and XC transmitters Every 10 deg C reduction in heat, doubles the life of electronic components. Not sure if this applies to tubes as well, but I'd suspect so. John K5MO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Covering 5 to 6 Mhz in R4A
What will happen if I attempt to use a 5 to 6 Mhz (actual coverage) crystal in the R4A? Will there be any reception at all, strange noise or will the radio explode? :) ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
