- 1. [Amps] 3CX800 and blower (score: 1)
- Author: "David J Windisch" <davidjw@cinci.rr.com>
- Date: Mon, 7 Sep 2009 10:26:42 -0400
- Does a 3CX800A7 require airflow any time the filament is lit, like, say, 3-500Z glass tubes with tender seals and 70-watt filaments? I'm thinking of leaving the (unobtanium) blower turned off, to low
- /archives//html/Amps/2009-09/msg00067.html (7,073 bytes)
- 2. Re: [Amps] 3CX800 and blower (score: 1)
- Author: Peter Junker <dg6man@pjconsult.de>
- Date: Mon, 7 Sep 2009 16:42:56 +0200
- Dear Dave, Planar tubes always have to be run with airflow. Failure to run a planar tube on filament without airflow is leading to the destruction of the tube. vy 73 de DG6MAN Peter _________________
- /archives//html/Amps/2009-09/msg00069.html (7,656 bytes)
- 3. Re: [Amps] 3CX800 and blower (score: 1)
- Author: "Carl" <km1h@jeremy.mv.com>
- Date: Mon, 7 Sep 2009 11:14:38 -0400
- Yes, according to the Eimac spec sheet. It also sounds like a good reason to install a 2 speed switch as is in a few commercial amps with that tube. It can be as elaborate as a thermal switch that ru
- /archives//html/Amps/2009-09/msg00070.html (8,202 bytes)
- 4. Re: [Amps] 3CX800 and blower (score: 1)
- Author: "Bill, W6WRT" <dezrat1242@yahoo.com>
- Date: Mon, 07 Sep 2009 09:06:37 -0700
- ORIGINAL MESSAGE: REPLY: Personally, I would not risk it with such an expensive tube. The answer to your question, and the only way to be sure is to measure the temperature of the metal-to-creamic se
- /archives//html/Amps/2009-09/msg00072.html (8,277 bytes)
- 5. Re: [Amps] 3CX800 and blower (score: 1)
- Author: Don Kessler <ki6sz@sbcglobal.net>
- Date: Mon, 7 Sep 2009 13:08:59 -0400
- According to the data sheet for this tube and from talking to the folks at CPI (Eimac) directly, forced air cooling is absolutely mandatory whenever current is applied to the filament. I know from pe
- /archives//html/Amps/2009-09/msg00074.html (8,558 bytes)
- 6. Re: [Amps] 3CX800 and blower (score: 1)
- Author: Bill Tippett <btippett@alum.mit.edu>
- Date: Mon, 07 Sep 2009 13:17:10 -0400
- The answer to your question, and the only way to be sure is to measure the temperature of the metal-to-creamic seals and make sure they do not exceed 250 degrees C. Does anyone have any idea how this
- /archives//html/Amps/2009-09/msg00075.html (7,351 bytes)
- 7. Re: [Amps] 3CX800 and blower (score: 1)
- Author: Bill Tippett <btippett@alum.mit.edu>
- Date: Mon, 07 Sep 2009 13:57:33 -0400
- and make sure they do not exceed 250 degrees C. I found the following in a March 2001 RadCom review of the Acom 2000/1000 by Peter Hart: "When the exhaust temperature reaches 90deg C, which it can t
- /archives//html/Amps/2009-09/msg00076.html (8,269 bytes)
- 8. Re: [Amps] 3CX800 and blower (score: 1)
- Author: "Carl" <km1h@jeremy.mv.com>
- Date: Mon, 7 Sep 2009 14:25:40 -0400
- The Eimac data sheet also plainly states: "Cooling must be applied before or simultaneously with electrode voltages, including the heater, ......................" It also goes on to suggest the use o
- /archives//html/Amps/2009-09/msg00078.html (9,328 bytes)
- 9. Re: [Amps] 3CX800 and blower (score: 1)
- Author: "Bill, W6WRT" <dezrat1242@yahoo.com>
- Date: Mon, 07 Sep 2009 18:36:13 -0700
- ORIGINAL MESSAGE: REPLY: No doubt there is a ratio, but it depends on how much air contacts the tube seals vs how much contacts the rest of the tube, especially the anode. Every physical layout is go
- /archives//html/Amps/2009-09/msg00082.html (8,087 bytes)
- 10. Re: [Amps] 3CX800 and blower (score: 1)
- Author: "Alex Eban" <alexeban@gmail.com>
- Date: Tue, 8 Sep 2009 10:01:23 +0300
- I can concure with that. If Eimac says it's not recommended it means NO Alex 3Z5KS a According to the data sheet for this tube and from talking to the folks at CPI (Eimac) directly, forced air coolin
- /archives//html/Amps/2009-09/msg00084.html (9,587 bytes)
- 11. Re: [Amps] 3CX800 and blower (score: 1)
- Author: Bill Tippett <btippett@alum.mit.edu>
- Date: Tue, 08 Sep 2009 07:08:33 -0400
- W6WRT REPLY: seals vs how much contacts the rest of the tube, especially the anode. Every physical layout is going to have a different answer. should be good enough. FYI I've learned the following a
- /archives//html/Amps/2009-09/msg00085.html (8,500 bytes)
- 12. Re: [Amps] 3CX800 and blower (score: 1)
- Author: Bill Coleman <n2bc@stny.rr.com>
- Date: Tue, 08 Sep 2009 10:29:35 -0400
- A quick story regarding a 2-speed switch... I had a 1st generation TenTec Titan (pair of 3CX800s), its 2-speed fan switch is located on the power supply. I regularly operate wearing headphones & one
- /archives//html/Amps/2009-09/msg00090.html (10,612 bytes)
- 13. Re: [Amps] 3CX800 and blower (score: 1)
- Author: "Randall, Randy" <Randy.Randall@healthall.com>
- Date: Tue, 8 Sep 2009 11:25:25 -0400
- That was a stupid design. Did the blower use two windings or two caps to change the speed or just a resistor? In the resistor type just shorting out the resistor would provide the same functionality
- /archives//html/Amps/2009-09/msg00091.html (12,527 bytes)
- 14. Re: [Amps] 3CX800 and blower (score: 1)
- Author: Bill Coleman <n2bc@stny.rr.com>
- Date: Tue, 08 Sep 2009 12:44:49 -0400
- Cheesy rocker style switch that would easily sit mid-throw.... OFF! _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/
- /archives//html/Amps/2009-09/msg00094.html (13,477 bytes)
- 15. Re: [Amps] 3CX800 and blower (score: 1)
- Author: "Bill, W6WRT" <dezrat1242@yahoo.com>
- Date: Tue, 08 Sep 2009 10:54:52 -0700
- ORIGINAL MESSAGE: REPLY: That isn't fail safe. It's fail and burn up the tube. Your comment about KISS is right on, but that means no resistor, no switch, full blower all the time. Noise is your frie
- /archives//html/Amps/2009-09/msg00102.html (8,885 bytes)
- 16. Re: [Amps] 3CX800 and blower (score: 1)
- Author: "Carl" <km1h@jeremy.mv.com>
- Date: Tue, 8 Sep 2009 15:17:36 -0400
- Using 2 suitably sized real WW resistors in parallel will virtually eliminate that failure mode. Cement resistors are failure prone garbage. Carl KM1H _______________________________________________
- /archives//html/Amps/2009-09/msg00104.html (9,711 bytes)
- 17. Re: [Amps] 3CX800 and blower (score: 1)
- Author: "David Windisch" <davidjw@cinci.rr.com>
- Date: Wed, 9 Sep 2009 08:34:33 -0400
- A round of thanks to all who replied. I'll keep looking for a spare blower for the Titans, jic, and hope for long life for the blowers I have. Brgds, Dave, W8FGX _____________________________________
- /archives//html/Amps/2009-09/msg00118.html (8,647 bytes)
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