Estimate Miller of Triode Strapped Pentode

dsavitsk · 13th January 2009, 12:23 AM

Is there a good method to estimate the Miller capacitance of a triode strapped pentode?

ray_moth · 13th January 2009, 02:43 AM

It makes sense for it to be Cg1g2 X stage gain. I'm guessing that the plate is too far from g1 for there to be a significant capacitance between them, but I could be wrong.

Poindexter · 13th January 2009, 03:29 AM

That sounds right to me; after all, that's the idea of a tetrode in de foist place, no?  The problem would be to find this capacitance.  The datasheets very seldom give such data for trioded pentodes; we're lucky to get plate curves.

I wonder, would this spec have to be tested for on a hot tube in-circuit, or could we just stick an LCR meter on the appropriate pins on a cold tube sitting on the bench?

Aloha,

Poinz
AudioTropic

ray_moth · 13th January 2009, 06:27 AM

Hi Ponz,

I don't see why the tube has to be hot to get this measurement. Temperature would make a difference, I suppose, but it should be slight.

13th January 2009, 12:23 AM	#1
dsavitsk diyAudio Member Join Date: Jan 2005 Location: Chicago	Estimate Miller of Triode Strapped Pentode Is there a good method to estimate the Miller capacitance of a triode strapped pentode? __________________ http://www.ecpaudio.com

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Pentode Miller Capacitance, and which spec value to use?	flysig	Tubes / Valves	5	30th May 2009 09:59 PM
Wanted Triode strapped curves for pentode of ECL82.	Shoog	Tubes / Valves	2	28th March 2007 09:03 PM
PP-Triode , PP-UL , PP-Pentode-strapped-as-Triode	percy	Tubes / Valves	23	22nd January 2007 01:36 AM
Recommendations needed for designs of PP pentode strapped as Triode	percy	Tubes / Valves	24	22nd October 2004 10:03 PM
E180F triode-strapped.	jim	Tubes / Valves	15	16th September 2003 12:00 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read

13th January 2009, 02:43 AM	#2
ray_moth diyAudio Moderator Emeritus Join Date: Jan 2004 Location: Jakarta	It makes sense for it to be Cg1g2 X stage gain. I'm guessing that the plate is too far from g1 for there to be a significant capacitance between them, but I could be wrong.

13th January 2009, 03:29 AM	#3
Poindexter diyAudio Member Join Date: Oct 2004 Location: Maui, Hawai'i, USA	That sounds right to me; after all, that's the idea of a tetrode in de foist place, no?  The problem would be to find this capacitance.  The datasheets very seldom give such data for trioded pentodes; we're lucky to get plate curves. I wonder, would this spec have to be tested for on a hot tube in-circuit, or could we just stick an LCR meter on the appropriate pins on a cold tube sitting on the bench? Aloha, Poinz AudioTropic

13th January 2009, 06:27 AM	#4
ray_moth diyAudio Moderator Emeritus Join Date: Jan 2004 Location: Jakarta	Hi Ponz, I don't see why the tube has to be hot to get this measurement. Temperature would make a difference, I suppose, but it should be slight.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)