testing voltage on tube filament, without the tube - diyAudio
 testing voltage on tube filament, without the tube
 User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

 Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
 1st February 2013, 04:12 PM #1 diyAudio Member   Join Date: Apr 2010 testing voltage on tube filament, without the tube I would like to adjust the tube heater voltage without using the tube. The tube rating is 5V/2A. I believe I can use a resistor in its place with the same effect, but I have never tried. Can someone confirm what should be the resistor's resistance and power rating? And if this is a good method? Thanks!
 1st February 2013, 04:25 PM #2 diyAudio Moderator     Join Date: Sep 2004 Location: Boston, Massachusetts Blog Entries: 6 Yes, this is a good technique. Use ohms law to calculate the required resistance and power.. At least double the rated power of the resistor based on calculation. R = E/I where E is the operating voltage and I is the desired current. P = I x E __________________ "To argue with a person who has renounced the use of reason is like administering medicine to the dead." - Thomas Paine
 1st February 2013, 04:33 PM #3 diyAudio Member   Join Date: Apr 2010 Hi, Thanks for the fast reply. So for the 5V/2A tube it would be a 2.5ohm resistor rated at 20W, that's it?
 1st February 2013, 05:33 PM #4 diyAudio Member     Join Date: Dec 2011 Location: Barrio Garay,Almirante Brown, Buenos Aires, Argentina Yes, OK, but use a higher wattage resistor, because it may run hot. Also, if the 5V is from a rectifier, be aware with the high voltages at their anodes. Good luck. __________________ Osvaldo F. Zappacosta. Electronic Engineer UTN FRA from 2001. Argentine Ham Radio LW1DSE since 1987.
diyAudio Member

Join Date: Mar 2009
Location: Buenos Aires - Argentina
Quote:
 I would like to adjust the tube heater voltage without using the tube.
Just curious, haw are you going to "adjust the tube heater voltage"?
Where's such voltage coming from?
Is it a rectifier tube?
Does it have HV applied to it?

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are Off Pingbacks are Off Refbacks are Off Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post jsternmd Tubes / Valves 0 25th October 2011 05:44 PM Bola Tubelab 9 14th September 2011 04:00 PM ilimzn Tubes / Valves 5 4th January 2010 05:53 AM Evenharmonics Tubelab 3 25th January 2009 12:10 AM ray_moth Tubes / Valves 14 4th July 2007 03:09 AM

 New To Site? Need Help?

All times are GMT. The time now is 10:54 AM.