Go Back   Home > Forums > Amplifiers > Tubes / Valves
Home Forums Rules Articles Store Gallery Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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

diyAudio Sponsor

Search for a tube at thetubestore.com                            Product reviews and more

Audio tubes for any amplifier: from high end home audio to classic guitar amps.

Quick links by tube type: 12AX7, EL34, 6L6, KT66, 6550, KT88, EL84, 12AU7, 12AT7, 6922, 6H30, 300B, 6V6, 6SN7 

Reply
 
Thread Tools Search this Thread
Old 25th October 2011, 05:44 PM   #1
diyAudio Member
 
Join Date: Oct 2011
Default Newbie- Tube Testing RF Amp tube

I am replacing a pair of 6293 (similar to 6146A) for my ham HF tranceiver. On testing a batch of NOS 6293 on a Hickok 539C, I find the occasional high outlier. Most of them test around 8800-1000 Gm with plate currents around 55-65ma (tube data shows min Gm 4600). Every once in a while I find a tube with real high Gm values almost double ~ 17,000 with lower plate current ~50ma. Is this due to a bad tube oscillating? Any special technique to test such a tube?

tia
jerry
  Reply With Quote

Reply


Hide this!Advertise here!

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

Advanced Search

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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Some general tube questions from a Tube newbie !! Minion Tubes / Valves 11 6th March 2010 01:38 AM
Tube Amp Kit for newbie starro Tubes / Valves 32 17th July 2008 01:37 AM
Harmon Kardon tube amp kit testing diamondsouled Tubes / Valves 10 8th April 2008 02:07 AM
Your favorite tools for testing when building a tube amp rokali Parts 3 20th October 2007 11:50 PM
learning, building and testing tube amp fragman56 Tubes / Valves 103 11th March 2003 10:53 PM


New To Site? Need Help?

All times are GMT. The time now is 01:48 AM.

Page generated in 0.06023 seconds (64.14% PHP - 35.86% MySQL) with 10 queries

Copyright ©1999-2012 diyAudio