TV-7B/U Vacuum Tube Tester Meter reading 120 on 6L6 Tube - Page 1
Forum section: electronics / repair

author: denimdragon
author_rank: Regular Contributor
timestamp: September 13, 2021, 10:07:58 pm
content: This is most likely an operator error, but the booklet say that a good 6L6 should read 43. I tried two NOS 6L6s and the meter went right to 120. Now take thisall with a grain of salt because I am new to tubes, and tube testing. However, I read/take instructions pretty well so I believe I am doing everything correct. I guessmy question here is, is that normal for it to read that high?I have diassemblied the unit because whenever I get old gear, I inspect it to make sure that there isn't any obvious visible issues. I have already replaced the bathtubecapacitor the was attached to the meter terminals and replaced it with a new 100uF 35Volt Rubycon. The old cap was 75uF and I followed a youtube video on howto calibrate and restore it (Blueglow Electronics). Mark seems pretty knowledgeable about the testers and was the reason I hunted down the TV-7 unit intially. TheAplitrex AT-1000 is above my pay grade.Any guidance on this would be greetly appreciated as I have 1000's of tubes that need testing and I want this to be my main box. I have a Knight 600B, but from whatI have read here, it's good for emmissions testing, so I will use it for that as a way to quick all the tubes before I put them on the TV-7.Again thanks for any advice on these matters.

author: bob91343
author_rank: Super Contributor
timestamp: September 13, 2021, 10:14:27 pm
content: I suggest you take your query tohttps://antiqueradios.com/forums/viewforum.php?f=8There is a ton of tube tester stuff on there.

author: Audiorepair
author_rank: Frequent Contributor
timestamp: September 13, 2021, 10:18:02 pm
content: If you are able, you may want to build your own tube tester from a modern kit, this will be far more accurate and reliable.https://www.dos4ever.com/uTracer3/uTracer3_pag0.html

author: Johnny10
author_rank: Frequent Contributor
timestamp: September 13, 2021, 10:38:27 pm
content: Why not ask Mark about it?BlueGlow That is one hell of a complete video on your tester showing also a 6L6 calibration tube on B setting going to 120V.Go Dos4ever !!!! Ronald Dekker, great guy, great Kit !I bought one of these as my very first kit build.

author: Audiorepair
author_rank: Frequent Contributor
timestamp: September 14, 2021, 06:51:25 pm
content: The uTracer kit is not just a tube tester, it is also a fully blown curve tracer.And you can even test a quad or more of tubes, and have all of the multi curves superimposed on the same graph to visually check how matched they are, or not.And then print it out.It doesn't yet have an "emissions" test, as I believe this is rather a grey area as to its validity, and it is also worth noting that some traditional tube testers have been accused of damaging the tube under test by carrying out their version of it.I believe they are working on a rectifier test at present, the current version doesn't do rectifiers.

author: denimdragon
author_rank: Regular Contributor
timestamp: September 14, 2021, 09:55:02 pm
content: And this is why I love this forum! I knew you guys would point me in the right direction.Quote from: Audiorepair on September 14, 2021, 06:51:25 pmI looked at the uTracer and considered it. I'll look into getting it next month. I also Have a Knight 600B for emissions testing. I heardgood things about it so emission testing won't be a deal breaker on the uTracer.Quote from: Johnny10 on September 13, 2021, 10:38:27 pmYes, I follow his TV-7 videos to a "T" and that's how I knew something was wrong. I condsidered emailing Mark, but I didn'twant to add to his list especially with him having some health situations. I'm sure people load him down with questions and I'm justgrateful the man is able to put out such great real world content. I'm truly thankful for that. Worst case scenario, I mayreach out to him if I can't figure it out. As soon as I get this going whereby I can test tubes and make sure the are good, I'm going to sendhim a sack of good hard to find tubes. The guys really a great fellow.I really appreciate the help guys. Thanks again*PS I also need the tester going because I have a Tek 575 curve tracer I need to restore. I have a Heathkit IT-1121 but, it only works very well with the 40V range.The 200V range is "meh"...