how to test tubes with your multimeter(filament continuity), from low to high power tubes

[@SCOTTYD2031]

You helped me fix an old radio and my keep my sanity. Thank you for this. I was trying to figure out how to count the tube pins and check the filaments. This radio had 8 tubes in series so to replace all or guess was not working. Eventually I found a broken trace on circuit board that was supposed to feed the last tube filament. I jumped it with a 2.5A slow blow pig tail fuse. It took me along time to troubleshoot because I hate working on stuff with "hot chassis" and I don't have an isolation transformer.

[@wyreandwood]

Awesome! Thanx for taking the time to do this video. Very informative.

[@YoungAhn]

Glad it was helpful!

[@Jr-xl3xe]

To start off im a novice. My cousin, who owned an antique shop, passed away a few years ago and his wife asked me to try and sell several items. I'm a complete novice at this, but i know enough to seek help through youtube videos. I purchased a fluke multimeter on ebay (i did the auction, so i got it for a good price). With that said I tested (16) of my 9 pin miniature tubes, all the filaments tested good on pins 4 & 5, but i got nothing with pins 4 & 9. Did i do something wrong or are they all bad? Thanks

[@YoungAhn]

Some 9 pin tubes have nothing on pin #9. Check the tube data. Good day

[@diecksl]

I have a 70 kV dental x-ray tube. The tungsten filament is in good condition, but when I measure it with a digital multimeter (10 MOhms Input impedance), I get values "bouncing" between .8 and 1.3 ohms. Do you have any idea, why? As far as I know, the filament changes its resistance when it gets hot, but not when its connected to a high Input impedance multimeter?

[@Jr-xl3xe]

I wish u did every tube that ever existed cause non of the ones I have were in the video. (Update): I was initially looking at the specific model #s, but now I'm assuming that they test the same as long at its the same number of pins. Is that correct or am I wrong in assuming that?

[@YoungAhn]

Thank you

[@fastteddyb]

Hi - on my multimeter the 'horseshoe/magnet' and the 'wifi' like curved bars ((((( are in separate place - whereas yours are in same setting/position. Q: are you choosing the horseshoe/magnet or the ((((( ? And is that setting you chose 200k? Thanks.

[@YoungAhn]

Hi Hi, I am not sure what kind of DMM you have but just move selector pointer to ((( and press 2nd function button if yours don't have separated buzz button. Thank u

[@izzzzzz6]

Hi, which is the procedure to test an EL 509? In the end i swapped all four one at a time into a piece of equipment that only uses 1x EL509. I found that one was not working well at around 10% of it's power output. It was also getting much hotter than the others!

[@YoungAhn]

Hi, there are 2 kinds of EL509. One is regular shape 8 pin type, the other is plate top type with 9 pins. please google and find correct pin layout. Thanks for your questions. Young

[@entropytango5348]

Very Helpful

[@henry-zs8hq]

why is the multimeter sounds like a whistle?

[@YoungAhn]

Thanks for watching my videos

[@macmusica]

oxydisation on the probes (rust) so needs to be pressed tighter

[@ryantoomey611]

Is there a way to test for emission by powering the filament and then checking continuity between the plate and cathode?

[@YoungAhn]

Hi, Yes of couse. I'm going to make a video soon(high power type). And I'll show how make a simple bias tester(with 1 multimeter) later. Please keep your eyes on my KZbin channel. 😀

[@hiseminencetheholymacdiarmada]

GZ34/5AR4??

[@YoungAhn]

Hi, technically 2 are very similar but I didn't try yet. Thanks

[@Blueguitar007]

What exactly does this test do? To test for continuity? But tubes can have shorts or have no strength left hardly.

[@YoungAhn]

You need a tube tester or mutual conductance meter. Thanks for leaving a comment on my video

[@wmp0074]

Hi I have no continuity on pin 4 and 5 on a ECC83-S pre-amp tube. It's brand new. Using it in a Fender Hot Rod Deville. The power amp in section works just no sound with the main inputs. If I followed video accordingly, this means the tube is a dud?

[@YoungAhn]

Hi, are all tubes glowing except a new ECC83? If yes, please check the socket(pin numbering is reverse of bottom view). Set your multimeter function to ACV. Measure VOLTAGE between pin 4~5, over 10 volt is good. If 0, measure pin 4(or 5) ~9, over 6volt is good. Finally measure pin 4(or 5, or 9) ~ chassis GND. Let me know the result. good luck. Young

[@wmp0074]

New one doesn't glow as bright will check voltage thanks!

[@wmp0074]

Back with measurements. Voltage between pin 4~5 is 0. 4~9 and 5~9 is 6.1. 4 and 5 to ground is 3v

[@YoungAhn]

OK, that's good. It's normal because heater supply is center tapped(grounded) to reduce induction noise. Try one more thing, select DCV and measure 4(5)~chassis, if it is 0(no DC leakage from other circuit), your amp is working as designed. good luck. thanks

[@wmp0074]

Thanks for the tips! It was indeed a defective tube!

[@billwilliams6338]

YOUNG AHN, why would a designer apply high voltage on the metal tubes shielding instead of using ground?

[@YoungAhn]

Hello dear Bill, please let me know the name of the tube, I will check it out. Thank you.

[@billwilliams6338]

@@YoungAhn various metal can power amplifier tubes dark metal can types PIN#1 is the shield and can be applied to either High voltage or to ground.

[@YoungAhn]

I know what you mean. We call this kind of tubes as "emitter tube", most of them are used for RF transmitter which needs very high voltage. Some tubes need "zero bias" because G1 should be 0V(GND). Some tubes need "positive bias" instead of negative voltage. Please see 805 Ip / Vp curve. thanks

[@billwilliams6338]

@@YoungAhn yes thanks for the help. Yes they used there black metal can vacuum tubes I think in RF transmitters and RF radios. Why does these Black Metal can tubes need a "positive bias"? because if you grab the tube with your hand it will have very high voltage on the black metal shielding of the tube and you will get shocked really bad.

[@PeterDad60]

bill during normal operation of a device using these tubes, do you from experience that a person will be shocked when they make contact with the outside metal jacket of the tubes you are thinking of?

[@motoputz3201]

awesome, thanks!

[@YoungAhn]

Thank you so much

[@calvobrizzolato]

Formidabile! Grazie!

[@YoungAhn]

Gracias fella, 😃

[@mikemcneiley9817]

Great video, Thank you

[@YoungAhn]

Thank you very much

[@joesheehan5475]

thanks man! great info

[@YoungAhn]

Glad it was helpful!

[@infinagon]

This is actually very useful information! Thanks

[@YoungAhn]

Glad it was helpful! Thank u

[@thomasdivito6221]

Is it possible to achieve perfect continuity, and still get a non fonctionnal tube ?

[@YoungAhn]

It is possible to measure filament continuity with general purpose MM. Please check the pin layout and numbering of your tube. Thank you dear Thomas

[@Westy-1]

To answer your question correctly instead of getting a totally different answer. Yes its possible to achieve perfect continuity, and still get a non functional tube. I have a tube here that doesn't work but still has perfect continuity. I hope this helps.

[@ryantoomey611]

Yes, tubes can fail in many ways, not just the filament. For example, the cathode can become depleted or air can leak inside those will both cause the tube to be non-functional even if it passes the filament test.

[@splity9]

What values should you be looking for? Thanks for the nice video

[@YoungAhn]

Thank you dear Guillaume

[@Blueguitar007]

I think it's just a continuity test.

[@YoungAhn]

@@Blueguitar007 yes, read the title again.

[@Nervosa80]

No value. Just make sure the proper pins are closing (or shorting) the circuit. 👍🏼

[@SCOTTYD2031]

There will be some resistance. I just checked a bunch of 12V tubes and they were 13ohms. I also checked a 35V tube and it came up as 32ohms. Hope that helps.

[@UDX-21]

Good info, thanks---21

[@UDX-21]

After watching again, will you do a test of more transmitting tubes, such as a 3-500Z/G, 4cx250B, 3cx3000, 8877, etc? Thank you, WWPDX21

[@remotexpolde]

I don`t suppose you could describe\(or know which pins to check, etc..} how to do this for a Gt. Britain~made Vintage Mullard 5AR4\GZ34 Rectifier Tube by chance.. Cheers!!

[@YoungAhn]

filament pins of 5AR4 is 2 and 8(bottom view). Pin layout is all the same even though manufacturer is different. Try again. Thanks

[@mattildahubbardo]

Do you kniw the name of the artist and the name of the cd

[@YoungAhn]

I can't find his listings anymore on ebay. I am sorry

[@danelynch2730]

What about EL84?

[@YoungAhn]

google "el84" please. get pdf file. Thanks

[@mattildahubbardo]

Great video, What is the song???

[@YoungAhn]

Thank you for your interest. I bought a royalty free music CD on eBay(Canadian seller). I am very satisfied with his songs.

[@SuperJV4x]

is this the same as a 'short'? or is another test needed?

[@YoungAhn]

any analog or digital multimeter will be OK.

[@arunaspaulionis8350]

Thank you

[@YoungAhn]

You're welcome, Thanks

[@petrektek1385]

Wow last tubes seem like boilers!

[@YoungAhn]

Thank you very much 😀

[@EJP286CRSKW]

I just plug them in and see if they light up. Your red meter lead is a major shock hazard and should be renewed. You didn't test 5 to 9 of the 12AX7, or state why it wasn't necessary.

[@YoungAhn]

I don't explain it from A to Z. Everybody understand how to do it because it's too simple. Thanks

[@EJP286CRSKW]

That just makes me wonder whether you know why it isn't necessary yourself. The whole thing is too simple to make s video about actually.

[@YoungAhn]

@@EJP286CRSKW Every human being has brain to analyze the object. utilize yours

[@EJP286CRSKW]

Young Ahn I'm not asking you for the answer. I know the answer. I'm wondering whether you know the answer, and if so why you didn't post it. Instead of just trying to BS your way out of it. Evidently you don't. You're welcome to prove me wrong by posting it, instead of just evading the issue.

[@vehemence2006]

@@EJP286CRSKW I'm wondering if you know what you are talking about. Video was short and to the point. I'm sure it wasn't meant to be a masterclass on vacuum tubes.

[@kikotrinfata8540]

Hi, my name is Fernando and I was a collector of old valves. And now I would like to get rid of my collection since it has been like 30 years. I managed to put together some 6000 valves including some very rare ones that are valued at € 400, they are all new and in their respective box. And I am willing to sell them for a very low price, I wanted to know if you are interested, I wait for an answer, thank you.

[@YoungAhn]

Hi, I'm sorry sir