TV-7 Tube Tester Calibration, Repair, and Service - a Practical Guide

If you need calibration tubes, I now sell them, follow this link: www.ebay.com/i...
If this video helped you, buying these from us is a great way to say thank you.
BG143 - Full in-depth walk through of how to calibrate a TV-7 Tube Tester. This applies to the TV-7D/U, TV-7C/U, TV-7B/U, TV-7A/U, etc. We also show how to replace the meter and bias potentiometer if needed. Also shown is how to replace the power cord with a modern 3 prong cord as well as a little history on these units.
A link to the instructions can be found here:
blueglowelectr...

[@fb341]

After a year of searching and pondering, I finally just pulled the trigger on a TV-7D/U (due to arrive soon), so Iv'e delved deep into related videos. Thank you, Mark, for your extremely informative videos and generous efforts to educate on so many topics.

[@ernesttempler9415]

I was in the military 20 years(1961 to 1981) ground radio communication. All types of equipment. Used the TV-7 a lot. Back in the day of tubes were used a lot!

[@alaricsylas6029]

not sure if anyone gives a damn but if you're bored like me atm then you can watch pretty much all of the new movies and series on InstaFlixxer. Been watching with my gf for the last few days :)

[@ronniesullivan9567]

@Alaric Sylas Definitely, been watching on instaflixxer for since december myself :)

[@ekbanjosworld4926]

Ok ! You made me do it ! I just got a TV-7D/U on eBay !!! Good price too and the case isn't beat up ! I'm going to watch your video again, take notes and make a detailed instruction manual as per your simpler method ! Thanks Mark, love all you do ! Curtis

[@Blueglow]

If you need a set of calibration tubes for it, I sell them on eBay or my website www.blueglow.net

[@EriksElectronicsWorkbench]

Great video, very informative and helpful. Just a note, your mention of the TV-7/U series going back to the early 1960's.. the tester actual dates back to the early 50's. My TV-7/U is from 1953 and my military tech manual is dated 9/53.

[@mguess]

Mark, thanks for the video. I've been borrowing a TV-7DU from a friend for over a year and want to calibrate it for him.

[@normbal]

Bought a recently repaired/somewhat updated (guy couldn't have cleaned the contacts as two selectors were kind of sticky/stiff until I cleaned them with Deoxit) TV7-D/U off an eBay seller recently and for the most part, readings on tubes pretty much matched what I was expecting, esp. triodes like 300b and 2A3, close enough anyway. Rectifiers were good, GZ34s sold as matched sets at 60/60 came in at/around 60/60. Thought I'd check the calibration anyway and meter checked out at 202mA, power resistor (about 9.35k), went ahead and replaced the 47 ohm resistors anyway with better quality vishay fireproof ones (i'm not a fan of the cheap Chicom resistors with the enamel that flakes off); a set of tubes I bought through Blueglow Electronics on eBay showed voltages (pins 8 and 4) were off by about 1-2 vdc on initial checks, took a few hours to run through the tests, calibration steps and everything is spot on now. ONE question. Why not replace that multi-tapped power resistor with two precision high-wattage linear potentiometers? THAT setting High/low screen voltages was tedious as anything and the two tabs I had to insulate from each other with a piece of heat shrink tubing they were so close. Actually thought about reversing all the wires and using the other side of the power resistor but I'll just use the tester as it and see how it holds up. Thanks for putting this together for us.

[@normanwalz8636]

Very easy to follow. Many thanks. Decided to purchase a Marantz 2275 and recap it myself because of your great videos. Thanks for doing this.

[@Tysman909]

A fix for meter is take cover off and soak bottom half in IPA for 30min and let dry for 1 hour

[@AntoNio-nw7kx]

what to say..... clear explanations, also your pronunciation is slow and clear (i'm italian, so it is not always easy to understand people that talk quickly), about Video quality... another great video and also added with writings that for sure helps understanding ! i'm going to subscribe your channel. Thx for all the explanations!

[@amiga8761]

you can slow the video down by clicking on Setting (gear Icon is located at the bottom of the video) on the screen and change the speed, usually 1/2 speed. I have done this for myself, a lot. You can also read the transcript that shows both the text of the speaking and the time for each sets of the words. Look on the bottom of the video and you shall see 3 vertical dots, click on that and then you can select transcript. It will appear on the right side of the video as a column.

[@kstlfido]

Great video, Mark. Thanks for making this TV7 calibration info available in a clear, straightforward manner! A couple of questions- #1- At 1:08:26, you refer setting the range switch to 5. Would this be #5 position of the shorts test section of the range switch? #Steel wool for cleaning? Eek! I keep that stuff and it's conductive fibers well away from electronics! Scotch pads work great for stubborn stuff. Again, thanks for a great video.

[@turnersparadise8368]

Looking forward to the wrap up of the single ended tube amp. I know you stay pretty busy but I hope it is on your plate.

[@Blueglow]

very soon. I just have to mix in some customer stuff along with my stuff to keep the natives from getting restless

[@Tysman909]

You don't blow air in meter it will distort the fine springs. The best is submerge meter enough to cover pivot in iso alcohol then let air dry for hour. I would do that to your meter should free up the sticky pivot

[@lmt200ish]

It would be nice if there were this detailed calibration video for testers like stark 9-66/hickok 533 testers.

[@Mcandmar]

Fantastic video, thank you for sharing your knowledge. I am working though the process on my TV-7 (the original with no adjustment pots) and everything was within a hair of where it should have been, close enough i am not going to worry about it. BUT i got as far as testing the Plate voltages as per the original calibration manual with a 375k resistor and i'm seeing 188v instead of 150v. The manual goes down a rabbit hole of swapping the plate wires around for each rectifier tube, but curious if you have any better ideas before i go there? Bias @22 = 2.86v Bias @75 = 25.26v Bias @100 = 39.04v Screen = 125v instead of 130v Screen = 54.3v instead of 56v Plate w/375k = 188v instead of 150v Filament voltages with line test centred, 120.2, 76.3, 53.8, 36.7, 26.45, 19.50, 12.40, 9.99v (10v setting), 7.54, 6.30 (6.3, 5.20, 4.31, 3.24, 2.71, 1.994, 1.273, 1.090, .728

[@jonkummer2451]

Interesting video. Helpful in many ways. Unfortunately he will not respond to any questions. I even purchased his set of calibrated tubes on ebay and wouldn't respond to any question on ebay either. Also, the 6L6 metal calibration tube he sold me was very rusty and looked like it was at the bottom of the ocean for a long time.

[@Tysman909]

Surprised they didn't have a bias fuse in that tester would of saved that control. My hickok 752 has one

[@zipstuff]

great tutorial!

[@johnlimbach9267]

Working with this on my new (to me) TV-7C/U. It's working now, but obviously needs the updates and calibration. I was surprised to see how small the case is relative to my big Hickoks and I notice that it generates a LOT of heat just idling on the bench. What's your opinion and experience with putting in solid state replacements for the 5y3 and 83? I would think it should reduce the power consumption and thus the heat by some factor.

[@fredericvidal7179]

Great, thinks, but nothing for the fist one the TV-7U plase? What's the difference?

[@johncunningham5435]

Excellent demonstration.

[@stephenstudley185]

Roger Waters is doing tube tester repair? ;) I thought he was touring... Good to see you are producing videos! Been a while since your last. Thanks Mark!

[@100uno100]

Impresionante trabajo !!! 👏👏👏👏👏👏👏

[@pgjopop]

Thanks to Mark for this informative and overall fine instructional video, my remaining question? How do I place slide reinstall the Hickok TV7 DU back into the chassis? (no kidding)

[@david25876]

Thx. Great content!

[@victorvalmus8135]

Excellent videos. Have you done a calibration of Hickok 800?

[@stevechadwick1296]

Great video. I just picked up one of these and used the old military manual to calibrate the voltages. I cannot find documentation on the gm calibration procedures in any of the online resources. If you don't mind telling, where did you get this procedure from? Sincerely, Steve

[@zundfolge1432]

hickok 600a is pretty similiar. Ive got one that will not test rectifiers when pressing the p3 button. I would also guess p2 functions do not work according to schematic

[@delatronics3257]

I got a TV3 C/U arriving Monday; can I apply some of this tutorial on that (Or are they totally different).

[@TheCleaner6969]

Any ideas what I could get for testing EL34 & 12ax7? I wanted to get the Orange VT1000 but they are discontinued. I was looking at the B&K 606 & the 747 but every seller seems shady & the prices are up there considering I'll need to re-cap it & change some resistors & calibrate it. It's for personal use just to keep an eye on my tubes.

[@steelcantuna]

Can you please elaborate more about the R130 power resistor? It makes me apprehensive about buying one that needs calibration. I googled it, & there seems to be replacement resistors that don't look like the original that came with the TV-7.

[@toby2655]

Does a TV-10 set up the same way as the TV-7 ?

[@MrJoejim]

Hi Mark, thanks for all the great videos. I'm in the process of recapping a Blaupunkt radio from the 1950s and have run across capacitors with marking I don't fully understand. For example: the caps are marked " 50/20 125V" The 125V I understand but I'm not sure how to read the "50/20" part of the marking. The caps in question are small and appear to be foil and paper in a clear plastic tube. Any help in reading the value would be appreciated.

[@DaveMcAnulty]

Might be 2 capacitors in the same package, how many leads are there?

[@MrJoejim]

Just the usual two leads so I don't thinks it's two caps in one package. I'm to the point where I'm going to disconnect a few and test them and see if that will give me a clue to how to read these caps. Thanks for the thoughts though.

[@dw3434]

Hi Mark, thanks for your video. My TV7 D/U can only get 13v for high screen, when I adjust R110. Can you advise which part may be wrong. Really appreciated.

[@frankgeeraerts6243]

I thank you for this very helpful and clear instructive video to align my TV7D/U ............. i have only one problem , i can't find a fuse lamp anymore in Belgium , can you help me ? Greetings from Belgium , Have a nice day Mark.

[@P.y.k.u.p]

Hi, seems that in TV7UB, there's no 13? pot on the chassis above R134 to calibrate/control the bias, like on the UD version. On my model, there's no 3rd pot like in the video. In addition, the last number R13? can't be seen, so it's hard to know where to check. Any idea ? Regards from France

[@fredericvidal7179]

Thanks and please...Sorry for my bad English

[@whiting444]

Hi Mark, absolutely great and easy to follow video. I contacted Dan Neilson regarding buying the calibration tubes. He advises that he doesn't have them. Any ideas on where else I could purchase them and or would you consider making a set and selling. Cheers

[@grimtale69]

send me an email

[@oscarvalencia9485]

how do I know if the unit is out of calibration?

[@Tysman909]

How would I build one of those diode circuits for my hickok 752 it's called cr1?

[@bobroth1951]

How do you make a set of calibration tubes?

[@Trex1268]

Hi Mark, Just wondering on your thoughts on the Hickok 752?

[@Tysman909]

I own one it's very accurate and can test dual tubes without having to change switches just press plate 2 button :)

[@tonynelsonlavoz.664]

Un amigo radioaficionado decidió retirarse a descansar y me regaló un aparato de estos. Dice: TUBE TESTER TV-7B/U SERIAL No 525 Forway industries INC. Lo conecté a la energía eléctrica y enciende perfectamente. Está en venta. También me regaló u otros elementos cables y antenas. Y más de 20 bombillos de vacío

[@ianbutler1983]

Thank you.

[@iccaros]

for the TV-7 U I can not find a R134 and in the manual for the Military aliment it states R124, so that would be the one I switch with a POT? For mine the line adjust is at 60 and easy to do, but all the filament voltages are half what they should be

[@iccaros]

got it, added a R134 (60 K 5 watt pot had sitting around) and changed R 124 to a 230K so I could make adjustments, as at 245K it was off.. also the half voltage.. du.. I was in 1 and 7 not 2 and 7.. double check..

[@Tysman909]

Strange that military tester would have sticky meter pivots.

[@Tysman909]

Send meter I will repair it so you will have a spare :)