How to identify unmarked vacuum tubes (European)
ฝัง
- เผยแพร่เมื่อ 9 ก.ค. 2024
- If you pick up batches of used vacuum tubes from time to time, you probably end up with quite a collection of vacuum tubes with unreadable or missing markings. Over time I've developed some methods to identify these tubes with a fairly high success rate.
Note: I mainly focus on European tubes in this video
00:00 Introduction
03:08 Using the type code
21:40 Identifying internal tube elements
33:15 Identifying the heater
42:51 Exhaustive example of identifying a tube
1:05:02 Outro
Philips-Mullard Factory Valve Codes: frank.pocnet.net/other/Philip...
WARNING: Do not attempt to repair electronic equipment if you don't know what you're doing.
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Since I live in the US, I've never worked on a European radio; I found this most informative. Well done! 👍
Thanks!
@@retro_tech - I sent this to David Tipton and Manuel at: Electronics Old & New.
Today I learned something new, thank you! I have quite a number of tubes that I haven’t been able to identify, and had no idea that there were manufacturer codes. Thanks 🙏
Thanks, Manuel. Honestly I was a bit uncertain about this video because I wasn't sure how common knowledge this was. Maybe everyone already knew this and I was just stating the obvious. Glad that it was useful.
This is an exceptional video, the best I have seen for many years, this will solve my vacuum tube stock issue 😄. Thanks, and have a good day.
Thanks a lot!
This is a great video - thanks ! I hardly ever watch anything longer than 10 or 12 minutes, but this was an hour well spent. It would be awesome if you could do one on American / Japanese tube numbering for those of us with a mix of equipment from all over the world.
Thanks a lot! I don't have a lot of experience with American tubes and none at all with Japanese ones. So maybe in the future but definitely not on a short term...
Another thing, had anyone been known to use old tubes to replace the inner working with ic, or fets, diodes, transistors, or whatever type semiconductor required for the circuit, maybe include a led red or blue to stimulate the operation of the original tube. In a resto mod, or a modern retro build. It would be cool to use tube sockets and false tubes hiding certain parts of the circuit. Maybe the power supply in one, a full bridge rectifier in another, a microcontroller in another assembled on a piece of colored acrylic , wood or some preferred non conductive material. Build a single board computer with raspberry pi, or similar, hide the DC to DC in a tube, make a semi transparent tube body by 3D printing, with a base with copper pins through it. Or just wire running through, or build a high end appearing hi-fi tube amplifier, using ic amps inside a false tube body, mounted to a copper or aluminum bar to connect to a hidden heatsink. Say the tube is 45 mm dia. And 70 mm tall. With a a 35 mm base, 3D printed, with a 25-30 mm wide and 6 mm thick copper or aluminum bar that is soldered to another piece(if copper) or use two 3 mm screws in aluminum. To form a inverted T shape with the base thick enough to have passages for wires to fit between the heat sink and the tube. 3D Printed from a clear material, the tube body made to look like a real tube. Include a led inside to give look of operation. Maybe design it to find with the music. Maybe 3d print old capacitor body shapes. And print out labels to make them appear to be the real thing, also resistors also. Having modern resistors and caps inside possibly use 2-3 layers of PCB board to mount the parts on to simulate the slate and other material they used back in the day. With it mounted to wood or plastic depending on how retro you want to go. And how accurate you want it to appear. I'd like to have atleast a 5 channel amp for a tv surround sound and stereo sound system. Possibly using a powered subwoofer, have a RH, LH, center mids and highs, a rear RH, LH, a RH, and LH, woofer with mids and highs would be preferred. But a 3 channel front stage with rear 2 channels, and a sub channel , at least 50 watts subs, low passed at 100 Hz. The front woofers high passed at 80-100Hz. With the surround doing around 100-200Hz, the center channel having two tweeters , two 5.25" mids and two 6.5"- 8", maybe 10" woofer, to handle 100Hz and above possibly the RH, and LH, having half this. But the subwoofer (*appearing*) to be a 18"-24" subwoofer inside a sealed or ported enclosure, with lexan window. The 12"-15" automotive subwoofer, mounted inside a first stage enclosure shaped like a 18" or 24" sub, inside a enclosure, the double front baffle having about, 4" between them, the space between Being most of the enclosure, the sub shaped inside enclosure, that makes the sub actually in a band pass enclosure. With either a 8" single port or a pair of 4"-6" ports with a single port, it's still going to have two ports to work. The sub chamber to the sealed chamber, then one going to the outside, and attempting to keep it reasonably sized, hopefully under 36" * 36" * 18" maybe making it the coffee table, two layers of .625" MDF with a .250" plywood skin, painted and epoxy coated. Maybe make the 12" * 12" to 18" * 18" * 1" thick window from clear epoxy. To see inside with the wall inside from aluminum foil epoxied to the sides and parts of the fake sub, to make it realistic, and use florescent paints and pigments, and glow in the dark also, use approx. 4, 1 watt UV LED's inside the enclosure, possibly also containing the amp. Around 150-250 watts. And a battery, LiFePo4. 12v roughly 25ah , with s DC to DC cc cv to charge the battery, using a 2-5 amp supply, with a volt meter coulomb mete, to show the actual charge. And include a set of 3-4, 3 watt white LED's inside the window. and a strip of .25 watt LED's to equal about 5 watts per side. All with main and each their own switches, and a dimmer. To. Supply light to the room Incase of power outage. 25-35 watts of led light is way more than a single room needs to light it! The dimmer is required. The sub should be tuned to play low, from 15-20 Hz. To 80-100 Hz. Possibly add a couple db gain from 15-40 hz. The peak should be 30-50 Hz possibly low pass at ,60-80 Hz depending on rolloff, if it's still audible to around 80-100Hz definitely go for 60 Hz l.p. the sub should be low passed below the frequency of speaking, so voiced aren't deep and boomy. Unless they're supposed to be in the movie. The explosions should rattle windows, big explosions should knock things off the wall! Music may need a slight higher low pass, 100 Hz should be plenty. Sorry to ramble, I kinda got into it a bit!
Nice detective work! I have been doing this quite some years.. The one you show at 21:48 is a triple diode triode (EABC80, or UABC80) as you found. Among Eu types these stand out. Several Eu factories made US tubes, like 5Y3GT. Only "Philips associated firms" like Mullard, Valvo and Adzam had these production codes. The "pre-1948" system on the ECH21 I didn't know of, but ECH21 is an old friend.. The first digit in the type no. is quite determined, but there are exceptions! The battery tubes DL21 and more, are actually octal types, not loktal! And the first digit "5" have several socket types. E.g. the PL504 has a "magnoval" base, but the older EF50 has a 9-pin variant of the loktal base. The D-21 valves and the EF50 are both 1940s types, so the pro-electron system wasn't "matured" yet, obviously. Nice, versatile tube tester, I have not seen Metrix testers here in Norway
Thanks for these useful additions
Well done. Thank you!
Thanks!
Breathe on the tube so that the glass fogs up, and hold it up to bright light as the breath fog evaporates, and sometimes the letters will briefly be illuminated. It is often helpful to rub the tube lightly through your hair first to pick up a little bit of air oil on the glass before breathing on the tube. Sunlight works better than artificial light for viewing the invisible numbers and letters.
Thanks for the tip. Unfortunately I've already tried different techniques of breathing on the tube lots and lots of times. None has ever worked for me. Probably I'm doing something wrong. :-)
@@retro_tech , ham radio operators say to put the tubes in the refrigerator or freezer long enough to get good and cold so that they fog up from atmospheric moisture when you take them out, but I haven't really found that to be necessary.
Awsome video, very informative.
I always wondered what the codes on tubes means. This was very helpful
Thanks a lot! Good to hear my video was helpful.
thanks for this great video. i have some tubes and was wondering how to identify them
Thanks! Glad it was of help.
Dag Kristof,
Bedankt voor de héél interessante info!
Die code aan de onderkant van de buis was voor mij onbekend ondanks dat ik al sinds meer dan 55j met buizen bezig ben..
Succes met de hobby!
Dankjewel! Leuk te horen dat mijn video nuttig was.
I was just thinking a while back. Do ppl or has anyone tried to rebuild any tubes? I guess the easy part would be opening them and closing them. If they don't crack when cooling. Then there's pulling a vacuum, and or filling with gasses. The replacement of plates or grids and coatings would be difficult, it would nearly be easier to build from scratch.
Now that we know what the valve is, how do we mark it in a way that it won't go 'ffftttt' when it running hot ?
Good question, but it only applies to tubes that actually run hot like power tubes or rectifiers. I would try a white paint pen, perhaps?
@@retro_tech Thanks Retro. I will be trying it on valves where the markings are fading.
@@paulperano9236 Most of the time, I just use a sharpie though.