I worked for Heathkit for over 10+ years, repairing customer assembled equipment. Just loved it! The biggest problem I found with the kits brought in for repair was the customer assembly & quality of craftsman ship. Often, just a solder job would make the repair or connecting the component to the correct termination where there was point to point hand wiring. The equipment they engineered was excellent for the cost! We used the test equipment line to fix our the kits. The IT-12 was a staple for fixing audio & RF gear. It never let me down!
Hi Roger, I do believe that it was fun working for Heathkit. So sad that Heathkit business model does not work any longer these days... Thanks for stepping in!
Heathkit always amazed me wjth what it is capable of doing, old technology can sometimes out perform modern. I built many Heathkits in the 70's and I am now starting to restore them just for fun, test and Ham gear.
That's the nicest IT-12 I've ever seen. When I worked at the repair shop, in the late 80s, I had one on my workbench, but it had been through a fire and its appearance was damaged by smoke and heat. (it still worked well) Years later, I bought another because I wanted to duplicate the workbench I had, but I wasn't able to find one that looked like new as that one does.
Good job on your video and troubleshooting. Recently, I dragged out an IT-12 that I built 50 years ago and fired it up. It worked but had much self oscillations as I turned up the volume and the eye was not sharp, but fuzzy. I went through all resistors and capacitors for values and functionality (using a Heathkit capacitor tester and ohmmeter) and all were good. No components needed to be replaced. The dc voltages were good. I tightened up all the ground connections and checked ground paths with an ohmmeter. I didn't like the mechanical connection at the can electrolytic c7 to ground so I added a jumper from chassis screw to one of the ground tabs. After all this I started to poke around with an insulated probe pushing and wiggling ground locations with the power on. Suddenly I found the culprit when I pushed the center post on the V1 tube socket. The base of the post had a poor connection to the foil on the back of the tube socket which goes to the adjacent mounting screw. I soldered it and that fixed the problem. Now I can turn the volume all the way up with no oscillations with or without the probe shorted and the eye is sharp and distinct. I've checked the unit with an audio source over a wide range of signals and it works very well.
Thanks for sharing I have just imported one of these from the USA. I found your video searching for the manual and have just started to make a video recommissioning the one I have. I am fairly experienced using valve equipment but it’s alway enjoyable to watch how someone else goes about his work. I also bought a step down transformer but it’s a much larger unit than the one you have as I have some higher power equipment I would like to run. I do like the smaller wall wart transformer you have as it’s smaller and more convenient to use. I also like test equipment and love that power analyser you have. Best regards Chris.
Thanks for the video...I have the exact same unit, and ironically, had nearly identical issues. Mine had the same cap backwards (jumped over to Mr. Carlsons foil vid to verify), and literally the same post and wire you had unsoldered, mine had too! I also found the ground connection in the probe came apart from the coax, so had to jumper that.
Very nice job on this video. I really like this signal tracer too. I would like to see you use it to trouble-shoot a defective unit or two for us. Thanks and see you again.
It would be interesting to change the detector diode in the probe to a microwave rated diode such as a 1N23A to see if there is any improvement in the sensitivity at higher frequencies. I've got one on my bench now so your video was most timely excellent attention to detail with the coupling capacitor. minimizing noise and hum especially looking for faulty components is very important. Its amazing that a piece of test gear that goes back half a century is still very useful today. Thanks Peter and best 73 from across the pond. Doug.
That is an incredible find in that kind of condition possibly manufactured between 1973 through 1975. Thanks for the Video always fun seeing an old piece of test equipment coming back to life. Oh, and I also subscribed to your channel. Thanks for sharing.
You got a nice unit there. Really great condition. You found the number one problem with kit assembled equipment, missed solder joints. Great addition to the bench. I would be lost without my tracer. You can do a surprising amount of troubleshooting with one of these. Think its sensitive now, build yourself one of Paul Carlson's super sensitive probes and it will turn it into a sensitivity monster.
Hi Mike, yeah glad that I found it. My modern one with OP amps and digital level meter and what have we can not compete with this old Cadillac :^) And you are right there are circumstances where this old stuff is more than helpful. I know Paul's super probe and that is incredibly sensitive but was it not build for finding noisy components with even not touching a component?? Have a nice Sunday 73
Hey Mike. I just bought a IT-12 with no probe. I was going to build a probe myself but the detector diode used is not found anywhere. Great suggestion that saved me was yours: "Think its sensitive now, build yourself one of Paul Carlson's super sensitive probes and it will turn it into a sensitivity monster." Oh yeah, I remember that video. Thanks for this suggestion! Tom
@ 57:00 it's always a good idea to add a fuse to the "hot" side of the mains/line cord, especially in equipment that has no possibility of finding direct replacements for things like it's transformer, and older Eico and Heathkit items like that seem to often be lacking any fuse in its main power line circuit. I often install a Littlefuse brand 03540001ZXGY - 3AB/3AG fuse holder, it installs nicely with 1 - 1/8 inch hole drilled into a chassis and a properly sized pop rivet holds it well, and it wouldn't have any outside physical indication to detract from its "original" look. Glad you got it working well with the work you did.
Extraordinary. I have an AVO universal bridge of the same vintage that is also apparently unused. It worked perfectly at switch on and is quite remarkably accurate. Measuring down to a few pF and up to a few Henry. Plus giving a quality indication,. I have had many 'time capsules' and they are wonderful things from watches, cameras, audio and test equipment.
I like the Vintage Section especially devices coming from an Era in which most devices are obviously designed for 1.21GW :) Thank you Peter for the effort to show us this neat device and how it works!
The OM did a very good job assembling the unit (less the missed solder joint of course!)...nice addition to your bench Peter, I actually gave mine away to a friend some time ago and miss the capability, may have to homebrew a new one. 73 - Dino KL0S
Yes I fully agree Dino the OM did really a good job back in his youth and I can imaging how much frustrating it must have been back in the 60tis...Oh that is bad luck that you gave your it12 away..Hope you can find something similar.. Have a nice Sunday 73
Check out Fran Blanche. She just built a NOS one of these, and her instructions came with wiring instructions for 120v and 240v versions. If you have the same transformer, you can make it into a 240v unit.
Thanks for information. I know Fran's video and she was lucky to get an European version .... I have the US version. The difference is that my line transformer is different so that I can't switch both 110V taps together for 220V...very sad :-( I guess I have to swap the line transformer with Fran's LOL. Again thanks for watching
Good one Peter; always good to get a quick refresher on vacuum tube circuits. Amazing that it detects up to 430MHz! i thought the Heathkit was the oldest gear on your bench until I saw your tube tester! Thanks!
Nice, I will look forward to watching this video, I have one of these on my bench, it works ok, but crackles a bit, and I'm not that familiar with valve gear, mine had a bad eye valve, which I replaced when I got it.
Hello Peter, I own the Heathkit IT-12 with the rare white housing. One year ago I was able to purchase the unit at an OM in my neighborhood. During the investigation of the device only a few defective Elektroyt capacitors were found. My version is running with a 230 Volt power supply. The magical eye was also in very good condition. I work very much with the signaltracer it is a really fine device. On Saturday I used the device at a special action of our repair cafe, where I work voluntarily. The visitors were able to see the error search with the IT-12 live and were very interested. It was possible to repair four of the 8 tube radios on site. I would like to thank you for your excellent tutorials. 73, DG3JA, Jörg
Hello Peter, my home Repair Cafe is Castrop-Rauxel. Many others I have visited and I am so crazy, to repair even on vacation, in the cafes Dresden, Saarbruecken and Saargemünd (France). I am fascinated by the volunteer work and have found many nice social contacts. Despite all the efforts of the manufacturers we get a lot of repairs. Often, it is an old heritage that nobody wants to repair. On Saturday we had a radio day at the International Repair Cafe week. 4 tube radios were repaired and the condition of the tubes measured with 2 devices. My Roetest 9 was in action and was demonstrated. Here is the link to our website: www.repaircafe-castroprauxel.de/ 73, Jörg
Another wonderful video. I would love one of these signal tracers, but too expensive for me! I am building an inexpensive solid state device at the moment from a kit. I hope it will be successful. 73 Lynton.
Happy saturday Peter, the old Heathkit stuff was the cats ass in the day. I remember the robot they produced. That tracer looks good physically I better shut up and watch the video with my coffee. Cheers
Just finished watching and I thought the soldering was good, the lead bends were great. The amount of applied solder was good no problem, and everything looked good. I like that you keep it original with the power cord, sure missing solder points are an issue. But good effort on the assemblers side, I remember Heathkits were so expensive to buy, buying assembled things were cheaper. I guess building back then from scratch cost you more, time and money. As always Sir, great video look forward to the next TRX Bench Adventure ............................. Cheers
Hi Tom, yes soldering was good and all was done in a good way...What a shame that he was not able to take the nice unit into service..But that is how it goes sometimes. Now he had lost all his interest in electronics...BTW what does the metaphor ""stuff was the cats ass in the day"?? Never heard it before.. Thanks for stepping in Cheers
Hi I love your videos and your excellent I wish I could find somebody around here in the US that could work on stuff like you I have an old icon 211 can't find anybody to work on it
Nice explanation of the unit and its design. I'm getting one soon and am very curious how its build and what it needs for upgrade to make it work as yours. This movie is a very good reference! 73. Louis.
Fran Blanch on UA-cam is building one of these at the moment from an unopened old kit. The transformer on hers is dual voltage (110v/240v) depending how you connect the primary. If yours is the same you could convert it to 240v.
Thank you Gary, I know...Fran has the European version and I have the US version. Unfortunately my transformer can't get wired other than for 110V...Again thanks for stepping in
Hi Peter, I have one on my bench, also like new perfect, watch the noise switch, when on it puts voltage to probe tip,, its shocking,, great video thanks again
A guy I work with gave me that same unit. Condition is not as good. I'll have to put it on the bench and check it out. Just got done making a schematic for a Sprague Mike-o-meter M1 capacitor tester. Had the same problem with that one, two wires on a terminal strip never soldered. 73, N9EUQ
Tools too. He would not let me back in. Just remember, you can have all your belongings taken but not your brain or memories. That's what is important.
Notice C5 in the schematic is not in the correction direction. That's why so many people put it in backwards. At 44:23, it's pronounced Cas-Caid (Cascade)
Hi peter. I know this video is a year old but I think I saw something that is not working correctly. When you turned the speaker off the eye tube stopped working but I think it should still work showing a signal when the speaker is off. I have one also and it worked that way. Just a thought, Carl.
I realize this is an old video, but I noticed that the probe wire did not have any strain relief. You might want to check the connection and add the relief. You might check the power cord for strain relief, too
I have watched a Video on the Heathkit Signal Tracer T-4 and noticed the Capacitor you reversed the polarity on due to high gain on the IT-12 is the same situation here on the T-4. Could this be an error in the original design or does the cap have to be reversed also?
Hi, Nice video! Just wondering if the "eye" tube should not be fully lite until a signal is present. When a signal is present, I would think that would sweep around both directions from the 12 o'clock position to correspond with the signal intensity and then it would return when the signal is removed.
Huh, just wondering how this eye tube is visually useful for this device. I had an old Tandburg reel to reel tape deck that had an eye tube which worked as I described above.
Before I went any where near modern electronics I would want to know the current and voltage between the probe tip and ground otherwise a good presentation and content.
If you wish to donate it I am your man lol it's very nice clean unit .Frans video of her building hers might be helpful for you it was pretty good watching her being built .
Well I'm pretty impressed with the sensitivity and the frequency range of this unit Peter. Wow! I just bought one without the probe. It was the cheapest out there. Ill just build the shielded probe myself. I cannot find out on the schematic or parts list what "Crystal Diode" is used in the probe. I would imagine the "Crystal Diode" is really a germanium glass diode. My goal is to find now; What is the original part? Any suggestion for good wide frequency replacement and/or substitution? Would it be pretty easy to crack open the probe and have a "look see?" Pretty Please? If you don't feel comfortable in doing that, that's 100% OK with me. Thanks and great job as usual! So much appreciate all your fine work for all of us out here. Take care my friend, Tom
I just read Mikes Radio Repair comment; "Think its sensitive now, build yourself one of Paul Carlson's super sensitive probes and it will turn it into a sensitivity monster." Great idea Mike! Peter, if I don't find the information I need for the "Crystal Diode", I'll just hop over to Paul's site and watch that video again that Mike suggested.
Hi Tom glad to see you! Well yes with the original part we have a challenge. Nor comment in the manual or on the component neither a hint on the web and yes I have already opened the probe and what I found is a normal looking glass diode. The crystal diode is the secret. This diodes are different from normal pn diodes. Crystal diodes commonly called POINT-CONTACT DIODES,, are the oldest microwave semiconductor devices. They were developed for use in microwave receivers and are still in widespread use as receiver mixers and detectors.Unlike the p n -junction diode, the point-contact diode depends on the pressure of contact between a point and a semiconductor crystal for its operation. During the manufacture of the point contact diode, a relatively large current is passed from the cat whisker to the silicon crystal. The result of this large current is the formation of a small region of p-type material around the crystal in the vicinity of the point contact. Thus, a pn-junction is formed which behaves in the same ways a normal p n-junction. Because this diodes were the first microwave components may explain why the unit is working up to 1GHZ. The problem is as we don't have a type we can't look for an equivalent modern type type to replace it and it is to risky to damage the diode by taking it out for reading the characteristic. May be we need to test some modern types with enough reverse voltage to handle the high voltage in tube radios...Thanks for stepping by Cheers
Thanks for the definitive explanation on "point contact diodes" Peter. No wonder your freq response was so impressive! OOPS, maybe I should have bought one with a probe for $20 more. Looks like the detector is the basis of the high performance that you have demonstrated. I'll have a look at finding one of these point contact diodes. Wish me luck! In the mean time I still could build a probe with a germanium diode and see if it covers the whole HF spectrum anyways for now. Thanks for the the feedback and take care my friend, Tom
Ah got it. Yes that is basically right because this resistors are known for being noisy or running out of tolerance. But for now the unit works perfect...Thanks for your explanation sometimes naming in Europe is different so I have my problems then...
It confuses me that you use the regular R measurement mode on the DE-5000, rather than its secondary measurement ESR mode (third button below red power button), when measuring the ESR of capacitors in your videos. I don't recall ever seeing you use the ESR mode on that meter for any capacitor ESR measurement. Could you please clarify why you do this? Would the meter's ESR mode ever produce a significantly different measurement value than the mode you do use?
I just opened up my unit, the foil capacitor is the same way around as yours was, I wonder if it is that way around in the manual? UPDATE: I just found the manual for this online, and the manual shows the line end as per original, so either the manual has an error, or there is a reason it is that way around, personally I don't have a clue which way around it should go LOL.
Yes that is an often seen issue. Folks mixing up plus and minus vs. foil end and inner foil connection. And you are right Heath put this cap in like a polarised cap what it is not. The cap is installed like a polarised cap > plus to plus side of the circuit..we need to put the cap with foil end to the lower impedance side and that is clearly the other way round... hope that helps
Very nice signal tracer you have there - amazing performance! Can you describe what the three "Output Transformer" banana sockets are for? One appears to be for a center tap, but I'm not sure what their purpose is on a signal tracer.
Hi and thanks for watching. Additional information you'll find in the manual www.pascalchour.fr/ressources/heathkit/it12.pdf and a quick view you find here ua-cam.com/users/TRXBenchcommunity?
Hi Peter, well done. A verry nice HEATHKIT gear. The most beautiful is the loudspeaker grill. :-) Is it realy "Jute" ? ( Kartoffelsackstoff ) :-D 73 Bernd
The designation IT has to be confusing for those who own Heathkit transistor testers; I have a Heathkit bipolar transistor tester whose model number is IT-18.
I lost all my test equipment to a greedy real estate agent that bought my townhouse. I could not get everything out by closing and he would not let me back in.
@@1pcfred , at my house the voltage on each leg typically runs 122 to124VAC. That's 244-248 VAC for the air conditioner! Never had to deal with any kind of brownout voltages. Most likely this is largely due to having my own 7700 volt line feeding my house and just one other house, and each of us having our own pole-mounted Transformer.
@@goodun6081 They are in the process of upgrading the high voltage transmission lines near me so things may change where I'm at when all of that comes on line. I am pretty far out in the country though so I'm lucky I have any power at all.
@@1pcfred , I live in woodsy southeast New England, perhaps now it is far out in the sticks as you are, but it's pretty rural. (Lots of deer, a few Bobcats, foxes and Fisher Cats, and there's a bear roaming the periphery somewhere; and a game warden purportedly saw a mountain only a twenty-minute ride from my house). We do have major transmission lines running all over the place only 5 to 10 minutes ride from my house at most, so the feeder voltages are probably pretty good to start with. Many of the old railroad lines have been converted to walking hiking and biking trails ( great for walking my three dogs! ) and the trails tend to run alongside of or intersect frequently with the transmission lines.
You made a lot of errors! The procedure should be: 1. Open the case and INSPECT to see if there is any damage. 2. Ensure it is correctly electrically connected on the mains side (220 VAC). 3. Check with your ohmeter that the mains input, switch, fuse and mains transformer are correctly wired. 4. Ensure that nothing goes to the metal chassis of the box that should NOT BE (220 VAC mains for example). 5. Connect your isolation-transformer and bulbs and switch on.
Interesting video. But (for me) way too long for such a simple device restauration. An exemple : you spend 10 minutes to explain that a signal tracer have to be very sensitive. 10 seconds are enough, no? Sorry because obviously, you’re skilled
Interesting but why do you spend so long explaining each minor point several times? Your viewers are intelligent and do not require mulit layered explanations about an unsoldered joint. I wish you would move on more quickly. Listening to you feels like wading throught treacle.
Great job on that lil unit .......That's a Blast from the Past .....
I worked for Heathkit for over 10+ years, repairing customer assembled equipment. Just loved it! The biggest problem I found with the kits brought in for repair was the customer assembly & quality of craftsman ship. Often, just a solder job would make the repair or connecting the component to the correct termination where there was point to point hand wiring. The equipment they engineered was excellent for the cost! We used the test equipment line to fix our the kits. The IT-12 was a staple for fixing audio & RF gear. It never let me down!
Hi Roger, I do believe that it was fun working for Heathkit. So sad that Heathkit business model does not work any longer these days... Thanks for stepping in!
Heathkit always amazed me wjth what it is capable of doing, old technology can sometimes out perform modern. I built many Heathkits in the 70's and I am now starting to restore them just for fun, test and Ham gear.
If you get a restored version of one of those ,I be interested
430 MHz WOW!!! Now you have me wanting one of those!!! Thanks for the video.
That's the nicest IT-12 I've ever seen. When I worked at the repair shop, in the late 80s, I had one on my workbench, but it had been through a fire and its appearance was damaged by smoke and heat. (it still worked well) Years later, I bought another because I wanted to duplicate the workbench I had, but I wasn't able to find one that looked like new as that one does.
Thank you! Glad that I found this IT12..Hope you will also find one which fits for your project duplicating your former bench.. Cheers
Awesome work, thanks for the performance tests, I can use that to test my unit to see how it compares.
Good job on your video and troubleshooting. Recently, I dragged out an IT-12 that I built 50 years ago and fired it up. It worked but had much self oscillations as I turned up the volume and the eye was not sharp, but fuzzy. I went through all resistors and capacitors for values and functionality (using a Heathkit capacitor tester and ohmmeter) and all were good. No components needed to be replaced. The dc voltages were good. I tightened up all the ground connections and checked ground paths with an ohmmeter. I didn't like the mechanical connection at the can electrolytic c7 to ground so I added a jumper from chassis screw to one of the ground tabs. After all this I started to poke around with an insulated probe pushing and wiggling ground locations with the power on. Suddenly I found the culprit when I pushed the center post on the V1 tube socket. The base of the post had a poor connection to the foil on the back of the tube socket which goes to the adjacent mounting screw. I soldered it and that fixed the problem. Now I can turn the volume all the way up with no oscillations with or without the probe shorted and the eye is sharp and distinct. I've checked the unit with an audio source over a wide range of signals and it works very well.
I just purchased one today at a hamfest. Looks brand new and this little thing is awsome. Thanks for the info peter. 73
Nice restoration and a useful piece of kit to have in your lab.
Powerful tool, lucky to find one practically unused. Simple enough even an old one would be worth saving. Good show thank you.
You are right Ken...thanks for stepping in 73
Fantastic restortion Peter!!! Congratulations!!
Thanks Mauricio! 73
Thanks for sharing I have just imported one of these from the USA. I found your video searching for the manual and have just started to make a video recommissioning the one I have. I am fairly experienced using valve equipment but it’s alway enjoyable to watch how someone else goes about his work. I also bought a step down transformer but it’s a much larger unit than the one you have as I have some higher power equipment I would like to run. I do like the smaller wall wart transformer you have as it’s smaller and more convenient to use. I also like test equipment and love that power analyser you have. Best regards Chris.
What a great show and find, I am going to get one for sure. Thank You, D
Thank you Dennis
Thanks for the video...I have the exact same unit, and ironically, had nearly identical issues. Mine had the same cap backwards (jumped over to Mr. Carlsons foil vid to verify), and literally the same post and wire you had unsoldered, mine had too! I also found the ground connection in the probe came apart from the coax, so had to jumper that.
Very nice job on this video. I really like this signal tracer too. I would like to see you use it to trouble-shoot a defective unit or two for us. Thanks and see you again.
I have one of those . Wow, Loved Heathkits
It would be interesting to change the detector diode in the probe to a microwave rated diode such as a 1N23A to see if there is any improvement in the sensitivity at higher frequencies. I've got one on my bench now so your video was most timely excellent attention to detail with the coupling capacitor. minimizing noise and hum especially looking for faulty components is very important. Its amazing that a piece of test gear that goes back half a century is still very useful today. Thanks Peter and best 73 from across the pond. Doug.
Amazing Heatkit IT-12 Working very well. I'surprise with results of tests !.. Really nice job Peter ! 73
Yeah it is awesome....The secret is the crystal detector diode in the probe... Thanks for watching Rene 73
excellent video, Peter,
very informative just like all of your other videos that I watch......thank you for sharing......
Thanks for stepping in Ray!
Great video Peter, enjoyed the restoration. 73
Thank you Larry 73
That is an incredible find in that kind of condition possibly manufactured between 1973 through 1975. Thanks for the Video always fun seeing an old piece of test equipment coming back to life. Oh, and I also subscribed to your channel. Thanks for sharing.
Hi Larry, thanks for feed back really glad that you like my videos and thanks for sub. All the best
You got a nice unit there. Really great condition. You found the number one problem with kit assembled equipment, missed solder joints. Great addition to the bench. I would be lost without my tracer. You can do a surprising amount of troubleshooting with one of these. Think its sensitive now, build yourself one of Paul Carlson's super sensitive probes and it will turn it into a sensitivity monster.
Hi Mike, yeah glad that I found it. My modern one with OP amps and digital level meter and what have we can not compete with this old Cadillac :^) And you are right there are circumstances where this old stuff is more than helpful. I know Paul's super probe and that is incredibly sensitive but was it not build for finding noisy components with even not touching a component?? Have a nice Sunday 73
Hey Mike. I just bought a IT-12 with no probe. I was going to build a probe myself but the detector diode used is not found anywhere.
Great suggestion that saved me was yours: "Think its sensitive now, build yourself one of Paul Carlson's super sensitive probes and it will turn it into a sensitivity monster."
Oh yeah, I remember that video.
Thanks for this suggestion!
Tom
Great Video, Peter. That was the second Kit I built, still have it. Thanks
That must be nice memories Gregory. Thanks for watching 73
yes so much learning and enjoyable and thanks again!
I'm really glad that you like what I'm doing here on youtube...Have a nice Sunday 73
@ 57:00 it's always a good idea to add a fuse to the "hot" side of the mains/line cord, especially in equipment that has no possibility of finding direct replacements for things like it's transformer, and older Eico and Heathkit items like that seem to often be lacking any fuse in its main power line circuit. I often install a Littlefuse brand 03540001ZXGY - 3AB/3AG fuse holder, it installs nicely with 1 - 1/8 inch hole drilled into a chassis and a properly sized pop rivet holds it well, and it wouldn't have any outside physical indication to detract from its "original" look. Glad you got it working well with the work you did.
Thanks for your efforts I enjoyed this :-) kind regards snell
you are welcome Snell. Thanks for watching 73
I bought one of these at a thrift store and made it into a tiny guitar amp/ pre amp / overdrive and it kicks royal arse !
Yepp a quite nice little device :^)
Extraordinary. I have an AVO universal bridge of the same vintage that is also apparently unused. It worked perfectly at switch on and is quite remarkably accurate. Measuring down to a few pF and up to a few Henry. Plus giving a quality indication,. I have had many 'time capsules' and they are wonderful things from watches, cameras, audio and test equipment.
Thank you Martin!
Fantastic great find WOW
Thank you Paul, yes really a great finding 73
I like the Vintage Section especially devices coming from an Era in which most devices are obviously designed for 1.21GW :) Thank you Peter for the effort to show us this neat device and how it works!
Glad that you like it Reb! What do you mean by 1.21GW??
It's legendary from the Movie Back to the Future ua-cam.com/video/I5cYgRnfFDA/v-deo.html
LOL got it haha
Great stuff!
The OM did a very good job assembling the unit (less the missed solder joint of course!)...nice addition to your bench Peter, I actually gave mine away to a friend some time ago and miss the capability, may have to homebrew a new one. 73 - Dino KL0S
Yes I fully agree Dino the OM did really a good job back in his youth and I can imaging how much frustrating it must have been back in the 60tis...Oh that is bad luck that you gave your it12 away..Hope you can find something similar.. Have a nice Sunday 73
sweet. I got an old signal generator, in the same condition. I think I need one of these too.
Yeah that is a nice peace of gear...73
Fascinating video
Thank you Marc!
Check out Fran Blanche. She just built a NOS one of these, and her instructions came with wiring instructions for 120v and 240v versions. If you have the same transformer, you can make it into a 240v unit.
Thanks for information. I know Fran's video and she was lucky to get an European version .... I have the US version. The difference is that my line transformer is different so that I can't switch both 110V taps together for 220V...very sad :-( I guess I have to swap the line transformer with Fran's LOL. Again thanks for watching
TRX Bench maybe you can swap the transformers, she is in the US and should prefer 110V and you in Germany well 220V. Great video Peter thank you!
Good one Peter; always good to get a quick refresher on vacuum tube circuits. Amazing that it detects up to 430MHz! i thought the Heathkit was the oldest gear on your bench until I saw your tube tester! Thanks!
They were designed for amateur radio use so it's not surprising that it works up into the 2-meter band, but yes 430MHz is exceptional.
I wish I would have kept all of my dads tube testers and equipment when he quit electronics.
LOL yeah sometimes you need even older gear. The tube tester is almost 70 years now. It is an old FUNKE. Thanks for stepping in 73
Oh Robert that must be painful in the flashback..
Well I was just a kid and not into electronics at the time, but yeah.
Very nice looking tracer Peter. I have one of these I need to restore. Mine has a weak eye tube. Thanks for sharing.
The Radio Shop - A lazy eye?! ;-)
Hi my friend, yes the unit is worth to restore and the magic eye is not the most important feature these days...Thanks for stepping in. 73
A black eye
Fran suggests testing the 1MEG resistor in the "eye" tube circuit.
Nice, I will look forward to watching this video, I have one of these on my bench, it works ok, but crackles a bit, and I'm not that familiar with valve gear, mine had a bad eye valve, which I replaced when I got it.
It can be the tube itself or another noisy component or simply the volume potentiometer or a switch..not to hard to find...
Hello Peter, I own the Heathkit IT-12 with the rare white housing. One year ago I was able to purchase the unit at an OM in my neighborhood. During the investigation of the device only a few defective Elektroyt capacitors were found. My version is running with a 230 Volt power supply.
The magical eye was also in very good condition. I work very much with the signaltracer it is a really fine device. On Saturday I used the device at a special action of our repair cafe, where I work voluntarily. The visitors were able to see the error search with the IT-12 live and were very interested. It was possible to repair four of the 8 tube radios on site. I would like to thank you for your excellent tutorials. 73, DG3JA, Jörg
Ah very good to hear that!. Where are you running the repair cafe with your friends?? Thanks for your report very interesting 73
Hello Peter, my home Repair Cafe is Castrop-Rauxel.
Many others I have visited and I am so crazy, to repair even on vacation,
in the cafes Dresden, Saarbruecken and Saargemünd (France).
I am fascinated by the volunteer work and have found many nice social contacts.
Despite all the efforts of the manufacturers we get a lot of repairs.
Often, it is an old heritage that nobody wants to repair.
On Saturday we had a radio day at the International Repair Cafe week.
4 tube radios were repaired and the condition of the tubes measured
with 2 devices. My Roetest 9 was in action and was demonstrated.
Here is the link to our website:
www.repaircafe-castroprauxel.de/
73, Jörg
Ah very good Jörg, sound like a lot of fun! Keep going this fantastic Job! 73
Another wonderful video. I would love one of these signal tracers, but too expensive for me! I am building an inexpensive solid state device at the moment from a kit. I hope it will be successful. 73 Lynton.
A solid state device will do the job as well. Thanks for stepping in
Breathing new life into Heathkit. Ebay gonna be busy!
Yeah that is really a nice unit. Happy that I found it. 73
Happy saturday Peter, the old Heathkit stuff was the cats ass in the day. I remember the robot they produced. That tracer looks good physically I better shut up and watch the video with my coffee. Cheers
Just finished watching and I thought the soldering was good, the lead bends were great. The amount of applied solder was good no problem, and everything looked good. I like that you keep it original with the power cord, sure
missing solder points are an issue. But good effort on the assemblers side, I remember Heathkits were so expensive to buy, buying assembled things were cheaper. I guess building back then from scratch cost you more, time and money. As always Sir, great video look forward to the next TRX Bench Adventure ............................. Cheers
Hi Tom, yes soldering was good and all was done in a good way...What a shame that he was not able to take the nice unit into service..But that is how it goes sometimes. Now he had lost all his interest in electronics...BTW what does the metaphor ""stuff was the cats ass in the day"?? Never heard it before.. Thanks for stepping in Cheers
Oh man, wait until Mr. Carlson see's this! LoL, another great video!!!!!
LOL he was already here haha Thanks for watching 73
Thank you, very informative, I also have one. Carl
Thank you Carl, glad that you like it Cheers
Hi I love your videos and your excellent I wish I could find somebody around here in the US that could work on stuff like you I have an old icon 211 can't find anybody to work on it
Hi Adron, get in contact with my friend Buddy "The radio shop" here on YT he can certainly help. Thanks for comment 73
That IT-12 is mint. The one I just got looks like it's dead brother.
Nice explanation of the unit and its design. I'm getting one soon and am very curious how its build and what it needs for upgrade to make it work as yours. This movie is a very good reference! 73. Louis.
They say that 95% of all Heathkit builds have at least one problem involved in their construction. This IS one of them!
Fran Blanch on UA-cam is building one of these at the moment from an unopened old kit. The transformer on hers is dual voltage (110v/240v) depending how you connect the primary. If yours is the same you could convert it to 240v.
Thank you Gary, I know...Fran has the European version and I have the US version. Unfortunately my transformer can't get wired other than for 110V...Again thanks for stepping in
Hi Peter, I have one on my bench, also like new perfect, watch the noise switch, when on it puts voltage to probe tip,, its shocking,, great video thanks again
Dennis N did you assemble it from a kit ?
I purchased it as new old stock, looks to me like factory perfect inside
Ah another lucky IT12 owner :-) Yes noise is 100V but only 1mA. You will get a shock but it should not dangerous to your life.. Thanks for watching 73
A guy I work with gave me that same unit. Condition is not as good. I'll have to put it on the bench and check it out. Just got done making a schematic for a Sprague Mike-o-meter M1 capacitor tester. Had the same problem with that one, two wires on a terminal strip never soldered.
73,
N9EUQ
Tools too. He would not let me back in. Just remember, you can have all your belongings taken but not your brain or memories. That's what is important.
Yeah never the memories!!
Notice C5 in the schematic is not in the correction direction. That's why so many people put it in backwards.
At 44:23, it's pronounced Cas-Caid (Cascade)
These make really good guitar practice amps if you replace the probe with a quarter-inch jack and disable the high voltage noise switch
Yes I fully agree. Thanks for comment
Hi peter. I know this video is a year old but I think I saw something that is not working correctly. When you turned the speaker off the eye tube stopped working but I think it should still work showing a signal when the speaker is off. I have one also and it worked that way. Just a thought, Carl.
Oh did not realise that.. have to double check it. Thanks for feed-back
I realize this is an old video, but I noticed that the probe wire did not have any strain relief. You might want to check the connection and add the relief. You might check the power cord for strain relief, too
Thanks for the vedio. I want to buy a tube tester by which you can advise me an old tester and which brand or a curve tracer like utracer3, etracer .
Subbed immediately
Thanks for watching
NOTE: DO NOT use the noise mode on solid-state equipment !!!
so true !!
I have watched a Video on the Heathkit Signal Tracer T-4 and noticed the Capacitor you reversed the polarity on due to high gain on the IT-12 is the same situation here on the T-4. Could this be an error in the original design or does the cap have to be reversed also?
I had one, built it new as a teenager. Got lost in the move.
Oh what a bad luck that you have lost it.. Thanks for watching 73
Hi, Nice video! Just wondering if the "eye" tube should not be fully lite until a signal is present. When a signal is present, I would think that would sweep around both directions from the 12 o'clock position to correspond with the signal intensity and then it would return when the signal is removed.
That would be an ideal eye tube but unfortunately the behavior is at it is shown in the video...Thanks for watching 73
Huh, just wondering how this eye tube is visually useful for this device. I had an old Tandburg reel to reel tape deck that had an eye tube which worked as I described above.
see this www.magiceyetubes.com/patterns.htm
Thank you for that and sorry for my doubt! My memory of that old tape machine must be a bit cloudy now that 40 or so years has past!
Really hard to buy these in the UK for reasonable money. I will have to make my own version from scratch.
I found 3 wires that were not soldered on a Heathkit IM-28 vtvm that I refurbished.
Before I went any where near modern electronics I would want to know the current and voltage between the probe tip and ground otherwise a good presentation and content.
If you wish to donate it I am your man lol it's very nice clean unit .Frans video of her building hers might be helpful for you it was pretty good watching her being built .
Where did you get that cap chart?
What is the date code on the potentiometer? That should reveal when this was kitted.
Hi David, we will check it next time when we open it..Thanks for watching
Well I'm pretty impressed with the sensitivity and the frequency range of this unit Peter. Wow!
I just bought one without the probe. It was the cheapest out there. Ill just build the shielded probe myself.
I cannot find out on the schematic or parts list what "Crystal Diode" is used in the probe. I would imagine the "Crystal Diode" is really a germanium glass diode.
My goal is to find now; What is the original part? Any suggestion for good wide frequency replacement and/or substitution? Would it be pretty easy to crack open the probe and have a "look see?" Pretty Please? If you don't feel comfortable in doing that, that's 100% OK with me.
Thanks and great job as usual! So much appreciate all your fine work for all of us out here.
Take care my friend,
Tom
I just read Mikes Radio Repair comment; "Think its sensitive now, build yourself one of Paul Carlson's super sensitive probes and it will turn it into a sensitivity monster." Great idea Mike!
Peter, if I don't find the information I need for the "Crystal Diode", I'll just hop over to Paul's site and watch that video again that Mike suggested.
Hi Tom glad to see you! Well yes with the original part we have a challenge. Nor comment in the manual or on the component neither a hint on the web and yes I have already opened the probe and what I found is a normal looking glass diode. The crystal diode is the secret. This diodes are different from normal pn diodes. Crystal diodes commonly called POINT-CONTACT DIODES,, are the oldest microwave semiconductor devices. They were developed for use in microwave receivers and are still in widespread use as receiver mixers and detectors.Unlike the p n -junction diode, the point-contact diode depends on the pressure of contact between a point and a semiconductor crystal for its operation. During the manufacture of the point contact diode, a relatively large current
is passed from the cat whisker to the silicon crystal. The result of this large current is the formation of a small region of p-type material around the crystal in the vicinity of the point contact. Thus, a pn-junction is formed which behaves in the same ways a normal p n-junction. Because this diodes were the first microwave components may explain why the unit is working up to 1GHZ. The problem is as we don't have a type we can't look for an equivalent modern type type to replace it and it is to risky to damage the diode by taking it out for reading the characteristic. May be we need to test some modern types with enough reverse voltage to handle the high voltage in tube radios...Thanks for stepping by Cheers
Yes Paul's super probe is very sensitive but if I remember right it is designed to find noisy components in a circuit without touching a component.
Yes, I found your answer about this in your comments to Mike @ MikesRadioRepair.
Thanks for the definitive explanation on "point contact diodes" Peter. No wonder your freq response was so impressive!
OOPS, maybe I should have bought one with a probe for $20 more. Looks like the detector is the basis of the high performance that you have demonstrated.
I'll have a look at finding one of these point contact diodes. Wish me luck!
In the mean time I still could build a probe with a germanium diode and see if it covers the whole HF spectrum anyways for now.
Thanks for the the feedback and take care my friend,
Tom
I can see you hear the signal but what does the magic eye do ? I see no change in it
the signal is so low the the sensitivity of the magic eye is not sufficient anymore
Nice score, Peter! I wonder how well it will work after all the AB resistors and old caps are replaced?
Hi Robert, what do you mean with AB resistors? All components are in spec so all should be fine by now. Thanks for watching 73
Alan Bradley resistors. Most people say to replace them all, including the bumblebee resistors that a lot of old equipment have in them.
Ah got it. Yes that is basically right because this resistors are known for being noisy or running out of tolerance. But for now the unit works perfect...Thanks for your explanation sometimes naming in Europe is different so I have my problems then...
I just made it up - AB is easier than spelling out Allen Bradley. Maybe with new resistors it will work even better?
It confuses me that you use the regular R measurement mode on the DE-5000, rather than its secondary measurement ESR mode (third button below red power button), when measuring the ESR of capacitors in your videos. I don't recall ever seeing you use the ESR mode on that meter for any capacitor ESR measurement.
Could you please clarify why you do this? Would the meter's ESR mode ever produce a significantly different measurement value than the mode you do use?
I just opened up my unit, the foil capacitor is the same way around as yours was, I wonder if it is that way around in the manual? UPDATE: I just found the manual for this online, and the manual shows the line end as per original, so either the manual has an error, or there is a reason it is that way around, personally I don't have a clue which way around it should go LOL.
Test the cap and see.
Yes that is an often seen issue. Folks mixing up plus and minus vs. foil end and inner foil connection. And you are right Heath put this cap in like a polarised cap what it is not. The cap is installed like a polarised cap > plus to plus side of the circuit..we need to put the cap with foil end to the lower impedance side and that is clearly the other way round... hope that helps
You can see how to test them here if you don't know how. Happy testing. ua-cam.com/video/BnR_DLd1PDI/v-deo.html
How many watt must the Adapter produce .?
not very much 20-40 W @110 Volt or so
Very nice signal tracer you have there - amazing performance! Can you describe what the three "Output Transformer" banana sockets are for? One appears to be for a center tap, but I'm not sure what their purpose is on a signal tracer.
Hi and thanks for watching. Additional information you'll find in the manual www.pascalchour.fr/ressources/heathkit/it12.pdf and a quick view you find here ua-cam.com/users/TRXBenchcommunity?
Hi Peter,
well done. A verry nice HEATHKIT gear.
The most beautiful is the loudspeaker grill. :-)
Is it realy "Jute" ? ( Kartoffelsackstoff ) :-D
73 Bernd
LOL yeah it looks like Kartoffelsack haha. But I have no clue if it is really Jute??? Thanks for stepping in Bernd 73
The designation IT has to be confusing for those who own Heathkit transistor testers; I have a Heathkit bipolar transistor tester whose model number is IT-18.
Ah okay I'm not so familiar with all the models numbers.. Thanks for watching 73
Would you consider selling it ?
I'm sorry no I don't sell it..
I think the original owner do not knows how this device work. :)
yes most likely...
I lost all my test equipment to
a greedy real estate agent that bought my townhouse. I could not get everything out by closing and he would not let me back in.
oh Mark that is really sad!
Adjust the levels going into the Magic Eye. TOO HOT. Should not be wrapped around like that with no incoming signal.
carefully review the patterns magiceyetubes.com/patterns.htm
is this Fran's?
Hi Wilfred, no this IT12 is mine. Why do you think it could be Fran's??
@@TRXLab Hi Peter. Well in V4 of the build of that thing, Fran had some problems. Maybe she liked you to fix it :-)
LOL yeah I would we pleased to help out
I like your video, but you could cut a good forty minutes off it.
Thanks for feed back
110V.
Vatsek - It was very common for older North America gear to be labelled as 117v.
In reality North American voltage is more 120V these days. But I heard years ago it was 110V.
@@1pcfred , at my house the voltage on each leg typically runs 122 to124VAC. That's 244-248 VAC for the air conditioner! Never had to deal with any kind of brownout voltages. Most likely this is largely due to having my own 7700 volt line feeding my house and just one other house, and each of us having our own pole-mounted Transformer.
@@goodun6081 They are in the process of upgrading the high voltage transmission lines near me so things may change where I'm at when all of that comes on line. I am pretty far out in the country though so I'm lucky I have any power at all.
@@1pcfred , I live in woodsy southeast New England, perhaps now it is far out in the sticks as you are, but it's pretty rural. (Lots of deer, a few Bobcats, foxes and Fisher Cats, and there's a bear roaming the periphery somewhere; and a game warden purportedly saw a mountain only a twenty-minute ride from my house). We do have major transmission lines running all over the place only 5 to 10 minutes ride from my house at most, so the feeder voltages are probably pretty good to start with. Many of the old railroad lines have been converted to walking hiking and biking trails ( great for walking my three dogs! ) and the trails tend to run alongside of or intersect frequently with the transmission lines.
You made a lot of errors! The procedure should be:
1. Open the case and INSPECT to see if there is any damage.
2. Ensure it is correctly electrically connected on the mains side (220 VAC).
3. Check with your ohmeter that the mains input, switch, fuse and mains transformer are correctly wired.
4. Ensure that nothing goes to the metal chassis of the box that should NOT BE (220 VAC mains for example).
5. Connect your isolation-transformer and bulbs and switch on.
FYI we will gain lifetime minutes if you play this @ 2x speed. To the point please.
your eye tube is off center.
(y)
Interesting video. But (for me) way too long for such a simple device restauration. An exemple : you spend 10 minutes to explain that a signal tracer have to be very sensitive. 10 seconds are enough, no? Sorry because obviously, you’re skilled
Interesting but why do you spend so long explaining each minor point several times? Your viewers are intelligent and do not require mulit layered explanations about an unsoldered joint.
I wish you would move on more quickly. Listening to you feels like wading throught treacle.