To learn electronics in a very different and effective way, and gain access to Mr Carlson's personal designs and inventions, visit the Mr Carlson's Lab Patreon page here: www.patreon.com/MrCarlsonsLab
Then again, there is the fact to consider that... Live and neutral in AC voltage do not matter, as they do not have a specific polarity. So that's probably why the fuse ended up on the neutral instead of the live, because it didn't completely matter which way around it went. So long as the ground went to where it's supposed to go for protection against any current leakage that may find it's way to the case of the device. Still very cool tho to see such an old device.
@@timteecvhn Except for the fact that in most countries Neutral is Bonded to ground and therefore presents a greater shock hazard . If you do not break the live side in switching and fusing
When I was a young girl, my daddy bought me Heathkits to build every Christmas. I remember the Heathkit LOGO! The shape of the logo and style of the lettering is the same as Heathbuilt. But, I never received a Heathbuilt.
Considering that this calibrator was designed for calibrating analog meters like the Simpson 260 and VTVM's, its pretty accurate. On another note, Mr. Carlson, what's your opinion of Underwriter's knots and do you think they should be redone when putting new line cords on old gear if the original grommets are OK?
I have been both professionally and as a hobby after hours devoting my life to electronics. This is by far the most accurate, detailed and educational electronics channel I have ever had the privilege of watching. The knowledge and professional approach taken in every video exceeds any formal training I have had over the years. I want to thank you for sharing your knowledge. What is being taught by you far exceeds anything close and to provide this to our future generations means more than words can express. Once again thank you so much for sharing your knowledge. Kia kaha. I worked for the Australian government designing and managing projects up to 66kV and the attitude is a "she'll be right" and "cover your ass". This is another reason why I respect and appreciate your professional and safe approach.
My dad worked for Heath for 32 years when I was growing up. Thanks for the memories. The iconic color and design of the metal case really takes me back.
If you're afraid of slipping screwdrivers over paint, just get yourself one of those sheets of plastic they use in binders, the thicker the better, and drill a few holes of various sizes at a decent distance. You lay the sheet over the screw you want to remove and it will protect the paint. :)
At 80 I'm a tad older than you, Paul. I assembled 9 Heathkits between 1972 and the mid 80s. GR-900, GR-2001, IO-30, IO-4205, IO-4550, IT-28, IO-4505, IT-21 & an IT-3120. I miss those days.
I've been quite depressed recently and I can honestly say that seeing this notification has given me the first genuine moment of excitement I've felt for a long time.
Tom, I feel your pain!!! There are about 5-6 RUclips Channels that I especially love to watch, this being one of them. Lately it has been months between uploads and I really miss seeing new uploads that use to be much more frequent...at least "someone" would put something up every week...now, well, as I said, it can be months and none of the 82 channels I have subscribed to show anything new. Just in case you might be interested, some of the channels I have subscribed to are: David Tipton Electronics Old and New Back To The Future Radios D-Lab Electronics Nick Zammeti I think that you will enjoy at least a couple of those.
It is so enjoyable to see Heath gear brought back to life especially by someone as careful and smart as Mr. Carlson. I built many kits back in the 60s, 70s and 80s including my first color TV and computer as well as lots of test equipment. Love these videos.
If there is enough meat in the interior of the knobs, why not machine a brass sleeve to go inside? Super glue will be a temporary fix. If it doesn't crack in the same place, it will close by.
Or, align them and remove the screw, insert a drill, and drill a divot into the shaft. The screw will just have to rest in that divot, with a minimum of pressure.
You can buy over the shelf very similar black knobs in many electronic's parts stores today. The only difference would be the circular design on the top would be missing.
@@iNerdier Like parking your car? In Germany we have the saying "wenns kracht noch en' Meter" .. roughly "3 further feet after that crashing noise starts".
Good job Mr. CARLSON. You stayed with it. Heath did a good job in their resistor matching. Amazing how good it was without feedback. Say at 100.00 VDC and you loaded 2 mA on the output by using a 50 kohm ...how much would voltage would the output drop? Perhaps Heathkit intend to use it like a std. cell...where you place a sensitive meter between your Heathkit reference...and the unknown voltage...then adjust the Heathkit to a null..which means no error current across⅞your Heathkit and the unknown DC voltage...then read the dials...to determine your unknown voltage. Nice handheld meters....I had no idea TEK made little DVMs.. I will eventually do some Patreon...and help support your cause. Keep up the good work. If I was assigned the construction of a 0 to 100 VDC reference..it would be totally different. ...
First picture, without any googling, without having a clue of HeathBuilt, i already knew that had to be some kind of school thing. And i'm European. Heh, has to show that when it came to that era, these things were universal.
thanks fo all the good videos, i'd like to ad a bit on a voltage standard for extremely accurate calibration of up to 1.5 volts DC... this comes from the cal lab at Systron Donner inertial guidance in the late 60s...i was a technician in the engineering dept there from 66 to 69. we were working with analog output from accelerometers and this required extremely accurate measurement of dc up to 7 volts....we had lots of fluke dc meters that required frequent cal checks.... our master volt meter was of unknown brand and it filled a box the size and shape of a coffin and was on a roll around stand...once per month our leader would grab a fresh D cel (zink carbon) and solder a 1k resistor across it then drop it in his coat pocket and head for the UC Berkley electronics dept where he measured it's voltage (about an hour drive each direction)...upon return he would read the voltage on the master ...that zinc carbon maintained accurate enough voltage with it,s 1.6 milivolt load to do that in picovolts
I was just perusing a Heathkit catalogue from the 1950's. Man, that stuff was expensive. The average American might have been able to afford them, but not not so much the rest of us.
Always nice to see gear brought back to prime condition by Mr. Carlson!!! Would see these show-up on EBay now and then. I recall Heathkit made a Scope Calibrator if my fuzzy logic brain is serving me correctly today.
I've been involved in electronics for *many* decades, and have never before encountered "Heathbuilt". Where did you find the schematic and other info for this unit?
It’s low mileage in the UK too. :) also I was thinking if those knobs are all identical in size it could be the broken ones broke somewhere else on the device and got swapped around.
@36m about stability. Don't forget that in the 1960s, meters had needles, not 3.5 or more LCD digits. So 1% was probably the target. That's one volt in 100. I know you know, I'm just making it explicit for those following along at home. :-) 73
Its so funny your doing this, A friend of mine just gave me a whole bunch of the Heath Kit equipment, Spent all day moving it to my house and all of mine works!!! Love the video's!
Here is a tip on the rotary switches to add to your bag of tricks. Some of those swirches require such high torque to turn the knob, the unreinforced knobs can easily crack. Also, if you do lots of repetitive tests where you are continually rotating the stiff switch, it can make your fingers sore. So, as a fix, you stretch the spring slightly that holds the ball bearing in place, which can substantially reduces the torque. You have to be careful though and do small scale spring stretching (careful trial and error). This is because, it is like trimming an antenna, if you over-do the stretching, you can't undo it. If you are not careful, you will wind up with a rotary switch that has almost no detent feel.
Hi Dale. I have designed many different devices with the same display layout. This makes the circuit board footprint the same, so others can use standard template for drilling.
Somehow, by the grace of the gods, about an hour away in Oak Ridge, TN. There still exists, an open electronic component supply store with attached Wearhouse. They are about 20 mins from ORNL (the atomic national research laboratory) so i've always assumed that had something to do with them being able to stay open so long into the 21st century.
@@MrCarlsonsLab I think it's really cool you actually read and reply to comments so often, and even on old videos. RUclipsrs like you are getting very rare these days.
Hmmm... As you mentioned about the Calibration & heating due to the cover being off; I would have did the mod. to add two sets of banana jacks & switches on the back; switch on for operation; & off with test leads inserted during calibration. Which is exactly what I did back in the day when I worked at Heathkit! We had to recheck & verify the cal. once a week. We also never turned it off as it took at least 2 hours to stabilize. Of course with today's modern designs, a reference can be on & stabilized in about 5 minutes. Great job! By the way, wish we had that capacitor tester back in the day! It would have made life so much easier!!!
@@jimdavis6833 Yes, Jim, that is what the switches are for! Switch on (closed) - for operation; when you open the switch (off), then you can calibrate it. Actually, you would normally use a double-pole, single throw for both since both "jumpers" need to be removed.
RE: "with today's designs, a reference can be on and stabilized in 5 minutes" ... I would give a qualified agreement to that. It's probably true for 99% of electronic equipment. However, there are still some devices that should remain on for their reference voltages to be stable. A couple of examples are: * timebase units with very high stability oscillators, such as Cesium and Rubidium frequency standards; * LASER systems used for precision dimensional measurements, and * electronic DC Voltage references, typically used to replace Weston Standard Cells. In these cases it is good measurement practice to regularly measure and record the relevant outputs, and analyze them to detect any non-random changes that may indicate a potential problem. Even the Weston Standard Cells required a stable power source to power the their typical temperature-controlled enclosures. In September 1989 I was transporting a group of standard cells from the Washington (DC) Navy Yard, where they had been calibrated, to where I worked at the Electronic Standards Calibration Lab at Charleston (SC) Naval Shipyard. That trip was interrupted by a bit of heavy weather known as Hurricane Hugo. At a stop on my route I bought a portable AC power generator to provide power to those units for a week until power was restored to the lab. (I also used it to power essential items at home, for a couple of weeks.) The Navy happily (partially) reimbursed me for the generator, because it meant we could restart DC calibrations several weeks earlier than would otherwise have been possible had the standard cells needed to re-stabilize and be re-characterised.
I'm 53, when I was about 7 or 8, my dad bought a heathkit color tv (with remote!!) and built it in the basement. I remember watching him solder the components in and putting the whole thing together. We had that TV a LONG time. You had to tune each channel separately with jumper wires and tuning capacitor. It would drift out every once in a while, but the side panel would pull forward for "easy access".
@@TheoSmith249 you know, I couldn't tell you. I googled that model but tough to tell. Watching him build that and me playing around with the tuning in the side panel really sparked my interest in how things work.
Hi Paul. You mentioned that Zener diodes don't make great voltage references on their own because the voltage drop goes up with increased current. Could this be exploited to simulate "sag" in a power supply for something like a guitar amp? The output voltage drift from you blowing on the Zener diode was barely more than 0.1% and stayed well within 0.5%. If this bit of kit claimed to be a *precision* voltage reference or a "reference standard", I might quibble over 0.5%, but for a bench reference, half a bee's dick is just fine.
Hi Peter. For the time (many VTVM's in use) this was more than adequate. Zeners are quite affected by temperature change, many IC's have a temperature compensated Zener reference right inside them (UA723 for example) Of course, the more current placed on the Zener, the more it will heat and drift.
@@MrCarlsonsLab Of course buried Zener references (basically a Zener diode, a heater wire, and an error amplifier in a can) are among the lowest drift references in bench multimeters, and I understand most handheld multimeters have a Zener reference that's trimmed out in software, but I was thinking more along the lines of *exploiting* the drift of a soft-knee Zener.
The Robertson screw and driver could have been bigger than the Philips but Mr Robertson wanted to make it all.. When Ford wanted to use Robertson screws to assemble their cars in the U.S. (in CA Robertsons were already in use) Ford wanted to make the screws and drivers but Robertson wanted to make everything and sell them. They could not reach a deal so Ford went with Phillips and the rest is history. Robertsons are still very popular in CA and are just now starting to show up in the U.S. markets. For warming the unit up when calibrating, I think I might have been tempted to run jumper leads out the slots in the back of the case that were attached to the test points inside, just to provide access while having the unit as close as possible to its operating condition. Clearly though, that wasn't needed as the results came out great anyway. Just me overthinking things, nevermind :P
Hi, I picked up a couple of old radios and the first step is to identify them. What would be a good source. I've spent hours looking at images online, but nothing close. Thanks
Ah, the EUW-16A. The later version was known as EUW-16 . It sold for $65 US in the 1966 catalog. Sprague "Black Beauties" was their trade name for the Di-Film caps. Rule of thumb on bumble bee caps lettering : if it's in red go ahead. Yellow is too mellow( replace) and white(replace) it's not right! Always remembered that!
I know the diagram shows switch and fuse in different sides of the mains, but i prefer the switch to be in the hot, followed by the fuse, the neutral should be direct to the transformer. Something like a couple of jacks with break contacts would be useful for calibration, but how often would a hobbyist do that. I guess you could run the wires out the vent so the cover could be closed during calibration, then remove the wires after. One thing i've done in the past is to insert a screwdriver under the wafer switch spring and gently twist to reduce the tension, this will help with not breaking the knobs, but don't overdo it.
Hi Paul, I just stumbled upon this video (I don't understand RUclips's algorithm) and was surprised at the number of glaring design errors with this Heath product. I don't know exactly when this voltage reference was designed, I suspect the mid 1960's. Zener characteristics were well understood at that time so, the designer was likely fresh out of school. The 100 volt zener was probably used as a simple way to get a 100 volt output. However, (as you mentioned) zeners at this high voltage breakdown are super temperature sensitive, so much so, that the part would actually make a good temperature sensor. There are 3 zener breakdown voltages that have zero temperature drift if they are fed a specific current: 4.7V @ 10mA, 5.1V @ 1 mA, and 5.6V @ 100uA. If you feed the zener with a constant current source, you have a precision voltage reference (although the current will need to be tweaked slightly to optimize the zero drift). Thanks Paul for another interesting video.
Hello Paul, well wishes from SLC UT. I have a Johnson. Messenger 4230 with no antenna. My apt is on the 3rd floor, windows facing west. I can place two 10' sections of 3/4 pvc out the window for an antenna. What cable configuration would be optimal in your opinion? I've been staring at my Johnson for two years, and still don't know how to handle it. Any advice would be greatly appreciated. Cheers! ;)
Unlike most of the rest of the world, in the UK we still measure road distances in miles. Crazy, I know, but the cost of replacing millions of road signs is prohibitive. Some years ago the Highway Code (a "rules of the road" official document) decided to do a straight conversion and cited a distance of X yards as being X metres. After all, they're nearly the same, aren't they? That edition was withdrawn pretty sharpish - they differ by around 10%.
Hello Mr. Carlson, I want to replace my thermistors on a magnum 2812 as you did four years ago but can’t find any as you did. The manufacturer only sells a new board for $800. Would you be willing to share your source and a source for the epoxy? Thanks, Rick.
A trick to fix those knobs.... strip some solid copper wire. Remove the existing grub screw and glue the crack closed. Next, wind copper wire around inside to create a "ferrule" - this may need to be two "rings" to keep away from the grub screw hole. Finally, fill the gaps between wire and plastic with the old "baking powder and super glue" trick. Care is needed to keep the grub screw hole 100% clear.
Interesting fact, color coding in electrical requirements is black is hot and white is neutral. In electronics, color coding is just the opposite. Where black is ground and white is hot. Very confusing.
A few questions for, I assume, THE expert on these matters from the owner of a few cherished pieces of valve-based audio gear: Is it better to leave valve gear on 24/7 or to turn it off when not in use? Does it really matter much either way, except as regards the electricity bill? And: Is unattended valve equipment really a fire hazard? I see the last accusation tossed about a lot on the web but I cannot conceive of any way in which my end stages would all of a sudden catch fire with the chassis being made of metal, with the valves themselves, of course, being all glass and metal and with the circuit boards inside being full of, probably toxic and environmentally unfriendly, halogenated flame retardants. Thank you for a great channel!
Valve equipment should be switched off when not in use. All electronics components age and heat accelerates this ageing. I also consider the electrical safety of old equipment as dubious safety standards have come a long way in the last 50 years.
Wow, that thing is beautiful for it age. It's older than me lol 1970. They don't make things this good anyone! We are better off rebuilding older electronics, maybe upgrading a few components if needed & enjoy using them for a long lifetime!
Putting the diode in a isothermal block will greatly increase its stability. Of course, it also causes stability lag. Being 1% resistors, it's somewhat moot. The best I have ever seen is the old Fluke differential voltmeters with a Epley standard cell. On another note, the measurement device needs to be a order of magnitude better?
And more pertinently valves instead of tubes. See Franlab for 1950's HIVAC square section valves in a German built "spy" wire recorder. ps Anytime I see Heath Kit, "Heath Robinson"* springs to mind, so in the UK you probably would be wise not include"Heath" in branding of anything even a little complicated. *Rube Goldberg in the US
When I repair plastic I use the old baking soda and superglue trick. It dose work but you have to work quickly. And have small files around to file ot down after it sets up. This is how I repaired my zerolemon cases that kept breaking on my note 9. And I will now use this trick on other plastic things. The trick I found is to use the least amount of baking soda so it dose not enlarge what you are reparing. Unless its completing missing a chunk of plastic. And then you can spray paint it or just permeate marker it.
Hot should be fused in case it shorts to ground, bypassing neutral. FYI. Fusing neutral may be ok if you also have ground fault detection, but that's a big if, and would be relying on a potential point of failure.
Hey, Long time fan here. I noticed your discussion on the line chord and polarity are right on. One thing you did not mention is to put the black line lead into the back of the fuse holder rather than the side lug of the holder. This, as you well know is quite important. it prevents the exposure of the hot line lead while replacing the fuse. Great video, as usual. Thank you.
Mr Carlsons lab do you no ware I can get Russian germanium transistors for my zenith Trans oceanic shortwave receiver I want to restore it? 😢😢😢😢😢😢let me no ware palu
Wow man, this is geek porn with those three meters. You are blessed to own such great equipment. I'm a hobbyist so I can't justify buying those dmms but you as a professional need them.
Good evening Mister This item si beautiful !!! i remember when i was young i have a similar reference voltage ...The schematic was in a magazine " radio plans " very famous in my country ( France in 60 's and 70 ' s) . Thanks for the share and your work .
Really nice video with good information on capacitors and that you informed about the thermal sensitivity of the zener diode, not many think about that until they actually notice it for real. Also so nice to see a plastic trim screwdriver. Though I noticed you did not use it when you aligned as it looked like a normal screwdriver.
Stupid design. Rotary switches with stiff detents should have flatted, knurled, or "D" shafts, and the knobs be fitted with inserts. Reef on the setscrew, and the knob is gonna break.
Be cautious when using Cyanoacrylate adhesives at it needs to be the correct one as some of the accually diffuse in to many plastic materials and by time give away due to microfractures, especially in rubber and plastic and in combinations. Cyanoacrylate adhesives doesn't go well either with leather, cotton, carbon or glas fibers as it generate a exothermic reaction with heat and gas as a result. I personnaly prefer mechanic attachment to off loading cables as it has been proven to last longer but not for ever than other options.
Thank you for the reminder about the need to replace the old capacitors! I have an old EICO DC VTVM that my father-in-law built from a kit in, I think, the 1960's. Note to self: order new capacitors before turning it on!
Wish you was in california your about the only one know as dr Bill they call him bill good he work on all radio some not like him because he would work on cb radio he fix what the factory made cheap better he was smart money is money he mite of made more money off those on the cb radio he fix a radio Kenwood work on it work for 6 month it broke down bill working on it 10 years went buy the radio never broke down on the guy again
I enjoy your video but most of the time I don't understand what you are talking about, that's ok. As a kid, I remember helping my dad build a Heathkit stereo amp and a separate tuner. I think he liked me to look at the little bands on the transistors to match the sets together. I also had a Heathkit guitar amp that we bought many years ago that would handle bass guitar as well. Thank you.
Note the original two wire line cord on the schematic. And likely for good reason. On a precision signal or voltage source, you would not want ground loops.
Hi Paul, First time I've seen any HeathBuilt. I know you could have some of their kits pre-assembled, but I always enjoyed building their kits. Stay safe. 73 WJ3U
Why not test some of the capacitors with the Mr. Carlson's Tester first? Some caps (Not paper) were built better back then than nowdays. Good is good, bad is bad! Just sayIng, Not all old caps are bad!
Nonsense. Process control was way looser and materials weren’t where they are now. Lousy caps these days all beat the crap out of the paper oil caps. End of story. You can waste your life away measuring it. The way it stands you just repeat the audiophool nonsense. About the only old caps that have a chance at being any good after 5-8 decades are Teflon, ceramic, poly, and wet slug tantalum. You go measure stuff if you need to convince yourself. We already know this stuff. You apparently don’t. “They don’t build them like they used to anymore”. Yes. And that’s a good thing! Space race was at the edge of what was possible. You needed a US economy backing you up to pull off a space program. These days SpX can do it without a whole country paying them several % of their GDP to do so. I’m really glad they don’t make stuff like they used to in that respect, lol.
I used a lot of Heath educational equipment when I was going through an apprenticeship in electronics in the early 1980s. Another Heath product line was the Heath/Zenith line of desktop personal computers in th 1980's. I had lots of memories with those things. (The computers were actually OK for the time. The users ... not so much.)
To learn electronics in a very different and effective way, and gain access to Mr Carlson's personal designs and inventions, visit the Mr Carlson's Lab Patreon page here: www.patreon.com/MrCarlsonsLab
Do the test meters add any load to the device while adjusting it.
@@Peterjames3535 The series meters reading current would not but the parallel meter reading output voltage would have a VERY tiny parasitic load
Then again, there is the fact to consider that... Live and neutral in AC voltage do not matter, as they do not have a specific polarity. So that's probably why the fuse ended up on the neutral instead of the live, because it didn't completely matter which way around it went. So long as the ground went to where it's supposed to go for protection against any current leakage that may find it's way to the case of the device. Still very cool tho to see such an old device.
@@timteecvhn Except for the fact that in most countries Neutral is Bonded to ground and therefore presents a greater shock hazard . If you do not break the live side in switching and fusing
When I was a young girl, my daddy bought me Heathkits to build every Christmas. I remember the Heathkit LOGO! The shape of the logo and style of the lettering is the same as Heathbuilt. But, I never received a Heathbuilt.
Thanks for not having mid-way advertisement enabled on your videos. And nice work as always.
Great seeing you here also Shariar!
RUclips are making it mandatory soon. They can opt out at the moment though. Advertisers wanted it because nobody watches the ones at the end.
These videos do have ads
It's still 'miles' in the UK, Paul!! :-)
Great video. I can't want to finish my capacitor tester.
Considering that this calibrator was designed for calibrating analog meters like the Simpson 260 and VTVM's, its pretty accurate. On another note, Mr. Carlson, what's your opinion of Underwriter's knots and do you think they should be redone when putting new line cords on old gear if the original grommets are OK?
I have been both professionally and as a hobby after hours devoting my life to electronics. This is by far the most accurate, detailed and educational electronics channel I have ever had the privilege of watching. The knowledge and professional approach taken in every video exceeds any formal training I have had over the years. I want to thank you for sharing your knowledge. What is being taught by you far exceeds anything close and to provide this to our future generations means more than words can express. Once again thank you so much for sharing your knowledge. Kia kaha. I worked for the Australian government designing and managing projects up to 66kV and the attitude is a "she'll be right" and "cover your ass". This is another reason why I respect and appreciate your professional and safe approach.
Thank You for your kind comment Peter!
He's Canada's perfect answer to Dave Jones. :D
My dad worked for Heath for 32 years when I was growing up. Thanks for the memories. The iconic color and design of the metal case really takes me back.
If you're afraid of slipping screwdrivers over paint, just get yourself one of those sheets of plastic they use in binders, the thicker the better, and drill a few holes of various sizes at a decent distance. You lay the sheet over the screw you want to remove and it will protect the paint. :)
That's a great idea! Thanks for sharing.
Or 3D print a collar to keep the screwdriver on the screw.
@@NiHaoMike64 Assuming one has access to a three dimensional printer.
Or get a screwdriver that's accurately sized for the screw. I like my Snap-On for this. :-)
At 80 I'm a tad older than you, Paul. I assembled 9 Heathkits between 1972 and the mid 80s. GR-900, GR-2001, IO-30, IO-4205, IO-4550, IT-28, IO-4505, IT-21 & an IT-3120. I miss those days.
I've been quite depressed recently and I can honestly say that seeing this notification has given me the first genuine moment of excitement I've felt for a long time.
LOL.
Tom, I feel your pain!!! There are about 5-6 RUclips Channels that I especially love to watch, this being one of them. Lately it has been months between uploads and I really miss seeing new uploads that use to be much more frequent...at least "someone" would put something up every week...now, well, as I said, it can be months and none of the 82 channels I have subscribed to show anything new.
Just in case you might be interested, some of the channels I have subscribed to are:
David Tipton
Electronics Old and New
Back To The Future Radios
D-Lab Electronics
Nick Zammeti
I think that you will enjoy at least a couple of those.
THC is the answer
Hang in there, Tom. Hope you feel better.
It is so enjoyable to see Heath gear brought back to life especially by someone as careful and smart as Mr. Carlson. I built many kits back in the 60s, 70s and 80s including my first color TV and computer as well as lots of test equipment. Love these videos.
Like the sound of when those mechanical switches snap into position making a good connection.
"Not bad for something from the 1960s." Hey, that was the Space Age! Anything was possible then. Even me!
No, in the UK it's "low mileage" too. Luckily we have a moat that saves our important units of measurement 😁
It was a joke. :P
I always laugh at the metriarchs who ask what a foot is. I reply, "you have two, haven't you noticed?"
did i hear "moat?" harry potter in tha house!!! (or metric eq. of a domicile).
@@sa8die better known as The English Channel 😆
Richard Twyning La Manche!
The History Guy chanel did a vid about the Robertson screw
"Those are some pretty screwy-looking MOSFETs...."
Hold up....did you just...?
This made me laugh harder than it should have.
The comment about having a very low on resistance killed me too.
All the thumbs up appear to be the same size, or mine would be bigger
If there is enough meat in the interior of the knobs, why not machine a brass sleeve to go inside? Super glue will be a temporary fix. If it doesn't crack in the same place, it will close by.
Fill 'em with Sugru?
Or, align them and remove the screw, insert a drill, and drill a divot into the shaft. The screw will just have to rest in that divot, with a minimum of pressure.
You can buy over the shelf very similar black knobs in many electronic's parts stores today. The only difference would be the circular design on the top would be missing.
Those knobs without the brass inserts get cracked when someone tries to torque down the set screw with too much force. Don’t ask me how I know this.
Keep screwing down until you hear a crack, then back off a quarter turn.
@@iNerdier Like parking your car? In Germany we have the saying "wenns kracht noch en' Meter" .. roughly "3 further feet after that crashing noise starts".
Good job Mr. CARLSON. You stayed with it. Heath did a good job in their resistor matching.
Amazing how good it was without feedback. Say at 100.00 VDC and you loaded 2 mA on the output by using a 50 kohm ...how much would voltage would the output drop?
Perhaps Heathkit intend to use it like a std. cell...where you place a sensitive meter between your Heathkit reference...and the unknown voltage...then adjust the Heathkit to a null..which means no error current across⅞your Heathkit and the unknown DC voltage...then read the dials...to determine your unknown voltage.
Nice handheld meters....I had no idea TEK made little DVMs..
I will eventually do some Patreon...and help support your cause.
Keep up the good work.
If I was assigned the construction of a 0 to 100 VDC reference..it would be totally different. ...
First picture, without any googling, without having a clue of HeathBuilt, i already knew that had to be some kind of school thing. And i'm European. Heh, has to show that when it came to that era, these things were universal.
thanks fo all the good videos, i'd like to ad a bit on a voltage standard for extremely accurate calibration of up to 1.5 volts DC...
this comes from the cal lab at Systron Donner inertial guidance in the late 60s...i was a technician in the engineering dept there from 66 to 69. we were working with analog output from accelerometers and this required extremely accurate measurement of dc up to 7 volts....we had lots of fluke dc meters that required frequent cal checks.... our master volt meter was of unknown brand and it filled a box the size and shape of a coffin and was on a roll around stand...once per month our leader would grab a fresh D cel (zink carbon) and solder a 1k resistor across it then drop it in his coat pocket and head for the UC Berkley electronics dept where he measured it's voltage (about an hour drive each direction)...upon return he would read the voltage on the master ...that zinc carbon maintained accurate enough voltage with it,s 1.6 milivolt load to do that in picovolts
Thanks for taking the time to write, and sharing your story John!
I was just perusing a Heathkit catalogue from the 1950's. Man, that stuff was expensive. The average American might have been able to afford them, but not not so much the rest of us.
Thanks Paul very interesting and educational. Regards Chris
Mr Carlson I wonder where you started your working life .Was it HP ,Fluke or Tektronix ?
Always nice to see gear brought back to prime condition by Mr. Carlson!!! Would see these show-up on EBay now and then. I recall Heathkit made a Scope Calibrator if my fuzzy logic brain is serving me correctly today.
The good old Heathkit days ! Always looked forward to their catalog back in the day.
"Screwy looking MOSFETs"; I saw what you did there!
We need a thread on those MosFets!
I've been involved in electronics for *many* decades, and have never before encountered "Heathbuilt". Where did you find the schematic and other info for this unit?
It’s low mileage in the UK too. :) also I was thinking if those knobs are all identical in size it could be the broken ones broke somewhere else on the device and got swapped around.
Paul, you do such good work and you’re an inspiration to do things the right way. I appreciate the tip about the Spragues.
Thanks 👍
@36m about stability. Don't forget that in the 1960s, meters had needles, not 3.5 or more LCD digits. So 1% was probably the target. That's one volt in 100. I know you know, I'm just making it explicit for those following along at home. :-) 73
Good point, easy to forget that 👍
Nice video but, blimey, you sure sent me down the rabbit hole of screw head research!
Its so funny your doing this, A friend of mine just gave me a whole bunch of the Heath Kit equipment, Spent all day moving it to my house and all of mine works!!!
Love the video's!
That thing would look great with chickenhead knobs.
"Gullwing" knobs like the ones used on the Tx/Rx switch on the "Benton Harbor lunchboxes". heheheh
Here is a tip on the rotary switches to add to your bag of tricks. Some of those swirches require such high torque to turn the knob, the unreinforced knobs can easily crack. Also, if you do lots of repetitive tests where you are continually rotating the stiff switch, it can make your fingers sore. So, as a fix, you stretch the spring slightly that holds the ball bearing in place, which can substantially reduces the torque. You have to be careful though and do small scale spring stretching (careful trial and error). This is because, it is like trimming an antenna, if you over-do the stretching, you can't undo it. If you are not careful, you will wind up with a rotary switch that has almost no detent feel.
"I'll look through my files"...
searches HeathBuilt EUW-16A into google
jk Mr Carlson's probably memorised all his files with that big brain of his
Somewhere in his brain is an encyclopedia, and somewhere within that is another, and... well, you get the idea.
Paul, didn't your magic box have orange LED'S in it? The LED'S in this box are green.
Hi Dale. I have designed many different devices with the same display layout. This makes the circuit board footprint the same, so others can use standard template for drilling.
Somehow, by the grace of the gods, about an hour away in Oak Ridge, TN. There still exists, an open electronic component supply store with attached Wearhouse. They are about 20 mins from ORNL (the atomic national research laboratory) so i've always assumed that had something to do with them being able to stay open so long into the 21st century.
That sure would be nice to have close by!
@@MrCarlsonsLab I think it's really cool you actually read and reply to comments so often, and even on old videos.
RUclipsrs like you are getting very rare these days.
Hmmm...
As you mentioned about the Calibration & heating due to the cover being off; I would have did the mod. to add two sets of banana jacks & switches on the back; switch on for operation; & off with test leads inserted during calibration.
Which is exactly what I did back in the day when I worked at Heathkit! We had to recheck & verify the cal. once a week. We also never turned it off as it took at least 2 hours to stabilize.
Of course with today's modern designs, a reference can be on & stabilized in about 5 minutes.
Great job!
By the way, wish we had that capacitor tester back in the day! It would have made life so much easier!!!
Then he would need to move the jumpers to an external point so they also would be accessible for removal and reinstall with case on.
@@jimdavis6833 Yes, Jim, that is what the switches are for! Switch on (closed) - for operation; when you open the switch (off), then you can calibrate it. Actually, you would normally use a double-pole, single throw for both since both "jumpers" need to be removed.
RE: "with today's designs, a reference can be on and stabilized in 5 minutes" ... I would give a qualified agreement to that. It's probably true for 99% of electronic equipment. However, there are still some devices that should remain on for their reference voltages to be stable. A couple of examples are:
* timebase units with very high stability oscillators, such as Cesium and Rubidium frequency standards;
* LASER systems used for precision dimensional measurements, and
* electronic DC Voltage references, typically used to replace Weston Standard Cells.
In these cases it is good measurement practice to regularly measure and record the relevant outputs, and analyze them to detect any non-random changes that may indicate a potential problem.
Even the Weston Standard Cells required a stable power source to power the their typical temperature-controlled enclosures. In September 1989 I was transporting a group of standard cells from the Washington (DC) Navy Yard, where they had been calibrated, to where I worked at the Electronic Standards Calibration Lab at Charleston (SC) Naval Shipyard. That trip was interrupted by a bit of heavy weather known as Hurricane Hugo. At a stop on my route I bought a portable AC power generator to provide power to those units for a week until power was restored to the lab. (I also used it to power essential items at home, for a couple of weeks.) The Navy happily (partially) reimbursed me for the generator, because it meant we could restart DC calibrations several weeks earlier than would otherwise have been possible had the standard cells needed to re-stabilize and be re-characterised.
I'm 53, when I was about 7 or 8, my dad bought a heathkit color tv (with remote!!) and built it in the basement. I remember watching him solder the components in and putting the whole thing together. We had that TV a LONG time. You had to tune each channel separately with jumper wires and tuning capacitor. It would drift out every once in a while, but the side panel would pull forward for "easy access".
Was it the GR 2000? What a fun project
@@TheoSmith249 you know, I couldn't tell you. I googled that model but tough to tell. Watching him build that and me playing around with the tuning in the side panel really sparked my interest in how things work.
Hi Paul. You mentioned that Zener diodes don't make great voltage references on their own because the voltage drop goes up with increased current. Could this be exploited to simulate "sag" in a power supply for something like a guitar amp?
The output voltage drift from you blowing on the Zener diode was barely more than 0.1% and stayed well within 0.5%. If this bit of kit claimed to be a *precision* voltage reference or a "reference standard", I might quibble over 0.5%, but for a bench reference, half a bee's dick is just fine.
Hi Peter. For the time (many VTVM's in use) this was more than adequate. Zeners are quite affected by temperature change, many IC's have a temperature compensated Zener reference right inside them (UA723 for example) Of course, the more current placed on the Zener, the more it will heat and drift.
@@MrCarlsonsLab Of course buried Zener references (basically a Zener diode, a heater wire, and an error amplifier in a can) are among the lowest drift references in bench multimeters, and I understand most handheld multimeters have a Zener reference that's trimmed out in software, but I was thinking more along the lines of *exploiting* the drift of a soft-knee Zener.
The Robertson screw and driver could have been bigger than the Philips but Mr Robertson wanted to make it all.. When Ford wanted to use Robertson screws to assemble their cars in the U.S. (in CA Robertsons were already in use) Ford wanted to make the screws and drivers but Robertson wanted to make everything and sell them. They could not reach a deal so Ford went with Phillips and the rest is history. Robertsons are still very popular in CA and are just now starting to show up in the U.S. markets. For warming the unit up when calibrating, I think I might have been tempted to run jumper leads out the slots in the back of the case that were attached to the test points inside, just to provide access while having the unit as close as possible to its operating condition. Clearly though, that wasn't needed as the results came out great anyway. Just me overthinking things, nevermind :P
Take a look at grace screwdrivers. They are for gunsmithing and come in lots of sizes that just fit slotted screws perfectly so slip much less often.
Hi, I picked up a couple of old radios and the first step is to identify them. What would be a good source. I've spent hours looking at images online, but nothing close. Thanks
Ah, the EUW-16A. The later version was known as EUW-16 . It sold for $65 US in the 1966 catalog. Sprague "Black Beauties" was their trade name for the Di-Film caps.
Rule of thumb on bumble bee caps lettering : if it's in red go ahead. Yellow is too mellow( replace) and white(replace) it's not right! Always remembered that!
Were Heath-Built units assembled in Benton Harbor, Mich.?
Many were assembled in the EU factories under the design and supervision of Drs. Malmstadt and Enke, according to the 1966 Heathkit Catalog I have.
I know the diagram shows switch and fuse in different sides of the mains, but i prefer the switch to be in the hot, followed by the fuse, the neutral should be direct to the transformer.
Something like a couple of jacks with break contacts would be useful for calibration, but how often would a hobbyist do that.
I guess you could run the wires out the vent so the cover could be closed during calibration, then remove the wires after.
One thing i've done in the past is to insert a screwdriver under the wafer switch spring and gently twist to reduce the tension, this will help with not breaking the knobs, but don't overdo it.
Being from Wisconsin, Robertson Screws are familiar to me. Many of old sheds in backyards and on farms seem to always have a mason jar of them LOL
I grew up 10 minutes away from the Roberston screw factory. My neighbour worked there,
Why the Zener diode was used? Would'nt the 100V regulator gas discharge tube (or even neon bulb) be more stable?
There are a lot of things this design could use to increase stability, this was designed at a price point.
@@MrCarlsonsLab Thanks, but would it be a good idea? Amateur level question.
I am from Brasil, south of Minas Gerais state (200 km of Rio). I love your vídeos! Very, very goods! Your channel is top! 😍😍😍
Thanks for your kind comment Adriana!
It's amazing how easy it is to let the smoke out of a component and so incredibly hard it is to get the smoke back into the device
LOL well said!
Hi Paul, I just stumbled upon this video (I don't understand RUclips's algorithm) and was surprised at the number of glaring design errors with this Heath product. I don't know exactly when this voltage reference was designed, I suspect the mid 1960's. Zener characteristics were well understood at that time so, the designer was likely fresh out of school. The 100 volt zener was probably used as a simple way to get a 100 volt output. However, (as you mentioned) zeners at this high voltage breakdown are super temperature sensitive, so much so, that the part would actually make a good temperature sensor.
There are 3 zener breakdown voltages that have zero temperature drift if they are fed a specific current: 4.7V @ 10mA, 5.1V @ 1 mA, and 5.6V @ 100uA. If you feed the zener with a constant current source, you have a precision voltage reference (although the current will need to be tweaked slightly to optimize the zero drift).
Thanks Paul for another interesting video.
Hello Paul, well wishes from SLC UT. I have a Johnson. Messenger 4230 with no antenna. My apt is on the 3rd floor, windows facing west. I can place two 10' sections of 3/4 pvc out the window for an antenna. What cable configuration would be optimal in your opinion? I've been staring at my Johnson for two years, and still don't know how to handle it. Any advice would be greatly appreciated. Cheers! ;)
I am looking for a home for antique Philco 37-650 floor model radio.....someone to restore.....?suggestions...
Unlike most of the rest of the world, in the UK we still measure road distances in miles. Crazy, I know, but the cost of replacing millions of road signs is prohibitive. Some years ago the Highway Code (a "rules of the road" official document) decided to do a straight conversion and cited a distance of X yards as being X metres. After all, they're nearly the same, aren't they? That edition was withdrawn pretty sharpish - they differ by around 10%.
Hello Mr. Carlson, I want to replace my thermistors on a magnum 2812 as you did four years ago but can’t find any as you did. The manufacturer only sells a new board for $800. Would you be willing to share your source and a source for the epoxy? Thanks, Rick.
A trick to fix those knobs.... strip some solid copper wire. Remove the existing grub screw and glue the crack closed. Next, wind copper wire around inside to create a "ferrule" - this may need to be two "rings" to keep away from the grub screw hole. Finally, fill the gaps between wire and plastic with the old "baking powder and super glue" trick. Care is needed to keep the grub screw hole 100% clear.
What would you use a voltage reference source this for?
Something like this could be used for VTVM alignment, "or the like" that falls into the 1% accuracy zone.
Interesting fact, color coding in electrical requirements is black is hot and white is neutral. In electronics, color coding is just the opposite. Where black is ground and white is hot. Very confusing.
A few questions for, I assume, THE expert on these matters from the owner of a few cherished pieces of valve-based audio gear: Is it better to leave valve gear on 24/7 or to turn it off when not in use? Does it really matter much either way, except as regards the electricity bill? And: Is unattended valve equipment really a fire hazard? I see the last accusation tossed about a lot on the web but I cannot conceive of any way in which my end stages would all of a sudden catch fire with the chassis being made of metal, with the valves themselves, of course, being all glass and metal and with the circuit boards inside being full of, probably toxic and environmentally unfriendly, halogenated flame retardants. Thank you for a great channel!
Valve equipment should be switched off when not in use. All electronics components age and heat accelerates this ageing. I also consider the electrical safety of old equipment as dubious safety standards have come a long way in the last 50 years.
I’ve found the switches on this old Heath gear that the switch shaft gums up, stick some Deoxit on the shafts and they get a LOT better.
Another product we used to use on switch contacts was Cramolin, some type of light oil. I have no idea if it still exists.
Are the 10 LEDs on the LV Capacitor Leakage Tester the Midnight Blue you like?
Wow, that thing is beautiful for it age. It's older than me lol 1970.
They don't make things this good anyone! We are better off rebuilding older electronics, maybe upgrading a few components if needed & enjoy using them for a long lifetime!
Putting the diode in a isothermal block will greatly increase its stability. Of course, it also causes stability lag. Being 1% resistors, it's somewhat moot. The best I have ever seen is the old Fluke differential voltmeters with a Epley standard cell. On another note, the measurement device needs to be a order of magnitude better?
Great video, very interesting.
P.S. we use miles here in the UK. It's the rest of the Europeans that insist on kilometers
And more pertinently valves instead of tubes. See Franlab for 1950's HIVAC square section valves in a German built "spy" wire recorder.
ps Anytime I see Heath Kit, "Heath Robinson"* springs to mind, so in the UK you probably would be wise not include"Heath" in branding of anything even a little complicated.
*Rube Goldberg in the US
When I repair plastic I use the old baking soda and superglue trick. It dose work but you have to work quickly. And have small files around to file ot down after it sets up. This is how I repaired my zerolemon cases that kept breaking on my note 9. And I will now use this trick on other plastic things. The trick I found is to use the least amount of baking soda so it dose not enlarge what you are reparing. Unless its completing missing a chunk of plastic. And then you can spray paint it or just permeate marker it.
Hot should be fused in case it shorts to ground, bypassing neutral. FYI. Fusing neutral may be ok if you also have ground fault detection, but that's a big if, and would be relying on a potential point of failure.
Hey, Long time fan here. I noticed your discussion on the line chord and polarity are right on. One thing you did not mention is to put the black line lead into the back of the fuse holder rather than the side lug of the holder. This, as you well know is quite important. it prevents the exposure of the hot line lead while replacing the fuse. Great video, as usual. Thank you.
Never seen HeathBuilt units in the UK. You could buy ready built units, a friend of mine had a part time job building kits for Heath.
Mr Carlsons lab do you no ware I can get Russian germanium transistors for my zenith Trans oceanic shortwave receiver I want to restore it? 😢😢😢😢😢😢let me no ware palu
Wow man, this is geek porn with those three meters. You are blessed to own such great equipment. I'm a hobbyist so I can't justify buying those dmms but you as a professional need them.
UK here: Nahh, we use miles for stuff. Speed is measured in mph. Milk in pints...we use an odd and seemingly random blend of imperial and metric haha
Good evening Mister
This item si beautiful !!! i remember when i was young i have a similar reference voltage ...The schematic was in a magazine " radio plans " very famous in my country ( France in 60 's and 70 ' s) . Thanks for the share and your work .
Really nice video with good information on capacitors and that you informed about the thermal sensitivity of the zener diode, not many think about that until they actually notice it for real.
Also so nice to see a plastic trim screwdriver. Though I noticed you did not use it when you aligned as it looked like a normal screwdriver.
Stupid design. Rotary switches with stiff detents should have flatted, knurled, or "D" shafts, and the knobs be fitted with inserts. Reef on the setscrew, and the knob is gonna break.
Hello!, great Work!, i want to know if its possible that you explain how to built one capacitor tester like you used in this video, please! 🙂
Hi great video. I have a heathkit Vox Keyboard that i would like to fix as it makes noise not musical tones any help vastly appreciated thanks.
Be cautious when using Cyanoacrylate adhesives at it needs to be the correct one as some of the accually diffuse in to many plastic materials and by time give away due to microfractures, especially in rubber and plastic and in combinations. Cyanoacrylate adhesives doesn't go well either with leather, cotton, carbon or glas fibers as it generate a exothermic reaction with heat and gas as a result.
I personnaly prefer mechanic attachment to off loading cables as it has been proven to last longer but not for ever than other options.
mosfets look screwed
I'll have you know the UK does not use kilometres & hope we never will!
Thank you for the reminder about the need to replace the old capacitors! I have an old EICO DC VTVM that my father-in-law built from a kit in, I think, the 1960's. Note to self: order new capacitors before turning it on!
Wish you was in california your about the only one know as dr Bill they call him bill good he work on all radio some not like him because he would work on cb radio he fix what the factory made cheap better he was smart money is money he mite of made more money off those on the cb radio he fix a radio Kenwood work on it work for 6 month it broke down bill working on it 10 years went buy the radio never broke down on the guy again
I enjoy your video but most of the time I don't understand what you are talking about, that's ok. As a kid, I remember helping my dad build a Heathkit stereo amp and a separate tuner. I think he liked me to look at the little bands on the transistors to match the sets together. I also had a Heathkit guitar amp that we bought many years ago that would handle bass guitar as well. Thank you.
I have used them in mobile homes and electrical panels. (Robertson screw)
Note the original two wire line cord on the schematic. And likely for good reason. On a precision signal or voltage source, you would not want ground loops.
Hi Paul,
First time I've seen any HeathBuilt. I know you could have some of their kits pre-assembled, but I always enjoyed building their kits. Stay safe. 73 WJ3U
Electronics were so beautiful back then!! I especially love the color and look of this one!!😍
Thank you...Mr Carlson's Lab
You're welcome!
You fuse the hot because if it shorts to ground it will bypass neutral. If you were confused.
Great work. ✔️💯🏆
Thanks so much for sharing. 😉👌🏼
Why not test some of the capacitors with the Mr. Carlson's Tester first?
Some caps (Not paper) were built better back then than nowdays. Good is good, bad is bad!
Just sayIng, Not all old caps are bad!
Nonsense. Process control was way looser and materials weren’t where they are now. Lousy caps these days all beat the crap out of the paper oil caps. End of story. You can waste your life away measuring it. The way it stands you just repeat the audiophool nonsense. About the only old caps that have a chance at being any good after 5-8 decades are Teflon, ceramic, poly, and wet slug tantalum. You go measure stuff if you need to convince yourself. We already know this stuff. You apparently don’t. “They don’t build them like they used to anymore”. Yes. And that’s a good thing! Space race was at the edge of what was possible. You needed a US economy backing you up to pull off a space program. These days SpX can do it without a whole country paying them several % of their GDP to do so. I’m really glad they don’t make stuff like they used to in that respect, lol.
👍👍
Wow, you calibrated it perfectly.
No "buffered" output?
Uuughh ....
Well, it is HeathBuilt you know :^)
First. Gaining knowledge. Amplified by skill and enthusiam
Hey love the channel
Just a quick comment from the UK we still use miles 😝 unlike the rest of Europe
I used a lot of Heath educational equipment when I was going through an apprenticeship in electronics in the early 1980s. Another Heath product line was the Heath/Zenith line of desktop personal computers in th 1980's. I had lots of memories with those things. (The computers were actually OK for the time. The users ... not so much.)
good project. Good did a video on regulator tubes and showed they more stable than zener diodes. You are proved right again.
Perfect callibration, Mr Carlson.
Thumbs up for no mid-roll ads.