I built one of these in 1969 and used it when I was a bench technician at a TV repair place I worked at when I was in high school. It did the job and worked in situations where the old Simpson 260 had too little input impedance. Thank you for the memories and I have to thank Heathkit for stimulating my interest in electronics. I later became an Electronics Engineer and had a wonderful 35 year career working at "Dave and Bill's place".
Wow, this brings back a lot of memories. I built one of these in my high school electronics shop back in 1970. I still have it sitting in my basement and it still works! Thanks for the memories.
Brings bake memories for me. I was a Heathkit bench technician in New Orleans for several years at their only retail location in Louisiana… I built and used one of these for years.
Jeff, I loved your video over all. You are a great presenter, have very good diction, delivery of material, and a professional approach. Your audio and video quality is great- something that most TH-cam videos sorely lack- I applaud you! I also love my old Heath pieces and your video has inspired me to fix my VTVM!
Battery corrosion can sometimes be removed using vinegar and cotton swaps or an old toothbrush. Once you get it apart you can clean the parts with sandpaper. The hard part is usually getting the pieces apart and you may have to risk breaking them if they are badly corroded.
I built two of these in my high school Electronics class in the mid-seventies. Three or four of these would not calibrate, and my teacher, Mr. Kuhlow asked me if I could troubleshoot them. I considered this to be an honor, as I really knew very little about electronics up to this point, not much beyond Ohm's Law. Anyway, there was a point in the calibration procedure where you would clip the test lead to a certain point in the circuitry, then move a trimmer pot until the the needle on the meter pointed to a small red dot, all the units were failing this part of the alignment. I got to thinking, how could three or four of these VTVM's all be failing in the same way, when they were each built by a different student? Were there a bad batch of parts? Also, we did have several unite which were calibrated fine. So . . . I got to thinking . . . I saw the spring cup which held I believe a C Battery. I was wondering if that spring was NOT making contact with the negative side of the battery? Also, I believed this only came into play when measuring resistance, so how could this be affecting the calibration of the VTVM. Well . . . I went ahead and jammed in a test lead between this spring cup and the batter and suddenly, the VTVM not calibrated! I yelled for Mr. Kuhlow to come over and see, he too was surprised that this would affect the calibration of the Meter. What we discovered was this . . . I all the units which were not calibrating, Panasonic batteries had been installed, my teacher having been given these for free some some source. Well . . . these batteries all had a clear plastic shrink wrap around them that just barely extended over and onto the bottom edge of the negative side of the battery, preventing contact with the spring cup. . Once I peeled off this clear wrapping, the spring made contact and all the meters now easily were calibrated. My teacher was very proud of me that day. Sadly though, about a month later out of frustration, my teacher quit teaching us electronics theory because of all the Stoners in the class causing disruption. He said, "those of you who want to be here, grab a kit out of the closet and build it, the rest of you just show up and you'll get a passing grade." That was the end of my electronics theory education, but the beginning of my love for kit building. I built two VTVM's and two Low Voltage Power Supplies. My teacher had won a federal grant wherein he was able to purchase over 50 Heathkits. How I envied the Seniors who were given the O Scopes to build :O
Hi Jeff and Subscribers. This is an older post so I hope Jeff still monitors the activity. Jeff, do you or any fellow VTVM Heathkit aficionados want to help me fix my old Heathkit VTVM IM-18? I bought one at a yard sale along with the assembly manual. The guy said it worked properly and had no use for it. I checked it over and whoever built it did a nice job. It powers up and that's all. The needle is supposed deflect upscale then settle down as the tubes warm up. The needle is static and does not move. The "zero" adjust moves the needle a little. With a new battery the ohms scale works but I can't zero it, it hangs up mid-scale. Both the A.C & D.C. scales are inoperative. I've replaced the two tubes and the Electrolytic cap in the power section and the A.C. coupling cap. No luck. Next will be the two ceramic caps. If anyone has any suggestions please let me know. FYI I built Heathkit, Eico and Lafayette (Remember them?) kits for many years. This was a nostalgia thing. I have made a set of the proper probes and done the usual work, I burnished all the rotary switch contacts, checked the solder joints etc. Next step will be to check the proper positioning of all the resistors and then a point to point wiring check. I'm asking for help here just in case there is a known problem with keeping the initial meter deflection at power up. THANKS, I'll check in here from time to time.
Tom, I'm (not an aficionado, yet, but) working on a Heathkit V-2 currently... I've recently rewired EVERYTHING, save for the resistors on the ohms-value rotary, and still do NOT have any needle deflection at all. I opted to separate the meter movement from the circuit and apply 1.5V (D cell) with a 10k ohm resistor... no needle deflection. I performed the same test to the S-meter on my Heathkit HW-32a transceiver and achieved deflection. My suggestion would be to verify meter movement across the sweep with a remote DC supply. The "Hangup" may be related to a physical obstruction within the meter movement, or an improperly balanced movement (there are videos on correcting this). In my case, I believe the meter movement to be shot entirely.
I had a senior moment, The meter works on the Ohms scale but not on the AC, DC+ or DC-. Being that the Vacuum tube circuit works on Ohms but cannot zero out and the AC and DC have two separate inputs it may be the selector switch. There is a good deal of oxidation. I purchased a can of Deoxit online (No more radio shack and no electronic stores here) once that arrives I'll clean the contacts. Those "V" series are all pretty old 1947-1950. You can find a V1 Schematic among others here, (Link at the end) I don't see any information on the V1 though. You may be able to find a loose meter on Ebay or a junk V1 and swap out the meter. As far as the meter check the coil with a VOM and see if they have continuity. The link I'll give you has a schematic for the V2. If yours has a 6AU6 and a 6AT6 the circuitry may be the same. Good Luck, I'll post a message after I clean the contacts, I've also been advised to clean all the pots and even the tube sockets. www.nostalgickitscentral.com/heath/heathkit.html
Nice presentation. I built a Knight Kit VTVM in the 50s and used it until fire destroyed my ham shack in 76. I recently acquired an IM 18 but without test leads. It shouldn't be a problem making up a lead assembly.
Jeff, I developed a habit of collecting VTVMs (currently have 8 of various Heathkit vintages, Simpson, and Eico models). I am rebuilding a Knight KG-625. The circuits, of course, are all remarkably similar. But I have often wondered if there's a cure for the ohms measurements being off? Do you have any recommendations besides replscing the resistors in the divider chain? Thanks for your videos, by the way.
Jeff, I enjoyed your demo on your Heathkit.VTVM. I also own several pieces of Heathkit Test equipment and always interested to learn tips abt keeping them in good running condition.. I am wondering, in your 5V ref, what did you use for your voltage reference chip?
Hi I picked up this same tester a a flea market recently and it looked very good both inside and out but when ever I take an ohms reading the meter bottoms out (to the right) no matter what scale I use or what resistance I am measuring. Would you have any ideas what might be the cause. It did not come with the original probe but for a/c and ohms it is straight thru as per the diagram. Thx in advance
What is the name/brand of the small beige analog multimeter you show in the beginning of your video as an example of an inexpensive one? I have never seen one that small before.
Solar Bunny It is marked CIRCUITMATE AM10. I bought it about 20 years ago for my son. I don't remember where I purchased it. I see a few of them on eBay.
I am a total novice and have acquired a V-7a that apparently was stored for ages with the C cell battery.. which has leaked. The good news is the leakage went away from the circuitry (towards the rear of the case -- must have been stored on it's back) There appears to be a screw on the 'support' bar that goes over the battery but the corrosion seems to have made it difficult to remove. But before I try anything hasty, I'm wondering do you have any ideas on how to get it loose?
I have a Heathkit V-7A that needs some work. I've replaced the 6AL5 tube and need to replace the old 16 MFD electrolytic capacitor and some of the carbon resisters. Any other suggestions? Strangely enough, the original Eveready 1.5 volt battery was still in place.The amazing thing is that this 40+ year old battery wasn't leaking and still has 1.12 volts! The reason I know it's the original battery is that there's some printed tape on it that says, "1.55 V" just like the manual says. Thanks, Tom
Note that you don't *have* to use a VTVM to work on old tube equipment - you can use a modern DMM. You may want one with analog bar graph if you need to adjust circuits for a peak or null. Of course using a VTVM of the same vintage as the equipment you are working on adds to authenticity.
The V6 is similar to the V7 and later models. It had some circuit differences and did not use a printed circuit board, which was introduced with the V7. but is substantially the same as the later VTVMs.
Hi After recieving the manual from the Heathki group on yahoo I went over all the resistors and found that the builder of the meter had inversed 4 transistors on the selector switch. So even thou this unit is over 40 years old it never worked properly. Looks like all the original 1% resistors. Ths for your reply Regards
I have this unit and like it a lot, but but my favourite VTVM is my Hickok 1600B that has died and I have been looking high and low for a schematic. i have gone all the standard sites, with no luck. Do you have any ideas where could find a schematic. Thanks for the video.
I assume you mean a stubborn "knob"? Open up the unit and try applying WD-40 or a similar product to the placed where it turns and see that will loosen it up after a while.
Try changing the battery, but most likely some part has failed or changed value over the years. You should be able to find a copy of the manual in the Internet -- It has some troubleshooting information in it. Most likely a resistor is bad although it could be the 12AU7 tube.
Jeff I hope you can help me I just bought a heathkit V-7A vtvm meter ,It didn't come with a center 1/4 probe the one in the center ,where can I get one or how can I build one ,my meter for the most part seems to be in good shape ,I will replace the two wax caps ,but I need that probe anyone who can help ,pleaser me no.
Fortunately, the V-7A didn't use a special switched probe like later Heathkit VTVM. You can make your own probes using banana jacks, test prods, and a 1/4" phone plug. You need to put a 1 Megohm resistor in the DC test lead. The V7-A manual describes the probes and you can get all the parts from sources like eBay.
I treasure those who try so hard to provide an amusing or interesting video for those of us who are dumb as a bag of rocks. But I really don't get the need for droll rote reading a script type videos. I just mentally go numb.its my problem I know.
![คุณอาเรียโต๊ะข้างๆ พูดรัสเซียหวานใส่ซะหัวใจจะวาย ตอนที่ 2 [ซับไทย] 【Ani-One Thailand】](http://i.ytimg.com/vi/kbbfYakMY8k/mqdefault.jpg)
Jeff, loved the professional way you presented unlike others who tend to ramble on. I plan on finding a good condition IM-18 now. Thank you.
I built one of these in 1969 and used it when I was a bench technician at a TV repair place I worked at when I was in high school. It did the job and worked in situations where the old Simpson 260 had too little input impedance.
Thank you for the memories and I have to thank Heathkit for stimulating my interest in electronics. I later became an Electronics Engineer and had a wonderful 35 year career working at "Dave and Bill's place".
Wow, this brings back a lot of memories. I built one of these in my high school electronics shop back in 1970. I still have it sitting in my basement and it still works! Thanks for the memories.
Brings bake memories for me. I was a Heathkit bench technician in New Orleans for several years at their only retail location in Louisiana… I built and used one of these for years.
Nice presentation. I use my IM-18 rarely, but I'm keeping it. It is more accurate than its specs
An excellent, and well-produced introduction to VTVMs. I liked the cat meow at 8:35, too!
Jeff, I loved your video over all. You are a great presenter, have very good diction, delivery of material, and a professional approach. Your audio and video quality is great- something that most TH-cam videos sorely lack- I applaud you!
I also love my old Heath pieces and your video has inspired me to fix my VTVM!
Battery corrosion can sometimes be removed using vinegar and cotton swaps or an old toothbrush. Once you get it apart you can clean the parts with sandpaper. The hard part is usually getting the pieces apart and you may have to risk breaking them if they are badly corroded.
thanks for the quality and informative demonstration. I learned alot. :D
I built two of these in my high school Electronics class in the mid-seventies. Three or four of these would not calibrate, and my teacher, Mr. Kuhlow asked me if I could troubleshoot them. I considered this to be an honor, as I really knew very little about electronics up to this point, not much beyond Ohm's Law. Anyway, there was a point in the calibration procedure where you would clip the test lead to a certain point in the circuitry, then move a trimmer pot until the the needle on the meter pointed to a small red dot, all the units were failing this part of the alignment. I got to thinking, how could three or four of these VTVM's all be failing in the same way, when they were each built by a different student? Were there a bad batch of parts? Also, we did have several unite which were calibrated fine. So . . . I got to thinking . . . I saw the spring cup which held I believe a C Battery. I was wondering if that spring was NOT making contact with the negative side of the battery? Also, I believed this only came into play when measuring resistance, so how could this be affecting the calibration of the VTVM. Well . . . I went ahead and jammed in a test lead between this spring cup and the batter and suddenly, the VTVM not calibrated! I yelled for Mr. Kuhlow to come over and see, he too was surprised that this would affect the calibration of the Meter. What we discovered was this . . . I all the units which were not calibrating, Panasonic batteries had been installed, my teacher having been given these for free some some source. Well . . . these batteries all had a clear plastic shrink wrap around them that just barely extended over and onto the bottom edge of the negative side of the battery, preventing contact with the spring cup. . Once I peeled off this clear wrapping, the spring made contact and all the meters now easily were calibrated. My teacher was very proud of me that day. Sadly though, about a month later out of frustration, my teacher quit teaching us electronics theory because of all the Stoners in the class causing disruption. He said, "those of you who want to be here, grab a kit out of the closet and build it, the rest of you just show up and you'll get a passing grade." That was the end of my electronics theory education, but the beginning of my love for kit building. I built two VTVM's and two Low Voltage Power Supplies. My teacher had won a federal grant wherein he was able to purchase over 50 Heathkits. How I envied the Seniors who were given the O Scopes to build :O
Hi Jeff and Subscribers. This is an older post so I hope Jeff still monitors the activity. Jeff, do you or any fellow VTVM Heathkit aficionados want to help me fix my old Heathkit VTVM IM-18? I bought one at a yard sale along with the assembly manual. The guy said it worked properly and had no use for it. I checked it over and whoever built it did a nice job. It powers up and that's all. The needle is supposed deflect upscale then settle down as the tubes warm up. The needle is static and does not move. The "zero" adjust moves the needle a little. With a new battery the ohms scale works but I can't zero it, it hangs up mid-scale. Both the A.C & D.C. scales are inoperative. I've replaced the two tubes and the Electrolytic cap in the power section and the A.C. coupling cap. No luck. Next will be the two ceramic caps. If anyone has any suggestions please let me know. FYI I built Heathkit, Eico and Lafayette (Remember them?) kits for many years. This was a nostalgia thing. I have made a set of the proper probes and done the usual work, I burnished all the rotary switch contacts, checked the solder joints etc. Next step will be to check the proper positioning of all the resistors and then a point to point wiring check. I'm asking for help here just in case there is a known problem with keeping the initial meter deflection at power up. THANKS, I'll check in here from time to time.
Tom, I'm (not an aficionado, yet, but) working on a Heathkit V-2 currently... I've recently rewired EVERYTHING, save for the resistors on the ohms-value rotary, and still do NOT have any needle deflection at all. I opted to separate the meter movement from the circuit and apply 1.5V (D cell) with a 10k ohm resistor... no needle deflection. I performed the same test to the S-meter on my Heathkit HW-32a transceiver and achieved deflection. My suggestion would be to verify meter movement across the sweep with a remote DC supply.
The "Hangup" may be related to a physical obstruction within the meter movement, or an improperly balanced movement (there are videos on correcting this). In my case, I believe the meter movement to be shot entirely.
I had a senior moment, The meter works on the Ohms scale but not on the AC, DC+ or DC-. Being that the Vacuum tube circuit works on Ohms but cannot zero out and the AC and DC have two separate inputs it may be the selector switch. There is a good deal of oxidation. I purchased a can of Deoxit online (No more radio shack and no electronic stores here) once that arrives I'll clean the contacts. Those "V" series are all pretty old 1947-1950. You can find a V1 Schematic among others here, (Link at the end) I don't see any information on the V1 though. You may be able to find a loose meter on Ebay or a junk V1 and swap out the meter. As far as the meter check the coil with a VOM and see if they have continuity. The link I'll give you has a schematic for the V2. If yours has a 6AU6 and a 6AT6 the circuitry may be the same. Good Luck, I'll post a message after I clean the contacts, I've also been advised to clean all the pots and even the tube sockets.
www.nostalgickitscentral.com/heath/heathkit.html
Nice presentation. I built a Knight Kit VTVM in the 50s and used it until fire destroyed my ham shack in 76. I recently acquired an IM 18 but without test leads. It shouldn't be a problem making up a lead assembly.
Another excellent tutorial video Jeff.
Many thanks.
Un abrazo.
73 de Rob.
YS1RS
The voltage reference chip was a Linear Technology LT1021DCN8-5.
Great video Jeff. I'd like to get my hands on a Heathkit VTVM (does not have to be Heathkit, just a fan of their products).
Jeff,
I developed a habit of collecting VTVMs (currently have 8 of various Heathkit vintages, Simpson, and Eico models). I am rebuilding a Knight KG-625. The circuits, of course, are all remarkably similar. But I have often wondered if there's a cure for the ohms measurements being off?
Do you have any recommendations besides replscing the resistors in the divider chain?
Thanks for your videos, by the way.
Yes, I would suspect resistors that have drifted out of value. Maybe also try swapping the tube if you have another one,
It's a solid state rather than vacuum tube voltmeter. I've never seen one but it is listed in a a 1971 Heathkit catalog that I have.
Jeff, I enjoyed your demo on your Heathkit.VTVM. I also own several pieces of Heathkit Test equipment and always interested to learn tips abt keeping them in good running condition.. I am wondering, in your 5V ref, what did you use for your voltage reference chip?
Ok thank you!
Hi
I picked up this same tester a a flea market recently and it looked very good both inside and out but when ever I take an ohms reading the meter bottoms out (to the right) no matter what scale I use or what resistance I am measuring. Would you have any ideas what might be the cause. It did not come with the original probe but for a/c and ohms it is straight thru as per the diagram.
Thx in advance
Any wax paper capacitors will likely be electrically leaky and should be replaced, My IM-18 didn't have any of these.
What is the name/brand of the small beige analog multimeter you show in the beginning of your video as an example of an inexpensive one? I have never seen one that small before.
Solar Bunny It is marked CIRCUITMATE AM10. I bought it about 20 years ago for my son. I don't remember where I purchased it. I see a few of them on eBay.
Jeff Tranter
Thank you! I'm going to buy one for my bag as a cheap portable multimeter. Keep up the good work Jeff!
Solar Bunny I also have a DMM the same size - a UNIT-T UT20B. I only bought it because it was ridiculously cheap, under $10.
I am a total novice and have acquired a V-7a that apparently was stored for ages with the C cell battery.. which has leaked. The good news is the leakage went away from the circuitry (towards the rear of the case -- must have been stored on it's back)
There appears to be a screw on the 'support' bar that goes over the battery but the corrosion seems to have made it difficult to remove. But before I try anything hasty, I'm wondering do you have any ideas on how to get it loose?
I have a Heathkit V-7A that needs some work. I've replaced the 6AL5 tube and need to replace the old 16 MFD electrolytic capacitor and some of the carbon resisters. Any other suggestions? Strangely enough, the original Eveready 1.5 volt battery was still in place.The amazing thing is that this 40+ year old battery wasn't leaking and still has 1.12 volts! The reason I know it's the original battery is that there's some printed tape on it that says, "1.55 V" just like the manual says. Thanks, Tom
Note that you don't *have* to use a VTVM to work on old tube equipment - you can use a modern DMM. You may want one with analog bar graph if you need to adjust circuits for a peak or null. Of course using a VTVM of the same vintage as the equipment you are working on adds to authenticity.
Is the heathkit V6 VTVM an ok meter...and are there any known issues with it? I see the IM-18 and V7a around alot but not the V6.
The V6 is similar to the V7 and later models. It had some circuit differences and did not use a printed circuit board, which was introduced with the V7. but is substantially the same as the later VTVMs.
I found a Im 11 and a IM 28 VTVM. I cant decide which one i want!
i had one of those meters good peice
Hi
After recieving the manual from the Heathki group on yahoo I went over all the resistors and found that the builder of the meter had inversed 4 transistors on the selector switch. So even thou this unit is over 40 years old it never worked properly. Looks like all the original 1% resistors.
Ths for your reply
Regards
I have this unit and like it a lot, but but my favourite VTVM is my Hickok 1600B that has died and I have been looking high and low for a schematic. i have gone all the standard sites, with no luck. Do you have any ideas where could find a schematic. Thanks for the video.
I took and look and did not find anything. You could set up an eBay search and see if one shows up there.
Thanks,,
Ihave been looking. I dont want to admit how much time i spend on ebay looking for things
Hi there. Any suggestions to get a stubborn know to turn on a heathkit IM-21
I assume you mean a stubborn "knob"? Open up the unit and try applying WD-40 or a similar product to the placed where it turns and see that will loosen it up after a while.
lol yup knob, thanks will give it a try this weekend. found 4 of these lovely old things.
I am looking for one so i can work on my old tube HF gear.
Your cat agrees!
Try changing the battery, but most likely some part has failed or changed value over the years. You should be able to find a copy of the manual in the Internet -- It has some troubleshooting information in it. Most likely a resistor is bad although it could be the 12AU7 tube.
Jeff I hope you can help me I just bought a heathkit V-7A vtvm meter ,It didn't come with a center 1/4 probe the one in the center ,where can I get one or how can I build one ,my meter for the most part seems to be in good shape ,I will replace the two wax caps ,but I need that probe anyone who can help ,pleaser me no.
Fortunately, the V-7A didn't use a special switched probe like later Heathkit VTVM. You can make your own probes using banana jacks, test prods, and a 1/4" phone plug. You need to put a 1 Megohm resistor in the DC test lead. The V7-A manual describes the probes and you can get all the parts from sources like eBay.
You could use a transistor and battery to make it portable check my Chanel and u will see a schematic
Good analysis. This equipment is so unstable...
Is it odd that the original 1940's era C batteries in my heathkit that are soldered in are STILL WORKING!?!?!?!
ola eu tenho um vtvm sico superior instruments model 400 preciso do esquema algue pode me ajudar
I have some cool looking old units. I want to make one a small guitar amplifier with a small DClass amp in it,
ola
I treasure those who try so hard to provide an amusing or interesting video for those of us who are dumb as a bag of rocks. But I really don't get the need for droll rote reading a script type videos. I just mentally go numb.its my problem I know.