hddennis Posted June 6, 2019 Share Posted June 6, 2019 (edited) Thanks to EdinMass for posting a picture of this meter. I was able to find another restoration project by searching for this meter. I believe I've found a Herbrand HT900 Tune Up Center. It includes the HT-660 Coil Tester Ed posted, a Tach Engine RPM Tester HT-864 and a Regulator Tester HT-400. I was able to download a manual on the HT-660 but can't find anything on the other 2 meters. Can anyone supply information on these 2 meters? Even pictures of the test leads for these 2 meters would help me. Howard Dennis Edited June 6, 2019 by hddennis (see edit history) 1 Link to comment Share on other sites More sharing options...
hddennis Posted July 20, 2019 Author Share Posted July 20, 2019 Still need info on these meters. Anyone have any idea where I might find instructions on their use? Howard Dennis Link to comment Share on other sites More sharing options...
Bloo Posted July 20, 2019 Share Posted July 20, 2019 (edited) I have no idea. Better pictures, close ups of where the leads attach, the meter scales, and inside, and I might be able to make some good guesses. I won't know until I see. I am currently restoring some similar gear of a different brand. The tachometer is a little baffling, but I have it sort of working, not calibrated yet. I am building a voltmeter from scratch for 6 volt charging systems. Here are some old auction pictures of the HT-400 showing the leads: It looks to be just a voltmeter and ammeter, with the heavy leads being for the ammeter. It is not quite a whole generator test set, as usually you would have a rheostat, or a carbon pile, depending on what method the shop manual gave you. Sometimes those were separate pieces. You would be able to see charging voltage on this without anything extra, and that's handy, as many DMMs will fail to work on a running 6 volt car. And here's the HT-864: This looks to be a typical two-wire dwell tach. Hook one wire to the points (at the coil), and the other wire to ground. I imagine for dwell you adjust that knob for full scale with the points open. RPM must just work. What does that switch say? Double? I guess they leave it up to you to pick an appropriate scale. Edited July 20, 2019 by Bloo (see edit history) Link to comment Share on other sites More sharing options...
hddennis Posted July 20, 2019 Author Share Posted July 20, 2019 Thanks Bloo, Your right about that switch it reads "normal" when up and "double" when down, think it has something to do with 4 cylinders and 8 cylinders. The dwell meter HT-864 only has 2 leads that attach to studs below the clear meter. It has one D cell battery above the meter and a tray that holds 4 C cell batteries below the meter. The HT-400 meter has 2 large diameter leads (10-12 Gauge?) that attach to a large copper band going around the entire inside of the meter housing and 2 smaller leads that attach to studs below the clear gauge. Howard Dennis Link to comment Share on other sites More sharing options...
Bloo Posted July 20, 2019 Share Posted July 20, 2019 (edited) On the Voltmeter-Ammeter, that copper strap around the outside is the shunt for the Ammeter. It makes sense that the wires would be big. Ammeters are as close to a dead short internally as possible. They never connect from positive to negative like a Voltmeter. Since they measure Current, you have to break the circuit and insert the Ammeter. All the current must flow THROUGH the ammeter. It looks like they intended you to disconnect the battery wire at the regulator, and connect this between the BAT post and the wire you took off... I think. They probably had the red clip on the regulator side, because the regulator would have slightly more voltage when the system is charging. If it is wrong, it will just try to read backwards, so that should be pretty easy to figure out. At the end of the day, it's just an Ammeter, and you can insert it into any circuit you want to measure current, as long as you are expecting less than 60 amps. I see two taps on the shunt. I don't know why two, but the distance between them probably sets the calibration of the ammeter. More distance between them would make the ammeter read higher. If you check it's calibration with another Ammeter, remember to put the two Ammeters in SERIES (not parallel). All the current must flow through an ammeter for it to be accurate. For the Voltmeter function, the leads can be a lot smaller. Voltmeters connect from positive to negative, and as such have very high internal resistance. They are as close to an open circuit as possible. Like the Ammeter, if the leads are reversed it will just try to read backwards. That should be pretty easy to sort out. I think the two variable resistors hanging on that board on the back of the meter movement calibrate the two voltage scales (one for each). To calibrate, a variable power supply would be handy. make sure the mechanical zero is set (the screw on front of the meter). To check accuracy, hook another Voltmeter in PARALLEL (unlike the Ammeter). In theory you would calibrate at full scale. In practice, it is usually better to start by calibrating at 3/4 scale, and then check at several places across the scale. If you can't get a scale to read high enough using the variable resistor, the associated fixed resistor (there is one for each Voltage scale, at about 7:00 in the picture) is probably at fault. For what it's worth, on 6 volt cars, accuracy around 7 to 7.5 volts would be most important. Edited July 20, 2019 by Bloo (see edit history) Link to comment Share on other sites More sharing options...
Bloo Posted July 20, 2019 Share Posted July 20, 2019 I can't see how the dwell/tach works. All those batteries! I also see that the test leads, of which there are two, only connect to that battery board, and I see no wires to the main circuitry. That can't really be right. Can you see how it was connected? Hookup of the two wires to the car is just going to be one to the points, and the other to ground. Link to comment Share on other sites More sharing options...
hddennis Posted July 20, 2019 Author Share Posted July 20, 2019 18 minutes ago, Bloo said: I can't see how the dwell/tach works. All those batteries! I also see that the test leads, of which there are two, only connect to that battery board, and I see no wires to the main circuitry. That can't really be right. Can you see how it was connected? Hookup of the two wires to the car is just going to be one to the points, and the other to ground. Bloo, I hate electrical work because I'm no good at it and don't understand it. When I opened this meter the batteries had about 50 years of corrosion so it all had to come out for cleaning. I took the gray and red wires off the studs to get the C cell tray out and allow me to take the two black leads off the posts just below the clear meter. The gray and red wires I just stuck back on the posts that mount the battery tray so I wouldn't forget where they go, they actually should be put on the posts after the tray is put back on. Howard Dennis Link to comment Share on other sites More sharing options...
Bloo Posted July 20, 2019 Share Posted July 20, 2019 (edited) OH Well that makes it easy. It might even work! Edited July 20, 2019 by Bloo (see edit history) Link to comment Share on other sites More sharing options...
1912Staver Posted July 22, 2019 Share Posted July 22, 2019 Snap- On sold very similar meters. Might even be the same basic unit with different branding. You might find Snap -On information that applies to the Herbrand meters easier to find given the interest in vintage Snap - On tools. Greg in Canada Link to comment Share on other sites More sharing options...
hddennis Posted July 23, 2019 Author Share Posted July 23, 2019 Thanks for those ideas guys, I've already found several Snap-On meters that seem as if they were the same. Maybe that will be a more productive search as Snap-On is still in business. Howard Dennis Link to comment Share on other sites More sharing options...
RRichards Posted May 4, 2023 Share Posted May 4, 2023 Mr.Dennis, my son recently acquired this old test kit in a barn sale in R.I. 2 Link to comment Share on other sites More sharing options...
hddennis Posted May 4, 2023 Author Share Posted May 4, 2023 Nice find! Looks just like mine. Howard Dennis Link to comment Share on other sites More sharing options...
RRichards Posted May 4, 2023 Share Posted May 4, 2023 It is available if anyone is looking, seems to have all the cords with it . Link to comment Share on other sites More sharing options...
chriscris Posted February 22 Share Posted February 22 May be a LONG shot, but if its it's still available, I am interested. Thanks very much Chris Link to comment Share on other sites More sharing options...
30DodgePanel Posted February 24 Share Posted February 24 On 2/22/2024 at 10:12 AM, chriscris said: May be a LONG shot, but if its it's still available, I am interested. Thanks very much Chris He hasn't been on the site since May 2023 so he doesn't frequent. Quote him and you may have a better shot because it sends him an email notifying him that someone is trying to respond to this. Link to comment Share on other sites More sharing options...
chriscris Posted February 27 Share Posted February 27 On 5/4/2023 at 5:43 PM, RRichards said: It is available if anyone is looking, seems to have all the cords with it . I am interested, if it still available. Thanks Link to comment Share on other sites More sharing options...
hddennis Posted April 4 Author Share Posted April 4 On 2/27/2024 at 6:53 PM, chriscris said: I am interested, if it still available. Thanks Chriscris, are you still looking for one of these units? Howard Dennis Link to comment Share on other sites More sharing options...
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