Wow, a Sencore product on The Signal Path, way to go Sencore! A great old American audio, video and TV test gear manufacture. Many TV audio repair shops across the country got a head start on productivity and profitability with Sencore test gear. Sencore worked with me with real world credit plans that allowed the purchase of quality test gear that put my shop on the map. Thank you Sencore!
The voltage output spec was plus 0%, -5% so the engineering manager felt best to offset the voltage to -2.5% of entered value. When the unit went through manufacture, it's calibrated in a couple of ranges with an offset and a slope. Regarding the comment on the auto discharge function problem with issues with voltages > 450v, I am guessing that was problem an older unit. The LC103 was updated to use both a transistor and a sandbar resistor to perform the discharge for that exact problem. The LC102 had only a sandbar transistor which burned out in the case of discharging the capacitors used in switching train tracks from what I understand.
"1 Gigohm hi-pot tester" which I find quite handy for checking out cabling and coax if their dielectric are suspect. From the original product brochure: The ReZolver’s high-voltage power supply and sensitive current meter can be used to measure high resistance to 1 Gigohm. The ReZolver is sensitive enough to detect as little as 0.01 microamp of leakage current in connectors, PC boards, and switches. Additionally, the ReZolver can be a hi-pot tester that measures resistance up to 1 Gigohm with up to 1,000 volts DC applied.
9:54 You might want to check if there is any AC modulation on the DC. The older LC53 has a AC component, or ripple, along with DC offset, if there is no larger value capacitor connected to the leads to smooth it out. Thank you for a peek inside that one!
One problem with the automatic discharge function is that it tends to burn out the power resistor when measuring large high-voltage (>=450V) capacitors. However that's been a straightforward repair every time.
That was the LC102. It had a sandbar resistor, the LC103 used a transistor and a sandbar resistor. The LC103 had no problem with discharging large capacitors of any size.
@@bradgross4271 My LC103 just has the power resistor with no transistor circuit, and I’ve had to replace it a couple of times. Perhaps that was in another revision? Mine matches the LC103 schematics found on the web, and on sheet 11 of 13, the +LEAD goes through the N.C. contact of K1, through R13 50 ohm, 50 watt resistor, then through the fuse to -LEAD that has a bidirectional diode clamp and 100 ohm resistor across it to detect when the fuse is blown.
@@ChrisSmith-tc4df The discharge transistor is on the power supply board. I believe the resistor you are seeing is the expensive high tolerance resistor for measurements. The discharge transistor is on the power supply board along with some discharge resistors. The discharge transistor will not turn on until the voltage is below 750 volts as that is it's forward biased limit. It can handle 1500 volts when driven off. All LC103s have that design. There was a large capacitor bank for train track switches that consisted of like 6 capacitors the size of a 1/2 gallon juice can that was destroying the sandbar resistors in the LC102. That was our target to design to handle. When the discharge circuit engages it will use just the sandbar resistors until the voltage is well below 750volts when the transistor is turned on. I think you can see them in the upper right of the power supply when it's being shown in the video around 2 minutes and 25 seconds in.
I have had an LC102 for years and I love it. If you read the manual it explains that the test signal that they use is unique from other LCR meters. Its not a sign wave but a chopped wave. I have used mine to tune large RF inductors for LC networks and many other things that you might need a bridge for. It is a really useful piece of kit.
I would be very interested in a deep dive of this instrument. Also if you could perhaps post up the firmware of the device so that others may upgrade their LC103 to newer firmware as well. From what i understand there is an EEPROM on the board that holds calibration data, and calibrating this instrument requires scripts that only Sencore had to run a Fluke Calibrator as well as you having a calibration box with various C and L high precision components as measurement references for the calibration procedure. Glad to see you get one of these Sencore instruments in your lab as I believe they made some unique test equipment back when repairing consumer and commercial equipment was profitable. Sencore has since moved on from Test Equipment into Video equipment and unfortunately seemed to have dropped any support for their test equipment.
I have the LC101 and also the SCR 250 add on. A very useful piece of test equipment that I use on a daily basis. Would like to pick up the LC103 some time, but they are very expensive. My LC101 was relatively inexpensive, but non-functional when I received it. After a few repairs it has been flawless for the past 8 years.
I have a LC102 and use it regularly. Surprising how many new caps from major suppliers are out of spec. Is does matter in which order the test are run or it can give false results. That’s a beauty! I too am interested in seeing it measuring in circuit since the LC102 does not have that feature.
I have also recently acquired a good working LC102, and you are correct on the order of what you test before you do the "Dielectric Absorbtion" test. The DA test first discharges a cap ( when you first connect your leads) , then, puts about a 3 VDC charge on it, no matter what your leakage voltage is set to, then shuts the charge off, gives it a few seconds of discharge resistor, disconnects the resistor , measures the "rebound" voltage and converts it to a percentage with a "GOOD" or BAD" indicator. If you measure leakage first, and don't discharge the cap for at least 20 seconds or more, almost every cap that passes the DA test if run first, will fail, because it will almost always have more of a rebound voltage. I've noticed that holding the DA button down will make it cycle the test, charging it at about 3 VDC, discharging, measuring again, and most caps that don't pass at first due to running a leakage test first will pass after 3 or 4 test cycles. None of that is mentioned in the LC102 manual, unfortunately.
Great instrument, I'm still using an LC75 (virtually the same as the LC101 internally with some small differences) which I love. Even the older ones are pricey though, I had to wait until I found a non functioning one just to afford it lol. Fairly easy repair though.
When measuring leakage on a high value and/or high-voltage capacitors, it can take quite some time to charge up. I've found that a soft white rubber drafting eraser will fit quite nicely between the handle and the rubber button without damaging the rubber button. This is also quite useful for reforming electrolytics at rated (or peak) voltage over an extended time.
Thanks for another great video. I suspect the offset is in done in purpose. I own a lesser model (LC77) and the LC103 and both have a similar offset. I am thinking to protect the DUT from operating at its absolute upper end of its SOA. Your thoughts?
Great Cap Tester.. I have an LC102 and just picked up a LC103. But it does have a problem with Cap Leakage test. It all ways shows "0.00Ua" and Ohms. What Could be wrong? Every thing operates like the one you have shown here in the cap leakage mode on the display, but never shows Leakage all ways shows 0.00Ua. There is no adjustment for this? Also how do you read the number on the E Prom to know if you have the latest version? Thank You for posting this video. TU Mark
among others Mr Carlson on UA-cam claim that leakage is a purely resistive property. and therefore it should not matter of you measure it with a high or low voltage. with low voltage you just need more sensitive current measurements. but even professional devices like this measure with high voltages. is that just to confirm the cap supports it's rated voltage. or is there another reason. like leakage being non lineair with voltage?
At low voltages, it is certainly a linear, resistive property. But dielectric breakdown is not a linear function and additional leakage and failure modes of capacitors will reveal themselves if you stress the device at higher voltages.
@@ChrisSmith-tc4df personally i don't believe in reforming capacitors. If they are bad enough to need it, they are bad enough to be replaced. I don't use all my vintage equipment every day. If it goes bad once it will keep going bad, i would not trust that in my stuff and would not want to put that load on it.
I have this ones predecessor in a shed somewhere given to me long ago. - I would love to see you show some details on this. Where did you find firmware?
Just before 5:00 where you switch it on, it's only showing version 1.46 which is the ORIGINAL firmware. I thought you upgraded it to 62 or something???
2 роки тому+1
Probably some video editing magic, like performing firmware upgrade after testing this unit but including it before. Nonetheless, this thing requires further investigation :)
The version number and version index aren’t the same on these unit. I had version index 46 installed which was version number v1.40. Now I installed the index 52 which is 1.46. :)
@@Thesignalpath If this was almost ANYBODY else on the planet, I wouldn't buy that story. However, in this case, it's a perfectly logical response!!! Cheers TSP/TNP
I have the chance to buy an old Sencore LC103 but I don't want to spend so much money on a device that I cannot calibrate by myself. In case you have a copy of the Sensore LC103 calibration software, would you mind sending me a copy? I would be very grateful. Thanks a lot in advance, Mike
The version number and version index aren’t the same on these unit. I had version index 46 installed which was version number v1.40. Now I installed the index 52 which is 1.46. I never said it was version 1.52; I said it was version 1.46.
Yes, very interested in how in-circuit measurement works. Thank you!
Wow, a Sencore product on The Signal Path, way to go Sencore! A great old American audio, video and TV test gear manufacture. Many TV audio repair shops across the country got a head start on productivity and profitability with Sencore test gear. Sencore worked with me with real world credit plans that allowed the purchase of quality test gear that put my shop on the map. Thank you Sencore!
I also did a repair on the Sencore variable AC source a while back. :)
The voltage output spec was plus 0%, -5% so the engineering manager felt best to offset the voltage to -2.5% of entered value. When the unit went through manufacture, it's calibrated in a couple of ranges with an offset and a slope. Regarding the comment on the auto discharge function problem with issues with voltages > 450v, I am guessing that was problem an older unit. The LC103 was updated to use both a transistor and a sandbar resistor to perform the discharge for that exact problem. The LC102 had only a sandbar transistor which burned out in the case of discharging the capacitors used in switching train tracks from what I understand.
Nice video,
Please share more about the usage of this instrument
Nice instrument - I wasn't familiar with that one before.
"1 Gigohm hi-pot tester" which I find quite handy for checking out cabling and coax if their dielectric are suspect. From the original product brochure:
The ReZolver’s high-voltage power supply and sensitive current meter can be used to measure high resistance to 1 Gigohm. The ReZolver is sensitive enough to detect as little as 0.01 microamp of leakage current in connectors, PC boards, and switches. Additionally, the ReZolver can be a hi-pot tester that measures resistance up to 1 Gigohm with up to 1,000 volts DC applied.
Interested in further videos. Thank you for a succinct description of how to get it up and running.
That's a very interesting user interface. Someone put a lot of thought into it.
True, ergonomics given due attention.
Although the number pad layout is a bit unorthodox!
9:54 You might want to check if there is any AC modulation on the DC. The older LC53 has a AC component, or ripple, along with DC offset, if there is no larger value capacitor connected to the leads to smooth it out. Thank you for a peek inside that one!
I will check it. Thanks.
One problem with the automatic discharge function is that it tends to burn out the power resistor when measuring large high-voltage (>=450V) capacitors. However that's been a straightforward repair every time.
I suppose if the capacity is large and the voltage is large you’d have to dissipate a lot of energy in that resistor.
That was the LC102. It had a sandbar resistor, the LC103 used a transistor and a sandbar resistor. The LC103 had no problem with discharging large capacitors of any size.
@@bradgross4271 My LC103 just has the power resistor with no transistor circuit, and I’ve had to replace it a couple of times. Perhaps that was in another revision? Mine matches the LC103 schematics found on the web, and on sheet 11 of 13, the +LEAD goes through the N.C. contact of K1, through R13 50 ohm, 50 watt resistor, then through the fuse to -LEAD that has a bidirectional diode clamp and 100 ohm resistor across it to detect when the fuse is blown.
@@ChrisSmith-tc4df The discharge transistor is on the power supply board. I believe the resistor you are seeing is the expensive high tolerance resistor for measurements. The discharge transistor is on the power supply board along with some discharge resistors. The discharge transistor will not turn on until the voltage is below 750 volts as that is it's forward biased limit. It can handle 1500 volts when driven off. All LC103s have that design. There was a large capacitor bank for train track switches that consisted of like 6 capacitors the size of a 1/2 gallon juice can that was destroying the sandbar resistors in the LC102. That was our target to design to handle. When the discharge circuit engages it will use just the sandbar resistors until the voltage is well below 750volts when the transistor is turned on. I think you can see them in the upper right of the power supply when it's being shown in the video around 2 minutes and 25 seconds in.
I like that it gives the actual numbers in addition to a 'good' indication.
Please more videos on the LC103 Thank you 😊
I have had an LC102 for years and I love it. If you read the manual it explains that the test signal that they use is unique from other LCR meters. Its not a sign wave but a chopped wave.
I have used mine to tune large RF inductors for LC networks and many other things that you might need a bridge for. It is a really useful piece of kit.
Nice and bright VFDs! I'd love to see more in-depth experiments with this device. Thank you!
It would be really interesting to see how it behaves with in-circuit measurements.
I really like the two display user interface! Very good design! You don't "have to press losts of buttons" to get your measurments done
I was given one of these and it works perfectly. I was truly excited to get one of these guys.
My LCR103 appears to be circa 2000 vintage from chip date codes with 1.45 firmware, but its bias voltage is 3% low across all decades just like yours.
Interesting. I will have to find a way to adjust it.
yes yes yes! Very interesting.
I would be very interested in a deep dive of this instrument. Also if you could perhaps post up the firmware of the device so that others may upgrade their LC103 to newer firmware as well. From what i understand there is an EEPROM on the board that holds calibration data, and calibrating this instrument requires scripts that only Sencore had to run a Fluke Calibrator as well as you having a calibration box with various C and L high precision components as measurement references for the calibration procedure.
Glad to see you get one of these Sencore instruments in your lab as I believe they made some unique test equipment back when repairing consumer and commercial equipment was profitable. Sencore has since moved on from Test Equipment into Video equipment and unfortunately seemed to have dropped any support for their test equipment.
Looks like a really nice unit
Excited for the new videos either way! 😀
yes, examples for incircuit measurement would be great, also how the percentage offset can be corrected.
and can you send a link to the eprom download for upgrading the firmware ? that would be great.
Yes , more on this instrument.
Great instrument, thx!
I have the LC101 and also the SCR 250 add on. A very useful piece of test equipment that I use on a daily basis. Would like to pick up the LC103 some time, but they are very expensive. My LC101 was relatively inexpensive, but non-functional when I received it. After a few repairs it has been flawless for the past 8 years.
Yes more on this please - also, I quite like the shorter video. 10~15mins is ideal
Oh yeah more on this puppy for sure. Mods, upgrades and fixes whatever really. Well done on the 100k! 😀
Always start with a like!
Love your videos. Please open it up!!!
Congrats on 100k subs
I did not know this exists. I liked the instrument, I would like to see more about it.
I have one of these complete with all of its optional accessories!
More info on the Sencore LC103! I actually have a lot of info on the calibration process that Sencore used. I may reach out on Patreon.
03:34 Black wire earth? Green-yellow and white to the load. Not even trying to guess, if the green-yellow is the hot wire!
Yes, I have a lc102 and lc103 and I would like to see more. Ty
I have a LC102 and use it regularly. Surprising how many new caps from major suppliers are out of spec. Is does matter in which order the test are run or it can give false results. That’s a beauty! I too am interested in seeing it measuring in circuit since the LC102 does not have that feature.
I have also recently acquired a good working LC102, and you are correct on the order of what you test before you do the "Dielectric Absorbtion" test. The DA test first discharges a cap ( when you first connect your leads) , then, puts about a 3 VDC charge on it, no matter what your leakage voltage is set to, then shuts the charge off, gives it a few seconds of discharge resistor, disconnects the resistor , measures the "rebound" voltage and converts it to a percentage with a "GOOD" or BAD" indicator. If you measure leakage first, and don't discharge the cap for at least 20 seconds or more, almost every cap that passes the DA test if run first, will fail, because it will almost always have more of a rebound voltage. I've noticed that holding the DA button down will make it cycle the test, charging it at about 3 VDC, discharging, measuring again, and most caps that don't pass at first due to running a leakage test first will pass after 3 or 4 test cycles. None of that is mentioned in the LC102 manual, unfortunately.
Great instrument, I'm still using an LC75 (virtually the same as the LC101 internally with some small differences) which I love. Even the older ones are pricey though, I had to wait until I found a non functioning one just to afford it lol. Fairly easy repair though.
When measuring leakage on a high value and/or high-voltage capacitors, it can take quite some time to charge up. I've found that a soft white rubber drafting eraser will fit quite nicely between the handle and the rubber button without damaging the rubber button. This is also quite useful for reforming electrolytics at rated (or peak) voltage over an extended time.
Thanks for the tip!
@Steve Foudray I think that I either misplaced it, or it broke, so I had to improvise.
I would be very interested in learning more about this unit. Some more experiments would be great as well.
Nice !
Thanks for another great video.
I suspect the offset is in done in purpose. I own a lesser model (LC77) and the LC103 and both have a similar offset. I am thinking to protect the DUT from operating at its absolute upper end of its SOA. Your thoughts?
i do want to see more of this
Great Cap Tester.. I have an LC102 and just picked up a LC103. But it does have a problem with Cap Leakage test. It all ways shows "0.00Ua" and Ohms. What Could be wrong? Every thing operates like the one you have shown here in the cap leakage mode on the display, but never shows Leakage all ways shows 0.00Ua. There is no adjustment for this? Also how do you read the number on the E Prom to know if you have the latest version? Thank You for posting this video. TU Mark
I was waiting for you to put 500V across that cap and see if it started to show leakage!
I haven't seen this one. I would be interesting to know more about it
among others Mr Carlson on UA-cam claim that leakage is a purely resistive property. and therefore it should not matter of you measure it with a high or low voltage. with low voltage you just need more sensitive current measurements. but even professional devices like this measure with high voltages. is that just to confirm the cap supports it's rated voltage. or is there another reason. like leakage being non lineair with voltage?
At low voltages, it is certainly a linear, resistive property. But dielectric breakdown is not a linear function and additional leakage and failure modes of capacitors will reveal themselves if you stress the device at higher voltages.
@@Thesignalpath Nice, that means that my Heathkit IT-28 vintage capacitor tester can stay👍😀
You could see it gently reforming the capacitor dielectric during the leakage test, which is a highly useful side-effect.
@@ChrisSmith-tc4df personally i don't believe in reforming capacitors. If they are bad enough to need it, they are bad enough to be replaced. I don't use all my vintage equipment every day. If it goes bad once it will keep going bad, i would not trust that in my stuff and would not want to put that load on it.
Did you get the owner's manual with the schematics?
Yes, they are freely available online.
4:53 I see some familiar looking test points. Looks like Keystone #5016.
👍👍
I have this ones predecessor in a shed somewhere given to me long ago. - I would love to see you show some details on this. Where did you find firmware?
Just before 5:00 where you switch it on, it's only showing version 1.46 which is the ORIGINAL firmware.
I thought you upgraded it to 62 or something???
Probably some video editing magic, like performing firmware upgrade after testing this unit but including it before. Nonetheless, this thing requires further investigation :)
The version number and version index aren’t the same on these unit. I had version index 46 installed which was version number v1.40. Now I installed the index 52 which is 1.46. :)
@@Thesignalpath
If this was almost ANYBODY else on the planet, I wouldn't buy that story. However, in this case, it's a perfectly logical response!!!
Cheers TSP/TNP
I want one of these LCR bench things but man they are so expensive
very interesting that you have to keep the buttons pressed!.
It seems it doesn't has any kind of GPIB bus or way to automate/interface, right?
There is a connector called "Remote" which can be used to trigger measurement from like a foot pedal or a switch on the probe.
This looks like a really interesting unit. What kind of chart does it have in the "pull chart" compartment?
It is a quick start manual!
I have the chance to buy an old Sencore LC103 but I don't want to spend so much money on a device that I cannot calibrate by myself. In case you have a copy of the Sensore LC103 calibration software, would you mind sending me a copy? I would be very grateful.
Thanks a lot in advance,
Mike
More is better in this case ;)
I'm waiting for your video about PLL
Firmware was 1.46, not 1.52.
The version number and version index aren’t the same on these unit. I had version index 46 installed which was version number v1.40. Now I installed the index 52 which is 1.46. I never said it was version 1.52; I said it was version 1.46.
@@Thesignalpath ok, thanks.
Wrong intro. Disappointed ☹️.
👍👍