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Hello! I'm back again with a couple questions about testing continuity and multimeters. I'm working with an AR-XA turntable.
So I have a multimeter that I probably bought a year or two ago at The Home Depot. When testing for continuity, it makes a little tone. It is so faint I can barely hear it, and I'm not sure I am hearing it all the time. The digital display on mine reads "1" when not testing and a slew of numbers bouncing around when it does establish continuity. Is that normal?
Are there any multimeters that make a more loud sound when continuity is established?
I hooked up the turntable last night and tried playing a record. I got nothing at all out of the left channel and a hum out of the right channel that varied in loudness with the receiver's volume control.
Got some work to do to run down the location of these errors.
Cheers
Follow Ups:
disconnect the leads from the cartridge, then check each wire from the cartridge connector to the middle part of the RCA connector on each channel. Look at the meter and should read 0.00ohms or close to that with a solid connection. Then do the same with the outer part of the RAC connectors to the other two cartridge connectors. If all readings are 0.0 then you are good with the wiring from point to point.
Then go and check the RCA's from center pin to outer shell. There should be no reading on the meter. If that checks out, then you are good with the wiring.
This will point back to the cartridge or connection on the cartridge pins. There is a way to check to make sure the cartridge is ok but save that for last.
one question, have you tried another table to make sure its not the any of the gear making this noise? receiver or phono preamp? Has this ever made this noise before? if not, what changed?
I had a similar hum issue happen with my setup after changing a wand on the ET2 arm. It turned out the connection on one of the wires connected to the cartridge wasn't tight very loose. I tighten the grip of the connector and it was all gone. It doesn't take much to cause that issue either.
let us know what steps you have done with the info here. Please write down what you so you have a check list of steps you did and results for process of elimination troubleshooting. It helps out and as we get older we tend to forget easy things. :) Good to review it after as well.
to zero the readout in ohms you have to also take a reading on the leads themself by shorting the 2 together at the ends. It will not read 0.00 unless it is a VOM that can do that automatically or manually.
The reading will be close but not exactly zero, and read something like 0.03 ohms.
Then proceed with the leads readout making note of the previous reading and what resistance is added to 0.03: + 0.07 or whatever it reads.
But not meters do that and that's I said or close to that reading. I just used the 0.00 as a reference. It will actually show what you put but should not go over 0. If it does, then there is a issue depending what the value is.
Edits: 03/02/24
Measure the resistance between the cartridge connections and the ends of the RCA cables respectively. There should be 1 ohm or less for all 4 circuits.
A continuity tester and a multimeter are not exactly the same thing. Continuity simply means there is a complete circuit or connection. A multimeter can measure the ohms of the said circuit. I have owned various multimeters over 34 years and used them regularly at work. Never have used one that beeped...
my Fluke VOM does.
Later Gator,
Dave
And silicone spray works wonders on that darn sliding door.!
Edits: 03/01/24
2" X 2" X 6" , weighs 4 pounds, and was last inspected on September 28, 1968. I think I found it an estate sale in Alaska, where I also found a TV-7/U tube tester for $10. The tube tester weighs 20 pounds. The military equipment was sure heavy duty.
Awesome. Not sure I have ever seen that on any Fluke automotive meters, but then again continuity is pretty much a useless test for automotive ckts save car stereo installations.
Regardless of whether you ever used a VOM with a continuity test function that beeped only shows your lack of experience. I own one that produces a tone when testing for continuity and I've seen a number of VOMs with this function. It's designed for when you're making multiple continuity tests when you don't want to look at the display each time. If you don't get a tone when you expect one, then you can look at the display and run further tests to determine why you aren't getting continuity. If everything is working properly, the continuity tone function save a lot of time.
Best regards,
John Elison
Hey John,You say you worked weapons integration on B-2? Did you know a Major Verrett AKA Sparky?
He's a ham radio friend of mine who also worked weapons integration on B-2.
Send me a private message if you knew him.
Edit: On closer inspection I see you worked on B-2 development, not weapons integration, so maybe not so likely you knew my friend Sparky. He says your name doesn't ring a bell, I think you were working at an earlier time than my friend, who is younger.
Edits: 03/01/24 03/01/24 03/01/24
Sorry, I don't remember Sparky, but I never went to Whiteman AFB. I was the Air Force armament logistics manager in the B-2 SPO at Wright-Patterson AFB during the B-2 development program. I was in charge of the design and development of armament support equipment from Sep 1985 through Feb 1990.
Best regards,
John Elison
maybe they did have a continuity function, but it would useless in the automotive and real world diagnostics. It is just not used or recognized.
As far as my experience I have been a master certified electrical technician for Ford, GM, and Chrysler since 1991 and authorized to do warranty electrical repairs on all of their vehicles.
And you...???
What difference does it make what I do? I own two digital multimeters with continuity test functions that produce an audible beep or tone. One is a BK Test Bench 390 handheld multimeter and the other is a Fluke Dual Display Bench-top Multimeter.
Just because you have no use for an audible continuity test function doesn't mean that others don't use it. As I mentioned before, if you have a number of continuity tests to make, the audible tone saves time. For example, suppose you have a bunch of cables to test for continuity. You can speed up the process when you don't have to continually look at the meter's display instead of simply listening for a tone or beep. If you don't get a tone, you can set that cable aside for further inspection.
I was also an electronic technician before becoming a mechanical engineer. I've been using electronic test equipment since I was 20-years old and I'm now 76. I've also been an audiophile for the same length of time, and I've done a lot of testing on my own audio equipment. Moreover, I was a PMEL technician in the Air Force where I calibrated and repaired oscilloscopes, meters, and signal generators. Then the Air Force sent me to school in mechanical engineering at the University of Arizona where I received my BSME degree and was subsequently commissioned a second lieutenant. I worked as an aircraft/nuclear weapon integration engineer until I was promoted to captain and transferred to the B-2 Stealth Bomber Development Program. I later retired from the Air Force with 23-years of service.
Here's a picture of some of the electronic equipment I own today.
Ok fine and fair enough. I never questioned YOUR experience. Yes continuity is OK for a quick cable check, but is an outdated test procedure nonetheless. Continuity in an electrical circuit proves nothing as far as diagnostics go. And that is where we are at with the original poster's question. "perfect" continuity and even "perfect" circuit resistance still leaves a lot of unanswered questions about circuit integrity.
The whole point in my initial answer before you horned in with that "lack of experience" nonsense was to let the OP know that continuity testing is not going to diagnose the concern. I would START with some resistance readings. And then move to ckts shorted together or to ground somewhere. Then lastly move on to checking the ability of the ckt(s) to carry amperage.
> Then lastly move on to checking the ability of the ckt(s) to carry amperage.
How much amperage do you think those phono cables need to carry? LoL
would indicate a broken connection.
First determine if the meter makes a decent volume sound by selecting the sound function on the volt/ohm meter and place the positive lead pin against the common pin.
I would do the easiest test first by testing each RCA interconnect. With the VOM in the sound mode, touch the RCA connector center pin with the red VOM lead, then touch the outer shield of the RCA connector with the black common lead. If the VOM switch is in the sound mode, you should get a good volume sound. If no sound, then that interconnect is internally broken, the RCA connector has a separated wire from a solder joint, the terminal strip under the turntable where the tonearm wires connect to the interconnect wires has a broken connection, the tonearm wire is broken, the cartridge pin connector wire is broken, or the cartridge is faulty.
The next easiest step is to observe the terminal strip under the table where the tonearm wires connect to the interconnect wires for any broken connection.
My next step would to observe the cartridge pin area for a broken wire.
Finally, replace the cartridge to see if the problem goes away.
Broken tonearm wiring is the hardest to find, but it can be confirmed by removing a cartridge pin wire. Then place one VOM lead on that wire end and the other VOM lead where the that wire connects to the interconnect wire under the turntable. If no sound or an infinite resistance reading on the VOM , then the tonearm wire is broken. Those tonearm wires are so small, that any rough handling of the tonearm can easily break the wire.
For the hum, the problem I have experienced is not a broken wire, but a loose wire at any of the points mentioned above. The cartridge pin connector wires are a good place to start. If a slight pull on the pin wire immediately disconnects from the pin, you have probably found the culprit. Someone correct me, but a very high resistance reading on the VOM might indicate a loose connection somewhere.
I would appreciate any corrections from folks with an electronic background.
I am using a Fluke VOM #81438. A closed circuit continuity test using sound is pretty loud. Using the resistance mode readings are steady, and a good connection reads almost zero ohms. An open connection reads OL or infinite resistance. Actually OL stands for input overload.
George, ah makes very good suggestions here.Upon reading your OP here my initial impression was shorted wire for hum and broken wire for no sound. The good news and bad news is the wiring with the arm is very thin and delicate. With original condition that produces very little distortion on the signal. But with wear damage can easily happen.
So just a guess but arm wire seems your most likely suspect. Check as advised by ah. If that is the problem then rewiring may be your best option. I expect repairing the original AR wire could be very difficult. Cardas wire is highly recommended and available from a few sources.
"The secret of life is honesty and fair dealing, if you can fake that you've got it made." Groucho
Edits: 02/29/24
the RCA connector on my Dual 1229. After nearing the loud hum, I unscrewed the connector and found a broken solder connection. That broken wire may have then touched another part of the connector creating a short. I wish I had observed that, but I just made a whole new RCA connector and forgot to research.As others have stated, the link below is an excellent description of rebuilding the AR-XA.
Dave at vinylnirvana.com is also excellent, and look for the tonearm re-wiring under the link titled AR Resources.
Edits: 02/28/24 02/28/24
Thanks very much for this thorough treatment of techniques to sleuth out the problems with my turntable. I shall try some testing today and report back here with what I find.
Much appreciated!
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