It's one of those cheap chinese chip/screen devices with external battery pack.
Not ideal, but it was very accurate to that listed when I tested all new XO parts I've ordered over the past, including Inductors, Caps & Resistors.
But tonight it doesn't want to display Inductor results, even though I've isolated the Iron Core example.
It's still working for Caps though.
Might need a replacement tool.
I must ask, are you sure you are connecting to the bare copper ends of the coil and not to the enamel coating?
If you still have the meter's instructions, check its specs. Perhaps the iron-core has a value exceeding the capacity of the LCR meter.
Try measuring the air-core - does that give a reading?
If you still have the meter's instructions, check its specs. Perhaps the iron-core has a value exceeding the capacity of the LCR meter.
Try measuring the air-core - does that give a reading?
Thanks Galu.
I'm connecting the leads on the un coated ends of the Inductor well away from any coating.
Also I scratched the leads to make sure I had good conductivity.
Iron core Inductor was also tested with same result.
I think the chip is caput but I'll check the specs.
EDIT: These meters quote Inductance but give no specs on range.
I'll try tomorrow using a new battery??
Will leave no stone unturned. 🙂
👍
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I suggest you invest in a decent LCR meter like the UNI-T UT603.
It will soon justify its cost of around £40.
It will soon justify its cost of around £40.
I'll work towards it.
A new battery & a few tries revealed 1.5mH coming from the iron core Inductor.
This was an average of 4 readings.
I'll initially work towards machining the boxes and fitting the speakers to the existing XO's. 👍
The meter is no longer measuring Inductance.
It still measure capacitance, but no go any longer with inductance.
I was lucky that it decided to work 5 times when measuring the Iron Core Inductor this morning before failing again for inductance.
I'm checking outlets for the my meters replacement and won't rely on 1.5mH value I was able to obtain.
EDIT: Interestingly, the meter is indicating 3.6ohms on the 3.3ohm resistor!
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This one seems reasonable.
https://www.ebay.com.au/itm/353950638645?hash=item52691a2235:g:jOUAAOSwNohhQaHi&amdata=enc:AQAHAAAA4J4ijUytNRro3jVi5Tuuk6uIwnmH4XHeCl+N68GH70z0ZjI8//1yWd7DCoPD7WX4tksaVgEBxXwEb86PRkfLsSP0C9JZ1orhgEsrcZ1FjXS5MNbNl+DBIaDdw70isaoqb4qIIxY/7OaZzVrsB7c/2643KClKOKcgjAjlHquDbmSrAQg3qermJmWFEpot4S47ydyP+GMgq3XtXiN3CYoqc15iLM4MI/TzsE9OCf/EKGQ487gsxIkiHAo5nwMk2AwF5ArC7F6sBccorNuJ/Nr/EiPPAWj8GWaQ2HPsqyIWZCyY|tkp:Bk9SR-SI-smTYQ
Reviews: I work in an accredited calibration lab and I verified the accuracy to be +/- 3% for all ranges and functions as soon as I got the unit.
The measurements are uniformly high but after reading the accuracy statement it is clear the readings are within the specified accuracy.±(2.5%
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Yes, 1.5 mH seems a bit on the high side to me.
The LCR meter you linked to doesn't have a 2 mH range, unlike the one I suggested. A 2 mH range would give accurate measurement of small loudspeaker inductance values.
Compare the two images, your meter also has a restricted capacitance range (although it does have an extended resistance range) compared to mine.
I would save up for the meter with the widest capability of measuring inductance and capacitance.
The woofer in those speakers look remarkably like the Peerless I just got at a garage sale.
I'be been unable to find any factory information about them but listening they are OK
I'be been unable to find any factory information about them but listening they are OK
Apart from the "MA252D" printed on the back of the driver, there are no identification markings.
Looks well built though.
Alex Encel used to sell the Rotel RL 870's along with Rotel Amps & CD Players.
I also have the Receiver Rotel RX 820, & Cassette Player Rotel RD 820which was sold with these speakers.
Both also need work.
Attachments
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Sorry Galu.
I hope your brain can get some rest.
🙁😉
😴
I'll continue tracking down a suitable meter. 👍
The 'MA' likely stands for 'Monitor Audio'.
As I said earlier, my sources say that the Rotel bass/mid drivers were made in England by Elac.
Elac supplied mid/bass drivers to Monitor Audio as well as to KEF (see attachment).
Attachments
Looking at the rear of that ELAC driver I'm thinking a lot of European makes got the baskets and magent sub-assemblies from the same sources
It makes you wonder how many things are actually made in the country suggested by their stamps/markings.
Do you think the difference might be in the voice coils, cones, dust caps, & wiring/terminations?
A contemporary of the Rotel RL850, the KEF Coda III, has a similar looking mid/bass driver which was said to have been made for KEF by Matsushita!
It's quite possible that baskets and magnet assemblies were made by a common supplier and that companies like Elac and Matsushita added the additional components to their own specifications.
It's quite possible that baskets and magnet assemblies were made by a common supplier and that companies like Elac and Matsushita added the additional components to their own specifications.
Would the UNI-T UT601 also cover my needs?
https://www.tools.com/uni-t-capacit...MIp_OUv8vD-wIVyzMrCh2o8g1HEAQYBSABEgJGJ_D_BwE