Author Topic: Mastech MS5308 LCR Tester member discount  (Read 3034 times)

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Offline SeanB

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Re: Mastech MS5308 LCR Tester member discount
« Reply #15 on: February 17, 2013, 04:19:31 AM »
So I got literally the last one at the old price then. I do like it, it is quite big, much bigger than any other meter I have.

Offline ddavidebor

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Re: Mastech MS5308 LCR Tester member discount
« Reply #16 on: February 17, 2013, 06:19:19 AM »
how much shipping to italy will cost?

Worldwide shipping (with tracking) is already included in the price. However, I'm already out of stock on these. I will likely get some new ones in April but pricing will be adjusted as Mastech has increased their pricing over their entire product range just before Chinese New Year.


oooh what a bad news!

Online iloveelectronics

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Re: Mastech MS5308 LCR Tester member discount
« Reply #17 on: February 17, 2013, 10:17:46 AM »
So I got literally the last one at the old price then. I do like it, it is quite big, much bigger than any other meter I have.

No, you didn't. I got 20 of those. Apart from my own and Martin's, you actually got one of first few units I sold.

Offline maxpayne

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Re: Mastech MS5308 LCR Tester member discount
« Reply #18 on: February 17, 2013, 02:05:58 PM »
I m the one who got the last two ...  :D  :D  :D

Offline Kryoclasm

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Re: Mastech MS5308 LCR Tester member discount
« Reply #19 on: February 18, 2013, 06:58:51 PM »
 |O
I wish I had waited a month later before buying mine. Paid about $20 bucks more on Ebay.
It is a very good LCR meter, just toss the power supply into the garbage, unless they changed them out with a better one.
“I predict that very shortly the old-fashioned incandescent lamp, having a filament heated to brightness by the passage of electric current through it, will entirely disappear.” -Nikola Tesla

Offline SeanB

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Re: Mastech MS5308 LCR Tester member discount
« Reply #20 on: February 19, 2013, 02:49:57 AM »
Finished the linear power supply today, and it works. Very simple, an old 12VAC 1VA transformer ( dead clock radio), a 2A bridge rectifier ( out of the box of bits as the first that was small), a used 2200uF 25V capacitor ( checked it on the LCR meter before use, it was passable for capacitance, ESR and loss so in it went) and a 7812 regulator on a small heatsink ( A little overkill as it will never get warm even as the bare TO220 package but the tiny heatsink made it easier to epoxy down) with the negative grounded to mains via a small inductor. Added a 0.22uF class x capacitor to the input and then epoxied the transformer and the components into the recycled plug top case. Made sure there was a lot of clearance along with placing plastic isolation barriers between the mains side and the low voltage side. Wired it up point to point and reused the original cable strain relief for the Mastech power cord ( persuade the old one out then use superglue to hold the new one in) and added a used green LED as a power indicator. All in all about 2 hours work excluding curing time for the epoxy.

Online PA0PBZ

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Re: Mastech MS5308 LCR Tester member discount
« Reply #21 on: February 19, 2013, 06:26:06 AM »
Received my MS5308 today from Franky, and had a short look at the power supply. It's probably the worst one I've ever seen!
It is rated for 12V/1A, but loading it with a 33 ohm resistor (so something like 360mA) created an output with pulses from 7 (low) to 17 (high) volt!
I'm not even going to use it for something else or trying to fix it, what a piece of cr*p...
The meter is fine though, and since we already knew about the power supply there's nothing to complain about.

Offline nixxon

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Re: Mastech MS5308 LCR Tester member discount
« Reply #22 on: February 19, 2013, 07:52:44 AM »
|O
I wish I had waited a month later before buying mine. Paid about $20 bucks more on Ebay.
It is a very good LCR meter, just toss the power supply into the garbage, unless they changed them out with a better one.

$20 is el cheapo for a whole extra month of fun & experience. It is just 67 cents a day ;)

Online staxquad

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Re: Mastech MS5308 LCR Tester member discount
« Reply #23 on: February 23, 2013, 07:05:19 PM »
Did I get a dud I thought to myself?

Tested the supplied power adapter and found it was as noisy as alluded to so cut the cord and mated it with a 12V wall wart.  Scrounged some batteries (until I could go to the store to purchase fresh primaries), loaded them in and observed 3 bars on the battery indicator of the unit, seems reasonable.

Tried out the unit back and forth with AC and batteries, same result, frustration.  The meter in auto LCR just would not settle on the type of component, let alone a proper value for L, C or R.  Switching to L, C, or R modes stopped the incessant dancing around from L, to C, to R in auto LCR mode, but still would not settle, or would settle on a completely bogus value.

Not knowing what was going on, I tested the wall wart's voltage and it fluctuated from 12.5V down to 12V depending on the load MS5308 drew.  So I tried a CV power supply (12v, 10A, switching), adjusted it to 12.00V and as MS5308 operated, the voltage remained constant, but this time MS5308 operated as you'd expect, homing in on the component mode then the correct value in auto LCR and the individual modes.

Afterwards checked the voltage on the supplied power adapter to see what it was adjusted to, 12.45V.

So for the unit to function properly, it requires fresh primary cells or a constant voltage power supply.  The unit is not a dud. 

1V/div, 100khz repeat (2 micro sec/div)
« Last Edit: March 06, 2013, 05:42:30 PM by staxquad »
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Offline chickenHeadKnob

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Re: Mastech MS5308 LCR Tester member discount
« Reply #24 on: February 24, 2013, 06:59:03 AM »
@staxquad: a little warning

Have you seen the other thread started by wavebits? ms-5308-power-supply-issues

That thread indicates that there is a LDO on the inside that is operating right at its maximum input voltage. I have been ultra cautious with my unit. First when I loaded it with fresh alkalines I measured a battery voltage of 12.79 (before inserting all) so I replace 4 batteries with some Nimh rechargeables to bring it back down to 11.75. It has been working fine with full battery indicator. It does hunt a bit with nothing connected to the inputs before settling on 9.2 pF but that is expected. When I build a dedicated bench supply for this thing I am going to set the output to 11.5 volts. I haven't used it that much yet  but find it is more fun than expected when I do.

edited: having trouble with the URL thing, think it is fixed now
« Last Edit: February 24, 2013, 08:26:41 AM by chickenHeadKnob »

Online staxquad

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Re: Mastech MS5308 LCR Tester member discount
« Reply #25 on: February 24, 2013, 05:18:59 PM »
@chickenHeadKnob...Thanks for the heads up.  I assumed if the manufacturer supplied a power source at 12.45v and required 8 cells that it ran on ~12v.  So much for assumptions. 

So the power supply has issues with noise and over voltage, MS5308 has battery voltage issues with 8 cells and MS5308 requires voltage stability. 

I tested the unit all the way down to when "batt" showed up on the display for a few seconds before shutdown.

the battery indicator shows:
four bars from 11.43 volts and up;
three bars from 10.38 volts to 11.42 volts;
two bars from 9.37 volts to 10.37 volts;
one bars from 8.34 volts to 9.36 volts;
shutdown at 8.33 volts (idling).
shutdown at 8.35 volts (running with back-light and RS232)

Tested MS5308 at 8.50 volts while using RS232 data logging and the back light on while changing frequencies and it worked fine, with stability, so obviously any higher voltage also did work, not dancing around.  No point risking the chips if it works at lower voltages.

Looks like voltage stability makes the meter work correctly, weak batteries and unregulated wall warts are susceptible to voltage dips making the unit dance.  So when I had scrounged mixed secondary batteries for the unit, it showed 3 bars (10.38 volts to 11.43 volts) and still danced around, because the cells' discharge wasn't capable to maintain the voltage under load.

Since MS5308 works correctly at 8.50 volts, and works right up to 4 bars starting at 11.43 volts, I'll settle in between on the low side with the CV power supply set to 9.00v and will use 7x NiMH batteries with the 8th battery a dummy, so the voltage will range from 9.94 ~ 9.66 volts (from 1.42v to ~ 1.38v under load), when the batteries are fresh to 8.50 (1.21v) when the batteries are low, or till the meter dances.  Will use a CV power supply set to 9.00v until the ordered matched NiMH batteries arrive, then will test my assumptions.  NiMH batteries are pretty flat in discharge.

Good thing I didn't buy primary batteries for it and was aware of the power supply issues, and luckily I didn't apply too many volts to the unit while not aware of it's voltage limitations. 

(mica and film caps tested nicely at 100kHz)

update 2/26/13

Received my rechargeable batteries, Chinese versions of Sanyo Eneloop XX, minimum 2300mAh, very stable discharge, preferred by photographers in their flash units, cameras, motor drives; flashlights.

Charged them up, 1.40~1.42v; used 7 of them in the MS5308 meter with one dummy battery giving a voltage of around 10V to start (after a couple of hours and some use, it's at 9.81v) and can use until 8.50v when the batteries are at minimum charge at ~ 1.22v each and at the lower limit of the voltage required to operate the meter,  using it's 2500mAh (min 2300mAh) capacity, so >100 hours use before recharge required is my estimate.

The resistance is a test standard at .0025 ohms, MS5308 displays either .002 ohms or .003 ohms. 

The meter is stable while using all it's capabilities with either batteries (10.00v to 8.50v using it's full capacity) or with a constant voltage supply of 9.00vdc, so I'm set and satisfied with low voltage use.

(The battery level was at one bar when I was using the 9.00vdc power supply)

update 2/27/13

Had one shutdown at 8.50 volts, so upped the lower limit to 8.55 volts.

video tests:
MS5308 test with a Constant Voltage Power Supply adjusted to 8.55V 
MS5308 test with a Constant Voltage Power Supply adjusted to 8.55V


MS5308 test with 7x NiMh inboard batteries (max 10v, min 8.55v)
MS5308 test with 7x NiMh inboard batteries (max 10v, min 8.55v)


Batteries being used, 7x BTONE AA 2500mAh (min 2300mAh) similar to Sanyo Eneloop XX, and one dummy battery to allow 7 batteries to work in an 8 battery holder.
 
Components under test:
.0025 Ohm test standard resistor;
1mH to 5mH variable inductor;
10 Ohm 1% resistor;
1k Ohm resistor;
1.2uF to 40pF decade capacitor
10 Mohm resistor;
3900pF mica capacitor;
1000uF electrolytic capacitor;
.1uF film capacitor;
.05uF ceramic capacitor;
.001uF polystyrene film capacitor.

update 3/6/13

(Maybe someone can report how well 1.5v alkalines x 7 works, ~10.5 volts down to 8.5 volts?)

Removed the batteries to drain some capacity, 2.5A for 30 minutes on a load, reinserted the batteries  at 8.70V to continue testing.

Completed the MS5308 test with 7x NiMh inboard batteries to shutdown at ~ 8.50v

MS5308 test with 7x NiMh inboard batteries to shutdown at ~ 8.50v)


Charging the cells: the smart charger determines how many cells are being charged, determines the charge current and terminates the charging when complete.  Charged to 10.19v taking 4hr53m (had set the max to .5A but the charger decided not to go higher than .43A), next day the cells settled to 9.80v or 1.40v/cell.

The smart charger even charges wood   ;D (a drilled through the center dowel with copper ends and a wire joining both and soldered, completes the circuit for the 8 battery holder).

update 3/27/13
(Maybe someone can report how well 1.5v alkalines x 7 works, ~10.5 volts down to 8.5 volts?)

Tested that.

8x Alkaline cells ends up @12.993V
7x Alkaline cells plus a dummy cell ends up @ 11.370V

Running with 7 cells, the meter worked as expected
I didn't try the meter with 8 alkaline cells @12.993V.

The dummy cell with either 7 alkaline cells or 7 NiMH cells is the way I will run the meter by battery power.
From a regulated power supply, the voltage will be adjusted 9V.
« Last Edit: March 28, 2013, 11:38:54 AM by staxquad »
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