True RMS DMM

A timely thread. I am looking for a 2nd meter to use alongside my Fluke 89 IV. Looking at the Brymen 869 and 789, etc, but these are both $180 - $220+ vs. the Uni-T UT-61e which would be ~$70. Do I really need to spend the money on the Brymen? The only real reason I could use a 2nd meter is for one that does 600V. My bench HP3268 is limited to 300V and I am getting ready to test an electrostat amp with +/-400V supplies that I built.
 
Thanks for the link ctrix. Based on that, I'm now leaning towards the EEVBlog BM786. The BM869 sounds like it is rather large physically, and with the Fluke 89 IV, I don't feel like I need additional capability.
 
Hi,

@#24: the difference between Brymen 869 and 869S is not date but accessoires. The 869S comes with a nice pouch and a set of better probes with softer silicon wiring. The probes alone justify the little up in pricing.
@#25: yes, the 869 as well as the 867 are quite big, very similar in size to Flukes 287/289. The shape of the Brymen is more hand-friendly though.
Everybody seems to discuss only the 869 ... I chose the 867, since the differences between those two were not worth the considerable price difference imho.
Today I'd probabely settle for the 786 with its slightly smaller casing but almost identical set of specs.

jauu
Calvin
 
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I found true RMS measurement to be beneficial measuring the carrier level of 19/20 kHz IMD signals. IIRC the average-responding measurements of AudioTester and the HP400, both averaging, and ARTA and the Fluke 8050 which are RMS, were about 2 dB different. The correct power sum 19/20 at 1:1 should be 3 dB. ARTA and the Fluke both got it right; Audiotester and the HP agreed with each other but showed error due to averaging response.
 
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So, I've been using the 869s for 2-3 weeks now and so far I like it. However, the "beep" sound is so bloody loud that goes straight into my nerves. Does anyone knows if it's possible to adjust the level.

I realise that it can be useful for outdoors loud environments but for a lab environment it's ridiculously loud.
 
A timely thread. I am looking for a 2nd meter to use alongside my Fluke 89 IV. Looking at the Brymen 869 and 789, etc, but these are both $180 - $220+ vs. the Uni-T UT-61e which would be ~$70. Do I really need to spend the money on the Brymen? The only real reason I could use a 2nd meter is for one that does 600V. My bench HP3268 is limited to 300V and I am getting ready to test an electrostat amp with +/-400V supplies that I built.
In a pinch, you can build a 10:1 attenuator with metal film resistors (don't use carbon comp which are non-linear at high voltages)
 
So, I've been using the 869s for 2-3 weeks now and so far I like it. However, the "beep" sound is so bloody loud that goes straight into my nerves. Does anyone knows if it's possible to adjust the level.

I realise that it can be useful for outdoors loud environments but for a lab environment it's ridiculously loud.
You can stop it:

Set Beeper Off
Press the RANGE button while turning the meter on to temporarily disable the Beeper feature. Turn the rotary switch OFF and then back on to resume.

To drop its level it would take to hack a trace and put a resistor in series to it I am afraid
 
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