[volt-nuts] Fluke 5200A repair.

[Kgoodhew]

Hi Gerd,
 C8 is on the drain of Q38 the Fet just near the input to the A7 amplifier,
according to Charles it is switched in parallel with C1 on the source of Q38
to vary the integration time.
Using the cro on dc to look at the output I get 15mv dc on the output and I
cannot vary it by R6.
Will do some further checking today.
Ken.





Message: 5
Date: Fri, 11 Jul 2014 12:38:05 +1000
From: Gerd <admin at controlelectronics.com.au>
To: Discussion of precise voltage measurement <volt-nuts at febo.com>
Subject: [volt-nuts]  fluke 5200a repair
Message-ID: <53BF4E0D.9030808 at controlelectronics.com.au>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Hello Ken,

Which board are you looking at? On the amplifier board (A7) C24 is the 
input cap. Where is C8?
Don't rely on the multimeter to filter out the AC on the DC ranges, it's 
best to use a CRO. How is the signal coming into the amplifier from the 
oscillator? If the input to the amplifier is disconnected, is the offset 
still there?



---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com