[Test-Equipment] Source for 1% capacitors?

[jbarnes]

The TRW capacitor factory is now:

http://www.ascapacitor.com/

They made a lot of special capacitors that are found in Fluke HP etc. I have some designed by them when I worked for Varian. The ones I worked on have Part number VAR 19 and VAR 20. These were derived from catalog poducts.

The values you are looking for may be found in a decade capacitor box. Capacitor are typically in a 1,2,4,4 sequence to make each decade.

I suggest making each capacitors from a parallel combination.

for 0.02uF connect two 0.01 caps in parallel. For 0.04 parallel 0.018uF and 0.022uF.

The temperature coefficient is also important. 

I would start with the capacitor that you can find and change them to better ones if you can find them.


Regards,

John VE3XRY

---------- Original Message ----------------------------------
From: Barry <n4buq at knology.net>
Reply-To: n4buq at knology.net, Discussion of Electronic Test Equipment<test-equipment at mailman.qth.net>
Date:  Tue, 29 Mar 2011 07:24:39 -0400

>The originals have "TRW" and "GR-8" printed on them.  Given the very odd values for the 50Hz version, I assume they were GR specials.
>
>Thanks,
>Barry - N4BUQ
>
>
> On Mon 28/03/11 10:58 PM , "Dale H. Cook" radiotest at plymouthcolony.net sent:
>> At 07:41 PM 3/28/2011, Barry wrote:
>> 
>> >I have a GR-1617A capacitance bridge that has a
>> detector board >designed for 50Hz operation (the rest of the unit
>> has 60Hz >boards/modules).  I can convert the detector to 60Hz
>> by changing >three capacitors.  I need two 0.020uF 1% 100V and
>> one 0.040uF 1% 100V caps.>
>> >Anyone know where I could get these?  They are odd
>> values and not >readily available.
>> 
>> The manufacturer's code is for the Sprague factory in North Adams, 
>> but the manufacturer's part number looks like a GR special. You might 
>> be better off trying to find a 60 Hz detector board.
>> 
>> Have you looked at any of the usual suspects, such as Digikey?
>> 
>> Dale H. Cook, GR / HP Collector, Roanoke/Lynchburg, VA
>> http://plymouthcolony.net/starcity/radios/radtop.html 
>> ______________________________________________________________
 




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