[time-nuts] Fluke 203A Distribution Amp available

[Dan Rae]

On 4/12/2011 4:27 PM, Dave M wrote:
>> From: Dan Rae <danrae at verizon.net>
>>
>> I have a nice Fluke 203A , modified from one 5 MHz in and 12 out to
>> one 10 MHz in and 12 outputs for sale.
>>
>> This is a 2U rack unit similar in function to the -hp- 5087A with
>> metering etc., with a printed copy of the pdf manual.
>>
>> Please contact me direct if interested with any offers before this
>> goes to ebay.
>>
>> Dan
>
>> ------------------------------
>
> Dan,
> I have a good Fluke 203A and manual also, but it's a standard unit, 
> only having standard 1MHz and 5MHz input and output modules.  Are the 
> 10MHz modules from Fluke or did you make the mods?  If the 10MHz mods 
> have been documented, amd it's possible for you, could you  scan and 
> post the applicable pages for those modules?


Dave,

I don't think Fluke ever made any 10 MHz modules, from the manual 
anyway.  I kept all the inductors as is; in the pre-amp, changed the 
tuning Cs C1 and C2 from 1000 pF to 220 pF.
In the output amp change:
C1 and C2 to 220 pF
C3 to 68 pF
C5 and C8 to 22pF

I also put a 2k2 resistor across T2 in the output amps.

The modified modules peak up nicely like that with the cores not far off 
where they were before.  Ive had it going for about five years and just 
rechecked it, it seems pretty reliable :^)

Dan