[time-nuts] FSCM 38243 Power Distribution Module

Charles Steinmetz csteinmetz at yandex.com
Sun Mar 2 19:53:57 EST 2014

>Thanks All for the information ! I'll try to contact "PG 
>Electronics" for the specifications.
>For now, I have no access to precision instruments to measure 
>certain parameters of that module. The whole idea is to have couple 
>of extra sine outputs from my Trimble T-bolt.

Just put 10MHz in from a 50 ohm source, terminate all outputs with 50 
ohms, and see what comes out.  You should lose just over 9dB (I would 
not expect to lose as much as 10dB if it is working properly at 
10MHz).  Your monitoring equipment could be as crude as an attenuator 
and a communications receiver .  If the loss is significantly more 
than 9dB, or the output is full of harmonics, then you know it isn't 
well suited for use as a 10MHz splitter.

If you make it that far OK, then feed your 10MHz to one of the 
outputs, terminate all of the other outputs and the input with 50 
ohms, and see what comes out the other outputs.  That will give you 
some idea of how much isolation it has.  Note that some outputs are 
"nearer" to each other on the division tree, so you will get a range 
of values for the isolation if you try all of the other outputs.

+13dBm (~1 Vrms) is a common distribution level.  To achieve that 
from a Tbolt, you would need an amplifier with ~9dB of gain that puts 
out ~+22dBm.  That will get you to the last thing you need to know -- 
whether or not it will handle that level.  From the photo I expect 
that it would, if it works properly at 10MHz to begin with.  The test 
would be to feed 10 MHz +22dBm at 50 ohms to the input with all 
outputs terminated in 50 ohms, and see if there are significant 
harmonics in the output.

Best regards,


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