[SI-LIST] : DC isolation between CATV/HDTV equipment? XFM or Cap?

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From: Jason Xiao (jxiao@riverdelta.com)
Date: Wed Nov 01 2000 - 06:36:39 PST

How does CATV/HDTV headend equipment provide DC isolation from others?

Isolation Transformer usually does not have enough bandwidth
(from 50MHz to 900MHz).
DC blocking cap does not provide enough isolation (1.5kV?).

I am also trying to separate our Chasis ground (most analog/RF ground
tied to it) from others (connected to us through long 75 ohm coaxial copper
But RF noise from others will see no ground (behave as an antenna to
So, I end up to need a cap to tie the grounds?

Mini-circuits TC1.5 or TT1.5 (75 ohm to 50 ohm)to provide DC
isolation instead of DC blocking cap. I could not find any Isolation
XFM to cover my higher end frequency range (upto 900MHz).

I am a microwave/RF circuit designer with very little signal-integrity
I just found this group yesterday. It's very helpful one.
Any comment and experience will be highly appreciated.

Jason Xiao

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