[time-nuts] SMD TADD-1 distribution amplifier - seeking comments and suggestions?

Chris Caudle chris at chriscaudle.org
Fri Dec 18 10:45:17 EST 2015


On Fri, December 18, 2015 3:38 am, Poul-Henning Kamp wrote:
> A significant reason for the TADD-1 existing in the first place was to
> break groundloops.  This is incompatible with tying all the BNC's
> together.

Assuming you mean power line frequency currents flowing between equipment,
the way telecom equipment vendors solved that problem was BNC connectors
which have the shells connected to the chassis contact through low
inductance capacitor structures, so that the BNC shell was connected to
chassis at RF frequencies, but isolated by a relatively large impedance at
low multiples of 50 Hz or 60 Hz.
Even in that case it is better to have the connectors on the same side so
that the high frequency shield currents are not forced across the PCB.

-- 
Chris Caudle





More information about the time-nuts mailing list