[Elecraft] Question About the CP-1 Coupler

[Ron D'Eau Claire]

With a high impedance input to the scope, yes. Some scopes offer a 50-ohm
termination at the scope as well. If you use that, you must not use the 50
ohm termination at the CP1. Be careful though. Many built-in terminations in
equipment like an oscilloscope has a very limited power handling capability.
My scope limits the input voltage to 5V RMS when using its internal 50 ohm
termination. 

I use my 10:1 isolation probes with the scope so the CP1's 50 ohm
termination is perfect. Actually, I'd have preferred they provide a test
point for such probes, but hooking them to the "hot" end of the 50 ohm
termination resistor on the CP1 board words too...

Ron AC7AC

-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Paul T. Rubin
Sent: Monday, October 02, 2006 4:45 PM
To: elecraft at mailman.qth.net
Subject: [Elecraft] Question About the CP-1 Coupler


Hi All:

 

I am not sure I understand the procedure for terminating the sampling ports.
If a port is unused it says to terminate it into the internal 50 ohm load to
maintain balance. This makes sense. But if I connect a port (or ports)
through a short piece of 50 ohm coax to a scope which has a high impedance
input, is this port properly terminated?

 

Thanks,

Paul N8NOV

Houston