[Elecraft] K3S K3EXREF 10MHz Voltage Help

[MaverickNH]

The manual says:
http://www.elecraft.com/manual/E740156%20K3EXREF%20Installation%20and%20Operation%20Manual%20Rev%20A2.pdf
Connect the external 10 MHz signal source to the K3 rear panel REF connector
. The 10 MHz source should have a signal levelbetween +4 dBm and +16 dBm,
nominal
. For square wave sources, 2VDC to 3.3VDC peak is optimum. If the source is
a 5V logic level, use a 50-ohm resistor in series with the input. 
Caution: To avoid damage to the K3EXREF, do not exceed these levels

My Jackson Labs LC-XO-Plus manual says:
http://www.jackson-labs.com/assets/uploads/main/LC_XO-PLUS-specsheet1.pdf
Oscillator Specification: Frequency Output 10MHz CMOS 5Vpp

So I'm concluding the need for a 50ohm resister in series with the input.

The K3EXREF board will come pre-installed with my new K3S, so I'd prefer an
exterior solution. Is there a tidy little SMA connector with 50ohm in series
that I can get off the shelf? Or would I have to make that? If so, how to
best do that? I can certainly chop a SMA(M)-SMA(M) jumper in half and solder
a 50ohm resister across the center wire, but I'm not sure how to maintain
the shielding ground web. Twist each side and solder, sure, but seems I lose
shielding of a delicate signal.

Thanks for the help!

BRET/KC1CJN







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