If you have an antenna present the receiver noise level should
increase when you connect the coax. If there is no antenna there
should be no or much less increase in the noise level. This assumes
you are using good low leakage coax.

Ron, W4TQT

Don Baker wrote:
I would like to be able to determine if antenna is present at the end of a
piece of coax. In some case antennas of type ?? would have a DC resistance
across the coax and that makes it easy. But..., how would you easily
determine if a coax shows an infinite DC resistance (NO RETURN PATH) no
current flow - like simple did-poke.

Trying to spare the group all the details of what I am doing but I will
gladly answer any questions. Thank you in advance for your help.

Don