I have a Drake SW8. Other than this I've never had any problems with this
receiver. With the whip selected or the external (with the antenna plugged
in) selected, I get an annoying pulse noise (about every 1/2 second) over
the speaker. If I select the external antenna and the antenna is not
plugged in, there is no noise. Plug the antenna in and the pulses start.
It only happens on the shortwave bands. I've turned off the computer,
router, powerline ethernet connection, etc with no results. The only thing
I haven't secured is the cordless phones but they've never caused problems
before. Any thoughts would be appreciated. Thx.