Topband: My beverage only hears static?
k7tjr at msn.com
Sat Jan 13 14:50:34 EST 2018
I may not have seen all of the posts on this topic but will comment anyway.
Two things come to mind about this noise. Number one is you do not want to connect the shield of the coax going to the receiver to the ground stake for the antenna. It's important that the transformer you use has an isolated winding for the output to the cable leading to the shack. The other comment is you may have some local arcing or digital noise that the Tx antenna does not hear. The best clue to checking for this is to use the AM mode on your receiver and listen for the characteristic hum from a power line or switching supply.
Lee K7TJR OR
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of terry burge
Sent: Saturday, January 13, 2018 11:09 AM
To: David Olean <K1WHS at metrocast.net>; topband at contesting.com
Subject: Re: Topband: Topband Digest, Vol 181, Issue 16
Hello Dave and Group,
I had responded directly to Martin and will include my comments to him. Right now I hesitate to pull the tape off the coax at the XFRM but will do that ASAP to check it out. When I took it off the old spool it had not been used but it is donated to me from a junk yard lot. I also got a 4 foot spool nearly full of 1/2" hardline I'm planning on replacing my ground run of LMR-400 with. 75 ohm but it should work if I can build the connections to the LMR-400 PL-259's, etc.
Disconnecting the ground as well as the BOG (in this case) from the XFRM causes the noise to drop down to about S-1 to S-2.
With ground connected to the XFRM I get about S-5 noise level without any antenna.
Per my note to Martin you can read my other test. Right now with the 550-600 ft. beverage hooked up along with ground of course, I get S-5 noise level and can't hear an S-9+10 over signal on 7.235 Mhz.
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