Hi Parker I think it depends on the noise source. If it comes from one direction, a loop antenna can be rotated to place its null on the noise source, improving the signal to noise ratio for the signals coming from other directions.
On the other hand, if your noise is more pervasive, and turning the loop won't reduce it, the loop isn't going to do anything for you. You might as well stay with your main antenna. One thing you can try that helps sometimes is use an existing dipole for reception on 160m or 80. As horizontally polarized antennas, they will have a different noise pickup than the inv. L. Sometimes this can make a useful difference. All receiving loops I know of have less signal pickup than any full size antenna, such as your inv. L. Larger loops may get by without use of a preamp other than what is already in your receiver. However, the lower in frequency you go, the less signal pickup the loop will have and will probably benefit from a preamp. Homebrew preamps are easy to make, and an Altoids tin makes a great housing. I've built several that way, and they all do just what is needed. By all means, give a loop a try. They are easy to make and inexpensive. A great cheap experiment. If it seems to do a useful job, then by all means make a more permanent version. Good luck and 73 Bob N6WG ----- Original Message ----- From: "Parker Buckley" <[EMAIL PROTECTED]> To: <Elecraft@mailman.qth.net> Sent: Sunday, February 03, 2008 2:33 PM Subject: [Elecraft] Re: Receive Antennas > I was interested to read recent comments on 160M receive antennas. As it > happens, I just completed a coaxial loop antenna for my K2 this weekend, as > described by KN4LF and KC2TX, and combined it with their recommended preamp. > It's the antenna design that's been in the handbook for years. I've wanted > to try one of these for some time, thinking I might hear that rare DX that > everyone else seems to be working. So it's all tuned up and seems to work > well, but let me ask a basic question. If I already enjoy relatively quiet > conditions on 160, in spite of living in the city, will the loop ever hear > anything that my full-sized inverted L won't hear? The inverted L seems to > work well, as I've worked all over the US, including Hawaii, during > contests; all the while at 5 watts (I know, it's all about their beverage > and not my whopping signal, but still I'm pretty happy for QRP). My nominal > noise level on the L is 2 S units. I peaked up the K2 and measured receive > sensitivity, and I think it's doing all that it should. So is this loop > antenna just a fun project, or will this let me hear things so far down in > the noise that I would not other wise hear them? > > Parker WD8JOL K2 #2636 > > _______________________________________________ > Elecraft mailing list > Post to: Elecraft@mailman.qth.net > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
