Need receiving loop advice

[AF9J]

Hi Everybody.

As many of you know, I have the powerline noise situation from hell (nothing quite like having 2 dozen powerlines [half of which are 125 kV or more], less than a block from you).  I also have two AM broadcast stations (with 4 antennas each) less than a mile from me, that give me breakthrough problems on 75m ( I SO love listening to the all-sports station, on 3725 Kc - NOT!!), on my SX-96.  A kludged together 2 turn loop around one of the walls helped a bit with my powerline noise.  But, when my best friend decided to pay a visit this weekend, I ended up taking it down, so she wouldn't look at me like I was crazy.

So, now it's time to replace my receiving antenna.  I'm wondering, should I go back to another loop?  If so, what size, and how many turns would be optimal (remember, I live in an apartment, so I can't do a half or full wave (single turn) loop.   I assume, I'd need a matching network - L or T, balanced or unbalanced?  I'm thinking mainly for 160, 75, and 40m.  Thanks for any input.

73,
Ellen - AF9J

[Pete, WA2CWA]

Here's one for 75:
http://www.seed-solutions.com/gregordy/Amateur%20Radio/Experimentation/3805er.htm

One for 160:
http://www.ok1rr.com/view.php?cisloclanku=2004122907

One might be able to scale these down and attach it to the back side of a closet door. No visitors, adjust door for best reception. Visitors, close the door. Doesn't work well on sliding doors.

Google "receiving loops" brings up lots of info.

[KE2EE]

Ellen - not the same topic but may help- Did you ever turn the powerline noise problem into your local power company ?
I work for one in the northeast and one of our jobs is to locate and help stop RFI power issues. We do use direction finding equipment (am receivers with yagis)  along with an ultrasonic dish to locate sparking on a pole. A lot of times the problem even in your area can be a lower power 13kv line close to your apt. But higher power lines do present a problem with corona leakage, ect. Give it a try and turn it in.
Mike   

[w5omr]

You might be suffering from fundamental front-end overload, Ellen, but something worth checking out is all of the antenna connections, and the wire itself.

Many has been the time when a solder joint on my dipole, or at the feed-point has gone cold due to weather exposure.  Usually when that happens, I start hearing broadcast station interference.  Any *minimal* loose connection can cause the rectification of aforementioned signals, causing them to get into places where the simply do not belong. 

And when I say "any", I mean "ANY" loose connection.  I need to get a brillo pad, or some silver oxide remover and work on my 'impedance matching device' (common misnomer is 'antenna tuner' - to me, a tuner is the person who physically 'tunes' the antenna).  The Roller Inductor on the Heathkit SA-2060 has a 'dark' spot in/around the area of 75/80m where I've rolled the thing around with the juice cranked up.  If the roller isn't making good contact with the inductor, I'll hear BCI.  Just FYI. 

From my experience, MAKE DAMN SURE that all solder connections are shiny, appropriate heat was used to heat up both sides of the joint, and the connection wasn't moved, while the joint was cooling off.   

Also, from my experience, twisting wires together is 'ok' for testing... if it's gonna be more than a couple of days out in the elements, SOLDER IT!  Make sure the physical connection is 'good-n-tight', first... then apply heat till the solder melts throughout the joint.

[w5omr]

But, when my best friend decided to pay a visit this weekend, I ended up taking it down, so she wouldn't look at me like I was crazy.

If she's that good of a friend, then she knows you, and don't give a rat's patootie about no steenkin' antenna.  Besides, who's life are you living, anyway?  Your's, or the life the world -wants- you to live?  (hint: to hell with what people think *I* should be doing!)

So, now it's time to replace my receiving antenna.  I'm wondering, should I go back to another loop? 

Tony/W5OD built a multi-turn receiving loop that was somewhere around 5' in diameter, and directional, somewhat.
I'm looking to see if I still have the website on that thing...