[TowerTalk] The Care and feeding of an 80 meter Zepp

[Justin Burket]

Hello towertalk,

After experimenting with various random wires strung around the 
apartment and attempting to gain reception off the rain gutter I gave 
up and begged my landlord to allow me to use my apartment window and a 
tree about 150 ft away for an antenna.  He agreed as long as I didn't 
break anything.  After doing a bit of reading I found that a dipole 
would have a serious problem with this arrangement.  My transmission 
line would be parallel to one of the ends of the dipole as it reentered 
my apartment.  From what I understand regarding dipoles this is a nono.

I settled on an end fed cut for 80 meters.  At first I fed it with 50 
ohm coax with the center conductor tied to the end of the antenna and 
the braid connected to a handy radiator pipe.  Keep in mind at this 
point that I'm not transmitting, simply receiving so nothing is really 
going out over the air over this antenna.  Eventually though I 
discovered a large amount of noise coming across this antenna.  Because 
the last foot of the antenna was intimately involved with the window 
frame I assumed that was part of the problem.  So I attached an 
insulator to the end and let it hang about 4 ft out past the apartments 
overhang.  When I did this I had to switch feed-lines to 300 ohm TV 
line because of umm..budget problems relating to my college tuition and 
lack of sufficient coax.

The result is my current configuration.  One end of the Zepp is 
connected to an insulator hanging about 2 stories above the ground and 
the other end is slopping downhill a bit as it heads over to the local 
handy dandy tree.   I feed this arraignment with 300 ohm TV line over 
to my rig where it turns into 50 ohm coax and heads into the tuner.

Because of my location downtown I'm experiencing a ton of noise with 
this setup.  Most frequencies I listen on have some sort of buzzing and 
a few are downright unusable.  Would a different feed-line arraignment 
or balun alleviate some of this noise?  Should I ground the other side 
of the feed-line to the radiator pipe in the bedroom?

I'm also worried about the time when I start operating on the air.  
Would an antenna setup similar to this result in large amounts of TVI 
to my neighbors?  I'm afraid I'm already known in the complex as "that 
weird electronics guy" so I can just imagine the mad pitchfork trample 
to my door once I get on the air with any level of power.

Because the graph paper was out doing some math homework I drew up a 
quick drawing of my "situation".  It can be viewed over at 
http://zorton.org/radio-nut/qth.jpg if so inclined.

Thanks and 73,
Justin KL1RL
Fairbanks AK