[TowerTalk] Rain Gutter Antenna

[Jim Brown]

On 11/28/2017 3:31 PM, Mike Ricketts wrote:
> 2. I've also seen a configuration where the coax shield was then connected
> to a radial field (I do not have one available), so this is not the likely
> scenarion.

End fed antennas generally need some form of counterpoise to transmit 
well. If you don't give them one, they'll use whatever they see, like 
the shield of the coax and whatever it's connected to.

> Both of these configurations have been done connected to the end of a
> downspout, so the antenna is basically end fed.
>
> I have 2 downspouts that come down together, but then go different
> directions, providing me with an extra 50' or so of gutter.
>
> 3. Would it be better to connect the coax shield to the other downspout and
> try to go with an OCF type of situation, since one gutter side has about
> 50% more length to it?
Probably not -- what you would end up with is a low dipole, which also 
would not radiate very well.

I have a friend near Chicago who has loaded the HVAC ducts in his wood 
frame house on 160M. I've worked him from my QTH near San Francisco. Not 
very different from what you're thinking about. Don't know what he uses 
as a counterpoise.

Some important concerns with either of these improvised antennas: 1) 
lots of RF close to the shack and to electronics in the home to cause 
RFI; 2) if you use it on receive, you'll hear lots of RFI from noise 
sources in your home (and probably from your neighbors as well; 3) 
there's a good chance that poor connections within the downspout will 
rectify both your signal and received signals, creating intermod 
interference. On receive, #3 would typically show up in the form of 
interference from AM broadcast stations.

73, Jim K9YC