[CQ] Greetings from KJ6ANT

Mark Cohen markc at binaryfaith.com
Wed Oct 28 06:00:35 UTC 2009



Hey Art,

Great seeing this on the CQ list..

I think you bring up a great point, here in the city we're space  
restricted and often legally restricted (condo rules) from putting up  
decent antennas. Often we have to compromise.

The PAC-12 is a great portable antenna, I know James Bennett the maker  
of this antenna. He's been known to show up to QRP meetings in  
Livermore and at Pacificon. He's also local and might be fun to have  
show up at our space sometime.

I've used the PAC-12 with great results. A friend of mine brought his  
over in July for Field Day where we worked about 50 stations on that  
antenna. We also used a BuddyPole that I own with good results. (If  
you haven't seen the buddypole, check them out. They are very  
expensive, but well engineered.

The trick to getting the PAC-12 working is setting up a network of  
wires on the ground to act as the groundplane. I found that getting  
ribbon cable in 20ft lengths works REALLY well for this. You can split  
off 3 or 4 wires from one end in multiple bunches or groups.. This way  
you have one solder point and lots of wire spread out in a fan around  
the antenna.

Another great antenna system is the Superantenna by W6MMA. He's got  
lots of decent designs as well as yagis. They are also not cheap, but  
are VERY efficient. A friend worked a bunch of EU stations on 5W  
recently from SLAC (We have a monthly gathering there called AmTech  
day, check it out.. Its great fun!)

As for your Wire Frame Antenna, I would actually stay away from those  
unless you need a listening antenna. *yes, you can tune them, but they  
are very limited* As I'm sure you're aware, we're experiencing one of  
the quietest solar cycles to date, this means that propagation  
currently sucks. (http://www.spaceweather.com and n0nbh.com (http://members.cox.net/n0nbh/ 
) are good sites for spaceweather info) So, the important thing to  
keep in mind is that you want something high up in the air (1/4 w of  
your working freq, so a 20m antenna should be 15ft up from the ground,  
a 160m wireframe would have to be atleast 131ft high)

Chances are, you are going to want to experiment with different  
designs, I wouldn't worry too much about getting permanent antennas in  
the air, unless you live in a place where you can put up a tower. (If  
you can raise a tower in the city, I would be the first to visit your  
shack! :) ) Try out a 35ft mast with a 10g piece of wire and a random  
wire tuner, you would be surprised how well those can do.

I just recently built a slinky antenna with a 1:1 balun and 4  
slinkies. (2 on each side, soldered together) and put it up on a  
tripod at 15 feet... It performed pretty well! The total build was  
about $30

Well, I hope this gives you some good info, I'm looking forward to a  
meetup soon!

Regards,

Mark (K6EF)



On Oct 27, 2009, at 10:10 PM, Art Peel wrote:

> I'm recently upgraded to General and am still working on getting on
> the air on HF.  I'll be trying out a newly-built PAC-12 portable
> antenna (for car portable operations) soon and will also be building
> something along the lines of this project: http://web.telia.com/~u85920178/antennas/frameant.htm
>  for home use.  Small loop antennas seem like a good way to go for
> folks like me living in apartments in the city.
>
> A meetup sounds like a great idea.   We could bring in gear, discuss
> possible nets as well as projects.
>
> Art
>
> _______________________________________________
> CQ mailing list
> CQ at lists.noisebridge.net
> https://www.noisebridge.net/mailman/listinfo/cq

Mark Cohen
markc at binaryfaith.com

Science is a way of skeptically interrogating the universe with a fine  
understanding of human fallibility.
-Carl Sagan, 1996




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