[Antennas] Fw: several driven verticals, >1/10 lamda apart

[Henry Mei'l's]

----- Original Message ----- 

To: meils at get2net.dk 
Sent: Tuesday, July 27, 2010 5:38 PM
Subject: Fw: several driven verticals, >1/10 lamda apart 



----- Original Message ----- 
From: Henry Mei'l's 
Sent: Tuesday, July 27, 2010 4:24 PM
Subject: several driven verticals, >1/10 lamda apart 


I read that experiments were made using several verticals at Fort Monmouth driven together, and spaced apart more than 1/10 wavelength. This was supposed to increase radiating efficiency dramatically, due to reduction of ground losses.
Very promising results n the 80m meter band were supposed to have been achieved - not sure by whom.
Pat Hawker,G3VA, wrote  that the idea was suggested as far back as 1920. These arrrays were not intended to be directional, as far as I understand.

I did a few crude experiments myself, using several whips mounted on a balcony rail (20, 15 & 10 meter bands), back in the mid 70's, but didn't have the means to make precise comparative signal strength measurements.  (A balcony on the 8th floor - not near physical ground level !)
All I could deduce with certainty was that it didn't worsen my sent and received signals and it seemed that I was getting slightly better reports.
(Have never tried this on the lower bands or any bands using close spaced (but >1/10 lamda) at ground level verticals.)

The actual item can be read in Pat Hawker's Amateur Radio Techniques  (5th ed., 1974), page 262, "Reducing Ground Losses with Verticals." Hawker refers to an article in IEEE Trans. on Antennas and Propagation; Vol. AP-21, No. 6, Nov, 1973  pp. 769-73.

(I found the article referenced on the internet and the article is available to IEEE download subscibers.)


Anyone with experience in this direction? Anyone have access to the IEEE articl? (would be nice to see a PDF scan).

73
Henry OZ1uF, Cph.