Call Search

New to Ham Radio?
My Profile

Friends Remembered
Survey Question

DX Cluster Spots

Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement

donate to eham
   Home   Help Search  
Pages: Prev 1 [2]   Go Down
Author Topic: Tarheel - Scorpion - Hi-Q Comparisons  (Read 14020 times)

Posts: 9930

« Reply #15 on: March 17, 2012, 07:22:15 PM »

An yes the ATAS is a crappy little antenna  that is marginal compared to these others.  But I use the ATAS on the car because it fits in the garage on the car and autotunes with my FT 857 while driving so no need to stop to re-tune the antenna while  running DX mobile.  mow on the truck (pickup truck) I have a 1.2g, a 2m /440, a 220mhz , and a 900 mhz  on nmo mounts through the roof and  a couple of 2m 440 antennas on the bed rails and also both a ATAS and a DK#.  I use the ATAS again with the ft 857 in the truck for most mobile work, same auto tune  while driving. And I have the dk3 for 80 m mobile and I even have a large  Knott ( BB3) coil to screw on between the DK 3 and the whip for 160 m mobile. Yes I have a rack  in the center front where the little seat used to be, and it has a 900 mhz spectra, a 220/2m icom, a straight 2m icom,  the ft 857 and  tribander ( ts 742??) with 2m 440 and 1.2 g on it.  That parks outside and  does not need to go in the garage. So the ATAS my not be  the best operating autotuned screwdriver ever built, but for an old disabled guy like me  who can barely walk and gets in and out of the car with difficulty, it is a very good antenna, and it mounts on a trunk lip mount and is an easy install to boot.  I'm just saying.......

Posts: 10248


« Reply #16 on: March 19, 2012, 03:45:42 PM »

Hummm. What do we define as high Q? Perhaps 100? Or maybe 150? Is that 250? The real truth is, the most popular, remotely-tuned, HF mobile antennas, just happen to have the lowest coil Qs! At this point in time, that's the ATAS, Lil Tarheel, and the Comet knockoff, and in that order of sales popularity. None of these antenna has a Q higher than 80, on any band!

While it is true that the difference in signal strength between a low Q antenna, and one with a much higher Q diminishes as we move higher in frequency, that's not all of the equation. Overall length, ground loss, and top loading (properly placed cap hat as an example) of the antenna; the position on the vehicle; the height of the vehicle above ground; the mounting method; and many, many more things; all effect what the field strength will be. It is so complex in nature, that simplistic answers are almost always wrong!

Let's dispel another myth. The body of a vehicle is essentially the ground plane, along with its coupling to the surface under said vehicle. While the body of the vehicle does indeed carry RF current much as a radial field does, the capacitive coupling of the body to the surface under it, limits the radiation to a rather small percentage.


Posts: 9930

« Reply #17 on: March 21, 2012, 10:53:21 AM »

One other nice thing about the Scorpion antenna is the credit he gives to Mr. Don Johnson o be around and the hobby will miss a real gentleman. SO  Thanks again Don for the nifty design on the DK-3 screwdriver antenna.
Pages: Prev 1 [2]   Go Up
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!