The Barker and Williamson Company has a long and rich ham radio heritage but their advertisement concerning their T2FD antenna is very misleading. But it does prove one thing, and that is hams will do anything to keep their CB SWRs down and will buy anything that promises to rid them of this plague. It proves that hams will not purchase an antenna handbook and spend three minutes looking at a loss graph and try to analyze what an SWR = 5:1 on 80 meters will do to them and the over all effect it will have on their antenna system.
Basically the antenna is a folder dipole with very large power resistor hanging in the center consuming power. To make things worse it is fed with a voltage transformer type balum. Why hams put a lossy voltage balum in their antenna system is a mystery, perhaps it helps them with providing a place to tie the two wires of the antenna, I mean why not just use a insulator. Notice that I am talking about a voltage balum not a current balum, if you don't know the difference between the two types of balums then at the next Ham-Fest purchase a Antenna Handbook instead of that goo that you put around your PL-259s
Does the T2FD antenna radiate a signal? Yes it does and so does my 100 watt light bulb when I used it for a dummy load, but what is the efficiency and what is the comparison to just a normal doublet? That is the purpose of this page.
I have included an old column of "Aerials' published in World Radio. World Radio is the only Amateur Magazine that has a regular antenna column and the only ham magazine that is not afraid to publish the truth about commercial antenna products. Instead of spending $ for that lossy balum at the next hamfest try subscribing to World Radio and learn something about "Aerials". I mean for $14.79 how can you go wrong you spend that much on hamfest burgers and potato chips.
Unfortuonealy the magazine is not longer published. (March 2016)
The column in WORLDRADIO "AERIALS"
by Kurt N. Sterba is show below:
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The B&W site is:
http://www.bwantennas.com/
Its very hard to believe that
B&W would publish this
statement.
Believe it or not there are still chicken banders out there on 75 meters that believe that the power that is not sucked up by their antenna is gonna back up on em and sneak down the coax into their rigs,remain there and eat the finals. How this myth got started I have no idea, its a CB thing that has permeated the ham bands and it is one of most popular topics of conversation by the CB groups on 75. other than food of course. (see notes below)
The book by Walt Maxwell was carried by the ARRL, title number REF2 and theprice is $19.95 but is not longer carried. If you want to learn something about antennas and be able to cancel your High SWR theary sessions then read this book. Its a little mathy but you can skip those chapters.
Notes: The number one conservation topic on the ham bands is food according to a recent Gallop Pole. The subject received an overall rating of 87 percentile out of a possible 100 points. The next most popular topic was: "the high SWRs is eaten up da finals of my rigs", this topic recieved 9 points. The most popular phrase used in the first five minutes was "how u do en". I am using the term "converstation" in the broadest context to try describe some of the CB exchamge on 75 meters.