Monday, 20 June 2011

ZS6U Mini Shack Special Vs EFHWA

With me doing research on the End Fed Half Wave Antenna or EFHWA antenna it dawned upon me that this idea is not new at all.
The link below is to a rather poor copy of a reprinted scanned article that Colin Dickman ZS6U wrote for Radio ZS in January 1973 on a antenna he refered to as the "Mini Shack Special"
I am not suggesting that Colin was the original designer of this antenna, but due to the articles he wrote on this antenna, the “ZS6U - The Mini Shack Special” The antenna becane very popular in the 70’s and was used by many South African operators.
I am sure we all will agree that this antenna is the same  as what has now become known as the End Fed Half Wave (EFWHA) antenna.
The included graphs make it clear why the ½ wave lengths (or multiples thereof) of wire is used. It was never meant to be a random length wire antenna.
Does anyone have a better or clearer copy of the above article? I would also like to get a good copy of the original article. The one I have is of very poor quality.
An article titled "The ZS6U Mini Shack Special" was published in the April 1981 edition of QST magazine.


Useful references to EFHWA antennas:
http://www.qrpproject.de/Media/pdf/MultibandfuchsEnglish.pdf

1 comment:

  1. Thank you Pierre. I have studied the principals, build one, and use one for more that 55 continents now.

    It is a great wire antenna for sure!

    This ZS6US EFHWA has very unique propagation characteristics. The more you study this principal, you realise Collin Dickman had something great with his EFHWA. Note: The radiation take off angle, the efficiency, as in low losses, the capacitance and reactance velocity Vs radiant efficiency, The very low take off angle super for Dx, and a low level noise on Rx. I have build many DIY antennas, there is fewer if any other that can provide so much for so little. Excellent multiband antenna, for the cost effective and space limited HAM.
    There are two versions, the smaller and the original full size, including the diagram for the impedance match design.

    DeA25SL

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