[Antennas] RE: 6M beam

Thu Nov 23 07:56:44 EST 2006

Carlos,
In most cased the advantage of buying over building is that usually they are 
already optimized, however it is for the taper and diameter of the elements. 
If you build it you have the option of using lager diameter elements which 
will give you better FB ,forward gain, and bandwidth without the normal loss 
of afore mentioned F/B and gain. 

In my case I have never bought a 6M beam, always built them. Started with a 
3 element based around the Cushcraft 3 element then went to a 4 element 
based solely on my own measurements. I used 5/8th inch diameter tubing and NO 
taper and spaced it at .25 wavelength. This gave me a much improved F/B and 
Better overall forward gain over a 4 element with smaller diameter tubing. The 
next project is a 6 element quagi to see how it works out. 4 elements will 
be quads and the last, er 1st, 2 will be horizontal directors. All of this is 
being made from scrap antennas and parts scrounged from hams throwing out 
stuff. Building one yourself will also give you a better understanding of how 
spacing, element diameter and matching techniques affect the performance of 
beam antennas. 
God Bless es 73
Sandor KG4FET 
In a message dated 11/22/2006 4:01:08 A.M. Eastern Standard Time, 
antennas-request at mailman.qth.net writes:
Hello all:
A good friend gave me a 6 meter transverter and I finally decided to get 
into the Magic Band action. 
Hoping to build a 4 or 5 element beam I began my search in the ARRL Antenna 
Book; on page 18-18, I found what seems to be a good choice for starters. 
Labeled 506-12 on the book, the antenna has a twelve feet boom, 5 elements, 
optimized for the 50 Mhz to 51 Mhz band section with a claimed gain of 10dbi, 
22db F/B ratio and an SWR of 1.6:1 or better. A quick check on aluminum prices 
turned me around and away from the building scheme. 
Another option, is to buy a ready made antenna that could cost less than the 
materials for the 506-12 on the ARRL Antenna book. Enter the HyGain VB-64DX 
for 144ドル. this antenna seems to be a good buy compared with the price for 
building the 506-12, however, the big word missing is "optimized". What am I 
missing here besides one director? Can I "optimize" the HyGain beam adding 
the extra element and changing the spacings following the Antenna Book 
schedule? Or should I settle for the HyGain as it comes? Are there any other 
choices in the price class?
Any thoughts would be greatly appreciated.
Carlos / KP4GL