[50mhz] antenna

[LANCE COLLISTER]

Lloyd C. Curry wrote:
> I am planning to replace my old Cushcraft 6 el yagi with a newer 
> antenna. I am leaning toward either the M2 6M7 or 6M7jhv. I like the 
> idea of the 6M7 because it is heavier but there is not much difference 
> in gain. Anyone have any other comments? Thanks Lloyd, NA4D
> 
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Hello Lloyd,

Most 6m operators only seem to get on during strong Es, F2 or TEP openings, when 
just about anything connected to the end of a piece of coax will do the job. 
However, since you are interested in upgrading your old antenna, you obviously are 
concerned with real performance under weak signal conditions :-)  In such 
situations, there is a HUGE difference between the old types of antennas and the 
newer, computer-optimized designs.

The M2 6M7JHV is a very well proven antenna, is lightweight, has very low wind 
loading and can be broken down to be a UPS-shippable and airline transportable 
package.  On 6m EME - where every dB counts - the 6M7JHV has earned the reputation 
as the antenna of choice for success on DXpeditions.

If you prefer to homebrew your own high-performance 6m yagi, I suggest you 
seriously consider duplicating one of the 7 or 8 element antennas designed by YU7EF:

http://www.yu7ef.com/

These antennas are no doubt heavier and less well suited to airline 
transportation, but are very well proven in the field to perform up to the very 
high performance shown on the website.  I have completed 6m EME contacts with a 
number of stations using these great designs.  In addition to the design 
information on his web page, there are dozens of construction photographs 
available that show how different people attached the elements to the booms, 
constructed the driven elements, etc.  Note that all the YU7EF antennas are 
designed to provide 50 ohm driven elements, so it is not necessary to build T 
matches, hairpin matches or folded dipoles...just connect the split dipole to 50 
ohm cable and provide a ferrite RF choke over the coax next to the driven element 
connection!  Simple and effective.

Most builders follow Pop's suggestion and insulate all the elements from the boom. 
  In case you don't have a handy plastics supply house just down the street, 
success has been had by simply cutting up a 1/2" thick HDPE cutting board to serve 
as element mounting blocks...such cutting boards are available in many hardware 
and grocery stores all over the world.  You simply can't go wrong with one of the 
YU7EF designs, and if you have any questions, Pop is always ready to help provide 
additional information for your particular situation.

And if one of your primary reasons for upgrading your antenna is to build a more 
rugged antenna, you certainly have that option with the YU7EF designs!  Note that 
Pop provides options for element diameters, so you can make the thing as heavy 
duty as is necessary...if you need the thing to be hurricane or ice-proof, he 
shows the dimensions for 3/4" diameter elements!

I hope to see you on Es with your new antenna in a few months!  GL and VY 73, Lance

-- 
Lance Collister, W7GJ (ex: WN3GPL, WA3GPL, WA1JXN, WA1JXN/C6A, ZF2OC/ZF8)
P.O. Box 73
Frenchtown, MT  59834  USA
QTH: DN27UB
TEL: (406) 626-5728   URL: http://www.bigskyspaces.com/w7gj
2m DXCC #11, 6m DXCC #815