[TowerTalk] 75 meter antenna

[David Jordan]

Jim,

I run a NVIS on 40m  2 full wave dipoles fed in phase just 15ft above 
the ground.   Within the first 50-75 miles the signals are extremely 
intense. My station is an Internet remote so I actually operate about 
50miles from the xmit antennas.  Typically, I pin the "S" meter from 50 
miles away.  The signals on 40m continue to be very strong up to about 
350-400 miles, then a dipole at 60ft begins to out perform the NVIS.  At 
around 350-450 miles the two antennas are about the same most of the 
time but when you get past 500 and well into 900-1000 the dipole at 60ft 
is about 20db stronger than the NVIS. So, the NVIS does do the job for 
closer in signals. The same would be true for 80m with the NVIS at about 
25-30ft above the ground.  The NVIS full wave elements are fed with 
homebrew 600ohm opern wire (in phase).  The two elements are spaced a 
half wave apart (on 40 that is about 70ft). The theoretical gain is 
about 7db with a main lob angle of about 80 degree (straight up for all 
intents and purposes) omin directional.

Another nice benefit of the NVIS is that it doesn't hear the foreign 
broadcast stations nearly as well as the dipole at 60ft. 

Your inverted V at 95ft would be great for DX but it's really too too 
high for short distance communications.

Having both a  NVIS and "V" at 95ft would be a lot of fun.

73,
dave
wa3gin

Jim Miller wrote:

>QST June 2002 Page 28 has an article for NVIS for 40 and 80.  Should be just
>what you are looking for.
>
>73, de Jim KG0KP
>
>----- Original Message ----- 
>From: "Joe Barnes" <n4jbk at bellsouth.net>
>To: <towertalk at contesting.com>
>Sent: Wednesday, April 06, 2005 8:33 PM
>Subject: [TowerTalk] 75 meter antenna
>
>
>  
>
>>can anyone recomend an antenna for 75 meters that would be optimized for
>>zero to about 400 miles? I am currently using an inverted vee with the
>>apex at about 95 feet. I have 2  towers here , one is 100 feet the other
>>is 125 feet, they are 100 feet apart.
>>Thanks , Joe N4JBK
>>_______________________________________________
>>
>>See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
>>    
>>
>Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
>questions and ask for Sherman, W2FLA.
>  
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>
>_______________________________________________
>
>See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.
>
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