[TowerTalk] Fw: 2 el yagi question

[Ron W8RJL]

Subject: Re: [TowerTalk] 2 el yagi question


Tom If you put a director in front of a dipole you have constructed a two 
element Yagi antenna. Assuming you use the proper spacing (0.1 to 0.15
wavelengths) between the dipole (now called the driven element) and the 
director (which is about 5% shorter than the dipole) and you match the
antenna to the coax (gamma match maybe) the gain will be about 5 dB greater 
than a dipole. A signal off the back of the antenna would be down about 10
dB compared to a dipole. Remember that an S Unit is equal to 6 dB. If you 
are interested in Yagi antennas there are many good sources but a good older
book is the "Beam Antenna Handbook" written by William I. Orr, W6SAI (now 
SK) and Stuart D. Cowan, W2LX. You can also read up on Yagi antennas and 
many others in the ARRL Antenna Handbook. You might also want to search on 
Google for "Wire Yagi Antennas". If you are thnking about a Field Day
 antenna you might look at this 
link.[http://www.qsl.net/ve3rgw/field98/beam.html] 73 and good luck. Ron 
W8RJL

> ----- Original Message ----- 
> From: "Tom Osborne" <w7why at frontier.com>
> To: "Towertalk" <towertalk at contesting.com>
> Sent: Thursday, May 17, 2012 7:42 PM
> Subject: [TowerTalk] 2 el yagi question
>
>
>> OK, this may be a dumb question, but I've been wondering.
>>
>> Say I put up a dipole going E and W, and there's an S-9 signal on the 
>> dipole coming from the South.
>>
>> If I put a director in front of the dipole, will the signal still be S-9 
>> on the dipole?
>>
>> Just wonderin'.  73
>> Tom W7WHY
>>
>>
>>
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>