[VHFcontesting] stacked yagi's

[Jon Casamajor]

Hi Paul,

I am a little confused on what you are doing I guess.   I have two M²
420-50-11 Yagis stacked vertically, that is one above the other.  I am using
a standard M² splitter and stacking harness and the distance between the
Yagis is 28” and the phasing lines are identical in length however I’m not
entirely sure of their length as they are living at about 100’ now.  J

 You said
 “(note that I might switch units without warning)”, so I may not
be seeing something here.  If both phasing lines are the same length
wouldn’t they be fed in phase?  My little stack is on my QRZ page in case
I’ve confused you in return.  The little stack works quite well but I’m
planning to replace it soon with a 4329WL as the stack is a little sharp and
I need a bit more ERP.

 

 

 73, Jon

 K6EL

-----Original Message-----



 

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Message: 2

Date: Sat, 10 Apr 2010 03:07:25 +0000 (UTC)

From: Paul Decker <kg7hf at comcast.net>

Subject: [VHFcontesting] stacked yagi's

To: vhfcontesting at contesting.com

Message-ID:

 
<1210296233.8429611270868845217.JavaMail.root at sz0009a.westchester.pa.mail.co
mcast.net>

          

Content-Type: text/plain; charset=utf-8

 

 

 

Hey group, 

 

 

 

I'm in the process of stacking two 11 element 70cm yagi's.? I've modeled it
in eznec and I think the optimum distance is about 42".? (note that I might
switch units without warning). 

 

 

 

Once I have the two 50 yagi's stacked, my model says I need to have one 180
out of phase, does this seem right? 

 

 

 

If that is the case, then I need different lengths of coax to feed each
antenna. 

 

 

 

Should I use a 50 ohm power divider and feed each antenna with 1.25w and
1.75w 50 coax, or should I feed with 1.25 and 1.75 75 Ohm coax and simply
use a T connecter.? Is there an advantage of one over the other? 

 

 

 

thanks for any help, 73, 

 

Paul (KG7HF) 

 

 

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End of VHFcontesting Digest, Vol 88, Issue 9

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