Depending on the degree of coupling, at VHF, the loss in 2, 8" cavities will be around 1.5 dB., send or receive. 10 LOG 25/42 comes to around 2.25 dB. A little on the high side. I don't understand where adding the remaining 2 elements to a 4 element antenna will change the loss.
Seems the repeater delivers 42 Watts. The Duplexer adds 2.25 db of loss. A 2 loop antenna will have around 3 dB of gain, and a 4 loop antenna should have around 6 dB. of gain. Adding the second 2 loops should help the send and receive by around 3 dB.
I am making the assumption that you are now using the top half of a 4 element antenna, and you plan to re-connect the bottom half?
Steve NU5D
On 5/30/06, KB6ZOP <[EMAIL PROTECTED]> wrote:
That seems like a LOT of loss... Have you had the cans and antenna(s)
tuned?
-----Original Message-----
From: Repeater-Builder@yahoogroups.com
[mailto:Repeater-Builder@yahoogroups.com] On Behalf Of atms169
Sent: Monday, May 29, 2006 9:46 AM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Double the gain or double the power?
Easy question for all other repeater owners. What should I do?
I have a pair of folded looped-dipole antenna's for my repeater which
pushes 42 Watts. Once I add the antenna and duplexers I get 25 Watts
output. The antenna has 4 looped-dipole antenna's with phasing
harness but I only use one set.
So what should I do, should I continue using the 1 set of
looped-dipole antenna's at 25 Watts or do I add the second pair of
looped-dipole antenna's and push only 10 Watts out on the repeater (As
there will be a loss).
Which would be better? I am sure I am doubling the gain for PEP.
Would I have a better receive on the antenna as well? Would it really
make it stronger?
Aaron
VA6AE
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