The only time where one a 0 is equivalent to two at –3 is if they are phase
coherent. Coming from the same source and phase locked with each other. I
honestly do not know if that is the case with the Mimo Radios.
From: Mathew Howard
Sent: Wednesday, March 25, 2015 1:58 PM
To: af
Subject: Re: [AFMUG] AF5X polarization
But in the case of dual chain radios, is what Ken said correct, that one signal
at 0db amounts to the same thing as two at -3db? If that's the case, there
wouldn't seem to be any interference rejection advantage to dual slant over
dual linear, regardless of what polarity the interference is.
On Wed, Mar 25, 2015 at 2:55 PM, Chuck McCown <ch...@wbmfg.com> wrote:
Depends on which chuck you mean....
Slant helps with multipath. Linear to slant rejection is only 3 dB. If your
interference is dual pol linear, you have two choices:
Stay linear with a different frequency and hope for the best. Or use dual
slant for a 3 dB reduction of the interfering signal. Better than a poke in
the eye with a sharp stick.
But if you are only running one single chain/radio and the interference is on
the same frequency, orient your antenna 90 degrees to the interference and you
will get 20+ dB of rejection. Irrespective of the absolute polarization. If
they are +45 make yours –45 etc etc.
From: Jeremy
Sent: Wednesday, March 25, 2015 1:47 PM
To: af@afmug.com
Subject: Re: [AFMUG] AF5X polarization
Yeah, I knew about the multipath advantages. It seemed to me that 3db of
rejection would increase your CINR by 3db. Am I wrong here? Chuck?
On Wed, Mar 25, 2015 at 1:44 PM, Mathew Howard <mhoward...@gmail.com> wrote:
I'm not sure that it really gains much if anything as far as interference
rejection... I've read that even though the interfering V/H signals are going
to be 3db weaker, you're now going to be seeing two signals (assuming dual
polarity H/V interference) at that same signal level and the two combined is
essentially the same as seeing the extra 3db. Hopefully someone who actually
knows can confirm whether or not that's true.
if that is the case, I think dual slant is mostly only going to help with
multipath issues.
On Wed, Mar 25, 2015 at 2:36 PM, Jeremy <jeremysmi...@gmail.com> wrote:
Well if I can gain 3db by turning 45/45 I'm all over that.
On Wed, Mar 25, 2015 at 1:32 PM, Josh Luthman
<j...@imaginenetworksllc.com> wrote:
That's what everyone keeps saying =)
Josh Luthman
Office: 937-552-2340
Direct: 937-552-2343
1100 Wayne St
Suite 1337
Troy, OH 45373
On Wed, Mar 25, 2015 at 3:30 PM, Jeremy <jeremysmi...@gmail.com> wrote:
3db right?
On Wed, Mar 25, 2015 at 12:54 PM, Josh Luthman
<j...@imaginenetworksllc.com> wrote:
Rejection from other V/H radios.
Josh Luthman
Office: 937-552-2340
Direct: 937-552-2343
1100 Wayne St
Suite 1337
Troy, OH 45373
On Wed, Mar 25, 2015 at 2:53 PM, Ken Hohhof <af...@kwisp.com> wrote:
Anybody know what you give up by using V/H instead of dual slant
with the AF5X?
If the path has clear LOS and no multipath, I can't see why it
would care or even be able to tell the difference.
