Ive actually been bitten by the same problem. Should have thought of that.Sent
from my Verizon, Samsung Galaxy smartphone
-------- Original message --------From: Mark Radabaugh <m...@amplex.net> Date:
4/1/20 8:50 AM (GMT-05:00) To: AnimalFarm Microwave Users Group
<af@af.afmug.com> Subject: Re: [AFMUG] PTP Microwave antenna question Old
thread but finally found the answer to what was going on with this link - and
it’s stupid.The 820C has 3 part numbers to cover the 11Ghz band. Apparently
the coordinated frequency was outside of the range of the radio part number we
were using. Amateur mistake. A couple of contributing factors - but one of
the bigger ones is that the 820C will happily accept a frequency assignment
outside of the sub-band without complaint. The older 800’s and other brands
we have used puke if you try to do that. We have kept all of our links in one
sub-band for sparing. I think there is a newer 820C high power that has
external swappable duplexers that will simplify the sparing but stocking one
pair of radios and just the duplexers. I need to have our NOC look into that
since we now have a ’spares’ problem.MarkOn Mar 6, 2020, at 2:49 PM, Mark
Radabaugh <m...@amplex.net> wrote:I think at this point we are just going to go
back out and try it without the Dragonwave adapter by swapping the mounting
plate on the back of the antennas to the Cambium plates. We have a set of
mounting plates on hand.MarkOn Mar 6, 2020, at 2:46 PM, Caleb Knauer
<cknauer.li...@gmail.com> wrote:He swapped radio pairs with known good in the
field and that wasn't it. And you can't rotate ODU flanges on C, they're fixed
and meant to go to some mediation devices. You can on the single core S. On
Fri, Mar 6, 2020 at 2:43 PM <ch...@wbmfg.com> wrote:
If somehow those rectangular sections are not aligned you could have that
problem.
I am leaning toward a bad radio.
You could put both radios on the bench. Divert one of the rectangular
waveguides on each end.
I would not block it but just put some kind of 45 degree reflector in front
of it to direct the signal somewhere else.
Or if you could find some absorbing foam to put in front of it.
From: Roland
Houin
Sent: Friday, March 6, 2020 12:35 PM
To: 'AnimalFarm Microwave Users Group'
Subject: Re: [AFMUG] PTP Microwave antenna
question
I believe that you can rotate the waveguides in the
odu.That could result in an incorrect
polarization..I believe we have run into that in the past Roland
From: AF <af-boun...@af.afmug.com> On Behalf
Of chuck@wbmfg.comSent: Friday, March 6, 2020 2:32
PMTo: AnimalFarm Microwave Users Group
<af@af.afmug.com>Subject: Re: [AFMUG] PTP Microwave antenna
question
Acorns in the
radome.
From: Mark
Radabaugh
Sent: Friday,
March 6, 2020 12:18 PM
To:
AnimalFarm Microwave Users Group
Subject: Re:
[AFMUG] PTP Microwave antenna question
Not a lot of
options to put these together wrong. Line up the hangers and it’s good to
go:
<image001.jpg><image002.jpg>
Mark
Radabaugh
Amplex
22690 Pemberville
Rd
Luckey, OH
43443
419-261-5996
On Mar 6, 2020, at 1:56 PM, Steve Jones
<thatoneguyst...@gmail.com>
wrote:
whats the OMT
look like? That V/H pin puts the plate at 45?
On Fri, Mar 6,
2020 at 12:48 PM Caleb Knauer <cknauer.li...@gmail.com>
wrote:
If that
center part is press fit in slightly catawampus and not 100%plumb then
it could cause issues. Or the pipe isn't 100% either.
Butkind of grasping at straws with that.On the C's I've bench
tested with XPIC without antennas, it'll talk toeither one IIRC if you
run 2/1 or 1/2 as I've played with it. It'sreally not happy about
it though. I'd have to confirm though, been abit.XPIC keys
or settings wouldn't affect the raw RXL levels, it justblows out your
MSE if they're crossed. I've seen links where theydidn't turn on
anything XPIC but set it up and it works, just kindajanky.You
could always mute one core on both sides and sanity check that
waytoo. If something is crossed, it'd show the right RXL one on
core and30ish dBm down on the other core.On Fri, Mar 6, 2020 at
1:12 PM Ken Hohhof <af...@kwisp.com> wrote:>> You
look at Mark's photo and think what could possibly be wrong, it's a round
hole. How many ways are there to install a round hole, it's like the
proverbial one car funeral procession.>> And I guess with an
820C + OMT, having H and V swapped shouldn't be possible, and even if they
were, it would still work if you did the same thing at both ends. I
wouldn't assume though that XPIC would straighten out an H/V swap, I don't
think it's like MIMO on WiFi. XPIC assumes the antenna cross pol
rejection does most of the work and it has to clean up what
remains.>> I'm assuming you have the XPIC keys enabled,
although that would probably create an alarm not the symptoms you are
seeing.>> -----Original Message-----> From: AF
<af-boun...@af.afmug.com> On Behalf Of Caleb Knauer>
Sent: Friday, March 6, 2020 11:40 AM> To: AnimalFarm Microwave Users
Group <af@af.afmug.com>> Subject: Re: [AFMUG] PTP
Microwave antenna question>> With XPIC it wouldn't matter that
slot 1 was talking to slot 2 on the other side, it wouldn't know. At
least I think anyways. Since it's just looking for RX on the frequency
it's set, and it's on the same on both ends, and it'd still have XPD to
separate the two. You could rotate one end 90 degrees to simulate on
the office rig to test I suppose. Plus anyways if you can't get signal
worth a flip on the office rig, even if it was a polarity thing, that short
of a link should blast it through to something you'd see.>>
Only thing I can think of is that something in that tube is not aligned,
bad
press fit or mill or something like that and the waves are getting blown
out
of phase or similar. There's not but one way to put it together, and
820c -> OMT takes it to circular and you have circular to
dish.>> On Fri, Mar 6, 2020 at 12:30 PM Mark Radabaugh
<m...@amplex.net> wrote:> >> > Odd thing is
I don’t see any way to assemble this any way that would swap polarity.
Only way to screw it up would be internal to the OMT itself. We
are doing XPIC with this link which we have not done in a lot of other
places, so that is different.> >> > Mark>
>> > On Mar 6, 2020, at 12:22 PM, ch...@wbmfg.com
wrote:> >> > > > V&H being swapped will
always cost you at least 20 dB and if you have them precisely aligned
V&H I can see where 40 dB is reasonable.> >> > From:
Ken Hohhof> > Sent: Friday, March 6, 2020 10:18 AM> >
To: 'AnimalFarm Microwave Users Group'> > Subject: Re: [AFMUG] PTP
Microwave antenna question> >> >> > OK, that
says the antenna should be dual pol capable. So … is a
puzzlement. You’d expect a problem would cost a few dB, not 40
dB. Unless H & V were swapped.> >> >>
>> > Sounds like Cambium is looking into it, maybe they come up
with some ideas.> >> >> >> > From:
AF <af-boun...@af.afmug.com> On Behalf Of Mark
Radabaugh> > Sent: Friday, March 6, 2020 11:00 AM> > To:
AnimalFarm Microwave Users Group <af@af.afmug.com>> >
Subject: Re: [AFMUG] PTP Microwave antenna question> >>
>> >> > It’s currently 2 single pol Horizons on a
Dragonwave OMT mount that combines the H&V to the round waveguide on the
back of the antenna.> >> > Mark Radabaugh>
>> > Amplex> >> > 22690 Pemberville
Rd> >> > Luckey, OH 43443> >> >
419-261-5996> >> >> >> > On Mar 6,
2020, at 11:19 AM, Ken Hohhof <af...@kwisp.com> wrote:>
>> > > >> > We put 11 GHz 820C w/XPIC on
existing Trango 3 ft dishes replacing single pol ApexPlus ODUs and
everything went as expected. I’d have to look up the details but I
think it worked because Trango used Remec circular even with single pol
except for 6 GHz. We should have adjusted for best XPIC cancellation
but instead we just made sure the ODUs were plumb. But I think what we
did was roughly the same as what you’re doing, so it should work.>
>> >> >> > We got a couple bad 820S radios
last year, failed the RF loopback test, but it sounds like you have pretty
thoroughly verified it’s not bad radios.> >> >>
>> > Were the Dragonwaves single or dual pol?>
>> >> >> >> >> > From:
AF <af-boun...@af.afmug.com> On Behalf Of Mark
Radabaugh> > Sent: Friday, March 6, 2020 9:37 AM> > To:
AnimalFarm Microwave Users Group <af@af.afmug.com>> >
Subject: [AFMUG] PTP Microwave antenna question> >>
>> >> >> >> > We have installed a
lot of Cambium 820C radios without much trouble. Yes, the
configuration takes some getting used to but we probably have 46 links
working and installed, so it’s not like it’s our first rodeo configuring
these things.> >> >> >> > And then
we tried something new - reusing a 4’ Andrew Dragonwave antenna in a
XPIC configuration. We purchased the Cambium adapter plate that
clips onto the antenna radio mount and presents the 820C mount for the
OMT. Take off the dual Horizon radio OMT, add the 820C and the
RF signal is shit - in the -80’s from the mid 40’s. Reverse the
process and put the Horizon’s back on and the signal is fine.>
>> >> >> > So we thought we had a bad
820C. It’s happened before. So we take two different sets
of 820C’s and test them one at a time swapping them in for known good
installed radios on working links. The 820C’s are fine.>
>> >> >> > Okay… we forgot to test the
OMT's when we did that. So we try the OMT’s in the shop - and
they work fine.> >> >> >> > At this
point the only thing left is the antennas themselves and the adapter
plate. The adapter plate is nothing more than a hole in a
aluminum bushing with a couple of small steps to match diameter between the
OMT and the antenna waveguide. Pretty hard to screw up.>
>> >> >> > We have a pair of Dragonwave
antenna’s in the shop that we can mount all of this to and try here - and
we
can’t get a decent signal even 20’ apart. I’m at a loss at this
point. The only part that doesn’t appear to work is the adapter
plate - and there is nothing interesting about it.> >>
>> >> > How the heck can this not work:>
>> >> >> > <image001.jpg>>
>> >> >> > <image002.jpg>>
>> >> >> > I can’t buy that the alignment
of the antenna would need to be adjusted. That makes no sense in
my head. Am I wrong in that assumption?> >>
>> >> > Mark> >> > -->
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