It will be interesting to see what “low” means when it comes to a fully tested
and guaranteed 18 GHz cable. Perhaps they will supply the cables too.
Perhaps advances in N connectors are something I am oblivious to.
From: Josh Reynolds
Sent: Friday, July 01, 2016 8:38 PM
To: af@afmug.com
Subject: Re: [AFMUG] Convert Andrew Dragonwave dishes to N
Right, and so do the people you're talking about - keep it in mind they've
already tested these.
I brought up this exact issue by the way, when they (idiot customer) fuck up a
connector and buy one from BillyBobs HAM shop and wonder why it doesn't work.
I was told the cost on these was low, and they would be sold like any other
connector or accessory. I mean, you DO buy spares for licensed backhaul, right?
I was also told they are working on "other accessories" for this radio that
will be some of the highest quality in the industry.
On Jul 1, 2016 9:27 PM, "Chuck McCown" <ch...@wbmfg.com> wrote:
Here is the thing, you buy a radio that has 11 or 18 GHz appearing on an N
connector.
Then you purchase a cable from your favorite cable place. Connect the two
and wonder why you are having problems.
If you get a cable that actually has connectors rated for the frequency if
they did not sweep it, there is no guarantee it will work properly. And if
they did sweep it it is going to cost a ton.
SMA is cheap, easy and always works at those frequencies. N is only cheap
and easy below 6 GHz.
I am not saying a connector that is rated for the frequency will not do the
job, but the connector is just the first step. If you do not use extreme
precision at 18 GHz then sweep the cable with the proper gear it is going to
have problems. Things like terminations at 18 GHz are not even trivial. It is
so hard to get a good 50 ohm termination for calibration you generally use a
sliding load. (Actually, you are normally using waveguide at 18 GHz. )
I do – do this for a living, you know...
From: Josh Reynolds
Sent: Friday, July 01, 2016 8:13 PM
To: af@afmug.com
Subject: Re: [AFMUG] Convert Andrew Dragonwave dishes to N
I'm saying the same thing. Take the connector designed for it, thrown your
opinion in the trash, and post the results. Repeat the test. Have someone else
repeat the test. Scientific method.
On Jul 1, 2016 9:10 PM, "Chuck McCown" <ch...@wbmfg.com> wrote:
Type N connectors are not in common use above 6 GHz. Believe me or not.
You wanna go above 6, there are plenty of other cheaper and better
connectors to use. N connector concentricity is not inherent to the design of
the connector. And concentricity is essential to good return loss.
You send me an N connector cable. I will put it on a load and connect it
to a vector network analyzer with a smith chart on the screen. Will record
video. Then I will wiggle the cable and back off the connector a bit you can
see for yourself the dot (arc actually) wander all over the place. The
higher the frequency the more it becomes a wild line.
Then I will do the same for SMA and you can see for yourself which one is
more stable. Opinions don’t matter. A dot is a dot, an arc is an arc and a
squiggly line is a squiggly line.
From: Josh Reynolds
Sent: Friday, July 01, 2016 7:53 PM
To: af@afmug.com
Subject: Re: [AFMUG] Convert Andrew Dragonwave dishes to N
So, nothing personal by this... but if the connector is designed for it
(and has several versions by other manufacturers to boot), has been used (and
is still used) on testing equipment... I'm probably more inclined to take their
word for it over yours.
On Jul 1, 2016 7:58 PM, "Chuck McCown" <ch...@wbmfg.com> wrote:
IMHO, 6 GHz is the upper limit.
From: Peter Kranz
Sent: Friday, July 01, 2016 5:22 PM
To: af@afmug.com
Subject: Re: [AFMUG] Convert Andrew Dragonwave dishes to N
“Originally, the connector was designed to carry signals at frequencies
up to 1 GHz in military applications, but today's common Type N easily handles
frequencies up to 11 GHz. More recent precision enhancements to the design by
Julius Botka at Hewlett Packard have pushed this to 18 GHz.”
http://inmet.apitech.com/inmet/micro-inmet-between-typen.cfm
Peter Kranz
www.UnwiredLtd.com
Desk: 510-868-1614 x100
Mobile: 510-207-0000
pkr...@unwiredltd.com
From: Af [mailto:af-boun...@afmug.com] On Behalf Of Chuck McCown
Sent: Thursday, June 30, 2016 3:24 PM
To: af@afmug.com
Subject: Re: [AFMUG] Convert Andrew Dragonwave dishes to N
Yeah, I think this is a case of somebody bowing their neck - a pissing
contest between a boss and underlings at UBNT.
From: Eric Kuhnke
Sent: Thursday, June 30, 2016 4:19 PM
To: af@afmug.com
Subject: Re: [AFMUG] Convert Andrew Dragonwave dishes to N
I have never in my life personally seen an N connector rated above 11
GHz. High-quality/expensive N connectors are used extensively in two way
satellite - such as with 3.0 meter C-band Tx/Rx earth station dishes... But
you only use N for the 50 ohm coax cables from the modem (indoors) to the
electronics which lives directly attached to the waveguide/feed on the dish (Rx
LNB and Tx SSPA/BUC).
The coax is used between 1.2 to 1.8 GHz to communicate with the Tx and Rx
electronics on the dish. A satellite LNB on the Rx side is basically a 10:1
ratio downconverter.
Like so: http://beta.satcomresources.com/sca/images/NORS3120N_detail-3.jpg
There's your single polarity waveguide interface on one side, N on the
other.
On Thu, Jun 30, 2016 at 6:49 AM, Chuck McCown <ch...@wbmfg.com> wrote:
First of all, I have never seen an N connector rated above 11 GHz, and
those are extra expensive.
If there is an 18 GHz version, it will be even more expensive.
This will not be a cable you can make yourself in the field and it will
be very sensitive to being fully seated so you will probably have to use a
torque wrench to make it work at 18 GHz.
Silly. You can weatherproof an SMA just as easy as an N connector.
Good heatshrink can be found for both.
Folks trying to use N connectors at 18 GHz are going to quickly get
introduced to the world of return loss problems.
Von: Af [mailto:af-boun...@afmug.com] Im Auftrag von Rob Genovesi
Gesendet: Donnerstag, 30. Juni 2016 01:32
An: af@afmug.com
Betreff: Re: [AFMUG] Convert Andrew Dragonwave dishes to N
From Gary-UBNT:
"We are working on data sheets right now so hopefully you will get more
questions answered shortly. The reason for N connectors relates to demand for
higher mechanical robustness and the ability for the connectors to be
weather-proof as a stand alone connector (fully weatherproof gaskets and the
ability to accept larger diameter jumpers readily). The N connectors we use
are rated to 18+ GHz."
An active thread on the UBNT forums right now, more available here:
http://community.ubnt.com/t5/airFiber/Some-AF11X-details/td-p/1512145
-Rob
On Wed, Jun 29, 2016 at 12:05 PM, Bill Prince <part15...@gmail.com>
wrote:
I'm looking at all the other AF-nnX radios from UBNT, and they all
use SMA connectors. What reason would they have to use N instead of SMA? Seems
the SMA connector would have fewer issues at 11 GHz.
