ch0/ch1...the polarity of sextant 5hnd

RouterOS Wireless Networking
1

hi every one…can anyone give me an idea about the ch0 / ch1 in the image down ? are they related with polarity ? in wihch case we should set them ?
need idea please

2

on the sextant ch0 is on the h pol and ch1 is on the v pol of the antenna. This is an 802.11n unit so it is capable of dual chain links. Those check boxes define what chain is used for tx and rx.

3

Also, usage of ch0 is a must.

4

what do you mean please ?!!

5

For example you can not unset ch0 and use ch1 only. Effectively your “one channel network” must be h-pol and not a more common v-pol.

6

You can uncheck chain0 tx if you use it on v-pol only

7

You can uncheck it as much as you like, but according to the MT officials it does not work. “The ch0 is a must to have!”

8

It absolutely will not work without ch0 used

9

To clarify, from the SXT manual page 5 http://routerboard.com/pdf/280/SXTug.pdf:

For single chain operation in V-pol, these options can be considered:

  1. leave everything as is, it will connect to Vpol devices by default if you didn’t disable any chains in RouterOS settings
  2. Turn antenna 90deg and use Chain0
  3. Don’t turn antenna but disable Chain0-TX in RouterOS
10

thank you very much..do you mean that the default polarity is vertical ( chain 1 ) ?
if we turn the device 90deg this will make the device work horizontally..( chain 0 )
but i have another question/ refer to this bage/http://routerboard.com/RBSEXTANT5HnD
we see 3 kinds of polarization / Linear, Vertical and Horizontal ..
if we want to use linear ? so what we have to do to get the linear with sextant 5hnd

11

it is linear horizontal or linear vertical, these are not 3 different polarizations.

12

sorry .this is the first time i hear about that :laughing:
but how we can work with linear mode ??
the wireless waves have just 2 behaviors ..H and V

13

I always enable all chains and SXT connect to Hpol Or V pol fine. Is there any advantage to disabling chains when connecting to single chain APs?

14

I believe not much. You only reduce channel polution in unused pol. if it matters to you.

15

you are on the right…i think if we check all boxes ..the sextant 5hnd will work with both H and V ..without to need to turn it 90deg

16

Exactly. In most situations, there is no benefit to disabling any chains.

17

Thanks Normis for clarifying this

18

I had asked some time earlier about antenna for the access point. Maybe I misunderstood, but I thought the by default the SXT-HND in the nomal mounting was Horizontally polarized. In ‘single channel’ mode, I’d have to use a horizontally polarized antenna with the access point. Pls clarify.

19

Hi,

I think what is being said here is, if you leave all chains active ( leave it in Dual channel Mode). The Sextant will then connect to either a Vpol or Hpol single channel AP with no problem, mount it as designed with drain hole at the bottom and it will automatically select the best chains for the job. As normis said there is no advantage to running a sextant in single channel mode. Is there a reason you want to run the sextant in single channel mode? I would not advise mounting these devices turned 90 degrees as their is a bigger risk of water ingress

20

I do not know the cause but I have seen when using the sxt2g as a wifi AP, enabling both chains causes connection instability with various devices like iphone 5.