MikroTik

Link is setup at Freq 5805 the station is a rb500 with the 400mw card. tx/rx is -73/-90
noise floor is -115
Signal to noise 23
rx/rx ccq 4/12
Using a 22db grid for 5805 freq with 6 foot cable

1/2 mile away is the tower using a 10db Omni using a 400mw card and 25 foot cable with the below stats.

tx/rx is -91/-74
Overall ccq 20%
Noise floor 99

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I have changed routerboards both sides, antani's, cables and pigtails. The station is ontop of a building which is mounted on the chimney. It has perfect line of site to the tower.

The tower is a 35 foot tower that sits 100 feet infront of a larger cell tower. I have done some testing for noise with several wireless radio's and there is only one other radio in the 5.8 range and it's freq is at the oposite range that mine is using.
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The way I read the above stats it seems I have a transmit problem on the tower do you agree?

http://www.smyth.net/tower.jpg (5.8g omni on right of this picture)
http://www.smyth.net/tower_box.jpg
(the older routerboard but the new one is in there now as of today)

http://www.smyth.net/office1.jpg
(on top of the building the 5.8g link is the grid antani on the right. the large dish on the right was 5.1 antani which ended up beeing too much wind loading on our tower and now has been removed form both sides. the 5.8g grid on the left of this picture is now where the 5.1 dish is now.)

Have you tried other freq.

whats the problem???? signal ??
if its signal issue i think ;;25 foot cable ;;; is too much for 5ghz frequancy whats the type of your cable?

Hi Michael

I was waiting to hear from you on this... thought it was solved since you didn't post anything in the other thread. For those of you just catching up it's here http://forum.mikrotik.com/viewtopic.php ... highlight=

We did talk some about the polarization on the grid antenna, have you made sure that is correct?

/Jörgen

I am using lmr-400 at both locations. At the station on the building it's 6 feet long into a 22db grid vertical polorized. No lightnight protection, goes to the outside box with n-female to n-femail plug on the case and then a pigtail directly to the card.

On the tower 25 feet lmr-400 omni vertical on top. At the base it goes directly to the box n-female to n-female then pigtail to the card.

The station reports a poor recieve signal of -90 and a transmit of -74.

The tower reports a poor transmit of -91 and a recieve of -75.

Could a bad group cause this?

I have not moved the fequency more than a few channels as I do the connection drops. The antani's that I use are specfic for the higher frequency's of 5.8

Forgot to mention the orginal link was the Mikrotik 230's on both sides with 65mw 802.11a cards. I have switched both units to the Mikrotik 112 units using the 400mw cards. So going up in power didn't change anything.

I have switched out the bigtails, and I have two of the lmr-400 cables running up the tower for backup so i've swithced between them several times. I have even mounted an identical Grid antani as what is on the office and both tr/rx drop to like -89

YES! I finally made some progress!

I had another 5.8mhz Grid antani arrive just the other day and since it was so nice figured I'd go set it up.

I used a 6ft cable at the tower and bolted the directional up to the leg of the tower and I am getting -54/-69 strenth (on the station).

It came up to 36Meg link for a while but now it's jumping up and down and falling all the way back to 6Meg.

So at least I am making some progress.

Tower Pictures
http://www.smyth.net/tower1a.jpg (the 22db grid that I am now using on 5.8ghz)
http://www.smyth.net/tower2a.jpg
http://www.smyth.net/tower3a.jpg (left is 2.4ghz right is 5.8ghz)
http://www.smyth.net/tower4a.jpg (front round grid is a 5.8ghz directional)

The Dish that I am using
http://www.wisp-router.com/product_info ... cts_id=239

Have you tried lowering the power on your radio cards? That link sounds too "hot" - 400mW on each end with high gain grid hitting an omni? Might be too much gain...what were your signals like with the old CM9 radios?

Any time that I drop the power of the 400mw cards the link just drops out. The older 65mw cards I had worked solid at 65mw 6 meg connection but would never do 12 megs. The transmit signal strenth seems to be my protlbme at the tower.

I'm wondering if I'm using the wrong type of cable? I'm using lmr-400 for both 2.4ghz and 5.8ghz. Is that correct?

Exactly what type of LMR-400 are you using??? There's several types and some of then do not have 50 Ohms impedance!

/Jörgen

HI i see this http://www.smyth.net/tower2a.jpg, and i have a question for you,


you no have problem with connector type N in the box, the connectors have contact with the metal of the BOX, i am thinking you can loss db there.

What you think about this, maybe the BOX work a Antenna or parcial antenna ???? i am thinking you need to isolate this connectors,

and how work the 110 VAC in the BOX, about the ground?

Best Regards
Daniel W



[quote="mperdue"]YES! I finally made some progress!

I had another 5.8mhz Grid antani arrive just the other day and since it was so nice figured I'd go set it up.

I used a 6ft cable at the tower and bolted the directional up to the leg of the tower and I am getting -54/-69 strenth (on the station).

It came up to 36Meg link for a while but now it's jumping up and down and falling all the way back to 6Meg.

So at least I am making some progress.

Tower Pictures
http://www.smyth.net/tower1a.jpg (the 22db grid that I am now using on 5.8ghz)
http://www.smyth.net/tower2a.jpg
http://www.smyth.net/tower3a.jpg (left is 2.4ghz right is 5.8ghz)
http://www.smyth.net/tower4a.jpg (front round grid is a 5.8ghz directional)

The rb-112 is screwed to the back panel metal to metal. The n-type conectors also touch to the metal case. The case is isolated for the most part execept for the two bolts that go from case to tower but there is a lot of paint so i doubt the is any real conductivity between the case and tower.

The electrical ground I belive is the only ground on the case.

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This tower is well below the cell tower behind it so has been protected from lightning and such.
----

Should I install a large ground rod, wire it directly to the case?

And then should I isolate the electrical power away from the case?

Regards :idea:
Michael

The rb-112 is screwed to the back panel metal to metal. The n-type conectors also touch to the metal case. The case is isolated for the most part execept for the two bolts that go from case to tower but there is a lot of paint so i doubt the is any real conductivity between the case and tower.

The electrical ground I belive is the only ground on the case.

----
This tower is well below the cell tower behind it so has been protected from lightning and such.
----

Should I install a large ground rod, wire it directly to the case?

And then should I isolate the electrical power away from the case?

Regards
Michael

you can isolate the conectors N of metal box, only isolate the connectors and test the links, and see the RSSI in both sides (CPE and in AP).

only for test maybe you can put electrical tape in the connector to the metal box or put the connector N out of metal box, and test.

i tell you this because i am thinking the metal box is part of antena , the metal box will radiate or make a loss dB , if you isolate the connector the box is only the box. and the 110 Vac no problem .

It came up to 36Meg link for a while but now it's jumping up and down and falling all the way back to 6Meg.

Is the speed falling when the link is idle, or when you're pumping traffic through it? For what ever reason, it's normal for those cards to drop the speed when they aren't doing anything. Prism cards will ramp up to their best speed and stay there, Atheros cards appear to be lazy and want to slow down when they aren't doing anything.

It came up to 36Meg link for a while but now it's jumping up and down and falling all the way back to 6Meg.

Is the speed falling when the link is idle, or when you're pumping traffic through it? For what ever reason, it's normal for those cards to drop the speed when they aren't doing anything. Prism cards will ramp up to their best speed and stay there, Atheros cards appear to be lazy and want to slow down when they aren't doing anything.

mmm you think, is go to down the speed, for make more secure links?, is strange for me, and when have traffic go to up ????!!!