i have MTbox in both sides
cm9 also bothe sides
1 watt amp with 25meter of LMR-400 both sides
18 dbi yagi antenna bothe sides
signal -71/-70
without nstreme the links goes ON OF ON OF connect for 2 sec then disconnect after 2 min the link become up, But the ping is 200ms-500ms
once i enable the nstreme the bing become stable from 10ms-25ms with high speed transfer rate,,
any idea guys whats my wrong?
"""i think the signal from the amplifre is not accurate """"
the link is 7.4 km
the framing on nstreme keep changing from 2560 to 512 alsways dynamic

Try not using the amps. May be causing more harm than good. At that distance you should not not 1watt amps on both sides.nless there is a specific reason that you are doing so. Under normal conditions cm9 should be fine for that link. imo.

Check your noise floor. You probably don't have a good signal to noise value. Especially if your in a noisy environment; the amp is probably your worst enemy because it will also increase the noise.

On one of my link, the noise floor jumped from -90 to -80 when I added an amp. Use a bigger antenna instead.

yes, do not use amps in this situation. you can go up to 50-70km with cm9 and no amps.

really????
65mw only can make 50km???

Oh yes you can do that... all you need is big enough ears (read high-gain antennas) and absolutely clear line-of-sight (including fresnel zone!)

Just run a link budget calculator (for example this one http://www.antennspecialisten.se/se/sup ... udget.html) and plug in the values you want to test before building the link

Your setup however, calculated on standard 18 dBm cards, pigtail, 25 meters of LMR400 cable and 18 dB antennas.... will not work over a 7.4 km distance. You will only get 1dB margin on 6Mb according to the math

Suggestions.....
- ALWAYS go with 802.11a! b/g is just to crowded to be usable
- use cards with good sensitivity, CM9 has -88 at 6Mb while SR5 has -94 at 6Mb!! That's an extra 6dB that you do not have to gain with antennas!
- always lock the cards on a lower speed (where they listen and transmit well, 24Mb is a good max limit) so that they do not try to step up and then fall back causing problems. Look at the link budget to see what kind of power you can expect and set the speds accordingly
- place the cards as close to the antenna as possible, 25 meters of LMR400 will cost you 8.8dB ON EACH SIDE! That's almost 18db lost in the cables that you have to make up for somewhere else... if you have to use long cables use 1/2 inch or 7/8 inch (3.62dB and 2.13dB loss for 25 meters cable length)
- use as few connectors, bulkhead adapters etc as possible.. each one costs you between 1/2dB to 2dB depending on quality
- use high gain antennas, it's easier to listen well then to shout loudly

So, after looking at those few points I would build your link using the Mikrotik RIC/522 integrated antenna with SR5 cards (excellent combination that I use myself).
This would give you the following signal strength (assuming legal output = reduced transmit powers, at least legal in europe.. not sure about the limits in your country), output power on the cards set to 8.3dBm = 30dBm at the antenna

Signal strength = -72dBm
Signal margin
6Mb = 22dB
9Mb = 21dB
12Mb = 20dB
18Mb = 17dB
24Mb = 14dB

So to summarize;
- reduce loss (few connectors, short cables)
- increase gain with PASSIVE methods (cards with better sensitivity, better antennas)

/Jörgen

good work really this should be printed as info

just got 2 RB112 and senao 400mw a/b/g i will built my new link
will give you the result with in one day guys


anyone have question about this hardware please dont histate to post your question

Are you going to move the RB's up to the antenna or will you still use the 25m LMR400?

/Jörgen

Are you going to move the RB's up to the antenna or will you still use the 25m LMR400?

/Jörgen

hahaha sure you are kidding
i will give it to my friend he like to ues kenwood 2 way radio
i already desgin my own outdoor box i will post it here later on

If you went ahead and bought RB's and cards then why didn't you go all the way and got the integrated 522 model?

No fuss in building boxes of your own, no problem with pigtails/adapters/ cables... just one box with proper weatherproofed connectors!

/Jörgen

new info,, guys
the 2ghz-5mhz doesnt work with Amps @ all

Correct me other experts if I am wrong:

2GHz-5 or 10MHz use OFDM. It's an atheros-specific version of "G"
OFDM + AMPs don't mix.
In fact, even in high-end professional gear including WiMax (also OFDM), the high "peak to average power radio" of OFDM makes this a big issue in designing the transmit amps.

2GHz-B-only uses DSSS, would be more likely to work with amps.

But, as everyone says, amps are generally a bad idea.

Regards

CableFree Solutions

RFLinx designs a 802.11g amp. I've used a pair of them (1/4 watt) on a PtP link before the days of the SR2/5 cards. Also they were pretty expensive. I believe the advice is sound; avoid the amps in favor of better cards and antennae. Long LMR runs will really nail you. particularly on 5ghz.

Everyone says long LMR runs are to be avoided and I agree to a certain extent, but when you look at the Alvarion and Aperto Network solutions they have their base station equipment in racks at the base of the tower and LMR or some other type of low loss coax running up the tower to dumb antennas.

In my mind that's the best way to do it, then you don't have to be 300' in the air trying to remove a routerboard from the outdoor enclouser to replace a minipci card.. Trying to keep track of those screws 300' up with wind and such is not an easy task.

The devices on the tower should be a dumb, physical layer devices that don't require much maintenance.

Cell company's do it, it can be done with alvarion, and other "packaged" solutions. What are they doing differently? They use the same frequencies (at least for the alvarion stuff)...

Just think if a RB failed or a radio fails, and its pouring rain outside, hailing, snowing, what have you. You do not want to be on a tower trying to replace equipment.

There has to be a way to mount the equipment at the base and not lose performance.

I agree with you Bill. The main trade-off is cost. Low loss heliax can get pretty expensive on 2-3 250 ft runs. If we look at 3 antennae with 250 ft runs each with 7/8" Andrew heliax, then the cable cost is going to run about $3400 (around $4.50/ft) for each side. And if one of them happens to be a 5.8 link, then you lose about 8.07 db per end of link. Of course you could go with the Andrews 1 1/2" or LMR 1700 which just doubled your cable price again.

The other thing I hate is second guessing is coax weather proofing. Most of the time, if done right, you won't have a problem. But there are always the ones that water seeps in and can totally screw the system.

But yep its definetely more convenient having the gear at the bottom of tower.

Eric

The reason MW people, Alvarion and others can do it is that they run the signal up the tower on "IF" frequencies (often 70MHz) - at the top you get the "outdoor unit" which has a power amp, low noise amp, filters and up/down coverters and not a lot else. There is relatively little loss, and also the signals are amplified at the top end. The "smart stuff" is in the Indoor Unit at the bottom, usually in a cabin/enclosure.
The mini-PCI concept doesn't allow for this type of "split" design, because the whole radio is integrated. Whether it could be, with a customised miniPCI/Atheros board, I don't know.

Regards

CableFree Solutions

I think the Alvarion stuff (like BA-II) is 4xx mhz IF. The coax carries the lowered frequency and the DC power for the outdoor unit, as well as signalling for the site survey and indicator LEDs. It's good stuff.

fainly i changed my 1 wat pcb amp with 200mw high power minipci,
now i m sure normunds is 100% right
i have omni direction 15 db i noticed BIIIIIIG diffrent the 200mw is lower signal in client side , BUT more stable and all links works more than great,
Big thanks for MT

SR2/SR5 vs. nmp-8602 - Showdown at dusk....

I have seen so much information posted back and forth about all three of these cards. I would like to get final summations from people who have an opinion (based in actual usage results) of which of the cards perform the best when used with MT APs. 2.4 and/or 5.8

One big reason to have a consolidation of opinions is becasue when one of the manufacturers runs short on distribution for 3 months (like the SR2 in the US) and you need to buy 5-10 per month, you either have to stop production, or have a viable alternative. It would be nice to know clearly what adv/disadv there would be if you had to switch cards if you could not wait.

Please consider posting you experiences with these products.

ok regarding the senao i test it
it doesnt support compression
noise floor higher than regular mpci (-97) <--senao ,regular 200mw a/b/g <----(-104)

very low power the senao low heat compare to SR2
senao has A/B/G
senao doesnt have stable output 25-26 dbm senstvity -96



i m using it (using senao)on 2 systems very stable proformance

Hi Taloot, i am trying the NMP-8602+ in a RB512 and RB532A, both with Mikrotik 2.9.20 and FW v1.11...
In indoor ambient, this have lowest quality then a little R52 (65mW)
In outdoor ambient i go test this next weekend... i go post results here
Personally i think all the problem is because of drivers in the RouterOS. When the guys of mikrotik renew the Atheros drivers to support the Atheros 6th generation cards, this card may be very interesting, i wait in 2.4Ghz can be compared with a SR2...
Regards!
Alessio

as normunds say fainly i say amplifire is totally uesless crab
did a test using 100mw board @ 24mbps working great TX @11-11.5 mbps RX same
i instaled amp 1000mw support Turbo mode as they said ,,, i got higer signal but higer nooise flooor and muc much lower speed arround 12mbps TX=6mbps = RX= 6mbps

warning: when using an amp.. the tx-power of the card must be 30 - 35 mW if you have a tx-power of 30 or 35mW the amp works perfectly. if you use an amp with a card power of 100 or 200mW you can easly damage the amp and the card too.

P.s i don't recommand to use amps.

Regards,

thanks proxy but this is basic info about amps,

normally its craaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab
thank god for the high power boards technology
btw i have more than 60 sites with amplifire setup it works ok but,,,,,,,,,,,,,,
14 month the amp is dead

so let say whats bad about amp,,,

1. expansive
2. noise generator
3. switching TX/RX and you have already Switching on ur Radio "clients problem limitation"
4. expansive cables and bigtails LMR-400
5. increase the point of failer "connector cables joint DC injector"
6. most important thing i didnt found an amp really support high speed 54mbps,
7. lead to non acurate radio signal reading,
8. non ajustable Output power ' AGC not working as its expected"
9. non stable output power ' i did test using netstumbler"
10. not functional when its too cold outside
11. in 11a mode its really expansive compare to SR5 with 400mw


Most of AP doesnt work well when you attache Amplifire for them as access point client mode
Dlink AP900 only the AP work with me in AP-client mode

So in summary, as almost everyone has said, "don't use them" ...

Regards

CableFree Solutions