R52Hn strange readings

[zgi]

I’ve bought 2 R52Hn, and set a ~9km link, with LOS. The signal strength reading are weird and it’s jumping a lot for about 10~20dB, or even more. (just look at the picture). Cards were never powerd ON without antenna attached.

CONFIG.:

2X433AH, R52n and R52Hn on one side, R52Hn on remote side.

1 R name=“sinkovec-tv” mtu=1500 mac-address=XX:XX:XX:XX:XX:XX arp=enabled
interface-type=Atheros 11N mode=station ssid=“WelKom HV” frequency=5640
band=5ghz-onlyn scan-list=default wds-mode=disabled
wds-default-bridge=none wds-ignore-ssid=no default-authentication=yes
default-forwarding=yes default-ap-tx-limit=0 default-client-tx-limit=0
hide-ssid=no security-profile=default compression=no



0 R name=“tv-sinkovec” mtu=1500 mac-address=XX:XX:XX:XX:XX:XX arp=enabled
interface-type=Atheros 11N mode=bridge ssid=“WelKom HV” frequency=5640
band=5ghz-onlyn scan-list=default wds-mode=disabled
wds-default-bridge=none wds-ignore-ssid=no default-authentication=yes
default-forwarding=yes default-ap-tx-limit=0 default-client-tx-limit=0
hide-ssid=no security-profile=default compression=no

On the side with good signal I have pannel with pigtail directly attached to antenna, on the side with bad signal strenght, i have pannel antenna with 1m coax cable, so I’ll try to change that cable, but still, i don’t think that there would be 20dB signal strenght jumps if it was a bad cable.

And another thing. This is my first three in a row mikrotik setup, so I got another problem. I allready have a working link on one AP with R52n and nstreme, but if I set nstreme on the other link, i get disconnections. Log says, lost connection, not polled for too long. And I wonder if nstreme could be ran on 2 interfaces at the same time on the same board?

[mishaM]

a what maximum thought of link bandwidth from a to c ?

[zgi]

about 9Mbit FDX

[colebert]

I have nearly a dozen of R5Hn cards that do this. I keep repeating that something is wrong with these cards. I have completely stopped using them. They all exhibit the same behavior you are reporting. One side of the link is 20db lower than the other and the CCQ is terrible.

Just get two Ubiquiti SR71 cards and keep using them until Mikrotik can produce a card that works reliably.

[normis]

Did any of you contact the MikroTik support with supout.rif files ?

[zgi]

Not yet. Will do it.

[Kencomp]

Think there’s a major problem either with the R52Hn’s or Router OS 4.10

Setup a test link at 100M using 20db hor.pol antenaes, and Proxim Tsunami radios at 5735MHz. The proxims have an output of 16.5db at the connector. Signal strength is -46db without attempting to align the antenaes.

Replaced Proxims with RB411AHs with R52Hns, 1 set as Bridge, 1 set as client. Wireless mode set to 5GHz, Freq to 5735, UK regulatory domain and superchannel using ONLY chain0 and TXPower set to default. Received signal is -62.

Put back Proxims and retested, still at -46db. Put back Mikrotiks, still at -62.

Changed TXPower to Card Rate 16db limit at both ends, received signal went down to -82. Weird as suggests default TXPower must have been 36db rather than the max of 22db!!!

Changed TXPower to Card Rate 22db limit (Should be same as default), received signal went back to -62. Hmmmm

Changed TXPower back to default, received signal went to -87. What the hell? Was -62 before.

Disabled wireless interface and re-enabled, received signal back to -62.
Repeated disable/enable several times and received signal randomly switches between -6x and -8x

Swapped R52hN cards at both ends, all exhibit this behaviour.

Interestingly, it is the RECEIVED signal that varies when you enable/disable the card, not the TX signal. This is true for whichever end of the link the tests are carried out on, hence my conclusion that either that cards are naff or there is bug in routeros.

Has anyone else experienced these effects and have a solution? Having no hair left to pull out, I’ve ordered some Ubiquiti SR71-5 cards to see if they do the same.

[zgi]

I’ve got mail from support and they say that this is normal.

Thank you very much for the report. It could be that such value is shown for
short period of time, when wireless card makes recalculations and you can
notice for a while wrong values.

@Kencomp

I’m thinking of buying SR71-5 too. Please post your results.

[Kencomp]

Disagree that it’s normal, no other make of radio I’ve ever used (Over 15 years experience) has ever behaved like this. Support replied “After a short time it will re-calculate”, well sureley 72 hours would be long enough!!! Went home Friday night with it bad, it was still bad this morning. Disable/Enable interface a couple of times and it’s ok now.

Anyway, when SR17-5s arrive will post results, at least that will eliminate the cards as the source of the issues.

[aaa]

I have same signal strength readings. But link is stable and true output is close to 100mbit. I think it is some kind of AR9220 chipset bug. I never see this on AR5414

[zgi]

Can you post your wireless settings, link distance and output power ?

[aaa]

Link distance is ~4km. TX power set to default.

[admin@xxx] /interface wireless> print advanced
Flags: X - disabled, R - running
0 R name=“wlan1” mtu=1500 mac-address=00:0C:42:3A:D3:13 arp=enabled
disable-running-check=no interface-type=Atheros 11N
radio-name=“000C423AD313” mode=station ssid=“xxx” area=“”
frequency-mode=superchannel country=latvia antenna-gain=0
frequency=5180 band=5ghz-onlyn scan-list=default,5320-5500
rate-set=default supported-rates-b=“” supported-rates-a/g=“”
basic-rates-b=“” basic-rates-a/g=“” max-station-count=2007
ack-timeout=300 tx-power-mode=default periodic-calibration=disabled
periodic-calibration-interval=8000 dfs-mode=none wds-mode=disabled
wds-default-bridge=none wds-default-cost=100 wds-cost-range=50-150
wds-ignore-ssid=no update-stats-interval=disabled
default-authentication=yes default-forwarding=yes default-ap-tx-limit=0
default-client-tx-limit=0 proprietary-extensions=post-2.9.25
wmm-support=disabled hide-ssid=no security-profile=default
disconnect-timeout=3s on-fail-retry-time=100ms preamble-mode=both
compression=no allow-sharedkey=no
station-bridge-clone-mac=00:00:00:00:00:00 ht-ampdu-priorities=0
ht-guard-interval=any ht-extension-channel=below-control
ht-supported-mcs=mcs-0,mcs-1,mcs-2,mcs-3,mcs-4,mcs-5,mcs-6,mcs-7,mcs-8,
mcs-9,mcs-10,mcs-11,mcs-12,mcs-13,mcs-14,mcs-15
ht-basic-mcs=mcs-0 ht-txchains=0,1 ht-rxchains=0,1 ht-amsdu-limit=8192
ht-amsdu-threshold=8192 hw-retries=8 frame-lifetime=0
adaptive-noise-immunity=none hw-fragmentation-threshold=disabled
hw-protection-mode=none hw-protection-threshold=0

[aaa]

[admin@xxx] /interface wireless> monitor w
status: connected-to-ess
band: 5ghz-11n
frequency: 5540MHz
tx-rate: “243.0Mbps-HT”
rx-rate: “243.0Mbps-HT”
ssid: “xxx”
bssid: 00:0C:42:3A:D3:0B
radio-name: “000C423AD30B”
signal-strength: -64dBm
tx-signal-strength: -63dBm
noise-floor: -116dBm
signal-to-noise: 52dB
tx-ccq: 95%
rx-ccq: 96%
p-throughput: 136840
overall-tx-ccq: 95%
authenticated-clients: 1
current-ack-timeout: 300
wds-link: no
nstreme: no
framing-mode: none
routeros-version: “4.3”
last-ip: 95.30.157.30
802.1x-port-enabled: yes
compression: no
wmm-enabled: yes
current-tx-powers: 6Mbps:18(18/21),9Mbps:18(18/21),12Mbps:18(18/21),
18Mbps:18(18/21),24Mbps:18(18/21),36Mbps:17(17/20),
48Mbps:16(16/19),54Mbps:13(13/16),HT20-0:16(16/19),
HT20-1:16(16/19),HT20-2:16(16/19),HT20-3:16(16/19),
HT20-4:16(16/19),HT20-5:16(16/19),HT20-6:15(15/18),
HT20-7:11(11/14),HT40-0:15(15/18),HT40-1:15(15/18),
HT40-2:15(15/18),HT40-3:15(15/18),HT40-4:15(15/18),
HT40-5:15(15/18),HT40-6:14(14/17),HT40-7:10(10/13)
notify-external-fdb: no

[zgi]

Tried with your setings, with no luck. I noticed, that at the one end, noise floor is -122dB, at the other end, sometimes its -109dB, sometimes -88dB, then I change a few channels and its -109dB back again for some time. We have another full operating link, at that location with UBNT Bullet M5 with no problems in signall loss or major CCQ drop.

[aaa]

What antenna you use? Is it Chain 0 antenna work in vertical polarization and Chain 1 antenna in horizontal polarization? Do you use RouterOS spectrum analyzer to find clear frequency? I test 23dBi panels on 10km distance with bad success.

[Kencomp]

Until I get some different network cards, I’ve given this up as a bad job. Despite the wild 20-30db fluctuation on received signal strength, there’s just too many factors to solve this problem.

FACT - using a Proxim 16.5db radio we get a received signal strength of -40
using a Mikrotik RB411AH with R52HN radio with an alleged output of 22db we get a received signal strength of -49
nothing has changed between the 2 setups other than the radios

CONCLUSION - Either the R52hNs have an actual output of 7.5db, the cards misreport the signal strength or ROUTEROS
doesn’t work properly with R52hNs. Personally think it’s a card problem hence the abandonment until I get
some SR71-15s to test with (Lead time 4-6 weeks so not a quick solution)

[zgi]

@aaa

One antenna Chain 0 (both RX and TX), on one side 23dB pannel on the other side 24dB pannel, both horizontal polarizaton on 5640MHz. Have measured link length again on Google earth and it sais 7km.


5540MHz is my A to B link freq. So it’s enough free freq. space between these two links.

[Kencomp]

@zgi

Your onto a losing battle, Mikrotik support have now confirmed that the noise level/received signal strength is not reported correctly. They still don’t know the exact cause but thinks it’s a problem with the Atheros Chipset Drivers. Don’t think therefore it’s anything to do with your setup but the same bug we have been struggling with

[charliebrown]

Can anyone from MT confirm this? Kinda bad if they are reporting odd signals, Is it just R52Hn’s?

[aaa]

You mean use only one Chain and one antenna on each side? Do you disable other chain on ht control panel? Try change both sides to vertical polarization. Else use spectral scan not frequency usage. Spectral scan recognize any signal like single carrier, FSK modulation. Frequency usage just 802.11a/n