WIFI works only on extremly short distance

Hi there.
I am stuggeling with a strange WIFI problem:

Wired my connection is no problem. But I can’t get a stable wifi-connection. I do get a good connection with my PI very close to my router. But with a distance of only 3-4 meters the connection breaks down very suddenly (web ui not reachable any more). All my other wifi gear works fine in the same net with much larger distances.
My system: Pi 2 Model B, HifiBerry DAC+, Wifi: EDIMAX EW-7811UN, Volumio 2.041, router: FritzBox 7272

(I already changed /etc/modprobe.d/8192cu.conf to options 8192cu rtw_power_mgnt=0 rtw_enusbss=0 rtw_ips_mode=1 with no improvement)

sudo iwconfig with the RPI close to the router:
wlan0 IEEE 802.11bgn ESSID:“Focometer” Nickname:“WIFI@REALTEK
Mode:Managed Frequency:2.437 GHz Access Point: 34:81:C4:BE:36:E2
Bit Rate:72.2 Mb/s Sensitivity:0/0
Retry:off RTS thr:off Fragment thr:off
Encryption key:------- Security mode:open
Power Management:off
Link Quality=100/100 Signal level=100/100 Noise level=0/100
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0
lo no wireless extensions.
eth0 no wireless extensions.


RPI directly next to router: Link Quality = 100/100 Signal level =100/100 noise level =0/100 >>> very good
RPI 2 m away from router: Link Quality=100/100 Signal level=84/100 Noise level=0/100 >>> very good
RPI 3 m away from router: connection lost!

I am a newbie at Linux and so I have no idea how to debug such a problem.

Thankful for any support or hint on this! Greetings.

This sounds to me like an hardware problem. We recently discovered a quality issues affecting those dongles: after a period of time some of them just show the same symptoms you report.
See here: amazon.com/review/R13MS9UQA … 6&store=pc

If yours is still in warranty I would ask for a replacement, or you can just use the Pi’s internal one…

Thanks Michelangelo for your support.

Can you recommend any other WIFI-Dongle that works good with volumio? (other than EDIMAX …)
Would be nice if no driver installation would be necessary, as I am not very keen on Linux.

Thanks in advance. I appreciate your work on volumio.

I think that many wifi dongles work very well. Edimax is often recommended because we know it does work, but even with this brand there are different chipsets… this is actually what controls how successfully it will work. Realtek RTL8188, 8192 seem to be good choices (someone please correct me if I’m wrong here … just going on what I’ve seen reported). I guess you were unlucky with your original choice

I bought an EDUP BC1186 (amazon.com/gp/product/B00KV … UTF8&psc=1) in early December and have been very happy with it so far. Worked without any need for installing a driver on Pi 1 model B. Customer Q&A would suggest it uses the RTL8192CU chipset.

The Edimax dongle that Michelangelo referred to uses the RTL8188 chipset.

systemd[1]: Found device EW-7811Un 802.11n Wireless Adapter [Realtek RTL8188CUS].

Cheers.

I just spent a couple of days troubleshooting a similar issue. Pi3 and HiFiBerry DAC+. My setup worked great over wired Ethernet but the wireless would come and go. Very frustrating. When I placed the unit next to my WiFI router it knocked out the wires to all of my home devices! That was the key to figuring it out - turns out the DAC+ has a lot of EMI which interferes with many WiFi frequencies.I spoke with the HIFIBerry support folks and they are working on a modified board with different oscillators to fix the root cause of the problem. In the mean time you can work around by shielding the pi/dac enclosure (I used aluminum foil for some of my test) and if you have to use wifi get the wifi antennae as far away from the dac as possible. I used a cable to a TP-700N I had lying around set up as a wireless access point. That definitely improved things for me.