Internet problems through network card?

For a long time now it has been the case with me that when I talk to friends in the Discord, their voices sometimes fail to be heard for fractions of seconds, so they stutter / stutter. That really annoys me, I hardly use the computer for discord. This also causes problems when gambling, because this seconds printer also occurs in games.
Where can the problem be, my brother does not have the problem with his laptop.
I own this network card: https://www.amazon.de/...006BSPTAQ/

I've been assembling the computer myself for 1-2 years. The software of this network card shows me Wi-Fi signal strengths from 50% (Good) to 70% (Excellent).

The case / computer / tower, is aligned parallel to the wall, on which it is ajar. If I let out the back of the case, away from the wall of the place, so that the antennas of the network card point away, I get a slightly better signal, so 80% but not constant.
In addition, I have too little room for my legs under the desk when I align the case as described.
What can I do? I've read in the reviews of this network card on Amazon, that the antennas are probably a bit weak. One said he had done other antennas and had full internet speed again.
Do you know where to get good antennas for that?

Cool, we have the same network card. Is the WLAN on 2.4 Ghz or 5 Ghz? Which RSSI value do you reach? -60, -70?

The software has Channel 1 - 2.4 G.
RSSI, what is it? Signal Strength is 50% -70%

How is yours?

Oh, that should work without any problems. Reinstall Discord and try to talk to him.

Mine is connected to the router via LAN.

Works mostly too. But every now and then her voices break off and I have to ask what he said again, because parts of his sentences do not arrive. In the long run that gets annoying

If the network card has standard connections for the antenna (s), you can buy large antennas and use them instead of the small one. There are many manufacturers. You can easily find this on Ebay or Amazon.

The following reasons come to mind:

Anti-virus program (for testing times disable)

Firewall (to deactivate the test)

The server used has a high load

Too many neighbors on the same WLAN channel (change channel 1, 6 o. 11)

Fluctuating reception strength (antennas weak, obstacles on radio link)

Also the alignment of the antennas is important (try it)

The radio link includes 2 participants with antennas, as well as turn the router turn tilt, which may also be badly positioned!

Antennas radiate with the long side, so never align the antenna tip in the direction of the router, but align the antenna across the desired radio direction, aligning both antennas at different angles!

Here are better antennas and options:

you need 2 pieces, align in different directions! Optimal would be visual contact with the router, radio is always rectilinear never around the corner! 3 dBi more means e.g. Double receive field strength. Your antennas have about 4 dBi reception strength I guess. The size of the antennas is not crucial, they have to be perfectly tuned (called HF adaptation), then they have good reception values. Too long bad thin cheap antenna cables are harmful, shorter ones are better, since also antenna cables attenuate the signal (attenuation in the HF technology).

For example, This 12 dBi antenna makes a good impression:

https://www.amazon.de/...B06Y43D6MC

With the Free Android app, you can check the Wi-Fi channel:

https://avm.de/...zapp-wlan/

https://www.wieistmeineip.de/speedtest-kabel/

The antenna must not be big. It must be tuned in length in resonance with WLAN at 2.4 GHz

The antennas are not Yagis and such a junk. You can forget the resonance.

Even a rod antenna needs to resonate at such high frequencies for it to work. Length 80% of 1/4 of the wavelength

And then you get a 1/4 wavelength of 3.12 centimeters at 2.4GHz and much less at 5GHz. Antennas are not so short. So q.e.d. Can't agree, because antennas are not so short.

300,000 km / second propagation speed, equivalent to 300,000,000 meters per second. At 5GHz frequency this corresponds to a wavelength of 0.06 meters = 6cm = 1.5cm quarter wavelength

Why can then cell phones receive Wi-Fi. It does not fit in much more than a few inches.

To receive at GHz reception, you absolutely need resonance. There are different methods. For flat antennas z.b. Arrays are used for camping.

There are dipoles with 1/2 wavelength.