CM4 uConsole defaults to PCB antenna resulting in poor wifi reception

The CM4 defaults to using the built-in antenna on its PCB. Adding dtparam=ant2 to my /boot/config.txt and rebooting causes it to use the external antenna and a massive improvement in reception.

I noticed by WiFi reception of my CM4 uConsole got worse when I put the back cover on, and reception was considerably lower compared to an external USB WiFi adapter.

I started modding it to add an adjustable antenna, and discovered that no matter what I antenna I used (or no antenna) the reception was the same. Digging deeper it turns out that the external antenna header on the CM4 board is disabled by default, and it prefers to use the onboard antenna instead. Switching it use the external antenna fixed the reception issues.


It’s also a thing that should be done on the DevTerm.

I haven’t received my uConsole, but some of these other DevTerm tips may apply too.


I hope that makes it into the default config for the next release.
No reason to depend on the internal one, especially when the uconsole has a metal shell.

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Thanks for this, I found that this did make a difference.

One thing I did find that turning this on actually reduced the signal - so I opened it up and not reconnected the antenna but just carefully rotated it in the socket a little bit and when it improved.

It could have been that it didn’t have a clean connection so rotating it helped it make a better contact. Anyhow after that and this config change has now improved WiFi.

For me it’s the other way around. Without dtparam=ant2 my wifi works without problems and with it I have connection problems and slow speed.

Do you guys use the newest OS image? I’m on

Yes, using the latest image. Without this parameter it can’t be using the external antenna, there is no antenna specific customization in the uconsole CM4 patches.

Hearing the mixed results others are having, I would guess there are a variety of environmental factors that might make one work better than the other due to the complex nature of wireless signals.

Just booted my cm4 and i can confirm wifi is weak web pages slow to load anyway i can fix this please.

Do you have the correct antennas plugged into their respective radios?

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Yes i have the wifi on the cm4 unit and 4g module connected. See my pucture above

Cool, just checking. The connector will be the same, but the antenna element should be different. Plugging the 4g antenna into the wifi radio would cause reception issues.

Well i have fixed it thanks to the guys over on the clockwork discord run the below command and reboot. Note inc all the quote marks my wifi is much faster now its a win.

sudo sh -c 'echo "dtparam=ant2" >> /boot/config.txt'

you can check if the command worked with cat /boot/config.txt


This is the same fix in the OP.


here if i switch to ant2 the signal is worse… i have two uConsoles so i tried both wifi antennas on the cm4… nothing always bad signal :frowning:

I am getting the same now too.

tried to make the connector inside more narrow… but that changed nothing x.x maybe the side on the pi is damaged? :frowning: but looks fine…

Edit: others - non-uConsole-users - have these problems too… External Antenna On CM4 - Raspberry Pi Forums

A06 wifi is pretty bad too :frowning:

I added the dtparam=ant2 line to the bottom of config.txt as recommended and my wireless is still miserable on my CM4. It actually seems to be slightly worse and disconnects more often while the signal strength remains roughly the same. This is very confusing behavior and i thought my connection or antenna were bad, but when i used an old antenna from an ancient desktop wireless card with the same connector there wasnt any improvement.

I got better results with a new antenna/cable combo. The cable is just too short, so I have one on order.
New antenna

Stock antenna

This is an iperf speed test to another computer on my network.


Yes that setting was much much worse on my 5ghz network.
Reverting to default gives better reception (but still poor in marginal locations in the house)


oh, i hope this isn’t my issue…

External Antenna On CM4 - Page 2 - Raspberry Pi Forums