I read the notice that you should not power on the device without the antennas attached.
Can somebody explain why?
Do the antennas need to be attached when wifi is diabled in the configuration?
RF output has to be terminated with appropriate load … usually that’s antenna with it’s impedance of 50 Ohm. If load doesn’t match designed impedance (open end cable doesn’t), then emitted power reflects from the open end … and in case of duplex devices (such as WiFi device) it hits receiver … really hard as receivers are designed to work with much lower power levels (Tx power is usually around 15dBm, Rx power with plenty of signal is around -60dBm, difference is 75dB, which is factor of 31 million). So operating wireless device without antennae attached may cause damage to receiver. Less frequently it may cause damage to Tx power amplifier if apparent load is much less than designed (50 Ohm), which can happen if length of remaining feeding lines falls into “sweet spot” creating a resonator (which can “pull” power from transmitter).
If transmitter is disabled, then it should not cause any problem. However, the problem with software controls is that they might be applied late in the boot sequence (and device might be transmitting for a while) or they might be (erroneously) changed. Alternative to attaching antennae is attaching terminators (50 Ohm resistors in shape of antenna connectors … they do come with certain power rating and if transmitter emits higher power, then they may overheat - just like any other resistor driver with too high power). These present as “normal” antenna load, but are most often almost invisible … if that’s the driver to detach antennae from wireless device.
thanks for the detailed explanation.
i think i go with the terminators then.
would this be the right one? https://www.mauritz.de/en/adapters/sma-adapter/sma-plug-terminator-50-ohm-6-ghz
That should probably be fine. One thing, missing from the page you linked, is power rating. Hopefully it can take at least 0.1W (20dBm) without destroying the terminator … if Tx gets somehow enabled for prolonged periods.
A bit pricier alternative (but better one, up to 18GHz … not that you’d need much above 6GHz for comodity WiFi) has specified power rating of 2W (33dBm) continuous.
When WiFI is disabled, there is no need to use terminators. The transmitters are off then.
Hello guys,
Sorry for the delayed response from my end in this old thread.
I want to put Ax3 with two CAP AX at an apartment. The case is I want to not put the antennas of the Ax3 because I will not use the WiFi feature. Will it be possible to run CapsMan without those antennas and is it fair option for the Ax3?
–
Georgi
You can use ax3 without a problem as a capsman controller while wifi is turned off. I have similar setup, ax3 router, two cap ax and one ax2 as CAP.
I don’t find it “smart” to run an Ax3 with no antennas connected, even if radio is off.
The radios are off, no antenna connected, everything is fine.
The radios are turned on accidentally, no antenna connected, radios may fry.
What happens when you reset the router (are the radios automatically on or not)?
I would use terminators (or very short suitable rubber duck antennas, that you can fold horizontally), better be safe than sorry.
http://forum.mikrotik.com/t/solved-is-it-mandatory-to-mount-antennas-on-hap-ac3/172910/1
I just left original antennas connected. I hope @doychevg will do the same.
Hi, is it possible to know if I fired the Wi-Fi router?
By accident, I slightly unsecured antennas, not fully detached but they were loosened. After putting it back it seems to be working, but now I am unsure if there was damage and now I will have issue with Wi-Fi signal.
Did you noticed any difference ? I doubt you damaged the wifi on your router.
Difference on the router or the growing brain tumour on the admin??? 
No, it seems to be working. But I was looking for an answer like “execute this command, and you will see the status of the hardware.” Or maybe someone can describe what should happen—for example, the device can connect only within a proximity of 1 meter; the device can be configured to only 17 dB of Tx power, etc.
Not that It necessarily applies to Wi-Fi radios, but in the (good?) all times, as a kid, I did fry a few radios (think of CB radios with 1970’s discrete components electronics).
Those radios never failed “gracefully”, one moment they worked nicely, the next they didn’t anymore, sometimes even visibly letting out the “magic smoke”.
I don’t think that the failure mode would be different on modern electronics.
It is AFAIK similar to overvoltage, you apply too high voltage to some electronics device, it usually either can bear it or it cannot.
It’s the same here I believe. There is no command you can use to see if radio is working or not. If you see your wireless network/s then you are good. If not, well, you need a new router.
Also you said that you slightly unscrewed antennas and you didn’t remove them so it’s unlikely you removed the load from the output as those pins go quite deep into connector.
Are you sure about that?
WiFi2 Disabled
interface/wifi/monitor 0,1,2,3,4
;;; operated by operated by
;;; CAP
;;; :%bridge, :%bridge,
;;; traffic process traffic process
;;; ing on CAP ing on CAP
state: running running running disabled running
channel: 5500/ax/Ceee/D 2412/ax 5180/ax/Ceee/I 5180/ax/Ceee/I
registered-peers: 2 1 2 0
authorized-peers: 2 1 2 0
tx-power: 22 14 18 18
channel-priorities: 0:5500/ax/Ceee/D 0:2412/ax 0:5180/ax/Ceee/I
WiFi2 Enabled
interface/wifi/monitor 0,1,2,3,4
;;; operated by operated by
;;; CAP CAP
;;; :%bridge, :%bridge,
;;; traffic process traffic process
;;; ing on CAP ing on CAP
state: running running running running running
channel: 5500/ax/Ceee/D 2412/ax 5180/ax/Ceee/I 2462/ax 5180/ax/Ceee/I
registered-peers: 2 1 2 1 0
authorized-peers: 2 1 2 1 0
tx-power: 22 14 18 15 18
channel-priorities: 0:5500/ax/Ceee/D 0:2412/ax 0:5180/ax/Ceee/I 0:2462/ax
If radios get damnaged due to antennas not being attached, then the dammage would be on analog side of wifi chip, in particular to the RF power amplifier. And I don’t think that low-cost devices include supervision of that part (it’d require measuring Tx power using a dedicated un-corelated circuitry adding to the cost of device … and in some cases simple measurements of output levels would not suffice because faulty RF PA can e.g. add significant levels of noise). The Tx power you see reported is what digital part of wifi chip orders to analog part to produce. Most of time on most devices it’s approximately what analog part then delivers (give or take a few dB, these PAs are not exactly lab-calibrated).
So no, device itself doesn’t notice if transmitter gets damaged. You can detect that by seeing signifficantly lower signal levels than expected (e.g. less than -70dBm at very short distances between transmitter and receiver, say at 1 meter).
What I meant, there is no command to see if radio is damaged or not 
Got it, thank you!