Decrease range by disabling modulation

[Etz]

This is s a very interesting subject, we are however quite a lot of topic right now, I don't know about the stick-to-the-topic rules here, hope it's alright.

I do however suppose this might be classified as an alternative solution to the original problem (hopefully).

Actually it is not off-topic.
To decrease the range you could either, tilt antennas to make them radiate less horizontally. (You will tilt doghnut)
Or use shorter antennas (quarter or even 1/8 wavelength) which pretty much equals the same as decreasing TX power...as you loose antenna gain...
Still running it with shorter antennas will pose a risk to amplifiers or radio circuit itself, depends how they are tuned.

And most likely those Asus originals are 1/2 or 5/4 in wavelength as those would be most efficent. 5/4 would be best, but would have resistance problems and needs additional circuitry for tuning.
As they are ~2dBi in gain (I've seen that number somwhere), most likely 1/2 wavelength, which means that casing is half-empty indeed. (But actual antenna may be on top of it)

But you are absolutely right, enough of antenna theory...

 

[dlandiss]

And most likely those Asus originals are 1/2 or 5/4 in wavelength as those would be most efficent. 5/4 would be best, but would have resistance problems and needs additional circuitry for tuning.
As they are ~2dBi in gain (I've seen that number somwhere), most likely 1/2 wavelength, which means that casing is half-empty indeed. (But actual antenna may be on top of it)

Several designs are on the market. Some look like J-poles, and others like multi-element verticals with every other segment phase-inverted.

 

[Etz]

Several designs are on the market. Some look like J-poles, and others like multi-element verticals with every other segment phase-inverted.

J-pole has pretty similar directional characteristics and gain as dipole.
But you are correct, designs may vary...

 

[dlandiss]

OK, here is the inside of the stock ASUS antenna. It is a half-wave dipole, generally oriented vertically.

The leg attached to the coaxial cable center conductor is 27.5mm long, a bit less than might be expected for a quarter-wave element; but the element also has 4.5mm diameter (giving it broader bandwidth) so we have to account for end effects.

The leg attached to the coax shield is only 20mm long. ASUS must have done that to compensate for some effect due the dipole being fed unbalanced energy from the coax.

In any case, it works and the true gain probably is about 2dBi (normal for a half-wave dipole).

 

[sfx2000]

OK, here is the inside of the stock ASUS antenna. It is a half-wave dipole, generally oriented vertically.

The leg attached to the coaxial cable center conductor is 27.5mm long, a bit less than might be expected for a quarter-wave element; but the element also has 4.5mm diameter (giving it broader bandwidth) so we have to account for end effects.

The leg attached to the coax shield is only 20mm long. ASUS must have done that to compensate for some effect due the dipole being fed unbalanced energy from the coax.

In any case, it works and the true gain probably is about 2dBi (normal for a half-wave dipole).

View attachment 4992

The cylinder object on the left (0 to 26mm) is the 5GHz Tx/Rx, and it adds the second cylinder (32mm to 52mm) is for the 2.4GHz - and we play this based on frequency loading/match...

(used to do this all the time for dual-band Cellular/PCS handsets back in the days before everything went internal)

This is why it is unwise to replace antennas from 3rd parties - from the OEM, that's ok, but not from 3rd parties - most "5 dB" antennas are matched for 2.4GHz only, and likely will impact 5GHz in a negative way.

 

[sfx2000]

Interesting. I'm still not entirely sure if it's good with Multicast rates (I haven't got IPTV), but it might be interesting to try to meddle with, if nothing else to learn how it works

The multiple AP-part is along the lines of what I was originaly thinking about with the mandatory/unsupported data-rates, sounds like something to investigate further. Thank you!

Again, the client makes some lazy decisions here, but setting the multicast rate to a medium-high value keeps the client from attaching to the AP (the AP will not let low-rate clients attach, so the client continues to search for a AP it can attach to) - so extremely handy in a multiple AP/dual-band WLAN for roaming decisions.

 

[kvic]

Interesting...multicast rate can be used to keep more distant devices to connect..

In Asus ARM routers, I see the wireless drivers can set coding scheme for individual bands. Are there any good use?