Use of radios for communication

[themick07]

Are we allowed to use radios for communication from the pit to the stands?

[engunneer]

They have been banned in the past, but I don't see a specific rule this year. Why not cell phones?

[themick07]

Originally Posted by engunneer

They have been banned in the past, but I don't see a specific rule this year. Why not cell phones?

Terrible signal. We are in The Wolstein Center in Cleveland. A college basketball court.

[ayeckley]

Originally Posted by themick07

A college Faraday cage.

Fixed that for you.

[Al Skierkiewicz]

Check in the "At the Event" rules.

4.15 SITE RESTRICTIONS
Please read the following common site restrictions and adhere to them in order to promote an orderly, safe, pleasant
and exciting competition. Please refer to Administrative Manual - Section 4.2 FIRST Safety for additional site
restrictions at your event.


Do not use walkie-talkies.

Just adding to the following post.

[Chris_Ely]

From the Admin. manual:

Originally Posted by Admin. Manual 4.15

Do not use walkie-talkies.

[goofy173]

So cell phones with push-to-talk would be exactly the same as a walkie talkie and therefore banned. How would they know?

[Joe Ross]

Originally Posted by goofy173

So cell phones with push-to-talk would be exactly the same as a walkie talkie and therefore banned. How would they know?

I suspect that the rule isn't intended to ban the function of the walkie-talkie, but rather the implementation. FIRST uses multiple sets of radios for communication between volunteers, which I suspect they do not want to be interfered with. Cell phone push-to-talk does not operate in the personal radio frequency range.

[Tungrus]

Hotspots using cell phones and similar technology creates interference too! PLEASE PLEASE do not mess our robots! Get pigeons if you can but no walkie-talkie!

[fb39ca4]

Doesn't say anything about ham radios. I don't see what the issue would be about interference, as those and walkie-talkies do not operate on the same bands as wifi.

[Libby K]

Originally Posted by fb39ca4

Doesn't say anything about ham radios. I don't see what the issue would be about interference, as those and walkie-talkies do not operate on the same bands as wifi.

Event managers and key volunteers use radios to communicate across the competition venues.

As has been said already, it's in the manual not to use them. So don't.

[RallyJeff]

Originally Posted by fb39ca4

Doesn't say anything about ham radios. I don't see what the issue would be about interference, as those and walkie-talkies do not operate on the same bands as wifi.

There are walkie-talkie style ham radios, which is what anyone at an FRC event would probably be using - I hope nobody's considering setting up a base station in their pit.

Depending on the power output of a ham radio, its distance from other devices, and the extent of the RF shielding/protection in those devices, a ham radio can most certainly cause interference in other devices on different bands... and even on sensitive electronics generally.

[JCharlton]

Originally Posted by Tungrus

Hotspots using cell phones and similar technology creates interference too! PLEASE PLEASE do not mess our robots! Get pigeons if you can but no walkie-talkie!

I think pigeons might mess with the robots too.

[Solidstate89]

Originally Posted by Tungrus

Hotspots using cell phones and similar technology creates interference too! PLEASE PLEASE do not mess our robots! Get pigeons if you can but no walkie-talkie!

They don't operate on even remotely the same frequency. There would be little to no interference between the WiFi that the robots use (I believe they operate on the 5Ghz channel) and the frequency that any cell phone would use over its cellular connection that can range anywhere from 700-800Mhz, to as high as 1700Mhz or even 2100Mhz - all depending on your carrier.

This if of course, assuming proper shielding was used in the cell phones and hotspots to reduce RF leakage.

[Al Skierkiewicz]

Originally Posted by Solidstate89

They don't operate on even remotely the same frequency. There would be little to no interference between the WiFi that the robots use (I believe they operate on the 5Ghz channel) and the frequency that any cell phone would use over its cellular connection that can range anywhere from 700-800Mhz, to as high as 1700Mhz or even 2100Mhz - all depending on your carrier.

This if of course, assuming proper shielding was used in the cell phones and hotspots to reduce RF leakage.

Sorry, Solid, That is not the way interference works. The third harmonic of 1700 MHz is right in the band. All it needs is a non-linear mixer and voila, interference. Loose aluminum hardware makes a great non-linear mixer. High power RF mixing in the input to a receiver can also produce the same effect. 800 + 2*2100 also comes out on a frequency that can interfere.