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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Wireless and Communications => Topic started by: brian maddox on November 25, 2019, 09:11:49 pm

Title: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: brian maddox on November 25, 2019, 09:11:49 pm
Okay, i've got my first gig coming up with Digital Axient in the X55 band.  It's been a long time since i worked with anything this high up in the frequency band, and the stuff i did use was old Line6 stuff with very limited capability.

So, anything to watch out for or is this just Digital Axient "business as usual"?

tia
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: Luke Geis on November 25, 2019, 09:26:38 pm
I try and do a whitespace estimate for my area before the show just to see, but generally, if you are in a legal band, the issues should be little to nonexistent. WWB also allows you to put in your zip code and it will block out the respective TV channels known ( at the time of the update ) to that area. If you ware running with full Axient ( auto switching ) I wouldn't worry too much. All I can say is that I LOVE the new Axient stuff. Nothing better than being able to change anything I need to on the fly, let alone the auto channel switching.
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: Jason Glass on November 25, 2019, 10:09:33 pm
Okay, i've got my first gig coming up with Digital Axient in the X55 band.  It's been a long time since i worked with anything this high up in the frequency band, and the stuff i did use was old Line6 stuff with very limited capability.

So, anything to watch out for or is this just Digital Axient "business as usual"?

tia

You MUST be Part 74 licensed to operate X55.  No exceptions.

You MUST, absolutely MUST, do an FCC ULS geographic search for your operating location and frequency range (I suggest a 5 mile radius and examine each licensee's map for TX vs. RX stations.  Avoid all RX within 5 mi and all freqs with P2P paths crossing within 1 mi of your location), and calculate your freqs to avoid each primary licensee's carriers, with appropriate channel freq spacings per emission designator.

Then you MUST, absolutely MUST contact the local SBE freq coordinator and request coordination approval for your freqs.  I suggest 1 week in advance.  Then, when you get on site, do a scan and add any newly found carriers to your coordination math, then do it all again and beg "Mia culpa" if you require an amended coord request.
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: brian maddox on November 25, 2019, 11:07:33 pm
You MUST be Part 74 licensed to operate X55.  No exceptions.

You MUST, absolutely MUST, do an FCC ULS geographic search for your operating location and frequency range (I suggest a 5 mile radius and examine each licensee's map for TX vs. RX stations.  Avoid all RX within 5 mi and all freqs with P2P paths crossing within 1 mi of your location), and calculate your freqs to avoid each primary licensee's carriers, with appropriate channel freq spacings per emission designator.

Then you MUST, absolutely MUST contact the local SBE freq coordinator and request coordination approval for your freqs.  I suggest 1 week in advance.  Then, when you get on site, do a scan and add any newly found carriers to your coordination math, then do it all again and beg "Mia culpa" if you require an amended coord request.

So, is there anything i MUST do?  :)

Good news is, i'm not actually doing the Frequency Coordination on this gig and my confidence in those that are doing the coordination is quite high so i have every reason to believe that all of your musts are already being followed. My role on this is largely RF QC with a little Frequency Rules Enforcement  thrown in [there will be press so there will likely be....  issues].  This is an annual gig with a very good crew of folks working on things, So i have every reason to believe things are gonna be well sorted before i even get there.  I was mostly looking for any practical advice that might be different than the typical "TV band" stuff i'm used to using.  Antenna placement differences, antenna cabling differences or any particular gotchas to look out for.  I'm mixing these with a pile of UHFRs and PSM1000s, which wouldn't be my first choice.  But i've got independent antenna rigs for each "family" of things [Axient, UHFR/analog, PSM] and i'm working outside, so that simplifies some things as well.

This is all still absolutely great info to have though, so thank you for that.  I do have to ask, of these MUST recommendations, which would NOT usually apply to a typical 470-630 gig?  I'm still trying to get a firm grip on things in our new FCC reality.  Plus, knowledge is power.

Thanks for the help!

Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: Jason Glass on November 26, 2019, 12:10:20 am
I do have to ask, of these MUST recommendations, which would NOT usually apply to a typical 470-630 gig?  I'm still trying to get a firm grip on things in our new FCC reality.  Plus, knowledge is power.

Thanks for the help!

The SBE coordination requirements aren't necessary for TV band operations.

If one were to inadvertently interfere with TV band operations in VHF or UHF, a 250 mW part 74 TX might cause problems for a few dozen viewers.  If one interferes with 941-960 MHz ops, it can take an entire station off the air for 100k+ viewers/listeners or interrupt data connections for an entire region.  Very, very serious stuff.
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: Henry Cohen on November 26, 2019, 12:56:50 pm
I try and do a whitespace estimate for my area before the show just to see, but generally, if you are in a legal band, the issues should be little to nonexistent. WWB also allows you to put in your zip code and it will block out the respective TV channels known ( at the time of the update ) to that area.

Not relevant to the [expanded] STL band.
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: brian maddox on November 26, 2019, 08:08:50 pm
The SBE coordination requirements aren't necessary for TV band operations.

If one were to inadvertently interfere with TV band operations in VHF or UHF, a 250 mW part 74 TX might cause problems for a few dozen viewers.  If one interferes with 941-960 MHz ops, it can take an entire station off the air for 100k+ viewers/listeners or interrupt data connections for an entire region.  Very, very serious stuff.

I feel like that would make people unhappy. A LOT of people.  As an A1 i have learned that making a LOT of people unhappy is undesirable.  Makes sense that that would also carry over to RF tech.  :)

Great info.  Thanks again!
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: Jason Glass on November 26, 2019, 09:58:48 pm
I feel like that would make people unhappy. A LOT of people.  As an A1 i have learned that making a LOT of people unhappy is undesirable.  Makes sense that that would also carry over to RF tech.  :)

Great info.  Thanks again!

Don't assume that your event frequency coordinator knows these details, and for the love of God don't assume that someone else's license covers your X55 ops.

The person who transmits the signal is the operator and is ultimately responsible [you (or the company directly employing you)], and requires an appropriate call sign.

Ask your RF coordinator to copy you on all SBE emails and raise Hell if you don't personally see a specific approval before you transmit.
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: brian maddox on November 26, 2019, 10:35:06 pm
Don't assume that your event frequency coordinator knows these details, and for the love of God don't assume that someone else's license covers your X55 ops.

The person who transmits the signal is the operator and is ultimately responsible [you (or the company directly employing you)], and requires an appropriate call sign.

Ask your RF coordinator to copy you on all SBE emails and raise Hell if you don't personally see a specific approval before you transmit.

Trust, but verify.  Always a good policy.
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: Scott Holtzman on November 27, 2019, 03:22:27 am
The SBE coordination requirements aren't necessary for TV band operations.

If one were to inadvertently interfere with TV band operations in VHF or UHF, a 250 mW part 74 TX might cause problems for a few dozen viewers.  If one interferes with 941-960 MHz ops, it can take an entire station off the air for 100k+ viewers/listeners or interrupt data connections for an entire region.  Very, very serious stuff.

Including if I recall quite a bit of medical telemetry gear operates in that region.  You could wipe out a nearby hospital wireless cardiac monitors.
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: Henry Cohen on November 27, 2019, 09:16:05 am
Including if I recall quite a bit of medical telemetry gear operates in that region.  You could wipe out a nearby hospital wireless cardiac monitors.

Nope. Wireless Medical Telemetry bands are 608-614 MHz (TV ch 37), 1395-1400 MHz and 1427-1432 MHz.
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: Scott Helmke on November 27, 2019, 10:02:50 am
You MUST, absolutely MUST, do an FCC ULS geographic search for your operating location and frequency range (I suggest a 5 mile radius and examine each licensee's map for TX vs. RX stations.  Avoid all RX within 5 mi and all freqs with P2P paths crossing within 1 mi of your location), and calculate your freqs to avoid each primary licensee's carriers, with appropriate channel freq spacings per emission designator.

Then you MUST, absolutely MUST contact the local SBE freq coordinator and request coordination approval for your freqs.  I suggest 1 week in advance.  Then, when you get on site, do a scan and add any newly found carriers to your coordination math, then do it all again and beg "Mia culpa" if you require an amended coord request.

Jason, could you expand on those two items a little, maybe a link or just spell out the acronyms?

I do get the occasional X band request, generally from somebody who is a TV broadcaster and presumably has a part 74 license, but the coordination is done by me for a local Big 10 school.
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: Henry Cohen on November 27, 2019, 10:41:02 am
Jason, could you expand on those two items a little, maybe a link or just spell out the acronyms?

ULS = FCC's Universal Licensing System (https://wireless2.fcc.gov/UlsApp/UlsSearch/searchLicense.jsp)

SBE = Society of Broadcast Engineers (http://sbe.org), more specifically, the local SBE coordinators (https://www.sbe.org/sections/freq_local.php)


Quote
I do get the occasional X band request, generally from somebody who is a TV broadcaster and presumably has a part 74 license, but the coordination is done by me for a local Big 10 school.

The broadcaster may or may not be licensed for 941-960 (or the previous 944-952 MHz). The other important question is, does TC have an STL license? (No, according to the ULS, unless it's under another name.) If you're not following Jason's description of the rules, the consequences, legal and operational, could be significant.
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: Jason Glass on November 27, 2019, 11:54:53 am
ULS = FCC's Universal Licensing System (https://wireless2.fcc.gov/UlsApp/UlsSearch/searchLicense.jsp)

SBE = Society of Broadcast Engineers (http://sbe.org), more specifically, the local SBE coordinators (https://www.sbe.org/sections/freq_local.php)


The broadcaster may or may not be licensed for 941-960 (or the previous 944-952 MHz). The other important question is, does TC have an STL license? (No, according to the ULS, unless it's under another name.) If you're not following Jason's description of the rules, the consequences, legal and operational, could be significant.

There's a loophole in the rules that allows Part 74 licensees to operate in any legal Part 74 band, even those not specified in the license, for up to *I think* 720 hours per year.
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: Henry Cohen on November 27, 2019, 12:15:42 pm
There's a loophole in the rules that allows Part 74 licensees to operate in any legal Part 74 band, even those not specified in the license, for up to *I think* 720 hours per year.

Not a loophole; an explicitly stated rule. 47CFR Part 74.24 (https://www.govinfo.gov/content/pkg/CFR-2014-title47-vol4/xml/CFR-2014-title47-vol4-sec74-24.xml) permits licensed Part 73 broadcasters to operate up to 720 hours/year/frequency on any subpart D, E, F and H bands/services. So yes, the broadcast customer could operate legally, given the appropriate coordination with the local SBE, but the rental house can not [without the appropriate Part 74 license].
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: Scott Helmke on December 12, 2019, 12:59:10 pm
I've been doing some research on this, and getting into contact with my local SBE coordinator as suggested.

I've actually not been able to find anything about this STL band on the ULS, though, unless it's hiding under another category.
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: Jason Glass on December 12, 2019, 03:46:50 pm
I've been doing some research on this, and getting into contact with my local SBE coordinator as suggested.

I've actually not been able to find anything about this STL band on the ULS, though, unless it's hiding under another category.

I've found that a ULS geographic "all services" search based on a radius from coordinates, within a frequency range, returns all TX and RX stations within that radius.  Examination of each station's license reveals the rest of the necessary details to determine which freqs to avoid and how wide their occupied BW's are.

Also, use Google Earth and download this KMZ file to get lots of good info about RF operations in a given geography, including STL paths.  This resource is pure gold for RF work.  https://www.fccinfo.com/fccinfo_google_earth.php (https://www.fccinfo.com/fccinfo_google_earth.php)
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: Scott Helmke on December 13, 2019, 10:19:39 am
Also, use Google Earth and download this KMZ file to get lots of good info about RF operations in a given geography, including STL paths.  This resource is pure gold for RF work.  https://www.fccinfo.com/fccinfo_google_earth.php (https://www.fccinfo.com/fccinfo_google_earth.php)

Wow!
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: Ike Zimbel on December 13, 2019, 12:11:36 pm
I've found that a ULS geographic "all services" search based on a radius from coordinates, within a frequency range, returns all TX and RX stations within that radius.  Examination of each station's license reveals the rest of the necessary details to determine which freqs to avoid and how wide their occupied BW's are.

Also, use Google Earth and download this KMZ file to get lots of good info about RF operations in a given geography, including STL paths.  This resource is pure gold for RF work.  https://www.fccinfo.com/fccinfo_google_earth.php (https://www.fccinfo.com/fccinfo_google_earth.php)
Thanks, Jason, for another invaluable contribution to our field!
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: John Sulek on December 13, 2019, 12:54:23 pm
I've found that a ULS geographic "all services" search based on a radius from coordinates, within a frequency range, returns all TX and RX stations within that radius.  Examination of each station's license reveals the rest of the necessary details to determine which freqs to avoid and how wide their occupied BW's are.

Also, use Google Earth and download this KMZ file to get lots of good info about RF operations in a given geography, including STL paths.  This resource is pure gold for RF work.  https://www.fccinfo.com/fccinfo_google_earth.php (https://www.fccinfo.com/fccinfo_google_earth.php)

Thanks!
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: Scott Helmke on December 13, 2019, 02:12:08 pm
Henry, would you consider making this thread a sticky?
Title: Re: Shure Axient Digital X55 Band [941MHz-960MHz]
Post by: brian maddox on December 13, 2019, 08:52:36 pm
...
Also, use Google Earth and download this KMZ file to get lots of good info about RF operations in a given geography, including STL paths.  This resource is pure gold for RF work.  https://www.fccinfo.com/fccinfo_google_earth.php (https://www.fccinfo.com/fccinfo_google_earth.php)

This is GOLD!!!!!!  Thanks for giving up some of the secrets to your magic tricks.  Much Appreciated!