FCC narrow band widths

A couple of years ago the FCC changed the required channel spacing in the 430-470Mhz frequency range (approximate) from 25Khz to 12.5Khz. These frequencies include a large number of the "older" robotic instruments and gps radios. I believe most of the older radios can't have their channel spacing easily changed, if at all. If you look at the newer radios, you'll find the 12.5Khz channel spacing. It also had to do with the bandwidth of each channel.

So yes, the older radios will be obsolete. I can't say how the FCC will enforce the new spacing. I've gone from the old Satel 2ax radios (costing several thousand dollars) to a bluetooth connection, similar to the BanTam, but made by Sena. You can get them from Lemosint http://www.lemosint.com/zigbee/proBee.php The BanTams are ready to go.

The FCC implemented these rules quite some time back, they finally go into effect in 2013.

ALL radio frequencies commonly used by surveyors as well as many others must comply with the FCC mandate for narrow banding, some newer equipment already has the hardware, BUT much hardware will need to be replaced.

In my small operation, this mandate will costs upwards of $2000, need to upgrade PDL radios for RTK as well as my voice radios AND my FCC license.

I intended to spread this over three years, didn't do anything in 2010, so 2011 and 2012 to get it done before 01-Jan-2013.

How this will be enforced is anybody's guess, word is that the FCC is going add some field staff to sniff out violators, the way the Federal budget is right now, who knows, regardless I am going to comply, you don't want the FCC on your back.

SHG

There are a bunch of articles about this if you guys google something like "narrowbanding" or "12.5 khz".

http://www.fcc.gov/pshs/public-safety-spectrum/narrowbanding.html

I found this from a FCC news release: "All equipment certified since 1997 has been required to have a 12.5 kHz operational mode."

All your radios are older than this?

All of my Motorola voice radios are too old. My Pacific Crest PDL base from 2001 is too old, and my 2007 PDL rovers are too old. Pacific Crest has told me that all of my PDL products must go back to the factory for modem board upgrades, it would be nice if this wasn't true. No matter what, you must have a FCC license for 12.5 Khz spacing.

SHG

Deos anyone know where the Trimble "GeoRadio 600" stands? We bought the original Geodimeter 600 around 2000 or 2001. This is a replacement radio made after Trimble took over, painted them yellow, and called them 5600s.

It says "GeoRadio 600 H25 0,1" on the back, and has "FCC ID: H46 B", as well.

Anyone know?

Are you talking about 2-way hand held radios, like the 2 watt Motorola type? I think this is what most of us use. I think this applies only to FCC Part 90 licenses, like big dispatch type systems. Public safety and government, police and fire, etc. Systems that require a FCC license, not radios anyone can buy for $150 for field crews to talk to one another.

This is for operating the 600 as a robot right? The range is what, 1000ft? If you don't have an FCC license, there is no way this applies to you, especially at these transmit powers.

Yes, they have very short range ... probably 1,500 feet max under good conditions. But, FWIW, I rarely got more range than that out of the HiperLites where I used to work.

Cost of radio is irrelevant, there are a few frequencies that qualify to operate without a license, however many of those $150 radios are capable of transmitting on frequencies that are regulated. I need to look at the rules again, there may be a power limit under which you don't need a FCC license too. In any event the FCC is going to take the stance that ignorance is no excuse. My experience has been that quite a few surveyors have been in the habit of only loosely complying with the FCC rules, if at all. I have a 35W radio in my truck and have a license for that, my $150 radios I bought at Costco are on the same licensed frequencies.

It is very possible that all users of the UHF band really do require a license, no matter the power. The more I read, the more I believe it. But I really wonder how many people have them for their 2 watt radios? I doubt I would pick up so many people on the default Motorola channels 1 & 2 if these people really had FCC licenses and assigned frequencies.

As I stated previously, I think there probably are a lot of violators. Likely we would all be assigned frequencies in the same area of the spectrum, I suspect that most surveyors with licenses are all on the same few frequencies.

SHG

how will they police it? if i use my existing radios in violation what are they going to do?

much ado about nothing, again.

i'll replace my equipment on my schedule, not uncle sam's.

damn the man.

While lacking the damn-the-man attitude, I'll probably do the same thing as Snoop -- use my gear until I'm ready to replace it or get busted by the FCC, whichever comes first. However, I'm only using 5-watt handhelds and a Georadio, both of which have relatively small emission footprints as well as being moving targets.

If I was using an RTK transmitter I'd probably spring for the compliance expense. Blowing 35 watts from a single location all day would be both more disruptive to other users and more susceptible to enforcement efforts.

P.S. I don't actually know if my handhelds (Motorola CP200s) are currently programmed for 25 khz or 12.5 khz channel width. I do know that I don't have a license to operate them. I guess maybe I should look into both issues.

GeoRadio 600 is a spread spectrum radio, so it doesn't require a license.

UHF/VHF radios require a license, like the Pacific Crest RFM and PDL radios.

Snoop is right, especially if you work in the boonies and move around a lot. No one's going to know or care. Different story in heavily populated areas. If you put a 35-watt broadcasting CORS on your office roof in the suburbs of Chicago and blast out 24/7, someone's probably going to come knocking.

35 watt is old and a modern radio "rtk" for a 35 watt base is old school
example 1 watt modern will go about 29 km line of site.

With newer rs232 1 watt radio modems most of with are configurable as repeaters
so fare have no need for 35 watt or even 1 watt radio are getting better all
the time just like cell phones which are "small"

Time to ditch the old 35 watt base to a 1 watt setup & repeater abbility

Peter K

> GeoRadio 600 is a spread spectrum radio, so it doesn't require a license.

Thanks, that's nice to know. (Guilt-free robotics!)

Edit: A little research suggests that I spoke too soon. A Trimble FAQ titled "Changes to FCC Part 90 Regulations," apparently issued in 2004, states that "[a]ll Trimble, Geodimeter, and Zeiss Robotic Total Stations operate in this [430-470] frequency band, and thus require a license. And there are 2 models of the Georadio: the original 430-470 MHz "red dot," which dates back to somewhere around 1994, and the 2.4 GHz "blue dot" that was released around 2004. The press release for the 2.4 GHz describes it as a spread-spectrum license-free solution that can be retrofitted to the older Geodimeter 600 / Trimble 5600.

So it looks like I'll have to resume the burden of guilt when running my robot.

There is no way that a 1 watt radio will go 29 km. Probably not even with a super high gain directional antenna. Certainly not with anything useful for rtk. Sorry, you just made this up. We're not talking about cell modems either man.

"[a]ll Trimble, Geodimeter, and Zeiss Robotic Total Stations operate in this [430-470] frequency band, and thus require a license."

I dropped a quote in my last post. The quote from the Trimble FAQ is only the text shown above.