Why is out of band transmit illegal? (was: Stupid question)

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#1
I'm sure it's been beat to death in years gone by, but i'm wondering why it's illegal to transmit out of band on modified ham gear, but okay for Part 90 radios such as the Wouxun and Baofeng to transmit on several different bands.
 
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#2
Re: Stupid question...

I'm sure it's been beat to death in years gone by, but i'm wondering why it's illegal to transmit out of band on modified ham gear, but okay for Part 90 radios such as the Wouxun and Baofeng to transmit on several different bands.
Radios have to be type accepted for part 90, they do not for the amateur bands, that's why you can homebred equipment.

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#3
You answered your own question (Part 90 Type Acceptance) but I'll take the explaniation further...

The reason that radios need to be certified for Part 90 for public service bands is to be sure the radio does not put out spurious emissions. Ham radio gear is designed by the manufacturer to only be used in the ham bands. The circuits and final output is designed to only be used within a certain spread of frequencies. When you start using frequencies that the radio isn't designed for there are unknown issues. Out of band, spurious emissions can come from the radio on frequencies other than the one you're transmitting on. Your radio display may say 155.000 MHz but you could be putting out several watts of power on 158.000 MHz, or 138.000 or 154.500, or anywhere else, which could cause intereference to other users and services. The Part 90 certification ensures that the radio is up to specs within the designed frequencies and ensures that the radio isn't causing harmful interference.

The Wouxun and Baofeng radios are technically Part 90 radios that are also marketed as ham rigs. No other ham gear (that I know of) has Part 90 or Part 95 acceptance.

And yes, this has been beaten to death here. Search the forum for numerous posts that say why it is illegal and why it's not a good idea.
 
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#4
WB4CS, thanks for the detailed explanation. That broke it down for me a little better than some of the more vague explanations I have come across regarding this. One more thing, though. Aren't MARS frequencies out of the ham bands as well? Isn't ham gear still allowed to be modified to transmit on those frequencies if you are licensed through MARS to do so, and wouldn't those cause the same spurious emissions? Just curious and trying to understand it a little better. Thanks again.
 
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#5
you're welcome! you're correct, MARS and CAPS is out of the ham bands, but the way I understand it the frequencies used for these are just out of the band around 148 so it shouldn't be far enough out of band to be out of the radio specs.
 
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#6
It's not a matter of being out of spec. You can't transmit outside of the ham bands, even with equipment designed to operate on those out of band frequencies, using a ham license. You aren't authorized to transmit on those frequencies. You are authorized to transmit on ham and MARS frequencies Assuming a ham license and MARS membership), with ham gear or with part 90 (or any other) gear, as long as the transmissions meet all the other part 97 or MARS regulations. Part 90 requires not only a part 90 license, but type approval of the equipment used.
 
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#8
WB4CS, thanks for the detailed explanation. That broke it down for me a little better than some of the more vague explanations I have come across regarding this. One more thing, though. Aren't MARS frequencies out of the ham bands as well? Isn't ham gear still allowed to be modified to transmit on those frequencies if you are licensed through MARS to do so, and wouldn't those cause the same spurious emissions? Just curious and trying to understand it a little better. Thanks again.
As was indicated above, the MARS bands are just outside of the ham bands and this is why the manufacturers provide the ability to modify the radios for out-of-band transmit. The design of the radios take this into account, which is why they work well on those bands, but can cause issues on frequencies, like the public service bands, that are well outside their designed range. Something like your engine will work fairly well if you go just up to the red line (or even a few RPM above), but will tear itself up if you push it well above that spec for any length of time.
 

gewecke

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#9
No tin foil hat needed here, but then there are those "special" type accepted talkies and mobiles which were actually DESIGNED by Kenwood, Yaesu,Alinco and others with out of band use in mind in certain government scenarios where disposable radios might be needed. Modding these was intended by the manufacturer to be simple so a large number could be done quickly ... but then you'll rarely see this in print! ;)

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#10
No tin foil hat needed here, but then there are those "special" type accepted talkies and mobiles which were actually DESIGNED by Kenwood, Yaesu,Alinco and others with out of band use in mind in certain government scenarios where disposable radios might be needed. Modding these was intended by the manufacturer to be simple so a large number could be done quickly ... but then you'll rarely see this in print
That scenario doesn't "feel" right. I suspect that the radios that can be modified are designed to be used in commercial environments too. Maybe in the U.S., maybe not. But be sure it's done out of economic considerations, and probably no other reason.
 

gewecke

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#11
That scenario doesn't "feel" right. I suspect that the radios that can be modified are designed to be used in commercial environments too. Maybe in the U.S., maybe not. But be sure it's done out of economic considerations, and probably no other reason.
True. Way back when some members of congress and those in charge of special ops considered the financial cost of certain deployments, then in place of motorola for comms consumer ham rigs were requisitioned and modded according to ops requirements. I remember this happening twice and those radios were either left behind or destroyed.
Remember the old Icom 02AT ? That was a early pick, before Azden or ADI became candidates.
Today, these are unlikely to be used for this but I'm sure the design didn't change much. ;)

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#12
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IIRC (and I may be mistaken!) the Civil Air Patrol changed the rules years ago, and no longer allow modified Ham gear on their channels. (MARS may have done the same?) And since at least some CAP units have gone P25, how many Ham radios are P25 capable?
 
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#14
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IIRC (and I may be mistaken!) the Civil Air Patrol changed the rules years ago, and no longer allow modified Ham gear on their channels. (MARS may have done the same?) And since at least some CAP units have gone P25, how many Ham radios are P25 capable?
As far as I know, MARS still allows Ham gear, since you have to hold a General Class or higher Ham license to join.
 
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#15
CAP did remove the modified Amateur from their list [not all Wings rely on P25 - still 98% Analog] however MARS still allows it [from the info found on the web]

FYI - CAP is dual mode

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IIRC (and I may be mistaken!) the Civil Air Patrol changed the rules years ago, and no longer allow modified Ham gear on their channels. (MARS may have done the same?) And since at least some CAP units have gone P25, how many Ham radios are P25 capable?
 
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#17
It's not a matter of being out of spec. You can't transmit outside of the ham bands, even with equipment designed to operate on those out of band frequencies, using a ham license. You aren't authorized to transmit on those frequencies. You are authorized to transmit on ham and MARS frequencies Assuming a ham license and MARS membership), with ham gear or with part 90 (or any other) gear, as long as the transmissions meet all the other part 97 or MARS regulations. Part 90 requires not only a part 90 license, but type approval of the equipment used.

So is it illegal to transmit out of band with modified ham gear on a public service frequency I am authorized to use during an instance where the agency's comms were to fail?
 
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#18
YES it is ILLEGAL, regardless of your authorization to use a frequency

Amateur Radio equipment is NOT type-accepted for Part 90 use

So is it illegal to transmit out of band with modified ham gear on a public service frequency I am authorized to use during an instance where the agency's comms were to fail?
 

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#19
The prohibition on using non-type accepted transmitters in a radio service where type accepted transmitters are required is absolute. In other words, if you have authorization to transmit in a Part 90 service (most public safety licenses are Part 90 licenses), you must use Part 90 accepted equipment. Period. End of story.

There is a clause in the Part 97 rules for amateur radio operators which permits them to use any means necessary to communicate in an emergency when no other communications services are available. Emergencies in this case are generally accepted to be situations where there is an immediate threat to life or property. This clause is perceived by some to permit out of band transmit using amateur radio gear. My take on it is that the situations are rare when a true emergency will occur and no other communications services are available.
 
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#20
The prohibition on using non-type accepted transmitters in a radio service where type accepted transmitters are required is absolute. In other words, if you have authorization to transmit in a Part 90 service (most public safety licenses are Part 90 licenses), you must use Part 90 accepted equipment. Period. End of story.
Yep, agreed. FCC rules are pretty straightforward that this is the correct answer.

There is a clause in the Part 97 rules for amateur radio operators which permits them to use any means necessary to communicate in an emergency when no other communications services are available. Emergencies in this case are generally accepted to be situations where there is an immediate threat to life or property. This clause is perceived by some to permit out of band transmit using amateur radio gear. My take on it is that the situations are rare when a true emergency will occur and no other communications services are available.
On Friday I sent an email to one of the FCC Enforcement Bureau officers regarding this clause. I'm hoping they will respond to me and can provide guidance on this topic. I'll be surprised if I do get a response, but if I do I will be sure to share with everyone so this subject can be put to rest.
 
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