Can you use FM in 10 Meter? Does anyone?
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mmckenna
I ♥ Ø
Yes, there are even some 10 meter FM repeaters.
However, the current band plan in the U.S. doesn't give Technician class licensees access to the FM portion of the band.
AM can be used, also, however I think what you might be looking at is "export" CB radios that are sold as 10 meter amateur radios with easy conversion to "freeband" or CB use.
However, the current band plan in the U.S. doesn't give Technician class licensees access to the FM portion of the band.
AM can be used, also, however I think what you might be looking at is "export" CB radios that are sold as 10 meter amateur radios with easy conversion to "freeband" or CB use.
Thanks, I hadn't found that yet.
I found this but it did not get in to as much detail
http://www.hamradioschool.com/wp-content/uploads/2014/06/band-plan.jpg
I see a lot of 10 and 12 meter radios out there.
It looks like there is no space on 12 meter for phone operation.
Not much advantage in a dual band unit over just a 10 meter one then.
I found this but it did not get in to as much detail
http://www.hamradioschool.com/wp-content/uploads/2014/06/band-plan.jpg
I see a lot of 10 and 12 meter radios out there.
It looks like there is no space on 12 meter for phone operation.
Not much advantage in a dual band unit over just a 10 meter one then.
KC5AKB
Member
Yes I use fm simplex and fm repeaters on 10m 29.660
RepeaterBook.com lists 104 10 Meter FM repeaters in North America, most of them with outputs on 29.620 mHz.
mmckenna
I ♥ Ø
These are the "export" radios. They get sold as amateur radios to bypass import restrictions, then the user does a slight modification to put them on the CB band or adjacent frequencies, running higher power than the FCC allows and using emissions that are not permitted.
Token
Member
The Band Plan is a recommendation / best practice, but not a technical requirement or hard limit.
By Band Plan and by long standing convention FMn is used in the top section of the band, from about 29.52 to 29.7 MHz. However, I don’t think there is any regulation that prevents you from using FMn on any portion of the 10 meter band where voice is authorized (except for Techs and Novices, they are limited to SSB in their allowed voice subbands).
My understanding of the limitations on 10 meters (and if anyone can show me I am wrong then I guess I will learn something, but I don’t think I am):
Part 97, Subpart D, defines authorized modes of operation. It says that (for General class and higher) “phone, image” is allowed from 28.3 to 29.7 MHz. The caveats are 1, 2, and/or 10, depending on the exact frequency range. 10 is the part that limits Novices and Techs to SSB in the 28.3 to 28.5 MHz subband. 2 limits the bandwidth of a signal to “not exceed that of a communications quality A3E emission”. This does not preclude FM in any way, but does say you must watch your bandwidth. 1 limits any angle-modulated signal (and FM is one such) to a modulation index of no more than 1 at the highest modulated frequency.
What this all means is that FM is expressly permitted above 29.0 MHz, and is not prohibited below 29.0 if the modulation index is 1 or less. For most HF bands you could legally use narrow FM in the voice sections as long as the modulation index did not exceed 1 and the total bandwidth was less than a communications quality full DSB + carrier AM signal. In fact, this used to be reasonably common before SSB hit it big, AM was the most used voice mode on HF, but FMn was not uncommon.
But, as an operating practice, using FM in a HF voice subband is poor hat, and probably would not gain you any friends. Shoot, even using AM, except on the few common AM freqs, sometimes raises a storm, no matter how legal it may be.
T!
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Actually, you can use FM in any band segment that allows 'phone- as long as it stays within the bandwidths specified in Part 97.307.
In essence, that says if its narrowband, it permissible below 29.0 Mhz., but no angle-modulated emission may have a modulation index greater than 1 at the highest modulation frequency. Since no one operates NBFM (at least I've never heard it on amateur HF... although I have used it very sucessfully on non ham frequencies) this standard is quite obscure.
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FM, as we know it, is semi-popular on the upper end of 10 metre's- 29.6 is the calling channel, and there are a number of simplex and repeater frequencies clutter'd about it. Simplex can be quite useful when the band is quiet- the longer wavelength gets into valleys and around hills and mountains much better than V/UHF.
When I was doing field work, our vehicles used lower-low band FM mobile to mobile, almost exclusively for our simple communications. No repeaters, just 100 watt radios to quarter wave whips- the range was often 80-100+ miles over the deserts of Nevada-
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But when there is 'skip' this usefulness can go into the toilet. 29.6 will come alive, and with everyone stepping on each other the frequency rapidly becomes a muck. The nearby simplex channels fare better-- but the repeater channels become one cacophonous squabble of noises as signals from multiple continents garble each other on the repeater inputs.
I know there are the 10 metre repeater aficionado's out there, and I don't want to engage in a debate- but today the concept of an HF (Ten should be consider'd HF for all practical purposes) repeater makes no sense to me.
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One of our work band of frequencies was in the 33Mhz segment. With the mass exodus of everything low band VHF this was perfect- we had the place to ourselves-- that is, except when there was skip. One of our channels we called SPC - the "Somali Pirate Channel." We never could figure out where these guys were coming from, but there was always boat noises and very animated conversations when they came on- we figured they were pirates out chasing a cargo ship, or something.
We couldn't understand a word they said.
Fortunately we'd flip to another frequency.
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While I am on this 10 metre subject- don't overlook 29.000Mhz, the low power AM calling frequency. It goes back many years to the days of 'hacking' CB radios to Ten (do people still do that ?)
I have had some suprising conversations on 29.0 AM from out in the Central Pacific- spanning several thousand miles- back when the Sun Spots smiles.
Clustered about 29.000 at 10Khz intervals are some alternate AM simplex channels.
If 10 opens its worth a listen.
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Lauri
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PS..
I just posted this and realized I mirror'd Token's comments-- proof Great Minds think alike ... lol...
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Actually, you can use FM in any band segment that allows 'phone- as long as it stays within the bandwidths specified in Part 97.307.
In essence, that says if its narrowband, it permissible below 29.0 Mhz., but no angle-modulated emission may have a modulation index greater than 1 at the highest modulation frequency. Since no one operates NBFM (at least I've never heard it on amateur HF... although I have used it very sucessfully on non ham frequencies) this standard is quite obscure.
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FM, as we know it, is semi-popular on the upper end of 10 metre's- 29.6 is the calling channel, and there are a number of simplex and repeater frequencies clutter'd about it. Simplex can be quite useful when the band is quiet- the longer wavelength gets into valleys and around hills and mountains much better than V/UHF.
When I was doing field work, our vehicles used lower-low band FM mobile to mobile, almost exclusively for our simple communications. No repeaters, just 100 watt radios to quarter wave whips- the range was often 80-100+ miles over the deserts of Nevada-
.
But when there is 'skip' this usefulness can go into the toilet. 29.6 will come alive, and with everyone stepping on each other the frequency rapidly becomes a muck. The nearby simplex channels fare better-- but the repeater channels become one cacophonous squabble of noises as signals from multiple continents garble each other on the repeater inputs.
I know there are the 10 metre repeater aficionado's out there, and I don't want to engage in a debate- but today the concept of an HF (Ten should be consider'd HF for all practical purposes) repeater makes no sense to me.
.
One of our work band of frequencies was in the 33Mhz segment. With the mass exodus of everything low band VHF this was perfect- we had the place to ourselves-- that is, except when there was skip. One of our channels we called SPC - the "Somali Pirate Channel." We never could figure out where these guys were coming from, but there was always boat noises and very animated conversations when they came on- we figured they were pirates out chasing a cargo ship, or something.
We couldn't understand a word they said.
Fortunately we'd flip to another frequency.
.
.
While I am on this 10 metre subject- don't overlook 29.000Mhz, the low power AM calling frequency. It goes back many years to the days of 'hacking' CB radios to Ten (do people still do that ?)
I have had some suprising conversations on 29.0 AM from out in the Central Pacific- spanning several thousand miles- back when the Sun Spots smiles.
Clustered about 29.000 at 10Khz intervals are some alternate AM simplex channels.
If 10 opens its worth a listen.
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Lauri
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________________________________________
PS..
I just posted this and realized I mirror'd Token's comments-- proof Great Minds think alike ... lol...
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Last edited by a moderator:
The 12 meter band allows phone and image between 24.930 and 24.990. Plenty of room. The band plan referred to above shows the segments of the band reserved for special uses like RTTY.
I'm not sure about the import radios, but I believe the the FM signal from the average Amateur HF rig is quite a bit wider than what is legal on the other bands. (The modulation index is greater than 1).
My IC-7600 has a waterfall display that shows the bandwidth of the transmitted signal. On SSB and AM it is less than 6 Khz wide. On FM, the signal is almost 12 Khz wide which would be highly illegal on the lower bands.
Apart from North America, I've worked stations in Japan, Europe, South America, Australia and New Zealand on 29.600. I heard a Chinese station once, but never managed to contact him. But as you say, the band can quickly get swamped. Ionospheric refraction isn't good for FM signals.. Add to that the capture effect and as you say, the band can get pretty mucky during major openings.
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Hey JTW...
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I agree; the standard amateur HF radio is probably way too wide on FM for the ham HF frequencies-- My thinking is they are not *Intended* for anything but the high end of 10 metre's-- in markets like the US (Canada too ?) and the countries that have narrow band requirements. But since many of these radios end up in places like the Republic of Lower Slobovia, where anything short of Spark Gaps goes, -- there isn't much incentive to make them wide band on 29.0 and up, but narrow below. Its up to the user to make sure they used them in compliance with their country's laws (like, Yeah- sure )
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I don't think compliant narrow band FM is much of an issue - no one uses it... but an interesting thing to ponder, all the same.
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Lauri
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I agree; the standard amateur HF radio is probably way too wide on FM for the ham HF frequencies-- My thinking is they are not *Intended* for anything but the high end of 10 metre's-- in markets like the US (Canada too ?) and the countries that have narrow band requirements. But since many of these radios end up in places like the Republic of Lower Slobovia, where anything short of Spark Gaps goes, -- there isn't much incentive to make them wide band on 29.0 and up, but narrow below. Its up to the user to make sure they used them in compliance with their country's laws (like, Yeah- sure
).
I don't think compliant narrow band FM is much of an issue - no one uses it... but an interesting thing to ponder, all the same.
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Lauri
Yes it is.
Yes. I monitor 29.600 MHz FM mode mostly on my scanners. When skip rolls in, I dial it up and enjoy a QSO. Also monitoring 29.620 MHz FM may help identify when propagation is suitable, as you may hear repeater chatter. Roll down to 29.6 MHz (simplex) and throw your callsign a few times.
There is a guy in Indiana or Illinois that I will hear throwing his call on 29.6 FM from time to time when conditions are right. I forget his callsign right off, but recognize his voice right away. The last time I spoke with him was a year or two ago. I was able to dial down to 25 watts and still had a good signal to his station. I was using an Imax 2000.
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Oh, and before I go SK for dinner--
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"..........It looks like there is no space on 12 meter for phone operation........ " LSM asked.
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There is plenty of 'phone segment on 12 metre's- 24.930-24.990 Mhz (US) .......... Well, if 60Khz is 'plenty' there is.
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12 metre's is one of those 'poor stepchild' bands- when 10 and 15 are alive, 12 is remarkably quiet. At least that's my experience- yet I have made many +8000 mile contacts there - (as a KX6 it seemed to be my direct line Florida)
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The nice thing about 12 is that when its open, its Open !, but I can't remember a time it was over crowded.... also its not one of those "kilowatt alley" bands like 20-- the average station stands a chance.
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Lauri
Oh, and before I go SK for dinner--
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"..........It looks like there is no space on 12 meter for phone operation........ " LSM asked.
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There is plenty of 'phone segment on 12 metre's- 24.930-24.990 Mhz (US) .......... Well, if 60Khz is 'plenty' there is.
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12 metre's is one of those 'poor stepchild' bands- when 10 and 15 are alive, 12 is remarkably quiet. At least that's my experience- yet I have made many +8000 mile contacts there - (as a KX6 it seemed to be my direct line Florida)
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The nice thing about 12 is that when its open, its Open !, but I can't remember a time it was over crowded.... also its not one of those "kilowatt alley" bands like 20-- the average station stands a chance.
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Lauri
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KB7MIB
Member
I would go with a multi-band radio over a single or dual-band one.
There are plenty of radios that cover all of the HF bands, plus 6 meters, and several also include 2m and 70cm as well. At least one somewhat older model (Kenwood TS-2000) has an option to include 23cm. (It does not include the 60m HF band as most newer models will.)
Buying an HF/6m(/2m/70cm) radio now will allow you to expand your interests without having to make additional radio purchases in the future, potentially saving you money in the long run.
John
Peoria, AZ
There are plenty of radios that cover all of the HF bands, plus 6 meters, and several also include 2m and 70cm as well. At least one somewhat older model (Kenwood TS-2000) has an option to include 23cm. (It does not include the 60m HF band as most newer models will.)
Buying an HF/6m(/2m/70cm) radio now will allow you to expand your interests without having to make additional radio purchases in the future, potentially saving you money in the long run.
John
Peoria, AZ
we0z
Newbie
FM on 10m
FM use on 10 meters is limited to 29.500 to 29.700 and must have at least a general class license!
FM use on 10 meters is limited to 29.500 to 29.700 and must have at least a general class license!
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Actually, FM is permitted from 28.3 to 29.7MHz if it meets #1 below (known as Narrow Band FM-- NBFM)
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Its the wide band stuff we all know that is relegated to the high end of 10, from 29.0 to 29.7MHz
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97.307
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10 metre's
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28.0–28.3 MHz ........... RTTY, data .........................(4).
28.3–28.5 MHz ........... Phone, image .................... (1), (2), (10)
28.5–29.0 MHz ........... Phone, image .....................(1), (2)
29.0–29.7 MHz ........... Phone, image .....................(2).
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97.307
(1) No angle-modulated emission may have a modulation index greater than 1 at the highest modulation frequency.
(2) No non-phone emission shall exceed the bandwidth of a communications quality phone emission of the same modulation type. The total bandwidth of an independent sideband emission (having B as the first symbol), or a multiplexed image and phone emission, shall not exceed that of a communications quality A3E emission.
(10) pertains to the restrictions imposed on Novice and Tech users.
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Lauri
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Its the wide band stuff we all know that is relegated to the high end of 10, from 29.0 to 29.7MHz
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97.307
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10 metre's
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28.0–28.3 MHz ........... RTTY, data .........................(4).
28.3–28.5 MHz ........... Phone, image .................... (1), (2), (10)
28.5–29.0 MHz ........... Phone, image .....................(1), (2)
29.0–29.7 MHz ........... Phone, image .....................(2).
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97.307
(1) No angle-modulated emission may have a modulation index greater than 1 at the highest modulation frequency.
(2) No non-phone emission shall exceed the bandwidth of a communications quality phone emission of the same modulation type. The total bandwidth of an independent sideband emission (having B as the first symbol), or a multiplexed image and phone emission, shall not exceed that of a communications quality A3E emission.
(10) pertains to the restrictions imposed on Novice and Tech users.
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Lauri
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You may be right.. The US regs are pretty vague.. What deviation and modulating frequencies are used when calculating the modulation index? What is the --exact-- bandwidth in Khz "of a quality phone emission "? What is 'quality' and where is it defined.?
Anyway.. Here in Canada they simplified everything back in 2000. There are no sub-bands or modulation types. So, for instance, on 20 meters, we can't exceed 6 Khz.. That's it. Technically, Canadians can legally run SSB on 14.050 Mhz (In the middle of the 20 meter CW band). But we don't..
By common agreement we follow the bandplan developed by the Radio Amateurs of Canada (RAC) which is our version of the ARRL. https://wp.rac.ca/rac-0-30-mhz-band-plan/
I just checked our government site for the current official rules on 10 meters. We're allowed to transmit bandwidths of up to 20 Khz over the entire band. 28.000 to 28.700 So going back to the OP's original question.. Canadians can operate NBFM anywhere on 10 Meters. But again, we limit operations to above 29.520 Mhz.
Just for interest I've attached a copy of the Canadian government regs dealing with amateur transmissions up to 6 meters...
Anyway.. Here in Canada they simplified everything back in 2000. There are no sub-bands or modulation types. So, for instance, on 20 meters, we can't exceed 6 Khz.. That's it. Technically, Canadians can legally run SSB on 14.050 Mhz (In the middle of the 20 meter CW band). But we don't..
By common agreement we follow the bandplan developed by the Radio Amateurs of Canada (RAC) which is our version of the ARRL. https://wp.rac.ca/rac-0-30-mhz-band-plan/
I just checked our government site for the current official rules on 10 meters. We're allowed to transmit bandwidths of up to 20 Khz over the entire band. 28.000 to 28.700 So going back to the OP's original question.. Canadians can operate NBFM anywhere on 10 Meters. But again, we limit operations to above 29.520 Mhz.
Just for interest I've attached a copy of the Canadian government regs dealing with amateur transmissions up to 6 meters...
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