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Question About Using AM mode on HF

Is a joke somewhere about where the Swan-net meets, and the Swan 3drifty, but to answer your question without some divine intervention yes they do drift :LOL:

That would be the Swan TooDrifty, I believe. If you are looking for the freq they meet on, just wait around and they will drift by soon.LOL
 
Yes Mister Know-it-all..... gee 100% modulation means your radidio is clipping and flat topping....

I think you need to build some more "radar jamers"

Wow, I didnt know I said at 100% you would flat top....maybe your problem is reading comprehension!!

HI DEF: You are correct, about the Asymetrical aspect but your numbers are a bit off. assuming your talking about class C.

So as to save on typing, I posted this in another thread also, A very good read!!!!

Amplitude Modulation
 
Most of what's here deals with opinion, and I'm not getting into that particular dog fight. I will say that the comments for signal bandwidth, 'practicality', and 'good practice', should be re-thought just a bit.
Do any of you happen to remember when th mode designator always included a number? CW was 'A1'. AM was 'A6E or J' IIRC, and so on. Do you happen to know what those numbers were? If you didn't, they were maximum bandwidth for that particular mode. They have not changed even if the mode designators have. Those numbers were in Khz, BTW. Does that tell you something about the acceptable bandwidth with 'AM' mode in the amateur services? It should. I'd also recommend that you NOT take my word for this, research it for your self. While you're doing that, you might also look for the acceptable band widths for FM, as in NFM and WFM, since those designatorsdon't tell you anything about their band width, just that they have one. It's all spelled out somewhere in the rules, you just have to find it. Makes for good practice with other questions like this!
Have fun.
- 'Doc

The FCC deliberately deleted the old mode designators and has replaced them with the words good engineering practice.

Bandwidth cannot be described as an absolute like a lot of hammy hambones like to do. Some slope always exists in an analog system. So do close-in distortion products.

Those old A3E type designators were generic.

Anytime analog bandwidth is discussed it should include a dB figure for roll-off.
Otherwise it's meaningless.
 
Wow, I didnt know I said at 100% you would flat top....maybe your problem is reading comprehension!!


Or perhaps, like most Government employees you simply lack any sort of communication skills....

And no, you didn't say at 100%, you said the following....


And just for your information, anything over %100 IS A FALSE /unrealistic number.


And the other

So lets see...... what happens at 101% ?????????????? Hhhhhmmmmmm

Oh I know, clipping /flat topping


I suppose I knew what you meant but many readers would not, whether your a knowledgeable individual, or an inarticulate individual that has issues being precise.



I should have been clearer


perhaps take your own advice?
 
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See what I mean about opinions? It's sort of odd, do you also classify quite a few electrical engineers as "hammy hambones"? That's where those 'generic' mode classifications came from you know, wasn't us "hammy hambones" that thought up those thingys. But if it makes you feel better to blame them/us "hammy hambones", be my guest.
I gotta go clean some of those opinions off my house-shoes, can't let that stuff build up, it'd never come out.
- 'Doc
 
See what I mean about opinions? It's sort of odd, do you also classify quite a few electrical engineers as "hammy hambones"? That's where those 'generic' mode classifications came from you know, wasn't us "hammy hambones" that thought up those thingys. But if it makes you feel better to blame them/us "hammy hambones", be my guest.
I gotta go clean some of those opinions off my house-shoes, can't let that stuff build up, it'd never come out.
- 'Doc


The opinion that matters here is the one used by the FCC.

Engineers deleted those mode classifications. They were most likely competent engineers who recognized hobbyists cannot measure occupied bandwidth. Many can't grasp the concept and prefer to make it into some sort of personal crusade.
 
:bdh: My HAM friend and I try all sorts of bands in AM mode and you have to adjust the rig just right and the sound is just classic! We even use AM on two meters, I have yet to find anything against that! and it too sounds great....
If you think about it CW is a simpler form of AM and I have "keyed" an AM CB with no modulation and made all sorts of contacts.... But that is fodder for a different post!

mechanic
 
The opinion that matters here is the one used by the FCC.

Engineers deleted those mode classifications. They were most likely competent engineers who recognized hobbyists cannot measure occupied bandwidth. Many can't grasp the concept and prefer to make it into some sort of personal crusade.

no, the emission designators still exist and are referenced in part 97.

this is standard ESSB strawman answer, "hobbyists cannot measure occupied bandwidth." :whistle:

the correct answer is in 97.307 (a) & (b).


(a) No amateur station transmission shall occupy more bandwidth than necessary for the information rate and emission type being transmitted, in accordance with good amateur practice.
(b) Emissions resulting from modulation must be confined to the band or segment available to the control operator. Emissions outside the necessary bandwidth must not cause splatter or keyclick interference to operations on adjacent frequencies.

and yes 97.307 (d) does state specific Db attenuation factors, but the bottom line is that it DOESN'T have to be exactly measured. read 97.307 (b) again.

:pop::pop::pop:
 
Exactly...if you are unable to measure your bandwidth, you certainly are incapable of measuring the quality of your signal...which you are responsible for, no matter what the FCC wording is.

The new wording only means you are responsible for your signal even more than before. The attitude that this means it is now a free for all, is exactly the problem that people bitch about with regard to less than clean or excessively wide signals. Either users don't care that they are interfering with adjacent traffic, or they don't know any better...which is just as bad if a user is using modified transmitters without knowing any better.

It is not o.k. to have 20kHz of signal energy simply because you don't know any better and the FCC isn't regulating bandwidth specifically. You will certainly interfere with others on the band if you are over 10kHz or even at 10 if outside the gentleman's agreement for AM channelization on the bands.

Improperly run AM or modified/home brew transmitters on AM can be a massive source of interference. Far worse than even the worst SSB I've seen on the bands.

A lot of the worst AM operators don't even realize it has two sidebands...so they never check up AND down from where they put the carrier. Then they sit and bitch that someone just encroached on their frequency....when they were in the USB of their carrier all along.
 
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no, the emission designators still exist and are referenced in part 97.

this is standard ESSB strawman answer, "hobbyists cannot measure occupied bandwidth." :whistle:

the correct answer is in 97.307 (a) & (b).


(a) No amateur station transmission shall occupy more bandwidth than necessary for the information rate and emission type being transmitted, in accordance with good amateur practice.
(b) Emissions resulting from modulation must be confined to the band or segment available to the control operator. Emissions outside the necessary bandwidth must not cause splatter or keyclick interference to operations on adjacent frequencies.

and yes 97.307 (d) does state specific Db attenuation factors, but the bottom line is that it DOESN'T have to be exactly measured. read 97.307 (b) again.

:pop::pop::pop:



Please show me exactly where Part 97 quotes phone BANDWIDTH numbers of any kind.
 
Exactly...if you are unable to measure your bandwidth, you certainly are incapable of measuring the quality of your signal...which you are responsible for, no matter what the FCC wording is.

The new wording only means you are responsible for your signal even more than before. The attitude that this means it is now a free for all, is exactly the problem that people bitch about with regard to less than clean or excessively wide signals. Either users don't care that they are interfering with adjacent traffic, or they don't know any better...which is just as bad if a user is using modified transmitters without knowing any better.

It is not o.k. to have 20kHz of signal energy simply because you don't know any better and the FCC isn't regulating bandwidth specifically. You will certainly interfere with others on the band if you are over 10kHz or even at 10 if outside the gentleman's agreement for AM channelization on the bands.

Improperly run AM or modified/home brew transmitters on AM can be a massive source of interference. Far worse than even the worst SSB I've seen on the bands.

A lot of the worst AM operators don't even realize it has two sidebands...so they never check up AND down from where they put the carrier. Then they sit and bitch that someone just encroached on their frequency....when they were in the USB of their carrier all along.

The bands are loaded with poor operators on all modes.

Dunno where all those AM guys who don't know about their upper sideband are. I hope I never find out.

I suggest you might want to let these guys know about this on the air.
 
The bands are loaded with poor operators on all modes.

Dunno where all those AM guys who don't know about their upper sideband are. I hope I never find out.

I suggest you might want to let these guys know about this on the air.

There are all too many because it is too easy to just push the "AM" button. The mailing lists for various rigs are loaded with people constantly asking for the service menu keystrokes to get the power up to 100W for AM as well.

I like AM mind you...just sayin. 75m in NE region has been loaded with ops randomly firing up AM in the weirdest places. 3.805 with a bunch of General class licensees was a recent entertaining one.

If you don't have an SDR receiver yet, get one. It's endlessly amusing to be able to see signal qualities across an entire band or 100kHz at least at a time. I can see how bad someone's signal is 200+kHz away from where I'm tuned...and yes, I often politely explain if someone has a bad signal, but they have to have enough understanding to care too.

Without a doubt there are bad signals of every kind, from digi modes through AM. AM is just a lot wider so when it's bad...it has a farther reach.

Worst SSB signal of a regular operator that I've seen so far is roughly 12kHz. 3kHz for the main signal, about 6 more down the band to the lower sideband and 3+ into upper sideband. Guy is a daily operator who has been told many times. My bet is he is running a class C CB amp into full compression.

Worst AM signals I've seen so far are home brew transformer modulated with voice signal energy at 10kHz, but significant (maybe 10dbm down from the carrier level) splatter out another 10 in either direction.
 

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