How wide is wide?

Discussion in 'Amplitude Modulation' started by W8AAZ, Jun 11, 2020.

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  1. W8AAZ

    W8AAZ Ham Member QRZ Page

    I enjoy a good sounding AM signal as much as other people and although I don't care to run that mode, I listen in sometimes. Just checking out 40M watching signals on the band scope. One fellow has a signal that is literally 18 KHz wide on voice peaks and the other stations are much less wide, about normal that you would expect. And no he is not so close he is overloading me or something. This sort of thing will not gain any allies from other users on the band. So I don't know if he cannot adjust his radio correctly, or if he is a I want to be a hi fi broadcaster, standards be damned, type. Is there ever any technical critique on these roundtables or is that a taboo subject? BTW I dislike the oddballs that run software controlled radios so they can make an SSB signal 10 KHz wide, too.
     
  2. KB3WFV

    KB3WFV Premium Subscriber QRZ Page

    To answer the question with a question...

    How much is wide enough?

    Surely there must be some number in mind. Otherwise there would be no need for this post.

    Answers that will likely appear on this thread.......

    1) How one operates his or her station is the responsibility of that individual.

    2) There are no regulations limiting bandwidth on phone on most bands. Only recommendations or guidelines.

    3) Accurate bandwidth measurement cannot be done with ham radio grade pan adapters, SDR's or Band Scopes.

    4) 6Kc or 9kc is enough.

    5) audio quality is terrible at 6, or 9. or 12 kc, some like 20 kc, some like more.

    6) Some will say they are forced to run wide to keep other startions from operating inside the RX pass band.

    What no one will say....

    I operate my station to the best of my technical abilities in accordance to good amateur radio practices, while respecting other amateur radio operators, their operating decisions and the modes they use..

     
    K0UO and W9WQA like this.
  3. WA3VJB

    WA3VJB Ham Member QRZ Page

    Tom, I seldom rise to the bait when the question you have posed is tossed out there, because it usually is from a troll, and/or a misguided dinosaur who dates back to SSB's struggle for acceptance. But, looking at your profile, I see no red flags, so I will offer up one person's opinion -- my own.

    A clean, transmitted signal can be situated on the dial wherever it fits. So, if the top of 40 meters is uncongested, it is friendly and appropriate to "use" as much as you wish. I put quotes around use, because it's not as if that slice of the band is forever consumed, like a precious resource. So, when bystanders appear who are not part of QSO #1, some accommodation becomes appropriate, just like pulling your blanket up a little to make room for others during outdoor concert festival seating.

    It is incumbent upon all of us to make way for the variety of modes and activities we enjoy on the bands. No QSO has a greater or lesser claim on available space on the dial, since it's all chit chat, unchannelized, unreserved, involving a mix of incompatible modes and activities.

    I wish the question you raised were put to certain activities like contesting that can consume entire bands. How wide is wide, then? Are bystanders respected? Do those participants pull up their blanket to make room for non-contestors? A lot of your notion of building allies is behavioral, not mode-specific, and I hope you will consider whether you have observed some sort of misbehavior, rather than just a technical parameter on your panadapter.

    Come join us some time.
     
    K4EI, K5UJ, WB1GCM and 4 others like this.
  4. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    1. Yes there a handful (literally) of AM miscreants who are not good neighbors and who regularly run extremely wide bandwidth regardless of the conditions, and sometimes intentionally do so to interfere with certain SSB nets.
    2. Ham radio has always had bad boys; even before there were licenses.
    3. Bandwidth is not directly related to signal quality. A 20kc signal can be as clean as a hound's tooth.
    4. SDR radios are not evil, and are just as much 'real radio" as spark machines and Collinses.
    5. While lab equipment may yield perfect measurements, it is still possible to obtain a pretty good estimate of a stations bandwidth with ordinary radios. Certainly one can tell when a station is operating "Too wide" for the band occupancy/spacing.
     
    Last edited: Jun 11, 2020
  5. W8AAZ

    W8AAZ Ham Member QRZ Page

    Nothing against SDR radios, just that they seem to be much more flexible in their ability to control bandwidth of transmitted signals from what I have seen. Also noticing alot of the stations running a nice clean looking AM signal within the typical AM bandwidth sounded as good as the guy with the wide shoulders. I am not sure I am a troll since I gave no objection to AM in principle and named no one. Then again I have seen some of the Chinese broadcasters on 40 appear as wide as this guy was, or close to it. In my opinion running a signal that wide below 10 meters is poor practice if done intentionally or without regard. That is a huge slice of the 40M band for one signal to occupy, is all. I perhaps could have spoken to the guy to find out why he was doing that but I doubt he would have responded to an SSB barefoot signal coming into the group.
     
  6. AC0OB

    AC0OB Platinum Subscriber Platinum Subscriber QRZ Page

    Flip your Mode switch to AM and join us and we will gladly tell you what we are running in terms of equipment.

    Most of us run vintage tube equipment which has audio responses up to about 4.5 kHz - if we are lucky.

    I have at times switched to the SSB mode on my Icom transceiver to ask some SSB operators to move down or up frequency because their signal was interfering with an ongoing AM QSO over 15 kHz away. I have found many SSB operators with this issue are either overloading their Amplifiers or are using maladjusted equalizers in an attempt to sound like AM. Poorly set equalizers and too much compression often cause these issues.

    AM does have two sidebands so if you decide to have an SSB QSO close by with someone this has to be taken into account.

    So come and join us as you will find AMers are friendly and have a lot of technical knowledge about all modes of operation.


    Pheel

     
    N1BCG likes this.
  7. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    I just finished restoring an FT-101B for AM service last weekend. I opened up the audio top and bottom ends a bit so that the bandwidth is set with processing. There's an 8 pole filter wired into the effects insert and it cuts off just below 5kHz. Others tell me that the radio sounds very nice. I'm trying to get a decent signal without being too much of a band hog. All of the parameters are easy to tweek.

    The filter doesn't make much of a difference on receivers with less than 10kHz bandwidth. You can see a big difference on an SDR though.


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    W2VW likes this.
  8. N2DTS

    N2DTS Ham Member QRZ Page

    There are all kinds on the bands, and on all modes.
    Some have no way to limit bandwidth, I have no way to hard limit my bandwidth at the moment.
    Some transmitters I have roll off well due to the mod transformers and rf final parts, some don't (screen mod ), and the sdr I set to not pass
    anything over 4500 Hz, but it only runs 25 watts so it hardly matters.
    I personally think its silly to run 10,000 hz audio on the ham bands, but if there is plenty of space and someone wants to do it that is fine.
    Some operators are clueless, some do not care, its all about them, and some run equipment that does not lend itself to tight clean signals.

    I think contests are silly but I don't mind them taking over the bands from time to time.
    Digital modes do not turn me on but I have no issue with people running them.
    As long as people are not rude about it, whatever they want to do is ok with me.

    More often then not, the bands are empty, so wide signals are not much of an issue, there are not as many active hams around as their used to be.
     
    KD2ACO likes this.
  9. K4KYV

    K4KYV Subscriber QRZ Page

    ... or Hal Turner wannabees craving attention.
     
    AC0OB and AG5CK like this.
  10. W1BR

    W1BR Premium Subscriber QRZ Page

    So long as the BW is actual audio and not splatter :) Regardless, my hearing range is more limited than most AM transmtters, at least on the high end.
     
    AE7LP, KA0HCP and AC0OB like this.

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