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Recent ER articles

Discussion in 'Amplitude Modulation' started by K4KYV, May 25, 2019.

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  1. N2EY

    N2EY Premium Subscriber QRZ Page

    OK - then we're in agreement.

    I don't know how many hams did or didn't know the difference, but IMHO that's just part of the picture. Regardless of the verbiage, at least some hams got the idea that they'd have to have calibrated test equipment that could prove their transmitted signal - regardless of mode! - was within a certain bandwidth limit.

    Not making it clear what "regulation by bandwidth" would REALLY entail was a major mistake that caused widespread opposition. Not doing so BEFORE submitting to FCC guaranteed even more opposition.

    Another very significant cause of opposition was "data modes in the 'phone bands", which is not allowed today (in the USA). The fear of 3-kHz-wide high speed data modes buzzing away in the 'phone parts of the band caused more than a few to send in strong letters of opposition.

    ARRL isn't the only one to make this mistake. NCVEC shot themselves in the foot with their "Communicator" idea.....

    What really bugs me is that such shenanigans don't help our image with the FCC. I can just imagine some poor staffer there having to read and categorize comment after comment in opposition to some proposal, muttering "aren't hams supposed to be communications people? Why can't they talk to each other and get their ducks in a row before submitting proposals?"

    73 de Jim, N2EY




    SSB with carrier is not AM; it's SSB with poor carrier suppression, and works poorly with a conventional envelope type detector. The reason for this lies in the fundamentals of modulation/demodulation; a phenomenon called quadrature distortion is inevitable when SSB + carrier is received with a conventional AM detector. What you are proposing is ESSB with carrier. You wouldn't need the full carrier, since a full carrier would not properly demodulate the signal in the first place; a "pilot" carrier reduced by 20 dB or so would be sufficient. The receiver would have to include a synchronous detector, which is a BFO that locks onto the pilot carrier to insert a full carrier with zero frequency and phase error, sometimes referred to as "exalted carrier". The ESSB boys have missed the boat by insisting on fully suppressing their carrier and manually tuning in the signal on the receiver.

    Considering the dwindling of all modes of activity on HF in recent years, the bands are no longer congested as they were in previous decades, when the obsession with "bandwidth" was felt justified by many.[/QUOTE]
     
  2. K4KYV

    K4KYV Subscriber QRZ Page

    That was true, under the long-defunct Docket 20777. Or at minimum, the ham would have been subject to a station inspection with the FCC inspector using their own measuring equipment.

    Under regulation by necessary bandwidth, the bandwidth listed in the rules would be the smallest bandwidth that would allow a certain mode to be transmitted. For example, a 6 kHz necessary bandwidth segment would mean a segment designed to accommodate DSB AM, since it is pretty well agreed that 6 kc/s is about the least bandwidth that could be used to transmit a readable AM signal, but it would allow other unspecified modes with that same necessary bandwidth to operate without having to list every possibility in the rules. That wouldn't mean that it would be mandatory for a ham to limit his bandwidth to 6 kc/s. Occupied bandwidth would still fall under "good amateur and engineering practice". "Necessary bandwidths" would simply replace the current specific emission designators.

    Such a rule would have to be worded specifically so as to clearly indicate that (for example) 6 kc/s wasn't a legal limit to occupied bandwidth, since the rule on purity of emission prescribes the "minimum bandwidth necessary for the desired communication", and some would try to argue that occupied bandwidth would therefore be limited to the necessary bandwidth for any given mode. In fact, that argument has already been used in unsuccessful attempts to prohibit ESSB.

    Besides objections to 3 or 6 kc/s digital buzzies in the phone bands under regulation-by-bandwidth, others have objected that tone modulated CW would once again become legal in the HF bands.

    Canada uses a regulation-by-bandwidth scheme, but their standard is occupied bandwidth, although I have never heard of a Canadian AMer being cited for exceeding 6 kc/s.

    A likely unresolvable problem with regulation-by-occupied-bandwidth is that it would not require observance of good engineering practice; it would be perfectly legal, for example, for a SSB signal transmitting narrow-band communications grade audio to have enough distortion that the signal would occupy the same bandwidth as a clean AM signal... or even a CW signal with enough spurious modulation to make it occupy 6 kc/s.

    Attached is a copy of FCC Docket 20777, April 1976
     

    Attached Files:

  3. KM1H

    KM1H Ham Member QRZ Page

    I still remember the day that Skip Tenney, W1NLB, the publisher/owner and Jim Fisk, K1DTY. came to National Radio in 1967 to drum up advertising for their soon to be launched magazine.

    I signed up for a subscription on the spot and stayed with them to the end, including Comm Quat.

    I dont understand why Pete and Craig fail to mention Skip in their writings. I also see that Skip is still listed in the FCC database.

    Carl
     
  4. W1VT

    W1VT Ham Member QRZ Page

    I got at least one vocal request to write AM articles. Really? A QRPer living in single room apartment who ran his gear off solar to avoid inconveniencing the other tenant. And who spent most of his hobby time building UHF contest gear to go mountaintopping.
     
    N2EY likes this.
  5. AC0OB

    AC0OB Subscriber QRZ Page

    What Magazine?


    Pheel
     
  6. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    OB:

    "Ham Radio Magazine".

    Glen, K9STH
     
  7. AC0OB

    AC0OB Subscriber QRZ Page

    In April 2019, ER Number 359, Ray had a 2 and 1/2 page editorial on RM-11828 encouraging readers to read the RM in depth and make comments to the FCC.


    Pheel
     
  8. WA3VJB

    WA3VJB Ham Member QRZ Page

    One of the phrases that in the past has been uttered and written in a pejorative way was "the carrier contains no information." This too is incorrect for operating aspects alongside your technical point below.

    The carrier, much like mark-and-space protocols for RTTY, provides information as to pauses in the spoken communication; the pacing as one collects thoughts and prepares to exchange a continued idea or topic, and as a cue that a transmission has ended during "break-in" style roundtables. None of these bits of information are available on the incomplete mode of SSB.

     
    W9BRD likes this.
  9. K5EF

    K5EF Ham Member QRZ Page

    Electric Radio is a magazine that targets a very small segment of the hobby: people who homebrew, restore and operate vintage radio equipment. That automatically whittles down the number of potential articles both received and available to be published on a monthly basis. It isn't a version of QST in the 1950s or 60s that carried a range of articles spanning antennas, ssb, am, cw, sstv, rtty, FM...you get the idea. QST had boatlaods of potential articles from which to pack issues. Same applied to Ham Radio, which I still believe was the best technical-based ham radio magazine ever.

    In a perfect ER World, perhaps an articles on an obscure rigs; concepts that explore better IM performance of AM as well as SSB transmitters would be great (there are plenty of crappy signals on the bands these days); a move away from simple rigs to those that are more complex and usable in Today world but pushing the envelop on tube technology. In early issues of ER, some mention was made of tubes developed near the end of the receiving tube era that were near perfect but saw limited to no use in then-made gear. Why not experimental thoughts and designs using those great end-run frame grid tubes, Nuvistors and even Compactrons.

    While some bemoan the many appearances of repeat authors in ER, I think it is amazing that some are so prolific with respect to making something out of hamfest junque box finds - and do it with great speed! This is a magazine that relies nearly 100% on subscriber input. If the content falls off or the articles are not as inspired, whose to blame?

    73 Nick K5EF
     
    N2EY, AC0OB and WA5VGO like this.
  10. K5UJ

    K5UJ Ham Member QRZ Page

    How many hams have said that, then fire up their 2 m. FM rig to yack with locals....TUT, no more of that my dear fellow, that FM carrier contains NO information! I bet a lot of hams don't know there's a carrier on FM and the usual FM rig nowadays is up to 10 kc wide.
     

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