K1TTT Technical Reference

Subject: 
        Summary: where exactly is the band edge?
   Date: 
        Tue, 12 Nov 96 21:39:33 PST
  From: 
        trey@cisco.com (Trey Garlough)
    To: 
        cq-contest@tgv.com


Here is the summary of responses I received to my request asking for a
pointer to the exact language that addressed the issue of out-of-band
transmissions.  The names of those who responded have been omitted for
no particular reason.  Personally, I liked the first answer the best.  :-)

--Trey, N5KO

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> You cannot have any - repeat - ANY energy outside of the band segment.

That's dumb.   Any object not at absolute zero radiates at all
wavelengths.  So each of us is radiating occasional photons at
any wavelength you like to choose, even with the transmitter
turned off.

Each of us gets hit on the head with an occasional photon from
Halley's comet, too, but it's not a problem for most of us.

- Dr Science -

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Trey, you might start at 97.307(b) and see if what you are looking for is there.

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I'm attaching the appropriate section of the R&Rs for your use. (I have
deleted all that doesn't apply)
Section 90.307 (b) specifically addresses the requirements.

SUBPART D - TECHNICAL STANDARDS

97.307  Emission standards.

     (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.
     (c) All spurious emissions from a station transmitter must be
reduced to the greatest extent practicable.  If any spurious emission,
including chassis or power line radiation, causes harmful interference
to the reception of another radio station, the licensee of the
interfering station is required to take steps to eliminate the
interference, in accordance with good engineering practice.
     (d) The mean power of any spurious emission from a station
transmitter or external RF power amplifier transmitting on a frequency
below 30 MHz must not exceed 50 mW and must be at least 40 dB below the
mean power of the fundamental emission. For a transmitter of mean power
less than 5 W, the attenuation must be at least 30 dB.  A transmitter
built before April 15, 1977 or first marketed before January 1, 1978 is
exempt from this requirement.
     (e) The mean power of any spurious emission from a station
transmitter or external RF power amplifier transmitting on a frequency
between 30-225 MHz must be at least 60 dB below the mean power of the
fundamental.  For a transmitter having a mean power of 25 W or less, the
mean power of any spurious emission supplied to the antenna transmission
line must not exceed 25 uW and must be at least 40 dB below the mean
power of the fundamental emission, but need not be reduced below the
power of 10 uW.  A transmitter built before April 15, 1977 or first
marketed before January 1, 1978, is exempt from this requirement.
     (f) The following standards and limitations apply to transmissions
on the frequencies specified in section 97.305(c) of this Part.
          (1) No angle-modulated emission may have a modulation index
greater than 1 at the highest modulation frequency.
          (2) No non-phone emission may 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.

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     The original message is not correct.  The details are addressed in 
     97.307 (a), (b), (c) and (d).

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Trey- I am new to this list, but this one is easy to find- try part 97.307--
"Emissions resulting from modulation must be confined to the band or segment
available to the control operator"
This means that your splatter that is greater (stronger) than 40 dB down has
to be in the band edge.

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   (8) Bandwidth. The width of a frequency band outside of which the
mean power of the total emission is attenuated at least 26 db below
the mean power of the total emission, including allowances for
transmitter drift or Doppler shift.

Part 97.307  Emission standards.

   (b) Emissions resulting from modulationmust 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.


So what does this imply for operating phone near the band edges? First
of all it must be stated that the IF bandwidth has little to do with
the occupied bandwidth referred to in 97.3 (8). The wide signals that
are heard from too many well known contesters are due to non
linearities in the final stages of the transceiver or the
amplifier. Most monitor scopes use a tap at the IF and thus are not
actually measuring the transmitted signal!  The only way to measure
the occupied bandwidth is with a spectrum analyzer. I have a
Hewlett-Packard 8568 in my shack to monitor my signal and those over
the air. At the 26 dB down points most SSB signals are 3 KHz wide, but
I've measured many over 5 KHz.

So can one really operate 2 KHz from a band edge on SSB? I seriously
doubt it. Without making a spectrum analyzer measurement of your
transmitter under actual conditions anything closer than 3 KHz is
likely to be in violation of Part 97.

----------

Part 97.307 Emission Standards
(b) Emissions resulting from modulation must be confined to the band or
segment available to the control operator.

Emissions outside of the band, segment or necessary bandwidth are required
by 97.307(d) to be 40 dB below the mean power of the fundamental emission
for transmissions below 30 MHz.


Subject: 
        RE: Summary: where exactly is the band edge?
   Date: 
        Wed, 13 Nov 1996 06:09:46 -0600
  From: 
        kr2j@ix.netcom.com (Robert E. Naumann)
    To: 
        cq-contest@tgv.com (cq-contest@TGV.COM), trey@cisco.com ('Trey Garlough')


Thanks for your summary Trey.

Someone long ago,  explained this band edge stuff to me like this:  (I'm 
hesistant to give credit or blame, but I think it was K1KI - sorry if it 
was not you Tom)

Principles 1 and 2:

1-  When you're on USB, your signal is above the indicated frequency.
2-  On LSB, your signal is below the indicated frequency.

Theory:
Theoretically is no energy between your center frequency and say 200 or 300 
hz or so ?  All energy is between whatever the lower start "point" of your 
bandwidth is at 200 or 300 hz and goes up to 3khz or more (if you have a 
bad signal) from center.

Agreed ?

If the above principles and theory are correct, and you have technically 
acceptable opposite sideband suppression that meets the guidelines set out 
in Part 97, you should be able to dial up 21.200.0000 and have at it on 
USB.  In fact, if you felt comfortable with the signal start point theory 
at 200 or 300hz, you should be able to dial up 21.199.9 or 21.199.8 and not 
have any signal below 21.200 (I'm hesitant to test this part of the theory 
- but if you think about it - it makes sense.)

Following the same logic, you should be able to dial up 7.299999 on LSB and 
have at it (not that you'd want to).

To verify this, listen to a station on USB at the band edge with your dial 
set on 21.200.00 (I particularly like 15m so I'll use it here as the 
example).  You are listening to the station's signal with your receiver 
"listening" ABOVE the indicated frequency for a USB signal.  To check below 
the frequency you are on, just flip to LSB.  I would suspect that you hear 
nothing.  This is what most do not understand.  The lids that badger 
stations on the air and OO's that give out notices for this band edge 
operation don't understand that their receivers are still listening above 
the band edge when they stay on USB and turn their dial to 21.19999 and 
start badgering or licking stamps for the OO notices.

I'm comfortable at the band edge with this logic.  What do you think ?

73,
Bob Naumann
N5NJ (ex KR2J)