"Stefan Wolfe" ) writes:

I give up. You keep talking about how the signal looks when it is
*received*. I keep talking about how the true A1A signal is supposed to be
*transmitted* (your last paragraph is exactly that but you dismissed it).
Part 97 is not concerned with how you receive, only how you transmit. I
agree it is true that you can fool anyone on the receiving end as long as
you can make the signal look like A1A on a spectrum analyzer. That might be
difficult because the sidebands generated by breaking a CW "square" wave
would be present on my A1A transmission and you would somehow have to
re-create them on your SSB pure tone transmission that is keyed in your
tightly filtered audio circuit. But re-check the definition of A1A and you
will see that there is only one way to *transmit* it. And A1A is the only
FCC definition of "CW". It is a moot point because tone generated data (as a
sinusoidal "mark" in your SSB transmission) is legal everywhere that CW is
legal. The same is not true of the voluntary band plans. It it is important
to know the difference, even if you think the difference makes no difference
so to speak. And I said that whistling CW into the mike is J3E voice, not
A1A, and the only thing that separates it from being legal on the CW
sub-bands is the way the data is coupled, not how it is received or
transmitted. You completely missed all of my points.


It has nothing to do with coupling. If you think the rules disallow
the method of a tone into an SSB transmitter, then it would most definitely
disallow whistling into the microphone.

Here. I cooked up an example that might hopefully explain all this,
but at this point I doubt it.

Take a 2MHz oscillator, and you key that (or, key a buffer stage after
that). Put it into a mixer, and the second input of the mixer is a
5MHz oscillator. Amplify it and feed it to the antenna. Now you've
got a signal with a carrier (5MHz) and two sidebands (3MHz and 7MHz), not a
good signal.

So you make the mixer balanced so the oscillators don't appear at the output.
That gets rid of the 5MHz "carrier", which leaves the two sidebands in place.
But you don't want that, so you add some filtering to get rid of the unwanted
sideband, let's make it the 3MHz signal.

Thus you now end up with a 7MHz signal.

How is this different from a 7MHz crystal oscillator being keyed and
then amplified and feeding the antenna?

How is this different from any number of SSB transmitters that also
send CW?

The rules don't allow it? But then a lot of SSB rigs break the
rules, and that really fancy CW transmitter described in QST in the
fall of 1971 would also break the rules.

Oh wait, it's legal.

But then why would a tone into an SSB transmitter be illegal
according to the rules? The tone becomes the 2MHz oscillator. It's
the same principle, just with a lower frequency being mixed with a
radio freqeuncy.

Of course you're going to get in trouble if you heterodyne two oscillators
together and don't get rid of the unwanted signals.

But, look at the output of the transmitter, and if it's designed properly
and adjusted properly, you cannot tell the difference between that
heterodyne transmitter and that simple 1 oscillator transmitter. You have
one radio signal at the output of that transmitter, and you can't tell
how it is generated.

Same with injecting a tone into an SSB transmitter. You will get one
signal at the output of that transmitter if the tone is pure enough and
carrier and unwanted sideband are properly suppressed.

You want to come up with some special case for this method, when the
other rules would take care of any problems.

If you've got more than one signal out of that transmitter, then
you've got a spur, and there are rules about that. The rules aren't
about how you can generate a spur-free signal, or allow spurs if you
followed a certain scheme, they are about not allowing spurs.

Take your simple CW transmitter. So the AC from the filament starts
modulating the oscillator tube, and suddenly you have an AM signal (ie
the keyed carrier and the two sidebands caused by the 60Hz ac signal).

Nobody is going to say "Oh, you've done that wrong, it's illegal". They
are going to say "You'd better do something about that AM signal in
the CW band".

Use an audio tone with harmonic content into the SSB transmitter
and then that signal when translated to radio frequencies will result in
multiple outputs, which is against the law. Have bad carrier suppression in
the SSB transmitter, and you'll get two outputs, again something which
is against the law. Have bad unwanted carrier suppression and you'll
have to sidebands at the output of that transmitter, yet again something
against the rules.

But do it properly, and wham, you only have one signal and nobody know,
or cares, how you generate it. Once again, it's no different than
a crystal oscillator feeding an amplifier; nobody cares how you generate
that CW signal, but they will care a lot if you've got hum on the signal
or you've got a harmonic.

In the end, you are waving your hands at your interpretation of the rules,
but can't even dig up those rules that you think mean what you say. Yet
you also can't explain the KWM-2 that used tone injection to generate
CW (surely Collins wouldn't have used the method if it wasn't allowed)
and I"m sure there were some other rigs of that same vintage that used
the same scheme. There were certainly articles in the ham magazines
about using the method to add CW to rigs that were SSB only.

You can't explain all those hams who used a frequency shifted audio
oscillator into an SSB transmitter to get FSK. Surely that would be wrong
if the FCC didn't allow the use of a tone to generate CW with an SSB
transmitter, though the principal is exactly the same.


Michael VE2BVW