Avery Fineman wrote:
So, if you want to examine the total RF in a time-domain situation,
you MUST examine it as amplitude versus an infinitely-thin slice of
TIME.

You might want to remind everyone that the mathematical Fourier transform of
a signal is an integral that extends from time=minus infinity to plus
infinity. Since Real Spectrum Analyzers (or network analyzer) need to
produce results in something, oh, less than infinite time (probably less
than the time between now and the next donut break), they're necessarily
limited in the low frequency detail they can provide. True, if Gary's
transmitter is transmitting a zero at the moment he connects a spectrum
analyzer, he won't see anything at all on the display, but as you point
out -- this is an equipment problem, not a mathematical one.

I'm still a believer in SSB-FM, BTW. :-) But I have enough respect for you
that I won't attempt to argue it further without first finding the time to
prepare a few drawings to demonsrate why!

---Joel Kolstad

In article , "Joel Kolstad"
writes:

Avery Fineman wrote:
So, if you want to examine the total RF in a time-domain situation,
you MUST examine it as amplitude versus an infinitely-thin slice of
TIME.

You might want to remind everyone that the mathematical Fourier transform of
a signal is an integral that extends from time=minus infinity to plus
infinity.

The series expansions of the basic modulation type RF time-domain
expression don't use Fourier series. The series expansions show
the sprectral content are still equivalent to that infinitely-thin slice
of time as the function of amplitude.

I think that Panters "Signals, Modulation, and Noise" text has it
worked out in there (by memory, don't have that one handy here).
The "Landee" text I mentioned is an old one and not that familiar
to most.

Since Real Spectrum Analyzers (or network analyzer) need to
produce results in something, oh, less than infinite time (probably less
than the time between now and the next donut break), they're necessarily
limited in the low frequency detail they can provide. True, if Gary's
transmitter is transmitting a zero at the moment he connects a spectrum
analyzer, he won't see anything at all on the display, but as you point
out -- this is an equipment problem, not a mathematical one.

No, it's an argument problem. :-)

There's no infinitely-fast RF power meter in existance. Yet.


I'm still a believer in SSB-FM, BTW. :-) But I have enough respect for you
that I won't attempt to argue it further without first finding the time to
prepare a few drawings to demonsrate why!

I'm not arguing that "single-sideband FM" won't work. I just don't like
the name. The technique DOES work from all the explanations of
experiments, is reproducible. [it isn't the "cold fusion" thing. :-) ]

I've not seen any convincing case that the single-whatever FM thingy
has any practical applications.

For narrowband voice, SSB AM is just dandy and a phasing system
using the Gingell-Yoshida polyphase network is quite easy and
error-tolerant to make a good phasing exciter. It can be used in
"reverse" to get an easy-to-select sideband demod or an ordinary
AM detector that yields false stereo (one sideband to each ear),
already done with simple CW receivers.

Len Anderson
retired (from regular hours) electronic engineer person

In article , "Joel Kolstad"
writes:

Avery Fineman wrote:
So, if you want to examine the total RF in a time-domain situation,
you MUST examine it as amplitude versus an infinitely-thin slice of
TIME.

You might want to remind everyone that the mathematical Fourier transform of
a signal is an integral that extends from time=minus infinity to plus
infinity.

The series expansions of the basic modulation type RF time-domain
expression don't use Fourier series. The series expansions show
the sprectral content are still equivalent to that infinitely-thin slice
of time as the function of amplitude.

I think that Panters "Signals, Modulation, and Noise" text has it
worked out in there (by memory, don't have that one handy here).
The "Landee" text I mentioned is an old one and not that familiar
to most.

Since Real Spectrum Analyzers (or network analyzer) need to
produce results in something, oh, less than infinite time (probably less
than the time between now and the next donut break), they're necessarily
limited in the low frequency detail they can provide. True, if Gary's
transmitter is transmitting a zero at the moment he connects a spectrum
analyzer, he won't see anything at all on the display, but as you point
out -- this is an equipment problem, not a mathematical one.

No, it's an argument problem. :-)

There's no infinitely-fast RF power meter in existance. Yet.


I'm still a believer in SSB-FM, BTW. :-) But I have enough respect for you
that I won't attempt to argue it further without first finding the time to
prepare a few drawings to demonsrate why!

I'm not arguing that "single-sideband FM" won't work. I just don't like
the name. The technique DOES work from all the explanations of
experiments, is reproducible. [it isn't the "cold fusion" thing. :-) ]

I've not seen any convincing case that the single-whatever FM thingy
has any practical applications.

For narrowband voice, SSB AM is just dandy and a phasing system
using the Gingell-Yoshida polyphase network is quite easy and
error-tolerant to make a good phasing exciter. It can be used in
"reverse" to get an easy-to-select sideband demod or an ordinary
AM detector that yields false stereo (one sideband to each ear),
already done with simple CW receivers.

Len Anderson
retired (from regular hours) electronic engineer person

Hi Len,

Avery Fineman wrote:
For narrowband voice, SSB AM is just dandy and a phasing system
using the Gingell-Yoshida polyphase network is quite easy and
error-tolerant to make a good phasing exciter. It can be used in
"reverse" to get an easy-to-select sideband demod or an ordinary
AM detector that yields false stereo (one sideband to each ear),
already done with simple CW receivers.

....or real stereo! The Kahn/Hazeltine AM stereo sysem did this -- L in the
lower sideband, R in the upper. Hence envelope detectors recovered L+R, and
AM radios built back to the beginning of (radio) time kept working.

On the other hand (and I know this is just asking for abuse), the Motorola
C-QUAM AM stereo system could be applied to SSB modulation and still work,
which obviously Kahn/Hazeltine can't. I don't imagine C-QUAM's designers
were considering this, however.

It's almost painful to look at the (complex) envelope of AM and notice that
the quadrature signal is completely unused. Sending stereo over I and Q
strikes me as a 'interesting,' (does anyone know of a commercial system that
does this? Surely somebody's must...) but of course it would break
compatibility with current receivers and I imagine someone who's more
knowledgeable than I could point out some pitfalls as well.

---Joel

Hi Len,

Avery Fineman wrote:
For narrowband voice, SSB AM is just dandy and a phasing system
using the Gingell-Yoshida polyphase network is quite easy and
error-tolerant to make a good phasing exciter. It can be used in
"reverse" to get an easy-to-select sideband demod or an ordinary
AM detector that yields false stereo (one sideband to each ear),
already done with simple CW receivers.

....or real stereo! The Kahn/Hazeltine AM stereo sysem did this -- L in the
lower sideband, R in the upper. Hence envelope detectors recovered L+R, and
AM radios built back to the beginning of (radio) time kept working.

On the other hand (and I know this is just asking for abuse), the Motorola
C-QUAM AM stereo system could be applied to SSB modulation and still work,
which obviously Kahn/Hazeltine can't. I don't imagine C-QUAM's designers
were considering this, however.

It's almost painful to look at the (complex) envelope of AM and notice that
the quadrature signal is completely unused. Sending stereo over I and Q
strikes me as a 'interesting,' (does anyone know of a commercial system that
does this? Surely somebody's must...) but of course it would break
compatibility with current receivers and I imagine someone who's more
knowledgeable than I could point out some pitfalls as well.

---Joel