Single Sideband FM
 

Can anyone direct me to some good understandable references on single
sideband frequency modulation? I have no real practical reason for
wanting to know about this. It is interesting to me in a "mathetical"
sort of way. Of course, that is dangerous for me because my brain gets
very stubborn when I try to do math. Such ideas as "negative
frequency" kind of send my mental faculties into total shutdown.

But I read schematic very well. It is a visual language I can usually
understand. Seems like years ago there was an article on SSB FM in Ham
Radio. That would probably be a good start. If anyone can send me a
copy of that article I would be much appreciative.

Thanks in advance

Bruce kk7zz

www.elmerdude.com

No such thing that I have ever heard of.
For an easy explanation of the modulation modes -- see URL:
http://www.williamson-labs.com/480_mod.htm

Perhaps you were thinking of commercial FM broadcasting -- there is a
baseband FM signal, a 19kHz pilot carrier, and a DSB suppressed signal at
38kHz.
All this yields stereo FM
Baseband is left plus right channel
the DSB signal is left minus right -- so after demodulation, adding them
gives Left and Right channels

--
73 From The KeyBoard In The Wilderness
"Bruce Kizerian" wrote in message
om...
Can anyone direct me to some good understandable references on single
sideband frequency modulation? I have no real practical reason for
wanting to know about this. It is interesting to me in a "mathetical"
sort of way. Of course, that is dangerous for me because my brain gets
very stubborn when I try to do math. Such ideas as "negative
frequency" kind of send my mental faculties into total shutdown.

But I read schematic very well. It is a visual language I can usually
understand. Seems like years ago there was an article on SSB FM in Ham
Radio. That would probably be a good start. If anyone can send me a
copy of that article I would be much appreciative.

Thanks in advance

Bruce kk7zz

www.elmerdude.com

No such thing that I have ever heard of.
For an easy explanation of the modulation modes -- see URL:
http://www.williamson-labs.com/480_mod.htm

Perhaps you were thinking of commercial FM broadcasting -- there is a
baseband FM signal, a 19kHz pilot carrier, and a DSB suppressed signal at
38kHz.
All this yields stereo FM
Baseband is left plus right channel
the DSB signal is left minus right -- so after demodulation, adding them
gives Left and Right channels

--
73 From The KeyBoard In The Wilderness
"Bruce Kizerian" wrote in message
om...
Can anyone direct me to some good understandable references on single
sideband frequency modulation? I have no real practical reason for
wanting to know about this. It is interesting to me in a "mathetical"
sort of way. Of course, that is dangerous for me because my brain gets
very stubborn when I try to do math. Such ideas as "negative
frequency" kind of send my mental faculties into total shutdown.

But I read schematic very well. It is a visual language I can usually
understand. Seems like years ago there was an article on SSB FM in Ham
Radio. That would probably be a good start. If anyone can send me a
copy of that article I would be much appreciative.

Thanks in advance

Bruce kk7zz

www.elmerdude.com

W7TI ) writes:
On 21 Oct 2003 10:06:26 -0700, (Bruce Kizerian)
wrote:

Seems like years ago there was an article on SSB FM in Ham
Radio.

__________________________________________________ _______

In the April issue? :-)


Bill, W7TI


No, the January 1977 issue of Ham Radio magazine, it was the
cover article. (I knew it was a January issue, and around that
time, but I used the online index at
http://webhome.idirect.com/~griffith/hrindex.htm
to find it, though it took a few tries to figure out which
category it was in.)

I could never really make sense of the article. My recollection
is that it didn't do a good job on conveying the theory to
the average ham, or even the purpose of such a mode, and then
went into some stuff about implementing using some circuits out
of a textbook and not a complete circuit. One or the other
would have been fine, but in straddling both theory and practical
it did neither well.

Michael VE2BVW

W7TI ) writes:
On 21 Oct 2003 10:06:26 -0700, (Bruce Kizerian)
wrote:

Seems like years ago there was an article on SSB FM in Ham
Radio.

__________________________________________________ _______

In the April issue? :-)


Bill, W7TI


No, the January 1977 issue of Ham Radio magazine, it was the
cover article. (I knew it was a January issue, and around that
time, but I used the online index at
http://webhome.idirect.com/~griffith/hrindex.htm
to find it, though it took a few tries to figure out which
category it was in.)

I could never really make sense of the article. My recollection
is that it didn't do a good job on conveying the theory to
the average ham, or even the purpose of such a mode, and then
went into some stuff about implementing using some circuits out
of a textbook and not a complete circuit. One or the other
would have been fine, but in straddling both theory and practical
it did neither well.

Michael VE2BVW

Michael Black wrote:
No, the January 1977 issue of Ham Radio magazine, it was the
cover article.
I could never really make sense of the article. My recollection
is that it didn't do a good job on conveying the theory to
the average ham, or even the purpose of such a mode,

I would think it would be for the same reason as SSB for AM? To achieve
half the bandwidth utilization for a given signal? (But at the expense of
3dB poorer SNR...)

I suspect that going through the math for the 'direct generation' means of
SSB-FM would be pretty gnarly, but the 'first generate FM, then add a sharp
filter' approach should work (although this will really generate vestigal
sideband modulation...).

---Joel Kolstad

Michael Black wrote:
No, the January 1977 issue of Ham Radio magazine, it was the
cover article.
I could never really make sense of the article. My recollection
is that it didn't do a good job on conveying the theory to
the average ham, or even the purpose of such a mode,

I would think it would be for the same reason as SSB for AM? To achieve
half the bandwidth utilization for a given signal? (But at the expense of
3dB poorer SNR...)

I suspect that going through the math for the 'direct generation' means of
SSB-FM would be pretty gnarly, but the 'first generate FM, then add a sharp
filter' approach should work (although this will really generate vestigal
sideband modulation...).

---Joel Kolstad

Joel Kolstad wrote:
I would think it would be for the same reason as SSB for AM? To achieve
half the bandwidth utilization for a given signal? (But at the expense of
3dB poorer SNR...)
^^^^^^^^^^^^^^
It occurs to me that this part of my comment is non-sense given the
machinations one has to go through to compute SNR through an FM channel
anyway. Sorry. One wonders what the SNR degradation _would_ be, however.

---Joel Kolstad

Joel Kolstad wrote:
I would think it would be for the same reason as SSB for AM? To achieve
half the bandwidth utilization for a given signal? (But at the expense of
3dB poorer SNR...)
^^^^^^^^^^^^^^
It occurs to me that this part of my comment is non-sense given the
machinations one has to go through to compute SNR through an FM channel
anyway. Sorry. One wonders what the SNR degradation _would_ be, however.

---Joel Kolstad

"Joel Kolstad" ) writes:
Michael Black wrote:
No, the January 1977 issue of Ham Radio magazine, it was the
cover article.
I could never really make sense of the article. My recollection
is that it didn't do a good job on conveying the theory to
the average ham, or even the purpose of such a mode,

I would think it would be for the same reason as SSB for AM? To achieve
half the bandwidth utilization for a given signal? (But at the expense of
3dB poorer SNR...)

It's been quite a few years since I looked at the article. There was
just something about the article that seemed like I'd been dropped into
something. Maybe the style was different from most articles in the
magazine, maybe because it didn't really seem to be a practical article.
There just seemed to be something missing. Yes, it would take up less
space, but then why not go to some other mode? It's the only time I've
seen something on the subject, and I think it could have better been handled.

Michael VE2BVW