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From: PalapaGuy on 20 Sep 2009 20:22
Single-sideband FM was a popular topic several years ago but I haven't seen
any articles on it since then. It looks attractive as a way to transmit
narrowband FM efficiently at VHF over short distances. Does anyone know of
current uses for this technology?


From: Jerry Avins on 20 Sep 2009 20:57
PalapaGuy wrote:
> Single-sideband FM was a popular topic several years ago but I haven't seen
> any articles on it since then. It looks attractive as a way to transmit
> narrowband FM efficiently at VHF over short distances. Does anyone know of
> current uses for this technology?

Narrow-band FM (NBFM) is the same as low-modulation-percentage AM with
the carrier shifted 90 degrees. If the modulation index is low enough,
what you mention is identical to the SSB-SC that is standard on ham and
CB bands. I suppose people eventually realized that. Or is there some
other meaning to what you write?

Jerry
--
Engineering is the art of making what you want from things you can get.
�����������������������������������������������������������������������
From: HardySpicer on 20 Sep 2009 22:13
On Sep 21, 12:57 pm, Jerry Avins <j...(a)ieee.org> wrote:
> PalapaGuy wrote:
> > Single-sideband FM was a popular topic several years ago but I haven't seen
> > any articles on it since then.  It looks attractive as a way to transmit
> > narrowband FM efficiently at VHF over short distances.  Does anyone know of
> > current uses for this technology?
>
> Narrow-band FM (NBFM) is the same as low-modulation-percentage AM with
> the carrier shifted 90 degrees. If the modulation index is low enough,
> what you mention is identical to the SSB-SC that is standard on ham and
> CB bands. I suppose people eventually realized that. Or is there some
> other meaning to what you write?
>
> Jerry
> --
> Engineering is the art of making what you want from things you can get.
> ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

Not sure it behaves the same. FM thresholds but AM doesn't. AM (SSB)
has problems demodulating it I suppose whereas with FM you can easily
use a PLL.


Hardy
From: Jerry Avins on 20 Sep 2009 23:01
HardySpicer wrote:
> On Sep 21, 12:57 pm, Jerry Avins <j...(a)ieee.org> wrote:
>> PalapaGuy wrote:
>>> Single-sideband FM was a popular topic several years ago but I haven't seen
>>> any articles on it since then. It looks attractive as a way to transmit
>>> narrowband FM efficiently at VHF over short distances. Does anyone know of
>>> current uses for this technology?
>> Narrow-band FM (NBFM) is the same as low-modulation-percentage AM with
>> the carrier shifted 90 degrees. If the modulation index is low enough,
>> what you mention is identical to the SSB-SC that is standard on ham and
>> CB bands. I suppose people eventually realized that. Or is there some
>> other meaning to what you write?
>>
>> Jerry
>> --
>> Engineering is the art of making what you want from things you can get.
>> �����������������������������������������������������������������������
>
> Not sure it behaves the same. FM thresholds but AM doesn't. AM (SSB)
> has problems demodulating it I suppose whereas with FM you can easily
> use a PLL.

NBFM doesn't threshold. You confuse the properties of FM with those of
SSB NBFM. As far as I know,n SSB version of high-modulation-index FM
doesn't exist.

Jerry
--
Engineering is the art of making what you want from things you can get.
�����������������������������������������������������������������������
From: HardySpicer on 21 Sep 2009 00:34
On Sep 20, 8:01 pm, Jerry Avins <j...(a)ieee.org> wrote:
> HardySpicer wrote:
> > On Sep 21, 12:57 pm, Jerry Avins <j...(a)ieee.org> wrote:
> >> PalapaGuy wrote:
> >>> Single-sideband FM was a popular topic several years ago but I haven't seen
> >>> any articles on it since then.  It looks attractive as a way to transmit
> >>> narrowband FM efficiently at VHF over short distances.  Does anyone know of
> >>> current uses for this technology?
> >> Narrow-band FM (NBFM) is the same as low-modulation-percentage AM with
> >> the carrier shifted 90 degrees. If the modulation index is low enough,
> >> what you mention is identical to the SSB-SC that is standard on ham and
> >> CB bands. I suppose people eventually realized that. Or is there some
> >> other meaning to what you write?
>
> >> Jerry
> >> --
> >> Engineering is the art of making what you want from things you can get..
> >> ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
>
> > Not sure it behaves the same. FM thresholds but AM doesn't. AM (SSB)
> > has problems demodulating it I suppose whereas with FM you can easily
> > use a PLL.
>
> NBFM doesn't threshold. You confuse the properties of FM with those of
> SSB NBFM. As far as I know,n SSB version of high-modulation-index FM
> doesn't exist.
>
> Jerry
> --
> Engineering is the art of making what you want from things you can get.
> ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

NBFM must threshold. In fact it thresholds worse than wide-band since
the beta is lower. That anoying sound on every police radio in the UK
(as it was of course).

Hardy
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