> On Jul 15, 3:35 am, "George Dishman" briar.demon.co.uk> wrote:
>

>> fc > fm means fc should be greater than fm, not the same.
>> For fm = 10,000Hz and fc = 10,001Hz you get a lower
>> sideband at 1Hz and an upper sideband at 20,001Hz.

>
> Sorry. I didn't read it correctly.
>

>> If you modulate 10kHz with 10Khz, the lower sideband
>> becomes 0Hz or DC. The value of that depends on the
>> phase of the modulating signal relative to the carrier
>> (which is now constant since they are at the same
>> frequency). Of course sending DC to an antenna won't
>> give you a transmitted signal but it doesn't produce
>> an alias either.

>

>> If you modulate 10,000Hz with 10,001Hz then your lower
>> sideband becomes -1Hz, and of course sin(-x) = sin(x)
>> so that is identical to a frequency of 1Hz which you ...

> On Jul 15, 11:52 am, "George Dishman" briar.demon.co.uk>
> wrote:
>

>> "Radium" gmail.com> wrote in message

>>> If so, then the minimum frequency required for my "project" would be
>>> only 20.0000000000000000001 KHz. Or just anything above 20 KHz, even
>>> if it's just an extremely extremely small number above 20,000. Right?

>> In theory, but you are missing the bigger picture. Space
>> is not a perfect vacuum and in the vicinity of the Solar
>> System, the Solar wind pushes back the inter-stellar
>> medium. You can read more on that here:
>> http://en.wikipedia.org/wiki/Heliosphere

>
> Thanks for the link
>

>> Both the material within the region and the ISM are almost
>> entirely ionised so are in a form known as "plasma", a
>> soup of charged particles. One of the feautures of plasma
>> is that is absorbs low frequency signals below what is ...

> On Jul 15, 11:52 am, "George Dishman" briar.demon.co.uk>
> wrote:
>

>> http://en.wikipedia.org/wiki/Heliosphere

>

>> Both the material within the region and the ISM are almost
>> entirely ionised so are in a form known as "plasma", a
>> soup of charged particles. One of the feautures of plasma
>> is that is absorbs low frequency signals below what is
>> called the "plasma cutoff frequency". Basically below
>> the VHF band, space becomes increasingly opaque and signals
>> from stars don't reach us.

>
> Okay so it seems like a no win-situation here. Too low and plasmas
> will cut it off. Too high and you lose strength really fast.
>
> http://www.terabeam.com/support/calculations/free-space-loss.php
>
> From the above link, it seems that a higher-frequency radio wave would ...

> On Jul 15, 11:52 am, "George Dishman" briar.demon.co.uk>
> wrote:
>

>> http://en.wikipedia.org/wiki/Heliosphere

>

>> Both the material within the region and the ISM are almost
>> entirely ionised so are in a form known as "plasma", a
>> soup of charged particles. One of the feautures of plasma
>> is that is absorbs low frequency signals below what is
>> called the "plasma cutoff frequency". Basically below
>> the VHF band, space becomes increasingly opaque and signals
>> from stars don't reach us.

>
> Okay so it seems like a no win-situation here. Too low and plasmas
> will cut it off. Too high and you lose strength really fast.
>
> http://www.terabeam.com/support/calculations/free-space-loss.php
>
> From the above link, it seems that a higher-frequency radio wave would ...