Re: Heterodyne

Hans,

But I LIKE 807's and 813's. Always built transmitters with them, not
receivers! ;>) Got a K2 5-band HF CW/SSB transceiver kit for last
Christmas!

Alan (KM6VV)

hans wrote:

>
> Ian,
> Heterodyne used to be the term used to describe the "whistle" produced when two adjacent signals where received in the old type TRF
> (tune radio frequency aka "straight receivers") receivers, the signal got mixed and produced an audible tone, early morse code
> receivers used a BFO (beat frequency oscillator), that deliberately made such a tone so that a simple CW (carrier wave) could be
> used without modulation.
> Super heterodyne is the term used was used to describe the process of mixing two signals and produce a difference signal that was in
> the RF (radio frequency) and was NOT audible. this type of difference signal is normally called the IF intermediate frequency.
> The whole point of developing a Super heterodyne was to make a receiver more selective and easier to tune, and therefore avoid the
> whistle..
> Gone are the days of 813's and 807's and thank goodness !
> Hans W
>
> Ian Wright wrote:
>
> > ----- Original Message -----
> > From: Mariss Freimanis <geckohall@...>
> >
> > > as superhetrodyne recievers when
> >
> > (super)hetrodyne - derived from 'heater' and 'dynamic' - in use they
> > whistled like a boiling kettle.........? ;o)
> >