[TenTec] Superhet Receiver Types?

[Bob Henderson]

All of that is pretty much dead on Ken until the last bit.

If a receiver has an IF (Intermediate Frequency) at all, it is not direct
conversion.  Direct conversion converts in one step from rf to audio without
an intermediate frequency stage.  Whether the IF is DSP or not doesn't
matter.

A single conversion receiver would be better described as a single IF
receiver because as you point out, two conversions occur.  The first from
the receive frequency to the IF frequency and the second from IF to audio.
This convention is long established.  A triple conversion receiver will have
3 IFs.

I hope that helps.

Bob, 5B4AGN

----- Original Message ----- 
From: "Ken Brown" <ken.d.brown at verizon.net>
To: <tentec at contesting.com>
Sent: Friday, August 06, 2004 8:31 AM
Subject: [TenTec] Superhet Receiver Types?


> Hi Bob,
>
> I have a question about terminology. Do I have this right? A "single
> conversion superheterodyne receiver" that does not have a DSP detector
> has a 1st local oscillator that mixes the incoming signal down to the
> 1st (and only) IF, and if in CW or SSB mode there is a BFO that then
> converts the IF to audio. In AM mode just a detector. And if it uses IF
> DSP there is an ADC that digitizes the IF for digital filtering and
> detection. So a "single conversion" superhet actually has two heterodyne
> conversions (and two local oscillators, the BFO being the second)  when
> it is operating CW or SSB, if it is does not have DSP at the IF.
>
> A "direct conversion" superhet just has one local oscillator and
> converts the incoming signal directly to audio.
>
> Have I got this right?
>
> Or if it has IF DSP and no BFO, is it then "direct conversion", or still
> "single conversion" or both?
>
> DE N6KB
>
> Bob Henderson wrote:
>
> >
> >Single coversion superhets are inompatible with the roofing filter
concept.
> >The filters in the K2 are those necessary to define the working bandwidth
of
> >the receiver.
> >
> >
> >
> >
>
>
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