[hpsdr] More on Horton LO

[Robert McGwier]

Guido:

Continue to work on it, you might have the right idea where we are failing!

We are trying to workout another proposal and there is some serious 
haggling going on over parts, divisors, etc.   Hopefully a preliminary 
version of semi-Horton will be out in a couple of weeks.

Bob



Guido wrote:
> Robert,
>
> Fully digital LO chain for a direct QSD control. I am still caught by 
> your idea!
>
> Have been thinking that with a high crystal clock it might be possible 
> to generate every frequency in 0-30Mhz by undersampling the QSD. Since 
> the QSD is preceded by a bandpass, the spurs generated by the 
> undersampling might be out of band.
>
> Trying to calculate it, but a clock of 133Mhz is still insuficient to 
> get frequency steps that are close enough (<50kHz) and the frequency 
> of undersampling gets to low so the bandpass filter needs to get too 
> tight. Also tried to model a fractional N with sigma delta 
> compensation but this did not turned out in anything useful yet.
>
> Guido.


-- 
AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats,
NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman
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