[hpsdr] More on Horton LO

[Robert McGwier]

I have used Valpey Fisher oscillators VFT7 and VFT8.  They are extremely 
low jitter,  VC ovenized oscillators.  The only problem with these parts 
is long lead times (2 months) and forget it on samples and minimum 
orders of ten (typically).   In the CNS-II clock, the extreme accuracy 
option uses one and a recently announced new high end SDR uses the other.

Bob
N4HY


Hans Summers wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> Chuck,
>
>   
>> Now a question, if the clock for a DDS has jitter(phase noise) how can
>> the output not have jitter?  I think if we use a DDS we will want the
>> highest possible 500 MHz multiplied crystal to get the cleanest signal.
>> I don't have data but I think the higher frequency clock results in
>> lower spurs.   Comments
>>     
>
> My understanding is that the jitter (phase noise) on the DDS reference
> clock does indeed go right through to the output (reduced by 6dB per
> octave division as usual). So it is important to use a high quality
> crystal reference for the DDS.
>
>   
--- snip ---


-- 
AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats,
NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman
Laziness is the number one inspiration for ingenuity.  Guilty as charged!


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