[time-nuts] Low phase noise VCO

[Bruce Griffiths]

Nick Foster wrote:
>    
>> From: bill at iaxs.net
>> To: time-nuts at febo.com
>> Date: Tue, 9 Feb 2010 18:24:39 -0600
>> Subject: Re: [time-nuts] Low phase noise VCO
>>
>> Which leads me to ask a novice question:
>>
>> Why not pull a 16 MHz crystal and multiply to 64 MHz?
>>
>> If you count down from 64 to 10 MHz, isn't the multiplication inside the
>> PLL?
>>
>> Perhaps the noise is multiplied by 4, but would it work for the intended
>> purpose?
>>
>> Bill Hawkins
>>      
> Can you do x4 multipliers? I thought odd-order harmonics were usually used for multipliers. I'd be happy to be wrong!
>
> Nick
>   		 	   		
>    
Yes x4 multipliers aren't too difficult:

1) Cascade a pair of JFET doublers as Wenzel does.

2) Generate a narrow pulse with an SRD and select the required harmonic.

3) Use a single transistor multiplier like those used in the 5370A/B 
10MHz to 200Mhz multiplier chain.

Bruce