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Stefan,

Thanks for the info and advice.  Yes,  ferrite beads sound like a
good idea.  The resistors and caps (1M 100k 68pF 680pF etc) between the
FET's are for lowpass or something else?

73
Joe VO1NA

On Sat, 9 May 2015, DK7FC wrote:

> Hi Joe,
>
> That choke was just intended to improve the supply voltage stability (low 
> pass filtering). It's value is not critical.
> Meanwhile i've learned that it can be helpful to spend a ferrite bead in 
> front of the jFETs gate, to prevent VHF oscillations...
> I am one of those who prefer to spend one more component here and there, just 
> to prevent eventual unintended behaviour...
>
> 73, Stefan
>
> Am 09.05.2015 02:44, schrieb jcraig@mun.ca:
>> Hi Stefan and group,
>> 
>> I am building a probe using your design. Could you
>> explain the interstage network and the 470 uH choke?
>> 
>> I hope to use this to detect some 36 km photons. So far,
>> using the PA0RDT miniwhip (without the VLF refit)
>> and Spectrum Lab has resulted in reception only of
>> near field electrostatic and induced artefacts
>> ie: my best DX is only 5.2 km.
>> 
>> Best 73 & TNX
>> Joe VO1NA
>> 
>> 
>> 
>> 
>> 
>
>