[Elecraft] Re: K3 6m pre-amp

[Don Wilhelm]

Bob,

While I cannot speak from my own measurements, but in EMRFD, Wes Hayward 
recommends the U310s for VHF/UHF rather than the J310.  The case of the 
U310 is connected to the gate, and when used in a grounded gate 
configuration, the case can be mounted (upside down) into a hole in the 
PC board, and I believe that alone should provide better input to output 
isolation.  The Vishay data sheet indicates a slightly lower noise 
figure for the U310.

I would suggest that you try the J310s.  If you find them lacking, it 
should be easy to change to U310s, I would guess that at 50 MHz, it may 
be a 'toss-up' decision.

73,
Don W3FPR

Bob Tellefsen wrote:
> Hi John
> I've been looking at this circuit for some time.
> I have a number of J310s, but no U310s.
> Do you know whether they are the same
> animal, just in different casings?
> 73, Bob N6WG
>   
>