[Heath] HW-101 VFO - more yet

[Kenneth G. Gordon]

On 6 Mar 2018 at 17:37, ChrisIwata via Heath wrote:

> 
> The J310 will probably work, but isn't a near replacement for the 
> MPF105.   The J310 has a much higher Idss, so the VFO will draw more 
> juice.  It also has a higher transductance.

Higher transconductance means that it takes less feedback to oscillate, or will oscillate at 
lower voltage.

> The MPF105 is no more, but I did find a shortened datasheet.
> 
> A nearer replacement might be the  MPF102 or 2N3819 that everybody seems 
> to like.  Personally, their tolerances are way too wide:  From one batch 
> to another they are very different.  I prefer the 2N5486 which has 
> tighter specs.

Yes. I like that one better too. I ordered 10 of them from Mouser. I'll probably use one of 
those in these VFOs.

I ordered the J310 (5 of them) since I have a couple of low-noise preamps which use them.
 
> Truth be told, almost any JFET will probably work

Probably. Thanks a bunch for your very kind advice. Much appreciated.

Ken W7EKB

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