Re: TV preamp FET choice

From: Paul Burridge (pb_at_notthisbit.osiris1.co.uk)
Date: 08/30/04 

Date: Mon, 30 Aug 2004 19:23:36 +0100

On Mon, 30 Aug 2004 15:13:37 +0000 (UTC), kensmith@green.rahul.net
(Ken Smith) wrote:

>In article <l196j01jq2u7leq0lv78235b8g99jckm3l@4ax.com>,
>Paul Burridge <pb@notthisbit.osiris1.co.uk> wrote:
>>Hi all,
>>
>>I've decided to build a TV preamp just for the hell of it. There's one
>>channel on 850Mhz I can't quite pick up without one, anyway. I've got
>>three JFETs in my junk box that *might* make the grade at this
>>frequency, but I'm not sure. The parts I have are the BF244, the J310
>>and J211. Is there going to be any worthwhile gain from any of them,
>
>
>The lead inductance of the J310 and J211, I think, rule them out right at
>the start.

I assume you're referring to the T092's internal bonding wire
inductance?

> IIRC both these devices have largish gate capacitances.

Just 2 and 4 pF for the J301? That seems manageable, surely?

>What you really need for this application is a parametric amplifier and a
>stirling cycle device on the idle load.

"sterling cycle device on the idle load"?? WTF does that mean? 

-- 
"What is now proved was once only imagin'd." - William Blake, 1793.
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