Arduino Forum

Using Arduino => General Electronics => Topic started by: mikedb on Feb 14, 2020, 12:27 pm

Title: 2n3819 Mosfet Rf amp
Post by: mikedb on Feb 14, 2020, 12:27 pm
Hi

I would like to know how to get a 2N3819 transistor to amplify a freq from 1MHZ to 50MHZ.

There is many diagrams on the internet but for a few years now just cannot get the 2N3819 to work.

I always end up using a 2n2222  or BC238 but I would like to measure lower Rf values,with a freq counter.

Thanks for any advice.
Title: Re: 2n3819 Mosfet Rf amp
Post by: vaj4088 on Feb 14, 2020, 07:26 pm
Why not use the 2N2222 ?  It is cheap and if you had it working for higher frequencies then you should have no trouble at a lower frequency.

You seem to be comparing a JFET with a bipolar transistor.  Did you use a different circuit ?  What is it ?
Title: Re: 2n3819 Mosfet Rf amp
Post by: MarkT on Feb 14, 2020, 10:31 pm
http://www2.eng.cam.ac.uk/~dmh/ptialcd/trf/trf.htm#rfamp (http://www2.eng.cam.ac.uk/~dmh/ptialcd/trf/trf.htm#rfamp)

Biasing for a JFET is totally different to a BJT, and depends on the device specs much more.

When you say "amplify a freq from 1MHZ to 50MHZ." do you mean to imply broadband?