Showing posts with label mosfet. Show all posts
Showing posts with label mosfet. Show all posts

16 Apr 2018

A high sensitivity MOSFET crystal set

Firstly, I should say I have not built this, but it looks interesting.

See http://www.arrl.org/files/file/Technology/tis/info/pdf/culter.pdf

10 May 2010

VLF up-converters and MOSFETs

Today I built a MOSFET up-converter, converting 7-9kHz VLF to around 20MHz. However, I was disappointed with the results: low conversion gain and sensitivity when using either a 3N211 and a BF981 device. I used an 82mH choke with a 4n7 cap as the tuned circuit on G1 (tapped capacitance for max sensitivity with 50 ohm input) with LO injection on G2. Despite optimising everything I couldn't better the sensitivity achieved with the SBL1 based up-converter that appears on my website.