Status
- not done - I'm fine tuning and documenting
Introduction
Gasp! Do I really want to say it? This is another NE602 / LM386 receiver. Well ok, there is an NE602 at one end and an LM386 at the other end. I have to at least do some filtering and amplification in the middle.
The two chip receivers are nice but I needed filtering. You see I'm visually impaired and have excellent hearing. Hearing tones and conversations at frequencies between 10-22Khz will drive you starkraving mad! I envy those of you who can live on 2 ICs. 80 meters is crowded and I just can't take it anymore.
The component values used in this project may not be the best choices. Some items I have are in excess and I'll try anything in a project once.
The Main Players
Minus the voltage regulator there are three players in this receiver.
NE602 / SA612
The heart of this receiver. Of course the NE602 has retired, but you can buy the SA612 instead.
I'm making use of the built in osc. A VFO using varactor diodes takes care of the tuning.
LM386
This is the headphone amp of choice. A simple and easy to use IC. Oh by the way, save yourself some trouble and leave the gain at 20.
LF353
A nice dual op amp that I have plenty of in my junk box. This IC will handle our filtering and amplification.
The Schematic
(honest its coming)