Amateur 40m receiver - will it work?

I have been dreaming again, about very simple but unusual receiver designs for CW and SSB reception. This one is the latest idea:


It has three parts:

1 The input mixer which heterodynes the incoming RF signals with the local VFO to produce an audio signal.

2 A simple audio amplifier.

3 A simple Hartley VFO with electronic tuning using a varicap diode.

The input transformer is a wide band one, using a ferrite core. The diodes are schottky type for low voltage drop. The RFC is 47-100uH "resistor" type. The FETs are the BF245A, a very, very useful transistor which can be used with zero bias (it conducts 2-6mA at a Vgs = 0). The values given here for the oscillator are about right for 7MHz, but may need tweaking a bit to centre the band and adjust the tuning range: to do this a variable trimmer can be put across the 100pF capacitor to centre the thing range, and the varicap series capacitor of 47pF changed to limit the width of the tuning range.

What I want to try also is to connect the output to my MacBook and run an SDR program, this then hopefully will display a +/-48kHz range of frequencies and let me tune across and change modes to LSB/USB or CW. The program I have is DSP Radio from DL2SDR, which works well with my dedicated SDR radio front end, from Kanga products.