In the shack building a 500KHz version of the PA0SE field strength meter for 500kHz which is basically a DC RX with audio and DVM readout.
Will use DVM M-830 B that can sense to 200uA and 2000uA.
Mixerwill be SA612 or TFM-335 (Mini ciruits, because I have some!)
TL072 Dual op amp
The LO still making up my mind but think a colpitts oscillator might be easiest. Either LC type or use a 500KHz ref crystal and pull it a little. Otherwise 4MHz colpitts with a PNP buffer and then divide by 8 using perhaps a 74HC4040.
For the front end will use an LF preamp/selector for 500KKz using J310/2N2222A and the preselector is simple LC filter using 1mH axial choke and 500pF capacitor.
I will use a ferrite rod, for the input, and as I have a couple I might try and use a superdrug (http://www.hanssummers.com/ for GQRP homebrew silliness) ferrite rod and add additional winding to the MW coil suitable for 500kHz. Will dip the coil for 500KHz.
No circuit at moment but I'll write it up.
It's snowed last night and it is cold outside the shack and the cat helped select the circuits.