My latest thoughts are of laying out some receiver printed circuit boards (pcb) for some simple receivers. These receivers will be minus the local oscillator (LO) so I can use a simple oscillator circuit or a DDS. There are several DDS ideas going around right now. My favorite is still the N3ZI DDS2 but there are lots of DDS oscillator circuits using the simple AD9850/51 DDS modules available on eBay.
My 1st version will be a simple 40m DC receiver. It will consist of nothing more than a front end DTC into a NE602. The output of the NE602 would then go to the Hi-Per-Mite module and the N3ZI DDS will serve as the LO. The output level of the DDS is just about right for a NE602. . so, the 1st model will be nothing more than antenna into a DTC, then into a NE602. That’s it.The Hi-Per-Mite audio module has a coupling capacitor on the input so the output (pin5)of the NE602 will just connect directly to the Hi-Per-Mite.
The next model will be a general coverage superhet consisting of multiple tuned circuits to cover the HF spectrum , a NE602 1st mixer, 2crystal ladder filters, a MC1350 IF amplifier, a product detector w/BFO and then the Hi-Per-Mite audio section as before. A number of folks have wanted a general coverage receiver that used the N3ZI DDS2 ever since Doug discontinued it. I'll layout a nice pcb for it and build a production prototype in a Ten-Tec enclosure. With the MC1350 I could later add audio derived AGC driving MC1350 pin 5.
In the next model maybe I’ll put the DNR in the audio chain especially since I already have the DNR module in my “junk Box”. I plan to arrange the Hi-Per-Mite so that I can switch the 200Hz filter in and out. . that way, with the 200Hz out I will have a 500Hz filter for most CW operating and the ability to switch in the 200Hz filter if needed. During FD on 40m in the evening a 200Hz filter would be most welcome.