P3ST Modular Transceiver PCBs

MDRF is pleased to offer a set of printed-circuit boards for N6QW’s P3ST SSB transceiver for 15, 17, or 20 meters (it can be built or modified or any one of these). It’s modular construction allows for easy assembly, testing, and modification. Most of Pete’s recent designs are intended as experimenter’s platforms. Any of the modules that make up the P3ST’s superhet SSB architecture can be swapped out for different designs or modifications. By the way, any of the modules can be used in other homebrew rigs as well, and they will be available for sale separately.

Modules plug into headers on the motherboard which carry relay-switched power. Where possible, components are spaced apart as far as possible for ease of assembly by those who suffer from FFS (fat-finger syndrome). With a standard module size–2.5 x 1 inch (5 x 6.4 cm)–and connector spacing, it will be easy to swap them out or to modify them. The motherboard is 6 x 7.5″ (15.2 x 19.5cm).

A key feature of the P3ST is the reuse of circuit modules for both transmit and receive. The mixers, the IF module, the band-pass filter, and the RF amp are switched by relay from RX to TX with a signal from the push-to-talk line.

Here’s some more photos of the transceiver and its modules (click on a photo to enlarge):

The P3ST is currently available as a set of PCBs only. All documentation–including a detailed parts list (with vendor part numbers)–is available on MDRF’s Github site (see link below).

For those who are interested in building the P3ST, here is a caution: This is not a project for beginners. If you’ve have some experience in building radio (or other electronics) at the discrete-component level, you should do just fine building the P3ST. Additionally, some level of understanding of the various module-level functions (filters, amplifiers, and mixers) is also essential. Of course one benefit of the modular approach the P3ST kit takes is to reduce its electronic workings to their essential functions–its “architecture”–as shown on the block diagram. Thus identified and highlighted, building the P3ST can also be a learning experience, even if you do need to know some things already. As Pete Juliano, N6QW, the designer of the P3ST likes to say, “When you know stuff you can do stuff.” The corollary of that is if you don’t know stuff you can’t do stuff.

Fortunately, we now have at our fingertips access to vast knowledge through the internet. There is also an ongoing forum available at groups.io/g/pssst-20 where you can ask questions or to search for previously-answered ones. This should be the go-to source for your inquiries. MDRF will not be able to provide anywhere near the level of support you can get from fellow builders on the groups.io forum. Pete N6QW will not be able to provide support at all except as he wishes to participate in the forum. Todd K7TFC will, of course, be a regular participant.

P3ST Schematic Diagrams

Github Repository (design files, parts lists, instructions as available)

Parts List PDF (with sources and part numbers)

Parts List Excel File (with sources and part numbers)