There it was as big as life and a way forward. A look in the Mostly DIY RF.com cupboard and we find all the boards and assemblies needed to build a SSB Transceiver. It's all there, all Commercial Off The Shelf (COTS) boards and assemblies.
The 1st realization must be that the era of designing your own rig and completely scratch building everything is on a precipitous downhill, over the cliff track. The center of the graph of today's average ham is not technical but contests and operating. The IARU and ARRL will tell you that! Sadly, those two organizations are at center of the shift away from the technical advancing the state-of-the-art ham to the ones who do contests and operating. It is what it is and certainly you could argue my position but basically you would be simply wrong.
So, when you have lemons and want to have something more, the answer is COTS.
The basic topology of our proposed rig is bidirectional which is a solid approach and not originated with the Bitx rigs. It is simple and just plain works.
Stock building blocks in a SSB rig includes Low Pass and Band Pass Filters, Transmit/Receive Mixers, Product Detectors/Balanced Modulators, Microphone Amplifiers, Audio Amplifiers, Crystal Filters, IF Amp Stages, Receiver RF Amplifiers, Transmit Pre-Driver and Transmit Amplifier stages. Last but not least is the Digital LO/BFO.
These are all COTS from K7TFC.
Transmit/Receive Mixer also Balanced Modulator/Product Detector
LM380 Audio Amp
Band Pass Filter
W3NQN LPF
Driver and Final Amp
Audio Amp Discrete Component Version
Broad Band Amp (Rx RF Amp and Tx Pre-Driver)
Crystal Filter ~ 4 Choices of IF
TIA Bidirectional Amplifier
Noteworthy at this time most of these COTS products come as a PC Board only, a complete Kit or a Finished Assembly. I have talked to K7TFC and three of the items at this time are a board only and those are the Low Pass Filter, the LM380 Audio Board and the Driver/IRF510.
From my perspective there are two boards that should be bought as finished assemblies and that is the Crystal Filter Board and the Digital LO/BFO. My choice of IF would be the 4.9152 MHz frequency. That frequency is what is used in the Elecraft K2.
Most of the other COTS assemblies available as a kit would be a great option. If you select the discrete component audio board then that leaves only two boards where a would-be builder would have to purchase parts and that is the Band Pass Filter and the Driver / IRF510.
So, there you go a possibility for a COTS SSB Transceiver. Full disclosure I have not built this as yet but given the individual boards and their specs... it should be like LEGO blocks. While I have identified COTS assemblies coming from K7TFC given the impedances of the units any circuit block that performs the function and is an impedance match will likely work. So, there is an added flexibility in this COTS approach.
Them that know can make things go.
73's
Pete N6QW
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