Me too. I might have to do some research and see if PSK and RTTY can be done with the SDR front end. Otherwise, I'll buy a simple external sounds card.
hey Charlie.. would love to see you go the homebrew rather than the conversion route.. i for one dont own a radio suitable for conversion but have built quiet a few of your homebrew modules.. cheers n 73 Al
And if I may another thought. Check out the new Teensy audio library "AudioSDR" (Google or PRJC site) which is an RX today, but will be TX also in the future
Thanks. I've used the Teensy several times for SDR transceivers. The AudioSDR library must be new, as I have only used the DSP library in the past. I'll have to take a good look at that.
What I'd love to see would be a HF-digital mode transceiver the size of a smartphone. It'd concentrate on just transmitting and receiving, off-loading the signal processing to the phone to save money, provide the time lock, and make it more versatile. It'd be low power, under a watt, and depend on below-noise level techniques to get through.
Thanks Michael. The 1 watt would certainly allow for a smaller build. I'll put some thought into it. SMD would help too. I'm surprised something like that doesn't already exist.
Hey Charlie, that Codan is the perfect candidate for a homebrew rig, find a Nextion touch screen roughly the same size as that front mounted speaker and you'll have a nice neat base to start building a multiband rig. How about your favourite HF bands plus 50MHz? If you use a pair of RD15HVF1 power transistors in push pull you'll get a good 10W across HF and VHF. Why not go down the route of including a roofing filter and IF Shift? You can still maintain the single conversion architecture and have IF shift/PBT by shifting the VFO and BFO in sync, I did this with a 70MHz VHF SSB rig a few years back, very easy to implement in software. Looking forward to see what you do with this mate, unfortunately my homebrew days have been few and far between due to work commitments, however this weekend I managed to finish my 160M/80M dual band magnetic loop project that has been WIP for around 12 months, I think the next project will be a homebrew low band rig for 160M/80M to compliment the mag loop.
You are essentially chosing between a hardware solution (except si5351 DDS which is simple software) and a digital solution - e.g. raspberry pi. But after what you did before how about thinking about a Teensy TRX, with IQ I/O to computer and suitable software for RTTY, WSPR, FT8 and any number of other digital modes. Seems to me this would be a "cleaner" more modern solution??? Two big headaches for the Teensy are to get a better filter (phase/Hilbert, or Weaver/LPF style) and a good balanced pair of mixers to mix the 0/90 RF and AF signals... both interesting developments
Thanks. I will make the conversion of the simple SSB rig first as I want to house that in an old FRG-7 case. I'm then keen to explore the Raspberry Pi, as I haven't played with one of those for some time. Thanks for the input.
