The one drawback of basic SDR dongles is the lack of HF coverage with most types cutting off around 25Mhz. This can be solved by using an upConvertor to act as the middle man and give the SDR a HF loaded signal at a frequency it can deal with.
Having just got a second RTL2832U SDR Dongle on the go, I’ve decided to have a stab at building an upConvertor this time round, instead of splashing out on a ready made device.
While Searching for a design that’s not going to be overly complicated, has good coverage and more importantly one that I already have most of the parts for (or can salvage from the mountain of defunct radio PCB’s hanging around the place), I stumbled on a radio blog by KF7LZE.
KF7LZE has a nice long list of kits, ready made and homebrew upConvertor projects over on his blog and I’m going to spend time today going though them to see which is more feasible. To be honest I’d rather avoid any circuit that requires the winding of too many coils as its not my strongest area and bores me silly 🙂
My first dongle is running on the excellent Ham It Up and its no surprise to see it right at the top pf KF7LZE’s list.
When Looks Aren’t Important
A few of the homebrew circuits listed have all the files to build up a proper PCB, but even though all the equipment could easily be set up, it can be counterproductive for something I may have to modify down the line. There’s nothing more disturbing than crafting a printed circuit board then having to chop it about later.
Building the upConverter onto bare board first for testing then finalizing it with a shiny PCB once its perfected, seems to save a whole lot of time.
If you have any ideas for a circuit I’d be most interested to take a look 🙂