At last - some Software Defined Radio kit in the shack. That's why I got back into Amateur Radio - time to get on with it.
I wanted some kind of full-coverage HF receiver. I have a softrock transceiver kit, but that only covers a few bands. Eventually I realised that the Radio Kits "Hunter" kit was a 1.8-30MHz receiver even if it is badged as a panadapter.
It's hard not to be impressed by the completeness of the kit. It includes the case, the wire and the solder. If you were to argue it should include more, you'd be asking for the PC to be included or so it seems. There are templates to mark the holes for the front and rear panels, and pre-designed artwork for front panel labels. I was able to laser print mine onto a form of "sticky back plastic". The PDF file provided has zero margins, and most printers will clip. You can tell the PDF reader to centre the image; 5mm margins would have given me more flexibility to use the rest of the A4 sheet. But never mind!
Most components are surface mounted. The components are all bagged so there's only one of each visibly different component type in each bag. Within one bag you might find one value of surface mount resistor, one value of surface mount capacitor and one semiconductor. This makes it very very hard to misplace a component. It's still possible to "ping" them across the room if you aren't careful in removing them from the tapes the hold them; in my case a hard wooden floor made it retrievable but carpet wouldn't.
With a good soldering iron, a magnifier and the solder provided you shouldn't have too much trouble. My only caution is that on the "ground" ends that are soldered to a large copper area there are no thermal reliefs, so you need to pour in a lot of heat to flow the solder. I did end up with several resistors not connected at one end.
Once assembled: time for test. Because of the aforementioned soldering issues, I had two faults to resolve. One was in the power supply, and picked up pretty quickly. The other was in the Quadrature Sampled Detector (QSD): this needed me to go round with an oscilloscope until I found that the QSD inputs were all biased to 4.6v not to 2.3v. The debugging method offered by the supplier is to use a multimeter to record all DC voltages; this approach WOULD have found that fault but I do like chasing signals.
One of the "setup" tests is to check the TX/RX relay when driven with RF from a transmitter. I set my FT817 to minimum power setting (0.5W) and that did NOT trip the relay. Setting it to 1W resulted in the board operating as described. The instructions do say to feed it with 1W+ of RF, so it does indeed do what it says on the tin.... I may look eventually at the circuit concerned to see if it can be made a bit more sensitive. Im not in a rush as I expect to use this as a receiver, probably on the IF output of a spectrum analyser.
OK, so I have a working radio sensor.... time to play with the PC, software and soundcard. That's a separate story, and as I discovered far more entertaining. If there's one thing this kit could use, its's a better "quickstart" into getting all of the necessary software up and running. But that, I suppose, is where users like me come in! I will be writing more on this subject, just as soon as I've got to the bottom of the issues concerned.
From a software perspective the board behaves exactly as a Softrock receiver. If PC SDR software supports a softrock with USB tunied Si570, it will support this receiver. For some programs, you will need to copy an EXTIO DLL file to the software directory; others don't need this.
Suffice to say, as a beginner: start off with the "HDSDR" software recommended. Install everything as described. If you don't have a frequency counter, ignore the calibration process described. Connect to your PC "line in"; if you have a laptop, be prepared for some entertainment making it operate as a "line in" and not as a mono microphone input. Disable any "DSP enhancements" or suchlike offered by your drivers. Sadly, each PC / operating system / sound card combination is going to be different: don't despair - you will be able to get there and you won't break anything inthe meantime.
So far I've had signals demodulated using HDSDR, SDR-RADIO and PowerSDR. The programs are all different from each other in some respects, and I've no idea yet which I prefer. Writing my own is one option but there are man years of work that go into some of these programs! What I'm not yet clear about is how to check the input level as seen by the sound card: it's important that it doesn't get overloaded. My laptops have "microphone" inputs that appear to be stereo, but I don't know the signal level they expect. Some kind of input amplitude bargraph display would be quite useful to know that all is well. I think KGKSDR can do this but I've not tried it yet.
Overall: a thoroughly excellent kit. It's so complete and so well delivered thait would be hard to go wrong. I so so wish this sort of thing were around when I was first an Amateur at age 14!