Bob, I know it is not trivial. That is one reason I have started and never finished such a project. Commitments have a weight, too, so hobby and experiments must often be postponed. Sometimes it may be easier to get a professional one borrowed for the weekend...
What is wonderful about PC's and soundcards is that they allow a good relative calibration. Absolute level calibration is something else. Soundcards can also achieve good resolution with FFT's, much better than many traditional hardware analyzers. A friend had once a project which involved a synthezised cable TV tuner (it gives a good calibration) doing discrete jumps and a swept IF amplifier. A full bandwidth sweep would involve several jumps and continuous sweeps on a whole bandwidth, "stitched" side by side on the CRT screen. A good idea he did not conclude... Sort of a 51J4 with a CRT instead of a speaker, if you get what I mean. 73 & GL, Jose, CO2JA --- Bob Macklin wrote: > In my day (the 60's) spectrum analyzers used a swept oscillator into an > IF amplifier and then through aconverter to baseband. We did not have > computers capable of doing the display by the FFT process. > > My plan is to use the sweepable oscillator to oscillator to provide the > LO for the first converter and convert the signal to baseband in the > external box. The computer will be used to convert the audio input to > the spectrum or scope display. > > I can write an application that would run the sweep oscillator from the > PC and display the result on the PC. But this is not a simple piece of > hardware like the simple SD receivers I know about. > > Bob Macklin > Seattle, Wa.
