[Radio Wrangler]

Well, it was the firm's money, for work-work. I'm still intact.

For audio testing, there are programs which use the 'soundcard' of a computer as both source and spectrum analyser. You'll need an attenuator on the source in order to go down to low levels for sensitive inputs. Don't use 'digital' level controls as you will go down into the quantisation noise of the DAC and the computational word-width. The analyser response is also limited by the anti-alias filter, so you don't get to see any higher frequency products... you aren't supposed to be able to hear them, but finding any can give clues to what's going on in the circuitry you're testing.

For RF testing, you're stuck with the expensive stuff. I visit radio rallies and keep an eye out for good quality test gear which is either needing to be fixed, or is too heavy for the trader to want to cart it back at the end of the day.

There is one way round the cost... build a pair of crystal oscillators your chosen separation apart, then your own moderate power amps, combiner and attenuators as needed. This gives you only one test level and spacing but it's a quick one-shot assessment of intermods. I built one years ago into a small diecast box. At an amateur radio show I could feed a test signal into a new model radio being demonstrated. Tune the set to the product frequencies above and below my pair, and see how strong the responses were as a combination of looking at the S meter and by ear. Inevitably someone borrowed this little box and accidentally transmitted into it. End of game. Remarkably few dealers twigged what I was doing, and the ones who found out weren't best plaesed. Obviously they lacked confidence that their product was much good?

David