Saturday, February 13, 2016

Poor Mans Tools

Way back shortly after I started blogging I pointed out some handy tools.  

So what other tools can I recommend?

Well at one point in my past (prior to having access to a service monitor), I'd use the IF birdee of my scanner as a low power signal source to tuning 5 pole filters and the like.  My old BC350 has a 10.85 MHF IF, so you subtract 10.85 MHz from the freq you need a carrier at, and voila a birdee.  I think I measured it once and it was about -40 dBm.  So when you need it weeker as you tune, you throw the scanner in the basement clothes dryer, or use a step attenuator on whatever you are working on.

Of course now days its pretty easy to use a Raspberry Pi to generate a narrow band modulated signal.  IK1PLD has created some nice code for that that will easily let you transmit a 1000 KHz audio tone that you can create in audacity.  His code even lets you adjust the power factor. This works nice up though the UHF bands.

I have that same old Bearcat scanner permanently fitted with a home brew deviation meter, which I wrote about before.

And of course with cheap RTL-SDR USB sticks you'll get a spectrum analyzer.