Re: 70 cm Prototype Receiver Testing

John, and group,

I set up my shop this evening to take a look at the microphonic issue that I had noticed before Dayton.  I decided to use my new SDR-IQ software defined radio instead of my HP 8566B spectrum analyzer.  The SDR-IQ has a lower noise floor, is quiet, and doesn't heat up my shack.  Of course it tops out at 30 MHz and the 8566B goes up to 22 GHz.  But for this application all I needed was something to look at the IF output at 10.7 MHz.

Before I got to the microphonics I noticed spurs and phase noise that I had not previously seen with the 8566B - a classic case of going to drain the swamp and then ending up fighting alligators...

I've posted screen shots and test details on EaglePedia's 70 cm receiver page.  Click here for a link to that top level page.

Then go down to the Project Status area and open up Troubleshooting Resumes.  I wouldn’t get discouraged.  This is why we built the prototype in the first place – to find all the little flaws that need attention.

More to follow in a few days...

P.S. I add new material to the end of these logs so if you’ve already read the earlier posting just scroll down to the new material at the end.  I always try to note the date and time I last modified the log at the top so you can see if there is anything new since your last visit.

73,

Juan

WA6HTP