On Sat, 27 Feb 2010, AJ wrote: > Anyone have a suggestion for a simple 50 ohm signal generator? I > have a number of VHF Phelps Dodge duplexers and several UHF flat pack > duplexers I'd like to be able to test prior to sale and possibly rough > tune for a few projects duing the waning weeks of winter. I realize > a network analyzer would be the best case option for doing this sort > of work; followed by possibly a service monitor and a spectrum > analyzer with tracking generator. I currently have an HP spectrum > analyzer available at work; unfortunately it did not come equiped with > a tracking generator. It does have a current calibration; I'm guessing > I could use it to determine the exact output from a signal generator > and subsequently the insertion loss from the duplexer.
You'd probably want to drive the VCO of the signal generator directly to make it sweep up, but if you don't have a good baseline on how it's power level varies over the range, you won't be able to compare with the antenna response. Something like an MFJ-259 attached to a sweep generator would probably do the job. Of course, the MFJ-259 doesn't have great frequency stability, but you're not staying in one place for very long. Then you can use the spectrum analyzer for what it does best. -- Kris Kirby, KE4AHR Disinformation Analyst
