Doug, Paul Harden N5AN has written good articles on the use of the oscilloscope. One can be found in text format in the QRP-L archives at http://home.frognet.net/~mcfadden/wd8rif/archives.htm - I know there are other places where this info appears, but I don't have handy references at the moment.
If you are doing nothing but observing RF voltages with your 'scope you might be able to get by with your 20 MHz 'scope, but I recommend a 100 MHz scope. As for buying an oscilloscope, I highly recommend purchasing one from Bob Garcia. He is known as 'Mr. Scope' and frequents many of the hamfests in the Southeast (he lives in GA). I have recently have had dealings with him and can say that he is more than fair both in price and his manner of doing business. You can email him at mailto:[EMAIL PROTECTED] and ask him what he has available. To make good use of the 'scope without loading the circuit under test, you will need some good 10X scope probes. The probes have a frequency rating too and should be rated for 100 MHz or higher for use in the HF ham band region. Regarding frequency ratings of probes and 'scopes - the rated frequency is the point where the response drops off by 3 dB, so 100 MHz will provide good calibrated readings at 1/10th of the frequency rating and is quite usable up to 1/3 the frequency rating. In other words, the response of a 100 MHz 'scope will be quite accurate through 10 MHz and reasonably accurate at 30 MHz, but will drop off significantly above 30 MHz. You will still be able to use the 'scope up to its frequency limit (and maybe above), but you should not trust the voltage measurements made with it at those limits (the waveforms may show some distortion at the limits too). 73, Don W3FPR > -----Original Message----- > > I have no formal electronics training. just what I learned along the way > as a ham for 45 years. I am interesting in learning about and how to > use oscilloscopes. I would like to learn how to trace and debug digital > as well as analog radio circuits. > > I'm have an old Elenco 1251 dual-trace 20mhz. No idea how well it works > or how well calibrated. I was thinking of finding something a little > newer and maybe better bandwidth. > > Any recommendations on a good used scope? Any thoughts on any books > that might provide a useful overview of using a scope to debug rf and > digital problems? > > Any assistance gratefully appreciated, > > 73, Doug -- KØDXV > _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
