Jack, A36GC asked: I am thinking of getting a scope to better build and repair Elecraft radios. I have a line on a Tektronix 2336YA 100 MHz 2 Chl. Oscilloscope that is calibrated! It is about $200. Is this a good deal? Is this a good scope?
----------------------------------- Teks are excellent scopes, overall. That's a very low price. The only caution I'll offer (and probably the reason for the low price) is the limited bandwidth. To observe signals accurately, a good rule is to have a 'scope that has a vertical bandwidth at least 10 times the highest frequency waveform you will be observing. That puts an upper useful frequency limit of about 10 MHz on that scope. It'll certainly show waveforms up to (and beyond) it's rated 100 MHz, but the amplifiers in the 'scope will "clean up" any aberrations in the waveform so you can't see what it really looks like. For example, if you put a square wave into the scope at 100 MHz, expect to see a nice, clean sine wave on the display! That's because a square wave has harmonics going up to at least 10 times the signal frequency, and unless your scope can faithfully reproduce those harmonics it won't show a very true representation of your signal. A 10 MHz square wave will look pretty accurate on the display since the 100 MHz bandwidth will handle all the harmonic energy needed to reproduce the signal. In the real world of working on HF gear, what such a scope will tend to do is to fail to display many high-frequency aberrations or parasitic riding on a lower-frequency signal, when those things are at or above the upper bandwidth limit. Also, the accuracy of the vertical amplifier "gain" (and so the accuracy of the amplitude of the trace on the display) suffers as you approach the veridical amplifier bandwidth specification. All that said, most adjustments needed on Amateur HF gear can be carried out at frequencies below 10 MHz, so that scope would find plenty of use on a Ham's workbench. I have a 200 MHz scope and only occasionally have to think about the bandwidth issue working on HF gear. Like any tool, understanding its limitations is as important as understanding its features. My 'scope is an HP, so I'll leave any suggestions about the value of that particular model to those here who follow the Tek scope line. Ron AC7AC _______________________________________________ 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
