John, I didn't see any other responses to this so I thought I'd jump in again. The PC-based oscilloscope using a sound card is severly limited in bandwidth. The typical sound card will limit your bandwidth to about 20Khz, which is hardly even sufficient for audio work and totally useless for RF. Whle this is a handy toy for working on low frequency and audio stuff, it's hardly an "oscilloscope". If you want a scope, look at a big hamfest or on e-Bay. You can frequently find 50MHz scopes (sufficient for most ham work) for under $100. There are also some PC-based scopes that have the "oscilloscope" in a box and connect to a PC through a parallel port or USB and use the scope for processing and display. I have one such scope ... a PICO 3206 ... that works really fine and gives the advantage of allowing cut and paste of scope images into documentation. PICO and others have a range bandwidth and resolution available for almost any application, and the prices are less than a comp arable Tektronix or LeCroy.
If your main interest is in looking at your transmitted waveforms (keying envelope and "christmas tree", you will be best served by a monitor scope such as the old Heath or Kenwood. These not useful as general purpose oscilloscopes but work great at their intended purpose ... to monitor transmitters. I have the Heath SB-614 I bought at a Hamfest about 24 years ago. Personally, I think it should be a REQUIREMENT that anyone with a high power amplifier have a monitor scope. It's the best way to be assured your amplifier is tuned properly for best linearity. I don't know if anyone is building a modern equivalent of the SB-614 or the Kenwood (model #?). Try a Google search for PC OSCILLOSCOPES and you will find a bunch of them available. By the way, several of the PC scopes double as a low-end spectrum analyzer. The PICO 3206 has a 200 MHz analog bandwidth and also a 200MSample/Second single-shot sample rate. It performs as a 100 MHz spectrum analyzer using FFT (Fast Fourier Transform) similar to Spectrascope. Good luck with your search for a scope display. By the way, I just did an e-Bay search for "oscilloscope" and got more than 13 pages of listings, some in the $40 range. If all you want is a transmitter monitor, you can probably get by with a 20 MHz scope and couple RF output directly to the vertical deflection plates. If you need more information, let me know exactly what you are trying to do. I can probably give you some more marginally useless advice. regards, Jim AB4CZ _______________________________________________ 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
