Friends,
I recently purchased a used B&K 1403A oscilloscope at a swapmeet. It is
in absolutely perfect condition and a real bargain for $25. The
vertical amplifier frequency response is DC to 5 MHZ (-3dB) while the
horizontal amplifier frequency response is DC to 250 kHz. The
horizontal sweep frequency is stated as being 10 Hz to 100 kHz in four
overlapping ranges. The manual says that frequencies beyond 5 MHZ can
be measured through the direct deflection terminals as long as they lie
somewhere between 10 Vp-p to 100 Vp-p. I have no problem seeing the
output of my (5-watt) 38 Special when it's connected to the scope's
direct deflection terminals (in parallel with a dummy load, of course.)
Unfortunately, the upper limit of the horizontal sweep frequency is much
too low to be able to view just a few cycles of 10 MHZ energy. On the
other hand, the scope *does* have provisions for external sync or an
external horizontal signal. So, here's the question. Would it be
practical to homebrew a saw-tooth generator (higher than 250 kHz,
maybe) and feed it to the EXT. SYNC/HOR INPUT binding post in order to
improve the resolution somewhat or would the frequency response of the
horizontal amplifier send me back to the drawing board? From the
schematic I can see no practical method of bypassing the internal
horizontal amplifier.
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