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Old March 16th 06, 12:52 AM posted to rec.radio.amateur.antenna
Richard Clark
 
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Default Current through coils

On Wed, 15 Mar 2006 15:38:32 -0800, Roy Lewallen
wrote:
Many analog scopes aren't capable of producing a meaningful Lissajous
figure at HF because of the limited bandwidth of the horizontal channel.


This is certainly true for poor scopes. If we are limited to HF, then
those with bandwidths above 100MHz might squeak by. However, there
are alternatives that were part and parcel to many older scopes: you
simply drive the plates directly like they did in the old days (1930s)
before the plates were driven by dedicated amplifier chains.

I have calibrated such old (very old) scopes that operated well out
into the 100s of MHz, but were often accompanied by a necessary
accessory, a microscope.

73's
Richard Clark, KB7QHC