Not me. I've repaired and calibrated a lot of 7000 stuff for my lab. That was the point of my earlier posts, where it was asserted that a good pulse response indicated frequency flatness for power measurement. It does NOT!
-John ================== >>In fact, on the Tek 7704 or 7704A (I forget which) there were "No Cost" >>options of maximally flat frequency response OR best pulse response. OR! > > I think you may find the option was best pulse response OR an increased > 3dB > frequency of 275 MHz. The difference is just an matter of adjusting the > compensation in the vertical amp. The best pulse response in terms of > least overshoot etc, also gives a flatter response in the pass band (which > it should as this is effectively adjusting to give a pure Bessel > response). > The higher 3dB frequency version gave considerable overshoot on the pulse > response, and a "bumpier" pass band. > > I was quite surprised to find quite HOW bumpy the pass band can be the > first > time I did a check on my 7904 using an SG504. > > Dave > > -----Original Message----- > From: [email protected] [mailto:[email protected]] On > Behalf Of J. Forster > Sent: 02 December 2009 01:31 > To: Mike S > Cc: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] OT: Power level reference > > I do. Very well, in fact. Unless you have swept a scope with a very well > leveled sine generator, you are only guessing it is flat. > > That's WHY Tektronix sells BOTH fast rise Pulse Generators and Leveled > Sine > Generators. > > In fact, on the Tek 7704 or 7704A (I forget which) there were "No Cost" > options of maximally flat frequency response OR best pulse response. OR! > > -John > > ================ > > >> At 07:00 PM 12/1/2009, J. Forster wrote... >>>Scopes tend to have non-flat frequency response. I'd consider a >>>precision load and something like an HP 3400A True RMS meter for up to >>>a hunderd MHz or so. >> >> You have to know your equipment. I have a Tek 485 350 MHz analog >> scope, so I'm confident it's flat into VHF (at least beyond 100 MHz). >> I've verified it exceeds the 350 MHz spec (i.e. < 3 db down @ 350 MHz) >> with a tunnel diode pulser. >> >> >> > > > > _______________________________________________ > time-nuts mailing list -- [email protected] To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
