From: "Terrell W. Fritz"
Date: Sun, 07 Jan 2001 15:50:15 -0700
Subject: Re: [TSSP] Top voltage testing
Hi Paul, At 10:14 PM 1/7/2001 +0000, you wrote: >Thanks Terry, > >You've given me enough info to set up a model of each of these >test positions. If I'm allowed to tweak the loss factor and >Ctop to match your measured Q and Fres, then we should get >a good match with Vtop/Vbase predictions. I tried not to leave anything out ;-) If I actually accomplished that, it would be a first! > >Did you happen to note the base input current or the V drop >across your pad resistor - not essential but useful for >autopsy if the gain prediction doesn't match. I drove directly from the low Z (<1 ohm) signal generator. Putting a 1 ohm surface mount resistor in the signal path with the HP meter would be easy if needed. > >It'll be interesting to see if we can obtain a reliable match >with the third test result, ie the ordinary scope probe. Would >be handy if we could. Capacitance to the screen of the probe lead >is probably the biggest random factor. The 1000X probe has a very long cable unlike the 10X probe so I could come off the ceiling. I could probably mount the small light scope to the ceiling too if the top down approach is best... > >With Marc's coils and vsd too, I'm a bit overloaded with jobs >for half-a-computer to do, but I'll try and run them tonight. No problem, the test stuff will stay in place all week as I pack and ship about 2000 MMC caps ;-) > >Perhaps, after we've got some working models of these, we could >select one configuration and instrument everything for simultaneous >readings of Ibase, Vbase, Vtop and Q. > Yep! Just specify what you want data on. >BTW, your relatively low Q coil would be ideal for a test of >pn2511, equ 9.18 which predicts the frequency difference >between that of max Ibase and that of max Vtop. Reducing Q >further by insertion of extra inner sonotube should increase >the frequency difference. I can cut the thinner tube to fit in the terminated coil. I think the Q is humidity dependant so I would have to retake the Q measurements to insure they didn't drift over time. Cheers, Terry > >Cheers, >-- >Paul Nicholson, >Manchester, UK. >--
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.