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As mentioned above, it kind of depends on what the meter is expected to be measuring. The 1, 2 and 5 used by Tek works well for scopes because you are looking at a graticule and, at least in the past,

Yes, that's a good, high impedance buffer. The bootstrapping suppresses the JFET's Cgd, and the inherent bootstrapping of a source follower takes care of Cgs. The external bootstrapping also

I ran across this as a possible start for a circuit to replace the 1659 tube. It's been a while so I can't remember what else in needs, but I don't think much. I was looking for a DIY high input

My 630-NA has the range switch positions 0.6, 3, 12, 60, 300, 1200/6000. In addition, it has a switch V/2 or A/2 which doubles the sensitivity, 0.3, 1.5, 6, etc. There are also 120 or 240 mV ranges by

Perhaps I missed something but I've seen no mention of 1, 2, 5. This happens to be the scale factors that Tektronix and others have settled on and they certainly seems reasonable to me for a general

[email protected]> wrote: Obviously if o

Meter FS Ranges It depends on the measurement being done and certainly the may be a change over time as to what is best. Each era has different needs. A couple examples: 1. Early on operational

I zapped the input jfet on my HP4342A some years back, due to static discharge--now I always touch the ground post before connecting anything to the Q meter posts. I replaced the jfet with a 2N4416A

TYPO: Original quote should have read 2 pF/(56 pF + Q1 input C + C1, 3 pF, in series with 2.87K). Why the 3 pF/2.87K RC network? 18.5 MHz corner freq. Looks like it lowers the output of the capacitive

I'm not getting it, maybe math failure (on my part). I calculated at 1MHz. Reactance of 56pf = 2,844Ω, 1.3pf = 122,489Ω, (FET guess) 5.2pf = 30,622 and the R = 2870Ω. Total = 158,825 / 2pf

My Marconi SHF power meter has what looks like sqrt(10) for the secondary scale, marked up to 3, and that corresponds to 9.5 on the 0-10 scale, which does suggest full scale would be 3.1623-ish. My

[email protected]> wrote:

Assuming a 1970s build, what would be a reasonable guess at the gate capacitance of that vintage FET? I think HP would pick a low gate capacitance. I'll try to do an excel spread sheet over the

Having used all kinds of multi-meters over a 50 year career, I have concluded that no matter where the range limits are set, you always come across a measurement that? falls around the overlap! AVO

What is 'optimal' to one user would be annoying to another. So it depend on what the use of the meter is and the preference of the person using it. Your criteria for what is optimal may not fit with

David, Probably not directly addressing your design intent, but let's note for digital units typically a 2V and multiples scale is typically present (due to display configuration, which oftentimes

Consider you built a volt meter with an analog scale, and chose full-scale deflections of 1, 10, 100 and 1000 V. Then you decided that the gaps were too big, so would add intermediate full scale

It helps as a sanity check to remember that the grid-cathode conductance increases quadratically with frequency, if the plate is terminated in a low impedance. By the time you approach ft (here, about

Bingo KenThanks for spotting and correcting that. Makes a big difference.RegardsChuck WD4HXGOn Aug 19, 2022, at 3:56 AM, Kenneth Greenough via groups.io <g8beqglossop@...>