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Re: How to explain how negative feedback lowers noise?
An employee does something wrong.? Management tells them about it.? They try to do better.? Management isn't satisfied, so they have another talk.? This cycle continues until management is
By Harvey White · #180772 ·
Re: 485 super weak brightness control
https://photos.app.goo.gl/rV6gSvehN2uzbaes7 This is what I get, the a sweep signal is very weak, under 20mV at the back of the scope but it looks fairly close to what you get
By Ondrej Pavelka · #180771 ·
Re: Recapping Tektronix 2465
Giorgio, 80-R82DC4100DQ60J for 1mfd 80-R82CC4470DQ30K for the three 4,7mfd on the power supply board 647-ULD1C221MPD1TD for 220mfd 647-ULD2C100MPD1TD for 10mfd. These are 160V. 647-UHE1C121MED for
By Mark Vincent · #180770 ·
Re: Tek 2225 that wont power up after a knock :-(
Is the 5.2V rail at 11V because it is unloaded ?? Dave
By David Slipper · #180769 ·
Re: How to explain how negative feedback lowers noise?
Bonjour ¨¤ tous Great topic, and as Dr Lee mentioned, historical links. We must deal separately the noise of the input signal vs internals noise of the amplifier opamp, resistors, etc. There is also
By Jean-Paul · #180768 ·
Re: Beware of old AntiStatic foam
Other time bombs: there are study cases made for transporting gear. Typically they have an aluminum extrusion frame with plywood panels that have been laminated with Kydex plastic sheet, and those
By rick · #180767 ·
Re: How to explain how negative feedback lowers noise?
Hi, "You cannot control what you do not measure" is how I introduce negative feedback to my freshmen. An example that they all seem to get right away is a thermostat. I go from there to explaining how
By Tom Lee · #180766 ·
Photo GR oscillator display with Russian D42 replacement, 750 MHz unsmoothed updated #photo-notice
The following photos have been updated in the Sampling with 3S2 ( /g/TekScopes/album?id=261250 ) album of the [email protected] group. * GR oscillator display with Russian D42
By [email protected] Notification <noreply@...> · #180765 ·
Recapping Tektronix 2465
I should do the recapping of my Tektronix 2465 (not A / B), I found on this group the list produced by Menahem Yachad of CondorAudio but from Mouser (Italy) there are some parts not available. Since I
By iv3ddm · #180764 ·
Re: 3T77 tunnel diodes (again)
OK, had a chance to play with it. In a word, performance is improved but still not perfect. After reconnecting the 300 ohm fixed resistor and readjusting R44 (the bias for this TD), I can now get a
By Charles, WB3JOK/0 · #180763 ·
Re: 485 super weak brightness control
I can't access B sweep without taking the case off so I don't know the exact shape but it should look similar to A sweep. A sweep maxes out at 10ns/div, B sweep can go 2ns/div (then there is a 2x
By Ozan · #180762 ·
Re: Tek 2225 that wont power up after a knock :-(
EDIT: U9028 should be U902A/B Dave
By David Slipper · #180761 ·
Re: 485 super weak brightness control
These look fine. Logic selects B sweep is selected in 5/2/1n mode. I was hoping this would be it but no smoking gun yet. Ozan
By Ozan · #180760 ·
How to explain how negative feedback lowers noise?
Hi all, I'm trying to explain to people at my company (none of whom are EEs or statisticians) how negative feedback works in a system. That's one thing that I'm trying to get across, and I can't come
By cheater cheater · #180759 ·
Re: 3T77 tunnel diodes (again)
Back to 3T77A tunnel diodes :) It took six full weeks (Feb. 11 order, until today Mar. 22), between the Russian and the US postal services, but I finally got a "Pellet" 1I308J (20 ma Ge TD). It
By Charles, WB3JOK/0 · #180758 ·
Re: 485 super weak brightness control
One more question, the A sweep is triangular but the B sweep has a flat top and becoming almost square, that doesn't look right? wrote:
By Ondrej Pavelka · #180757 ·
Re: Tek 2225 that wont power up after a knock :-(
OK I replaced Q913 and Q923 and I'm using an external supply of 45V I have isolated W984, W987, W989, W972, and W991 W972 reads 35V W984 reads 95V W987 reads 8.5V W989 reads -8.5 but W991 is showing
By David Slipper · #180756 ·
Re: FG502 doesn't start at some specific settings
If it works like the FG 502 (making an assumption) that is the heart of the unit everything is derived from the triangle wave. If there is any setting where the triangle wave is not running that is
By Eric · #180755 ·
Re: Type 106
I would definitely keep the original GR connectors, and if you need to, use an SMA adapter. They're made by GR too and it doesn't have any effect that I can see on my ~ 650 ps (so far) avalanche
By Charles, WB3JOK/0 · #180754 ·
Re: Type 106
Yea that is why I only changed the normal connector as it only has a wire to it. I did not mess with the fast rise and fall either. Eric
By Eric · #180753 ·