开云体育

Hi Richard, The speed in a cable is mostly a function of the Dielectric Constant of the filling between the inner conductor and the outer shield. The dielectric constant of the filling along with the

Hi Tom, Wikipedia is your friend when it comes to Velocity Factors. Scroll down this web page https://en.wikipedia.org/wiki/Coaxial_cable Or in your web browser type "wikipedia coax" and it is usually

Hi John, Best would be to swap the trigger hybrid from one of your 2465 family scopes that does work into the one that doesn't work, as a test. (as long as you restore the original to the calibrated

With 134v on Q1496 collector, you should see +61v at Q1490's base. This will completely shut down the regulator by reverse biasing Q1494 b-e. That said it only leaves R1483, Q1496, CR1498, and R1488

Hi Chuck, The parametric functions do not work on one of my 2445Bs, the one you didn't calibrate.? It also doesn't sync on signal on start-up but does work well manually.? I chased this around? on

Hi all, I got (yet another for my collection) 2465, it was stated it had problems before I got it, so no problem there. What have I done so far: Recapped the Power Supply, cleaned the Siemens fan and

Hi Chuck, Nope. I found others for sale, but these were cheaper. Tom

Exactly! Have you tried their product? -Chuck Harris Tom B wrote:

On the 474A L.V. schematic it shows the expected voltage at the emitter of Q1496 as being 135.6 volts, which is quite close to your 134.66 reading at your +110 test point. It shows the expected

Hi Chuck, Like this: http://smallbear-electronics.mybigcommerce.com/nut-starter/ Tom

The document says: "The speed of light in a vacuum is 224844343.5 m/Sec= 0.2248m/nSec. " I guess Dennis already used some kind of velocity factor here. But this makes his following derivation invalid:

All members of the 2465 family use interchangeable trigger hybrids. To remove them, remove the four nuts at the corners of the module. Tektronix considered them all to be "selected"... which I think

of course, but only cal03. -Chuck Harris joe@... wrote:

Where does it show the speed of light in a vacuum? The TDR should be calibrated to the speed of light (electricity) in the cable. For 50 Ohm cable its about 66% of c. Varies with the impedance of the

Interesting stuff Dennis! I have to look at it in more detail. I consider repeating these tests since I have both Tek cables, though I don't have quality SMA-BNC adapters. Most remarkable is the slow

Very timely: this weekend I picked up a Tek 1502B, and it came with a 012-0482-00 cable and a 011-0123-00 BNC 50ohm terminator. Apart from that I only have "generic" connectors and terminators, of

I?m going to solder a 1m RG223 cable for my SG503 so this is interesting stuff for me. Nice detailed piece of work Dennis, thanx!!

Michael- I also would check the eb voltages? of Q1496 and Q1497 make sure nothing strange and xstrs are operating in their proper regions. I would then take a hard look at CR1489 ( protection ec

Those are interesting measurements Dennis. And particularly interesting that although the Pomona/Belden the impedance is not 50 ohms, although the variation seems to be very low. And it will be more

I have searched for a previous thread that was referred to in a post about a "high" 110 voltage rail on a 475 from back in 2012. I failed to find that post or any other applicable answer, perhaps I am