|
Re: 577 Curve tracer ringing CRT and noisy step generator
Have you worked through the adjustment procedure, checked the waveforms against the manual? I usually find any faults/oddities that way, The step generator waveforms should be very clean. Getting the sockets out is very time consuming, I avoid it if possible. Some Deoxit on the ic's and a couple of insertions cures almost all but the worst sockets. Also deoxit into the pushbutton switches cures a lot of problems.
|
|
Re: 2467B geometry
Hi Chuck,
toggle quoted message
Show quoted text
Have you had the tube out of the scope and inspected for bits of broken glass inside the tube? Regards On 3/13/2019 8:03 AM, Chuck Harris wrote:
I am certain that they are NOT all like this.... At least |
|
Re: Opinions on the 465B
UK pound is roughly equal
to $1.30 At the moment. Jim Ei2BB. On Wed, 13 Mar 2019 at 06:55, Craig Sawyers <c.sawyers@...> wrote: I have a chance to buy a 465B which seems to work fine Both time basesshow good traces etc Theowner is asking 100.00I was going to ask a stupid question: is the USD, UKP or EUR. But they are |
|
Re: 2247A PSU Troubleshooting
Raymond,
Per your advice (and that clearly marked on the PCB!), I have purchased an isolation transformer. After watching a few videos online, I am still unsure whether I should connect ground from the Tek to the transformer. One video showed use of a 3-prong to 2-prong adapter where the ground wire is left unattached. Is this what you describe as ¡°floating the 2247A¡±? Thanks for your help! Nick On Sun, Mar 3, 2019 at 8:48 PM Nicholas Keller via Groups.Io <Nirokeforums= [email protected]> wrote: No, I was not using an isolation transformer (I don¡¯t have one) and yes I |
|
Re: 2246 no display/odd behavior
PSU is most likely culprit, you will have fun digging down to get to it. Search the archives for info on this, there were many threads regarding the way to test the PSU out of the scope (carefully) and likely suspects for replacement. Personally I had no problem with the 3 legged caps in the PSU (You will see which when you get in there) however others on this board disagreed. There is also a battery on the digital board which leaks (depends on version) that can cause problems. Its been a while since I repaired any of these so working from (poor) memory here.
|
|
Re: Tek Blue Paint - the story goes on ... :-)
Dave,
I recently stripped mine with acetone. That and gloves, a mask, and loads of paper towels had it stripped and sorted in a reasonable time. Work outdoors for best safety. My mistake was using an abrasive attack at the start. Don't do that. After a couple of coats of 'Etch Primer' the paint went on a treat. Sadly not the exact Tek blue but close enough to make me happy. Getting the right paint here to Australia (or the UK) is just too expensive. Cheers, Brian. |
|
Re: 2246 no display/odd behavior
Do you have the service manual? You can find it at w140.com/tekwiki. Your measurements of ripple are only slightly greater than the specifications in table 6-4 which also lists the limits on the DC values of the supplies. The service manual also explains the function of the front panel buttons in the case of a diagnostic error at start up.
Roger |
|
Re: 2467B geometry
Ed and Chuck:
I cranked up 7104/7A29/7B15. These were originally made for AES nuclear testing and 1000s used at LLNL, Los Alamos, LBL, etc. It was CALed by a silent key, Walter, a super TEK/HP/Ham/Broadcast Engineer. Setup squarewave test, transitions on graticule grid. Perfect, NO observable distortion over the entire CRT faceplate! ! As the 7104 is 1 GHz BW and a huge bench scope, the CRTs must be completely different designs, although both use the MCP. Perhaps the CRT of 2467B was a compromise? bonne journ¨¦e Jon |
|
Re: 2467B geometry
Chuck Harris
Hi Ed,
toggle quoted message
Show quoted text
Vertical deflections that remain flat for the entire width of the screen, regardless of the sweep speed, are by my definition low frequencies. Sweep speed has no effect on my scope's distortions. Nor does the relative position of the horizontal or vertical position controls. The warp is always the same at the same point on the screen. If it were a power supply coupling problem, the distortion should move with the horizontal and vertical position controls, not remain stapled to a physical location on the screen. This really has to be a static problem with the CRT. I am hopeful that it can be minimized through some careful jiggering of bias adjustments to the static properties of the CRT, but long ago I lost hope for that. It meets tektronix's specs, but no customer would have put up with such a warped base-line trace in the middle of the screen. When I noticed Jean-Paul's posting describing his geometry problem, and then Siggi weighed in with a similar issue, I began to have a little hope that it might be a common issue with the scope.... But, I now think the commonality is simply a common response to being thrown into a scrap bin. -Chuck Harris Ed Breya via Groups.Io wrote: Chuck said: |
|
Re: 2467B geometry
Chuck Harris
I am certain that they are NOT all like this.... At least
toggle quoted message
Show quoted text
not to the same degree mine is. For instance, mine cannot, ever, under any circumstances develop a straight trace at the center of the screen. It always bows upwards. The center should be the one place that is golden for any CRT, as it is the sweet spot for the vertical deflection plates, geometry, and the box lens. The center should not be affected by the geometry control; only the outer 1/4 of the screen. And, on further more careful observation, the center wiggle on my CRT is not affected by the geometry control... only the outer edges. Most folks run into some trouble with the geometry setting because they can't see, division-by-division what the geometry setting is doing to the screen's distortion. Displaying a grid, with 1 division/square, shows this up very easily... allowing you to simply turn the geometry from one side to the other, observing the effect, and deciding what is least annoying to you. Similarly, the Edge Focus, only affects the outer 1/8 of the screen. I think it is probable that my scope has been the subject of a series of Dr. Frankenstein experiments by its previous owner. The scope was probably subject to a major hit, and all of the broken bits of the case or front panel were replaced. There is probably a good reason why it was relegated to the scrap bin. -Chuck Harris John Ferguson via Groups.Io wrote: Chuck, |
|
Re: Tek Blue Paint at Stuff Day
Agreed...perhaps a shipping container......what really grieves me is before moving out there I spent 4 years commuting back and forth from the UK to Everett every 4 weeks or so and my route was to fly? Air Canada to Vancouver and drive down Route 99/I5 so was passing within a couple of hours drive of this gold mine and didn't know it existed! With all the air miles I ended up as a Star Alliance Gold-pressed Latinum member (or something) and with that baggage allowance I could just about fill the aircraft hold for free each trip!
toggle quoted message
Show quoted text
On 3/13/2019 12:22 AM, David Slipper wrote:
What a shame there is no "Stuff Day" in the UK :-( |
Timothy
Brian Cockburn
Jean-Paul