Re: Asking for Help with Verifying Genuineness of 2465B from Ebay


Chuck Harris <cfharris@...>
 

Trace rotation can change if you bang the scope around....

But more likely is that "calibrated and tested" means that
it was calibrated and tested at some point in its life.

I would expect an A to be about 1ns rise time.

trise = 0.350ns/fbw(in MHz) -> 1ns.

I don't hold much confidence in the trise measurements
these scopes make for themselves...

Note, that the screen is all marked out for trise measurements.
The 0% and 100% markings at full scale are for the flat tops,
and flat bottoms of the waveform. The measurement is at the
10% and 90% graticule lines.

Many seem to think that the full scale is for the peak spike,
but it really isn't a part of the measurement.

-Chuck Harris

Mr. Eric wrote:

Thank you everyone.

Yes Zenith, I messed up the title and wrote 2465B, I meant 2465A in the title. Thank you for catching that.

It is definitely not a 2467, no microchannel plate crt.

So it sounds like the consensus is that a 670-9268-07 A1 board is a 2465A, and the 07 just refers to a revision of the board that was made after the published date of the 2465A/2467 service manual that I have and therefore the revision 07 is not mentioned in it.

The ebay seller was picky2000. I had searched the messages of this group and didn't find anything negative about this seller which is one of the reasons I bought it from him. What threw me off was that the description said calibrated and tested, but when I received it the trace rotation was wayyyy off and the geometry setting is noticeably off too. Voltage levels look good, but I only have a basic 15Mhz function gen to test with, I don't have a leveled sine-wave gen to do any better tests.

I did a basic bandwidth test using the leobodnar 30ps risetime pulsegen and I measured a risetime of 1.09ns on this 2465A. I have another 2467 that with the same test shows a risetime of 0.98ns. I was hoping that my 2465A would be a little closer to 1ns. According to what I have read 1.09ns indicates a BW of 0.35/1.09ns = 321.1Mhz (assuming a gaussian response). It was set to the 50ohm load setting. How accurate or adequate of a test this is, I'm not sure...

The 2465A does pass all self tests and the Cal 05 shows Hrs On 1508 PWR On/Off 620, I know the hours can be changed but the CRT looks really good, clean and crisp compared to my 2467 which has 22584 hours, so it would be nice to think that my 2465A actually does have 1508 hours.

Thanks for all the help everyone and sorry for messing up the title.





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