开云体育

What I think is happening is the control grid circuit is rectifying the positive input peaks to set the bias. A JFET replacement would operate in the same way although I may have to change the grid

As I gather up all the stuff I need to test and maintain my newly purchased 2235 I am wondering how necessary it is to use a 50 ohm feedthru termination when sending test and calibration signals into

I see calendars on (PDF) pages 32, 56, 82, 88, and 112. I can't make out a year in any of the photos, but the one on page 56 appears to be from December, with Christmas on a Friday. This would suggest

R969, 0.25 Ohm. Albert

Don't worry, there was no attachment, comes from something wrong with my mail. Fabio.

It's the isolated type, outer bus wired to GND via a << 1 Ohm resistor. That resistor sits nearly against the bottom panel of the 'scope. I guess that resistor is broken. Albert

Is the 547 "CAL OUT" connector from the calibrator supposed to be a normal BNC? According to the schematic it is. But on my 547 it's a "floating" BNC, with the barrel separated from the flange with a

Here is another photo album similar to the one I posted before. http://w140.com/undated_tek_photo_album.pdf Can anybody figure out the date of this one? thanks, -Kurt

Sorry, Yahoo seems to be blocking the image, won't accept my login without multiple layers of entering captcha codes, and generally being such a pain to use that its not worth it.

Wow - that means the grid currents must be over -100 uA to get that much on 100k grid leak resistors. I don't recall what the screens were hooked to, but I think you should calculate the screen

Sorry for the attachment, probably I messed up with html/text in mail... Fabio.

Hello Peter, excellent work, my 7704A had many contacts bent or broken, they are thin, fortunately the broken pins were not many. There are many unused pins on the connector (on the 7704A at least)

I have seen this problem before in the vertical direction where a load resistor in the CRT vertical amplifier was open. Be sure to check power supply voltages and that the deflection plates are

Just to clarify this, the 6802 and 6808 are the same die, it was just that the RAM wasn't guaranteed to work on the 6808. It wasn't disabled.

Hmm... I recently got this 549. Haven't opened it up yet, so I haven't checked voltages yet. The trace is compressed on the right third of the screen. If I rotate the horizontal position control to

wrote: Electro static discharge could have damaged an internal circuit connected to that pin such that it still worked but would fail later. In TTL when this happens, I usually see one of the totem

I have a few other Tek pieces with AMI 08s. It may be of interest that the 68xx family has an instruction, H(alt)C(atch)F(ire) that does nothing except turn the chip into a counter. Seems to be

The scope worked for 10 years with the 6808, so I would say it did not need the ram. I don't know if the 6808 was there because of the service as a replacement(I don't know for sure where all the

!!!! Could just be a random failure of the output driver. An AMI part should be fine, but note that 6808s were sold as RAM-less versions of the 6802, which means the on chip RAM may have failed test.

Jerry, Note that this applies also when you want to check only one channel. Then also the cable should be terminated at the end (the CH1 or CH2 input), not at the SG503 side. So you might have to