开云体育

While you're at it, you should also verify Vcc to the processor, pins 8 and 35, if you haven't already done so. Use a scope when checking power and ground pins to make sure there's nothing weird

That certainly explains why I have not seen the ghost/reflection on my 475s, all of which are later production, but my 485 is from 1980 (based on the date codes on some ICs) which is even later than

After checking through most of the circuit involved with the Ext Horiz function, and finding the signal going through all the way to Q824, and still no trace, I figured out what was wrong. After

This attitude is a good way to get kicked off of the list, in my opinion. It's not respectful dialogue, just saying. Ross

The "ghost" image is caused by secondary emission from the mesh. Some changes were made to later CRT's to reduce the effect. -- Bob Haas

Can you direct me to a web site describing this tutor device? The first place to start is with a description of the signal. The next is to determine your expectations.

And here you are AGAIN. Don't like it, don't read it. How is your last post not spamming the list? LOL

VMA is not a tri-state output, so it should never be floating. And it is quite strange you are seeing a strong input clock signal (5MHz) on VMA. The XTAL input is indeed floating on my 2465 too, but

Rick, My first inclination is that your outside signal source is not working. Can you give us some sort of feeling for what type of signal that this device produces? This is a 100Mhz scope, so I

Mark - jeez, that sounds perilous, huh? Mega high voltage in there?

Actually no, I haven't checked the voltage of the generator, but there is a light that says that it's "on".

Pseudo, It sounds like you have dirty contacts with the position knob, v/div and possibly transistors inside. Mark

Another behavior I noticed: The tutor generator has a trimmer where you can adjust voltage down to 0. The flat line on the screen goes up and down but it remains a flat line.

" The VMA output pin is at about 4VDC but has a 0.4VAC p-p" I would try shorting this to ground through a 5K resistor. If it pulls down close to 0 volts it means that it is either open or

Hi David - thanks for your reply. The knob is locked, set to auto, I set coupling to DC (it was on AC) and turned the volts/div knob up and down. All I get is a flicker and it goes back to that

I'm still very new at learning how to use a scope, but I'm getting mighty frustrated. I bought a used 464 and have been able to get it to display a straight line as well as its square wave from the

Barry, I used PETG. This material is fairly stable up to about 90C and I have extensive experience printing with it and obtaining good quality prints. I would recommend PETG, NYLON 6 or ABS, all

Looks great. What material did you use to print that part? Thanks, Barry - N4BUQ

Here is an update on this project. I have now reassembled and installed the board with this 3D printed part. It works great. The 3D print and other files are available on Thingiverse. This is a

And yet, here you are posting again. Why don't you stop responding and reading, if it's irrelevant to you? I did, after all, use a 564 and a 7403 to make the measurements :) Some of us are actually