开云体育

Harvey, Thanks for your thoughts. Right now I definitely don't have the floor space for a scope cart, but I'm planning a move in the near future and am looking at houses. One criteria is enough floor

Hi Nenad, I agree that the avalanche pulse alone is probably so slow that the clipping lines simply act as a shortcut. But how to explain the response to the Offset control? When you change Offset

Hi Sean, Where are you located? Dennis Tillman W7PF

Hi Albert, In my case (without the snap-off signal) the head sensitivity to input signal was zero. The explanation is in the structure of the strip line to which C52 and C54 are attached. This

I have a scope mobile cart that will hold a 7000 series scope (no, not for sale). Some observations: The scopemobile was designed to be a roll around home for a scope in a lab/facility that had a lot

I wanted to thank everyone for their replies, direct emails, and advice. After consideration of many kind offers, I ended up purchasing a 7904A + plugins from John Griessen. It arrived yesterday!

Hi Nenad, I overlooked your second last message in which you answered my question about DC response and more. I have to admit that I fail to understand what is exactly going on when R62 is

Whaw Nenad, what a good luck that you discovered the fault in S-

It's alive - sort of. I had to perform quite a bit of surgery on the guts. I found that the mounting posts on the big board that attaches to the right side RF module had broken loose from the board,

Heh, I just fixed it, it's working now. While probing all components inside S-4, I found that the bottom lead of R62 was cold soldered (the one soldered to the gold plated PCB strip), it snapped off

A termination would present the same issue of wear. I'm not going to be monitoring a data link 24x7, so I'll be connecting and disconnecting more often. My 11801 had 44,000 operating hours but was

Thanks for the responses. I think I'll skip that project. It's not something I need. I'm getting a custom 1 MHz version of Leo Bodnar's <40 ps rise time square wave generator for TDR work with a DSO.

If possible, position things so that the tip of the drill points up. Stray shavings will fall away from instead into the hole. Thanks, Barry - N4BUQ

Do the 1502 (A/B) even have the tunnel diodes? I know that the 1503 has an avalance transistor pulse generator, which does not have the same sensitivity to static damage as the tunnel diode (which is

The easiest way is not to let them get in in the first place. What I do, though I don't do this very often, preferring to disassemble pots where I can, is to first slide a piece of brass tubing over

Hi Richard, And how do you get the drill shavings out of the pot? Dennis Tillman W7PF

The interesting counterpoint is that the weak point in the 1502 is the unobtanium tunnel diode. I did have one with a bad CRT and a bad HV power supply (and a bad horizontal amplifier). Finding one

The LCD display on these are miserable.. An early electroluminescent backlight with a heater for cold environments, difficult to read in almost any condition. If the display is bad, ie, looks like it

Unknown, but I suspect (don’t really know) that the tunnel diodes are broke. Most of the earlier 1502’s that we sent to customers on rent came back with blown diodes Regards, Stephen Hanselman

There are a slew of them on eBay for pretty nominal prices as parts units. How hard are they to repair?