10*10^2=1KHz, so it seems to be partly working. All functions should be 1KHz so something is off. Check that the oscillation is coming from the oscillator. The oscillator may be behaving normally and

Ok, so I did lift that jumper. GOOD MEMORY BTW!!! A-5 it was!! Remind me NOT to ever play Naval BattleS with you! The CRT came to life. I had something when playing With the Intensity and pushing

I can get that done in the U.K. so I guess it’s still common Robin

Generic steps: turn scope off, wait 5 minutes or so, turn scope on.  See if -25 is good (something could have latched up). with power off, check continuity of fuses or with power on, check for very

Oops! I have checked the voltages and while the +25V (+24.99), +15V (+14.98) and -15V (-14.98) are just about bang on, the -25V is sitting at -3.58V. I really can't remember if this was the case when

Hi Raymond Thank you for the information. Saroj

There is a wire jumper at board location A-5 that provides the ground to the HV multiplier. (note that I am going from old memory so take with a grain of salt). Measure to ground to see if it is

For those seeking a 7J20/J20 or parts, after the other posts on this, I’ve decided I won’t continue searching for one other than out of interest of what the price might be. It would be a novelty

Hi Satbeginner Understood Thanks

Hi Saroj, Connect one winding to oscillator, also Ch1 of the scope to the same winding. Now use Ch2 of the scope to check the other windings. I would connect the dot-side of the first winding to

Hi Satbeginner Right now I am looking for kapton tape in the market. Yes, I have another scope and signal generator.If I am not wrong, probing at dotted points scope should show voltages at same

The other problem is that once mixed, it is difficult (but not impossible) to spray it on the parts to be painted. If one has a paint sprayer, it’s not too big a deal, except for having to clean the

The J20/7J20 spectrometer had two (optional) fiber optic probes available. As nearly as I can tell, the base instrument did not come with a probe. One of the optional probes was described in the

Yes, All automotive paint suppliers will colour match and create a good match for you. The problem with quoting a specific paint supplier’s base or mix colours is that only works where that

Thank you my friend!

I have a 7J20. Unfortunately, I don't have the sampling head. I've had it for a long time, and when I got it, I knew it was uncommon, but I figured a sampling head would eventually turn up. No such

In an over-the-counter repair shop, this would be sage advice, and I'm not sure I'd take you up on that bet. I believe Vincent is, however, more interested in the journey than the destination, and by

Early on e.g. 1960's, WD-40 used fish oil. It changed to petroleum around the 1970s when fish oil became more valuable as a food supplement. That has not stopped the salmon fishermen out here from

That's not too surprising. The only inverter input where it is reasonable to do is the 1-2 inverter. The input there is weakly biased, rather than being positively driven from another logic

I think now I understand what you asked me to do. If you were referring to these wave forms shown before the CRT section I should be expecting at different points, I don’t. Point 87 (J6-10) and 88