Hi- I used hot air from top of PCB. If I had any issues, I would have used my preheater to heat from bottom - but turns out it worked fine without use of preheater. James

RG-58 works fine for this although it may be marginal at 200 MHz and above. An Armature Radio swap meet will usually have cheap 50 ohm patch cables also. You might not have recognized them. I have

An LM317 is fine as far as noise goes; they are relatively noisy but quiet on the scale of oscilloscope input noise unless you are using something like a 7A22. At higher output voltages, a bypass

Alex, previously you measured 14.4 V between pins 9 and 4 of the time-delay tube 6NO45. Then about 20 V -14.4 V = 5.6 V should remain between pin 4 and ground, so 5.6 V across the coil of the relay.

This would imply that K600, the warm up tube, is defective... To make sure K601, the relay, is working - you could try to short pin 9 and 4 and see if the relay clicks. You should only get one

Hello all, Sorry for not replying earlier, did not have time to look at the scope again until today. Yes, I think I did confuse K600 (the tube) with K601 (the relay). From a visual inspection,

Hi David, I checked connections to pins 1 and 5 and they seem to be fine. What is interesting, though, is that after I reseated the hybrid, the scope permanently went into the "second mode" where it

Yes the +10V is fine, I recall measuring it at 10.01V when I was dealing with the false overload issue. I was just commenting on the my situation with poor external equipment to do the calibration

Rob, Well it's a good sign that dots appeared on the screen, at least it was oscillating! But not so good when they faded away :( Anyway maybe I'm not reading something correctly here. Due to the

SMD electrolytics in the control panel. If you've replaced them you may need to clean the front panel PCB as best you can to remove any dirty shorts. Look for the group photo album I just uploaded

Thanks, What would be the procedure for that? BTW, what is the reason for using an aliased display? I'm sure there is one. Szabolcs

Hi, Have you checked the 10V reference voltage in the scope? And the other voltages for value and ripple? Also, check the voltage measurements on both channels and at, may be one of the

Hello, From a cold start the display will slowly zoom for about 30min, then zooms a lot faster loosing brightness and linearity before completely loosing the display. Since I have replaced U438

David and Group, Thanks for the response. The restorer diodes (A4CR4122 and A4CR4123) are P/N FDH5004. Where can I buy these? I want to replace them. Also is there are good source for the HV caps? It

---In TekScopes@..., <davidwhess@...> wrote : I spent some time going through the service manual and that was more or less what I found of them failing in a 22xx oscilloscope. Ok

Hello, Have you also replaced and cleaned-up SMD electrolytics on front panel? If you're in Europe, would you sell your dead PSU? Paul 2016-06-01 14:47 GMT+02:00 marc.zoellin@... [TekScopes]

I had another LM317T homemade power supply to try to cal my 2440. This one seems less noisy, using the scope itself to look at noise, it was around 2mV RMS which is still bad, but not nearly as bad

Hi James , could u post a couple pics? I gather you desoldered from the bottom of the PCB and not the top of the chip?

I've just bought a Tek 475 with an IBM logo on the front. The auctioneers couldn't test it because it has a "funny plug ", which looks like it might have been something in a mainframe rack. Is it

In response to your earlier question about whether this behavior could be normal, I would say definitely not. Sometimes channel 3 and 4 will have fewer specialized trigger types but I have never seen