Hi Ernesto, I'm not surprised that the focus and astigmatism are still OK with reduced HV but don't forget that the CRT deflection factors will be affected by the HV which means the calibration will

Hi Gary, The Prescale Input contains a high-pass filter (R2368/R2466/L2362/C2362) designed to engage Input-Out-Of-Range at low frequencies that could cause false triggering of the U2350 prescaler IC.

I found this to look at Gerber files online .  I have not tried it. https://www.gerber-viewer.com/ Tom Bryan

I would also be interested in a couple of these adapters. I looked over the files at the link but don't have the appropriate apps to open them.

I recently purchased a 1L5 off of eBay and popped it on the bench and attempted to start calibrating it. 10KHz up seems fine, but it is completely deaf in the 50Hz-9990Hz range. On the oscilloscope

Victor, Obviously there is not enough secondary HV, or a diode is bad. If you remove the plastic cover of the HV box you can access at least one diode which is connected to a hot winding end (I don't

Hi Morris, Thank you for your informative message. I went to the "files" section and found the transformer specifications. This is a big plus! Meanwhile I am exploring other options. I started

Albert, With the 454 energized today I could make some of your recommended test. I start with the "less risky test" and the results was far from my expectations. After follow your process I applied

Hello every Tek expert: I just finished a long reply for thank you all for a long list of helpful hints. Unfortunately my wi-fi connection was lost at the time I keyin "send" command. Everything was

Yes, It's stated in the service manual. Reg

Hello, in case anyone needs one printed in Europe: I am willing to give it a shot with my RF100 and some white or grey material I have left over. Shipping also for free. But _ONLY_ via Slovak

I have never seen a fault on a 5000 series EHT before either. The epoxy used on the 5000 series, and the 7000 series, EHT's is very different from the epoxy I find on 547's, etal. It is clear amber,

Good Day Yeun-Jung, apart from the discussion on HV probing, my recommendation is to check the HV capacitors in the high volt section. I have seen a few which failed in other 5000 series

Hi Ernesto, Thanks for the discussion which I found really interesting. I am also a 547 admirer and use one as my main bench scope with a 1A4 plugin. That combination really brings out the best in

Hi, Thanks a lot for this information! Did you ever find out if 10000 .. 1FFFF actually is the the NVRAMs on the A5 board (U500 and U511)? Ragnar

Dave, Thank you for the tip. I read and see the photo album and this is a great information and a great job ! I believe also that HV transformer is the same on 453 and 454.  Actually I am trying some

"I had never cleaned it from some dirt accumulated in 40 years through the cover holes, many tubes are dirty, but I didn't dare to blow with compressed air or... god forbid ...wash it." After you

Albert, Thank you for all that great tips that you sent yesterday and now.I was busy today with the  interference filter dead. I couldn't find any spare on the market with the same size as the

Hi Albert, thank you for the information. I verified the action of the negative pulse by R562, C562 on power up of the -150V that shifts the trace to the right. I could do something similar when the

It is not only the enjoyment of the scope working, but also of the challenge of going around its HV problem. I had incorrectly written that the plug-in on my scope is the 1A1, but it turns out the