Hello I had the exact oppsite symptom: CH1, 2 30% nonlineariyt as traces enter lower 1/3 of CRT, but fine in center or top. CH3, 4 OK. I used a triangle wave to see the nonlinearity clearly. Chuck men

Francesco this sounds like the classic HV transformer epoxy failures. Did you check the CRT HV during the failures? Be careful, use correct HV probe and follow service manual on HV section. Both the H

Dear Jeff seems easier to follow your progress and problems if you can post some photos, did you create an album in the photos section? especially photo of the damages, and CRT displays will be far be

Bonjour Sr Guiseppe, re the EPAY listing the photos of that epay lot in the photo album, show dirty cables and one inner housing tip seems a clone replacement. Not good signs. Trusting and returning i

Hi there, the OP asked for TEK 2465 probes specifically, P6137. The 2465B has 350 MHz BW and 2467B 400 MHz BW. Those that have tested the Chinese knockoffs accurately find the specs are way off. We ha

Bonjour Roy: I have used the same P6137s (have five) for many years. The larger probes are of course more robust. The BW and smaller components eg SMD prompted the probe tips and cables to shrink over

Dear Chuck The CTT option operation and self test seems to be dependent upon 1/ CTT board, EEPROM on board 2/ Trigger Hybrid U500, only certain ones work, even though they may work fine in a non CTT s

Sr Giuseppe 1/ The Chinese knockoffs probes are not capable of the specified BW or RT and will proove clumsy and unreliable. 2/ We have used P6137 for decades, they must be treated with care like any

Chuck many thanks thought so, Yes I have gone thru Calibrating CTT proceedure and aware of the specific requirements for the signal. Have all the stuff needed to do it. As I have mounted a subsitute A

Chuck, with known good CTT board exchanged for the one in the failed scope, all cables properly reattached. A5 board is know good and had no SMD leaky caps. Only, partial success, CTT works but the fo

Sr. Marullo, Keep scope inputs away from TX or exciter outputs, there are various techniques to monitor the modulatiion, power etc. using directional couples and splitters. A power rated load may have

Rebonjour, the 485 spec is 50 Ω /1 MΩ//20 pF https://w140.com/tekwiki/wiki/485 I assume the 20 pF applies to either Zo. Best measurement of Cin is the classic TEK 130 LC meter, very easy to use and ac

Dear Chuck: I swapped only the U5930 of the OPT boards, as it was easy and socketed, the EEPROM. No change. I am just now removing and exchanging the OPT bd of known good unit to fault unit. Will repo

Tom is the 485 input 50 Ohm free of any capacitance? Or just lower than the others? In case the 15 pF is an issue a Zo proble or active FET probe brings the tip C to ~ 1 pF. Jon

Hello: Yes P6137 is the specified for the BW and Cin. Hard to find good one, many junkers out there. For 50 Ohms use a coax like RG/198/U on a BNC. For probing wideband we use a Zo probe P6156 eg 1K O

Hello again: The continuing saga ... (see my pervious posts re CTT and vet nonlin) 1/ New U400 channel switch 155-0236-00 has fixed the CH1, 2 nonlinearity. 2/ Chuck mentioned that the CTT test fails

Hello all: PG506 are tricky to buy on epay: hard to fix as cleaning the switches or replacing certain ICs is not easy. Virtually no sellers on epay can properly test all the functions. So expect repai

The 100 MHz noise can be parasitic oscillation, rather than power rail lack of bypass The Ft of the transistors can shift over the decades. One tip-off is if the 100 MHz changes amplitude or disappear

Chuck, perfect information as always, and very useful to those who suffer with an ornery CTS option. Bon Journee, Jon

Hello, CT référence to Counter Timer option, see separate Options manual, I think on BAMA archive or TEK WIKI. The self test menu has a separate test for CTT. Often the fail is related to U500 the the