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Nothing can be made 100% reliable as a daily driver, so no,
your 485 might break, and it might need an expensive repair.

If that is your only consideration, go with something new.

The 485 is a nice scope, but with its tiny screen, and lack
of readout and cursor, most would find it tedious to use as
a daily driver. When the 2465 came out, the 465-485 scopes
disappeared from lab benches very quickly. We were getting
them in government scrap lots by the ton back then.

-Chuck Harris

Ondrej Pavelka wrote:

Hi folks,

I scored 485 with few missing knobs and very blurry trace. It was for

about $30 so I didn't expect much from it.

I have 2445B as a main scope I rely on for my everyday work as a vintage

audio repair business. I did bump on a few occasions into 200MHz bandwidth
limit of the 2445B and 485 is really tempting with its smaller size and
higher bandwidth.

Would you say if I invest the time and money into the 485 I can bring it

to state where it can be 100% reliable dependable instrument?

Otherwise I will pass it onto a friend who will repair it to have it as

his only scope but if this has the potential to take the place of the 2445B
(as much as I will miss the cursors) ?

Printed circuit boards are generally made with one of two materials
(there are others), either a paper epoxy (FR-3) or a fiberglass epoxy
(FR-4).? There are others, but these are most common.

Paper epoxy (FR-3) has a lower temperature tolerance, is not as
mechanically stable, can be burnt easily, and is constructed of paper
and epoxy holding it together.? You see it in a lot of commercial
(expensive or not...) equipment.? It is mostly brown...

hi Guys

Am spending the first few days of the newly instigated UK national lockdown
calibrating several 500 series scopes – a 545B and a 547.

In each case there is an intriguing point where the manual, as part of the A and B
timebase trigger level centering calibration asks you to:

for A Time Base Cal- ground the junction of R19 & R20 – both 545B (Change
instructions) and 549 (manual)

for B Time Base Cal – ground the junction of R69 & R70 - both 545B (manual) and 549
(manual)

Now here is the issue. Finding and connecting to the required junctions can be/is
hazardous particularly for those of us who have something of the shaky hand syndrome
and a well developed sense of self preservation when working with high voltages in
cramped spaces.

But wait: there appears to be a simple solution in every case. With the timebase
trigger switch in the *Auto* position there is a direct path between those resistor
junctions and chassis – the schematic says so and a simple continuity test with the
scope off confirms it. Interestingly my version of the 545B manual uses this method
in the manual, before changes brought in by the change information.

So am I missing something here? Does the suggested 'jumper lead' provide magic
continuity properties? Is there some hidden feature not shown on the circuit diagram?

Any ideas why the obviously easy way is not followed, indeed is specifically
disavowed it the case of the 545B change information.

Thanks in advance

On Jan 6, 2021, at 9:33 AM, thenrz@... wrote:

?I bought this off of Offerup for $20. I wouldn't have even bothered, but the woman had a lot of good dealings, and I don't feel like she had any reason to lie. The scope among other things were her late husband's. As I have been kick starting my atrophied comp sci brain compartments lately to get back into circuit design with my new desktop CNC that is precise enough to cut some nice tightly pitched boards and a plethora of 3D printers for making whatever else I feel at the time. For the most part, I just want to get myself back to the days of prototyping and beta testing all kinds of electronics for a company I worked for over about eight years.

This Tek seems to be dead. I get a soft green illumination over some of the CRT, but other than that, I cannot make it do anything. There is some semblance of a focused beam when turning on and off the second time. A maybe 1/4" circle shoots in from the left middle and that's all I get to see of anything illuminated beyond the soft glow of about half the screen.

I have nice soldering irons, hot air reworks, a hot air and infrared BGA station, etc. so repair work is something I do a lot of on the side... but as I move into development again, I'm going to need a nice scope along with something I can learn the nitty gritty like with this one...

If this is worth working on, then by all means whatever advice for such an open ended problem would be amazing. If it isn't worth the time/money, *please* let me know so I can more effectively manage my time...

Thanks!