Product ReviewsTektronix 485 Analog Oscilloscope

a solid 350MHz oscilloscope for everyday bench use

The 485 is a better-than-entry-level dual trace scope. It is good up to 350MHz (50 ohm input) and 250MHz (1 Mohm input), making it usable for most amateur radio work. Like all Tek scopes of this era is is built like a tank, with first quality components. It has some nice added features, too: like the ability to use active tek probes. For most people, this is the only scope they will need.

Several cautions... this is one of the Tek scopes with custom ICs, which makes repair more difficult. The mechanical construction is also very tightly packed and the simplest repairs may require a lot of disassembly, including a fan that isn't easy to remove. Finally, like any scope this age, checking the power supply capacitors is a must, especially if this scope is destined for regular use on your bench.Read full review...

Verified purchase:  Yes | Condition: pre-owned | Sold by: obtainium!

One of the Finest Scopes of its Day - Light, Small and Fast.

I Have used a Tek 485 as my main go-to bench scope for all general purpose trouble shooting and measurement. Rarely do I ever tax its impressive speed of 350MHz, but have on occasion challenged it with signals approaching 400MHz which it does not falter at. They do have some issues though, being that they are now well over 30 years old. Plan to experience capacitor end-of-life failures. The power supply is one of tektronix' early switch mode designs, and can be finicky. It is reliant on a switching transformer that has a history of being the weakest link in the system, and is only obtainable from another 485 donor scope.If you have one of these scopes, and plan to keep it in regular use, keep you eye peeled for a parts donor unit, and plan to replace the capacitors in the power supply and regulator boards, and to check the tantalum caps that feed off the various power rails. Otherwise this scope, like most Tek scopes is built like a brick outhouse, but behaves like a chicken on methamphetamines. Crisp, tight and fast CRT can get show me images that my $11,000 DSO can't always see, and when I want a simple but capable analog view, this is my faithful little workhorse. Though there are a number of custom unobtainuim Tek ICs and other critical parts, like that main switching transformer, I expect to keep this fine old scope sweeping until fate does us part.Read full review...

Verified purchase:  Yes | Sold by: jonvoightscartv...

Expected Troubleshooting

I first turned on the scope a resistor burned up in the power supply board . I found a shorted tantalum cap causing the problem. I also found that several diodes had been lifted on the power supply board. I replaced one of the lifted diodes and installed the other diodes. I powered up the scope and I got it functioning on one channel. The fan was very noisy and needs attention along with one of the channels. I am still in the process of troubleshooting the scope.Read full review...

485 scope for parts or repair

I Don't recomend this because it was a "one-off" ! A very high quality instrument, let down it seems, by the Mains PSU - a Tektronix I.C. of which appears to have died. The rest proved to be functional. It remains in its box awaiting major PSU surgery !Read full review...

Bought for parts. Solved my Tektronix 485 problems.

I bought this for parts to repair my Tektronix 485. Luckily the parts I needed were good on this unit. My 485 is now working properly!

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Verified purchase:  Yes | Sold by: e_lectron

Scope

I replaced a very tired 485 with this one and am very satisfied with it

Verified purchase:  Yes | Condition: pre-owned | Sold by: gootgear

Very nice TEK 485 for the age! Thank you!!

Very nice TEK 485 for the age! Thank you!!

Verified purchase:  Yes | Sold by: outback6