Tek 2440 vs 520a

[the_grue]

Hi all!

A newcomer here. I found two nice scopes at a local second-hand equipment store, but which one to take? Tek 2440 or 520a? Both are the same low price (USD $150), claimed to be in perfect working condition. Still, I am a bit worried by advice here on the forum to replace all the caps on 520a because they are known to leak, and I don't want to trust myself not screwing it up (not to mention the amount of work it would take). Which is a better and more noob-friendly scope, all things considered?

[ahbushnell]

Hi all!

A newcomer here. I found two nice scopes at a local second-hand equipment store, but which one to take? Tek 2440 or 520a? Both are the same low price (USD $150), claimed to be in perfect working condition. Still, I am a bit worried by advice here on the forum to replace all the caps on 520a because they are known to leak, and I don't want to trust myself not screwing it up (not to mention the amount of work it would take). Which is a better and more noob-friendly scope, all things considered?

I don't know about a capacitor problem but I would take the 520a.  $150 is a good price.  Make sure it works.

[CrazyTiger]

I would suggest go with the Tek2440 it has a 300 MHz analog bandwidth and a 50 ohm input impedance selection. Once you start buying test gear you will end up buying more  so space will be a concern in near future, tek2440 is relatively smaller than tek520A. I have purchased 6 scopes in a period of two years and still looking to buy more 

The only downside of Tek2440 is those hybrid chips is extremely difficult to find and if you ever want to have a look inside the tek2440 never operate it while the cover is open, that is the easiest way to kill a Tek2440.

Good Luck on your first scope

[David Hess]

Assuming they both work, I would prefer the TDS520A despite its lower sampling rate simply for its much greater set of features.  This goes double if it has the advanced math as this is one of the few examples of a DSO which can be used for transient response FFT magnitude and phase measurements.

[the_grue]

2:1, 520A wins!

[lowimpedance]

 Once you get it open it up and check those caps have not already started leaking. You will most certainly want to replace them and as you have found there is plenty of information out there regarding this.
Don't be afraid of doing this as you will then have a capable oscilloscope without the worry that the next time you turn it on will be its last !.

[the_grue]

I got the unit today, at least primary functions appear to be working on both channels.

Once you get it open it up and check those caps have not already started leaking. You will most certainly want to replace them and as you have found there is plenty of information out there regarding this.
Don't be afraid of doing this as you will then have a capable oscilloscope without the worry that the next time you turn it on will be its last !.

Okay, will try. Any advice on where to get the caps and which brand to order? Will cheap Chinese caps from Ali Express do?

[the_grue]

Also: I found it to be very noisy. Is it worth the hassle switching the fan?