with regards to the oscilloscope Tek475A

[Stefanoo]

Hello guys...

i have followed the various 3ds on oscilloscopes on the forum and the counsels received here of buying one rather then focusing on USB or PC-Based oscilloscope.......and i finally.....I came out with a Tektronix 467A, payed $200 on ebay which if i'm not wrong should be on the proper range of price.
i was undecided till the end IF a 465/B would have been the right choice or not.

This Tek 467A is not recalibrated unit but the pictures were showing the scope at work, propertly displaying a sine wave on the first channel and a square on the second one.


Unforutnatelly, the oscilloscope won't come with probes...and now i'm realizing how expencive they are ... augh!!!

I don't want to give up...

I need your help on this subject guys.
On the link below

http://www.tek.com/site/ps/0,,60-15264-INTRO_EN,00.html

It shows the probes matching for the different tek models.
There are 2 choices: passive or active probes.

Accordingly on what i have been thought by reading on the net, active probes seem to be the best choices and they would give the best result.
Conversely they are quite of expencive ones and pointless having a 2 channel oscilloscope if you don't have two probes ..and two probes...is equal to...lots of money ...so...one is already too muccchhhh for right now....GGGGGGGRRRRRRRR!!!!

Another point of indecision is...attenuation... 1X, 10X 100X... :

the 10X seems to be the most used since it allows a medium width range signal analysis.

What would a reasonable price be for such a probe as the P6205 (10X active)?

I think this is the correct one for the mentioned oscilloscope, correct?
ehehe i wouldn't like to end up spending lots of money for a wrong probe that doesn't even fit on the scope in-let ...

I have found one used on ebay for $185:

- Is this the right price for such item or can I go for a better deal?

- Is really true that an active probe is better than a passive one?

- How much for a passive probe?


I'm sorry to put all this questions, but i'm really not an expert and this is the reason of why...
Thanks in advance for the attention and the patience.



Stefano.

[Ren]

Stefano,

I also bought a used Tek oscilloscope on EBay a couple years ago... a 2215 (60MHz dual channel). I bought 2 probes from this company: www.probemaster.com (not a commercial endorsement; just reporting a positive experience I had).

The 1X / 10X probes came with some handy little accessories, and cost less than $50 each. They may not be as bullet-proof as Tek probes, but they meet my simple needs.

Cheers!

Ren

[Omicron]

For audio work you won't need an active probe. It would be WAY overkill for that. Most basic audio work doesn't even need a probe, although using one is always recommended.

Your best choice would be to go for a 10X passive probe, which will cover 99.99% of all practical uses you will encounter. Choose one with a bandwith that's a little larger than the one of your scope. Such a probe shouldn't cost that much. You can find brand new ones for less than 50$ (depending on bandwith). Just don't forget that when you use a 10X probe you need to calibrate it!

All oscilloscopes and probes use a BNC socket so don't worry about probes not fitting. More modern oscilloscopes use some additional pins for autodetection of the probe type, but I don't believe your TEK has that feature.

[Stefanoo]

i have read here on the forum that the 465B had the auto detection of the probe, means a led would light up marking a 10X rather than a 100X probe.....

but i don't know since i don't have that scope and i still don't have the 467 on my hands.


What do you mean for calibratiing the probe??

If it is a 10X proble and the maximum swing is 40V i will read 4V when at the input there is 40V; is that what you meant?

[Omicron]

No, that's not what I mean. You need to adjust the compensation trimmer in the probe to the input capacitance of your scope otherwise the wave forms will be distorted. Your scope has a probe compensation output for that purpose. It has a square wave waveform on it. Just connect the probe to it and adjust the trimmer you will find on it so you'll get an undistorted square wave. The procedure should be described in the manual of your scope and or probe.

[Stefanoo]

wow...

so i could get whatever used probe on ebay just keeping in mind that since my scope is a 250Mhz i should get a 300Mhz probe with whatever capacitance and resistive characteristics since i can trim this two parameters with my scope triggers,to adjust the correct adapted condition, correct?

[Stefanoo]

i have found this item to be very interedsting

http://cgi.ebay.com/A-Set-of-2-Brand...QQcmdZViewItem


but the specification of the scope are:

http://mgoodguy.com/files/TEK475A.pdf

it says 1Mohm 20pf

but the probes are rate 1Mohm at 1X but 10M at 10X
Does it mean that it would correctly work at 1X but not at 10X?

[Omicron]

No, the probes shown will do fine. The compensation range is 10 to 35pF so your scope's 20pF falls in that range.

Maybe you should read up on basic probe theory. E.g. see http://www.syscompdesign.com/probes.pdf

[Green Marlin]

hi, if you need one scope, i have one 465b with 1 probe.
Bye

[Stefanoo]

i have already bought it on ebay...haven't paid it yet....but just for curiousity..how much for that scope? Where are you from? I'm from Pergia.