Help with techtronix 465B scope what to do

[sam67]

Re: Help with techtronix 465B scope what to do

Hi Radio Fox,

Here is the pic of the waveform ..any ideas appreciated

[larrymoencurly]

Re: Help with techtronix 465B scope what to do

Tweak the trimmer in the probe?

Clean the mechanical switch of the attenuator?

[sam67]

Re: Help with techtronix 465B scope what to do

Hi i do not see a trimmer on the probe so not really sure what you mean ...this probe is p6105 x10 100mhz 13pf 10m ohm 2 meter tek ..now i only see a button for the gnd ref..so am at a loss at the moment.Thanks

[sam67]

Re: Help with techtronix 465B scope what to do

Just noticed this ..Would this be the trimmer that you mention..if so what do i need to do ..do i turn it while the probe is in channel 1 and connected to calibrated bar ?

Thanks

[PlainBill]

Re: Help with techtronix 465B scope what to do

Just noticed this ..Would this be the trimmer that you mention..if so what do i need to do ..do i turn it while the probe is in channel 1 and connected to calibrated bar ?

Thanks

Yup, you got it in one. The objective is to eliminate the curve at the beginning of the horizontal traces.

PlainBill

[stj]

Re: Help with techtronix 465B scope what to do

datasheet

[Dgtech]

Re: Help with techtronix 465B scope what to do

If you were wondering why the verticle edges were faint, the simple answer is: this is perfectly normal for most tube scopes. This is a picture of an LCD scope. You're not doing anything wrong.....yet. Once you smooth out the edges of your calibration square wave, then you'll be ready to move on.

[Radio Fox]

Re: Help with techtronix 465B scope what to do

If you were wondering why the verticle edges were faint, the simple answer is: this is perfectly normal for most tube scopes. This is a picture of an LCD scope. You're not doing anything wrong.....yet. Once you smooth out the edges of your calibration square wave, then you'll be ready to move on.

Yep.

The "problem" with CRT's when looking at square waves, is that the vertical transitions are so fast that the beam of electrons doesn't strike the phosphor for long enough to make them glow.

If you were to look at a sine wave, or triangle wave, then the whole waveform would be visible.

[sam67]

Re: Help with techtronix 465B scope what to do

Thanks guys for the help

I have smoothed out the trace but want to test my scope but i have not got hold of an isolation transformer and cannot find one that would work with this scope as i am not sure what type i would need.

Any ideas anyone ? do i only need an isolation transformer when working on primary side of smps ? I would like to do a few experiments but don't want to ruin my scope on the smps at this moment .

Is it ok to to measure STEREO AUDIO AMPLIFIER IC on my speakers just to see the wave form as i repaired them a while ago when the amp blew ..All are working now but at the time someone suggested to try a scope to make certain that the -amp was the cause.

I did not have a scope when i repaired the speakers so i just got a few spares and changed the amp and they were fine .I know the pin out for the STEREO AUDIO AMPLIFIER IC but does anyone know what type of waveform to expect so i can have a little practice lol.

Are there any links for certain waveforms that should be expected when testing certain ic's ? I already know what to look for on smps i.e crystals ,ripple on caps and power ic's and pwm ic's but i am waiting to find an isolation transformer before i test on them because of the higher voltages on primary side..

Sorry for all the questions but if i don't ask ,i will never learn.



Thanks

Sam67

[Radio Fox]

Re: Help with techtronix 465B scope what to do

The waveforms you will see on the audio in & audio out pins of your amplifier I.C. will depend on what you are putting into it. If you are playing music through the amp, you will see a random waveform. Try it & see.

[stj]

Re: Help with techtronix 465B scope what to do

you dont need an isolation transformer, another option is an isolated probe.

and watch out when buying probes, they have a maximum safe voltage.
some are 300v, some are 600.
some are even 1000v but those are mostly x100 rated.

if your poking at primary psu signals i'd be wanting a 600v probe.

[sam67]

Re: Help with techtronix 465B scope what to do

you dont need an isolation transformer, another option is an isolated probe.

and watch out when buying probes, they have a maximum safe voltage.
some are 300v, some are 600.
some are even 1000v but those are mostly x100 rated.

if your poking at primary psu signals i'd be wanting a 600v probe.

Thanks stj

Looked for these probes but cannot find the one you refer too?


Everyone keeps on about getting an isolation transformer but no links to any.. i have searched but cannot find what i need ..surly this should not be to hard to find..

Can someone please link me to some think that i can use that either i plug my scope into or a probe that is safe to test the primary side..I am trying to go about this as safely as possible but feel i am going round in circles..Don't forget guys i am new to this so please forgive my not so good knowledge on this i want to try the scope out but cannot do it till i get the right safety feature ..come on guys

[stj]

Re: Help with techtronix 465B scope what to do

look on the back of the scope, how much power does it use?

if you know how many W or ma it will be easy to find a transformer.

[PlainBill]

Re: Help with techtronix 465B scope what to do

Thanks guys for the help

I have smoothed out the trace but want to test my scope but i have not got hold of an isolation transformer and cannot find one that would work with this scope as i am not sure what type i would need.

Any ideas anyone ? do i only need an isolation transformer when working on primary side of smps ? I would like to do a few experiments but don't want to ruin my scope on the smps at this moment .

Is it ok to to measure STEREO AUDIO AMPLIFIER IC on my speakers just to see the wave form as i repaired them a while ago when the amp blew ..All are working now but at the time someone suggested to try a scope to make certain that the -amp was the cause.

I did not have a scope when i repaired the speakers so i just got a few spares and changed the amp and they were fine .I know the pin out for the STEREO AUDIO AMPLIFIER IC but does anyone know what type of waveform to expect so i can have a little practice lol.

Are there any links for certain waveforms that should be expected when testing certain ic's ? I already know what to look for on smps i.e crystals ,ripple on caps and power ic's and pwm ic's but i am waiting to find an isolation transformer before i test on them because of the higher voltages on primary side..

Sorry for all the questions but if i don't ask ,i will never learn.



Thanks

Sam67

As far as what kind of isolation transformer you require, it should be adequate to power whatever equipment you are testing. For example, a 250 volt-amp isolation transformer (such as ebay item number 350357727136) is quite adequate for most monitors or small TVs. Of course, it must also be of the proper voltage for your area; I am sure this one is not.

PlainBill

[sam67]

Re: Help with techtronix 465B scope what to do

look on the back of the scope, how much power does it use?

if you know how many W or ma it will be easy to find a transformer.

Hi stj,

Back of the scope says 90w (max)

So what would you recommend that would handle smps and tvs ? do i just plug my scope into the iso transformer as i have never used one so don't have a clue..i have looked up what they do but cannot find any info on what to do with the damn thing if i manage to get one

@ plainBill thanks for the link ,i am from the uk so my line voltage is 240v .. I did ask at my local maplins about an isolation transformer but the guy looked at me as though i was speaking another language lol.

Believe me guys i do appreciate the help it's just i am not up to date with all this electronics jargon..there is a lot more to it than i first thought and i only have you guys to ask as i do not know anyone near me to help me out..Wish one of you guys lived near me as i would pay for some tuition just to advance a little more..

I mean when it comes to cars i am pretty decent at repairing and servicing them and do all my own work but electronics is another ball game. But i am eager to learn in this field even though it's not easy .Have i bitten off more than i can chew with getting a scope ? did not realize i would have such a hard time trying to get up and running safely.

Best

sam67

[Dgtech]

Re: Help with techtronix 465B scope what to do

I have to tell you, I've done lots of troubleshooting just with my Fluke Multimeter. Most of my boards I have worked on had mostly visual or simple power supply problems that could be found using a meter. Only a few boards with PWM failures (Pulse Width Modulators) sent me searching for a scope. Even with those boards, I had already proved the PWM chip in question was the fault based on my knowledge of the circuitry. The scope just gave me more of an understanding of what type of signal I was losing.

We are all merely students of electronics meaning - nobody knows all of it. Just remember, electricy can be unforgiving. Once a mistake is made, it is done. Electricity WILL take the easiest path to ground. It doesnt know the difference between you or the board. Nor does it care. But we do so please be safe.

[sam67]

Re: Help with techtronix 465B scope what to do

Hi Dgtech,
Thanks for the kind words ..The trouble is with me i don't like things to beat me and i thought a scope would one day come in handy ,which i know it would.

I agree that using a few other test equipment like analogue meter ,dvm and blue ring tester and esr meter that i have will suffice most trouble shooting and i am ok at using these but had an opportunity to buy this scope and try to learn just that bit more .Thought i would be able to just type isolation transformer into fleabay and just connect my scope to it and away i would go but that is not the case ( i cannot find one that will let me do that) ..So now i am stuck with my scope and wondering what i can actually test with it without an isolation transformer lol is it ok to test the STEREO AUDIO AMPLIFIER IC without one as there are no high voltages being used in my speakers as they are only desktop ones so i guess i should be fine with them till i can either find the right test probe or isolation transformer for smps testing.

At least i have asked rather than jumping in head first and either electrocuted myself or blown my scope by not using the correct safety measures lol ..I have been reading about floating the scope but i think i will not go down that route just yet lol

Thanks

[PlainBill]

Re: Help with techtronix 465B scope what to do

Hi stj,

Back of the scope says 90w (max)

So what would you recommend that would handle smps and tvs ? do i just plug my scope into the iso transformer as i have never used one so don't have a clue..i have looked up what they do but cannot find any info on what to do with the damn thing if i manage to get one

@ plainBill thanks for the link ,i am from the uk so my line voltage is 240v .. I did ask at my local maplins about an isolation transformer but the guy looked at me as though i was speaking another language lol.

Believe me guys i do appreciate the help it's just i am not up to date with all this electronics jargon..there is a lot more to it than i first thought and i only have you guys to ask as i do not know anyone near me to help me out..Wish one of you guys lived near me as i would pay for some tuition just to advance a little more..

I mean when it comes to cars i am pretty decent at repairing and servicing them and do all my own work but electronics is another ball game. But i am eager to learn in this field even though it's not easy .Have i bitten off more than i can chew with getting a scope ? did not realize i would have such a hard time trying to get up and running safely.

Best

sam67

Don't use an isolation transformer to isolate the scope. That places any exposed metal on the scope at some portion of line voltage. In your case probably 110 - 170 volts.

Here's the one you should use. It's overkill for any likely work you do, but the price is good.

PlainBill

[sam67]

Re: Help with techtronix 465B scope what to do

Hi PlainBill,

Thanks for the link ,i did come across that isolation transformer but did not have a clue whether or not it would work with my scope ..So if i buy this is this all i would need to be able to use the scope for most testing or would i need anything else ..Just thought i would ask as i don't mind buying this but don't want to find out that i then need some think else..

Much appreciated .

Thanks
p.s sorry forgot to ask how your cataract surgery went ,my mother in-law said it helped here a great deal.

[Radio Fox]

Re: Help with techtronix 465B scope what to do

you dont need an isolation transformer, another option is an isolated probe...

Not sure what you mean by an isolated probe.

Do you mean a differential probe? These are very expensive (>£300).