RE: Oscilloscope arrived - black market sucks

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Peter Reid" <peter-at-reidconsulting-dot-com.au> 

Are you loading the output from the 4 diodes? If you don't its quite
likely that stray capacitance located in the leads and the CRO itself
will make this look like filtered DC, hence the line you described. It
sounds to me like your CRO is working perfectly normally. It just sounds
you haven't had a lot of experience using one.  :)  Just be patient and
play with it lots, it'll start to make sense.

Peter.

http://tesla.reidconsulting-dot-com.au


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Monday, 5 April 2004 11:25 PM
To: tesla-at-pupman-dot-com
Subject: Re: Oscilloscope arrived - black market sucks

Original poster: Skip Malley <skip-at-ladybughell-dot-com>

If you connected a transformer rated at 9VAC output to the input of your

new O-scope, It would be likely that you would see a sine wave of
approximately 15V peak.  A transformer with a rated 9VAC output into a
certain load would likely show what you have described.  The transformer
is
rated to be 9VAC at a certain load.  That is the RMS value.  The peak
voltage would be approximately 1.4 times the RMS (rated) value.  If your

transformer has no load, then the voltage would be a bit higher.

15 V peak or 30V peak to peak would be expected from a 9VAC transformer.

How are you connecting diodes???

Skip


At 01:04 PM 4/4/2004 -0600, you wrote:
 >Original poster: Kreso Bukvic <kreso.bukvic-at-kc.htnet.hr>
 >After playing with my new scope for almost whole night it look like it
is
 >not good!
 >
 >What should i check before i beat the crap from the black market
seller?
 >:-))
 >
 >What are the basic check steps to see if it is good?
 >
 >I tried conecting 9 VAC transformer at input, scope measures 15 V with
odd
 >showing, ok i tried adding one diode no improwment 2 dioes nothing,
greatz
 >then i get only a line it cannot be a line only with a greatz - right?
It
 >cannot be full DC with only 4 diodes? Or when i touch the table the
waveform
 >gose here and there it moves by it self, scope is not fizically
connected to
 >table it does  alot of crap etc and etc.
 >
 >Help
 >
 >Best Regards
 >
 >Kreso Bukvic