I need to buy a probe for my oscilloscope which is 60 MHZ.

My question is can I buy a probe that rated 100 MHZ or must I make sure it is rated 60 MHZ the same as my system?

Thanks

On May 30, 3:12�pm, Plasmah77
wrote:
I need to buy a probe for my oscilloscope which is 60 MHZ.

My question is can I buy a probe that rated 100 MHZ or must I make sure
it is rated 60 MHZ the same as my system?

Thanks

--
Plasmah77

The 100 MHZ probe will work fine. The 60 MHZ specification on your
scope means its vertical amplifier and display will start to degrade
at 60 MHZ or higher in frequency. Therefore using a probe with a 60
MHZ rating will allow you to realize all of your scope's capabilities.

Gary N4AST

Thank you very much Gary.

I just won a set of 100 MHZ probes with kit on ebay.
I'm building 15 HZ zapper circuits and I need the scope to make sure my signal is as close to 15 HZ as possible. I almost bought one of those DSO nano's but someone told me they are **** . They told me I was better off spending money on an analog unit rather then waste cash on the Nano.

Me being new to all this it took me a bit to learn how to read an analog scope but I'm picking it all up pretty good.

Thanks again and have a great day.

Jim

Gary wrote:
On May 30, 3:12�pm, Plasmah77
wrote:

The 60 MHZ specification on your
scope means its vertical amplifier and display will start to degrade
at 60 MHZ or higher in frequency.

No. It is 3dB Bandwidth. Degrade will start earlier. You will have lost
half power or in voltage around 30% of the signal.


Therefore using a probe with a 60
MHZ rating will allow you to realize all of your scope's capabilities.

There is also a capacitance specification that should match. It is
however unlikely that it should not. Go ahead with the 100MHz probes if
you get them at a fair price.

nobody wrote:
Gary wrote:
On May 30, 3:12?pm, Plasmah77
wrote:

The 60 MHZ specification on your
scope means its vertical amplifier and display will start to degrade
at 60 MHZ or higher in frequency.

No. It is 3dB Bandwidth. Degrade will start earlier. You will have
lost half power or in voltage around 30% of the signal.


Therefore using a probe with a 60
MHZ rating will allow you to realize all of your scope's
capabilities.

There is also a capacitance specification that should match. It is
however unlikely that it should not. Go ahead with the 100MHz probes
if you get them at a fair price.

Here are some guidelines to determine more exactly what the interaction
between the scope and probe is:
Bandwidth is BW
Risetime is Tr
BW = 0.35/Tr
Tr(overall) = Sqrt(Tr(scope)^2 + Tr(probe)^2)

Then if
Scope Tr at 60 MHz = 5.9nS
Probe Tr at 100 MHz = 3.5 nS
Overall Tr = 6.80 nS, making overall -3db bandwidth = 51.4 MHz
--
David
dgminala at mediacombb dot net

Dave M wrote:
nobody wrote:
Gary wrote:
On May 30, 3:12?pm, Plasmah77
wrote:

The 60 MHZ specification on your
scope means its vertical amplifier and display will start to degrade
at 60 MHZ or higher in frequency.
No. It is 3dB Bandwidth. Degrade will start earlier. You will have
lost half power or in voltage around 30% of the signal.


Therefore using a probe with a 60
MHZ rating will allow you to realize all of your scope's
capabilities.
There is also a capacitance specification that should match. It is
however unlikely that it should not. Go ahead with the 100MHz probes
if you get them at a fair price.

Here are some guidelines to determine more exactly what the interaction
between the scope and probe is:
Bandwidth is BW
Risetime is Tr
BW = 0.35/Tr
Tr(overall) = Sqrt(Tr(scope)^2 + Tr(probe)^2)

Then if
Scope Tr at 60 MHz = 5.9nS
Probe Tr at 100 MHz = 3.5 nS
Overall Tr = 6.80 nS, making overall -3db bandwidth = 51.4 MHz

Though this sounds plausible, and it's thought through,
I think the result is mistaken.
A 60MHz scope is not a 60 MHz scope only if used with
(say) 3 GHz probes; its a 60 MHz scope if used with the probes as
provided or specified by the maker.

Brian W

brian whatcott wrote:
Dave M wrote:
nobody wrote:
Gary wrote:
On May 30, 3:12?pm, Plasmah77
wrote:

The 60 MHZ specification on your
scope means its vertical amplifier and display will start to
degrade at 60 MHZ or higher in frequency.
No. It is 3dB Bandwidth. Degrade will start earlier. You will have
lost half power or in voltage around 30% of the signal.


Therefore using a probe with a 60
MHZ rating will allow you to realize all of your scope's
capabilities.
There is also a capacitance specification that should match. It is
however unlikely that it should not. Go ahead with the 100MHz probes
if you get them at a fair price.

Here are some guidelines to determine more exactly what the
interaction between the scope and probe is:
Bandwidth is BW
Risetime is Tr
BW = 0.35/Tr
Tr(overall) = Sqrt(Tr(scope)^2 + Tr(probe)^2)

Then if
Scope Tr at 60 MHz = 5.9nS
Probe Tr at 100 MHz = 3.5 nS
Overall Tr = 6.80 nS, making overall -3db bandwidth = 51.4 MHz

Though this sounds plausible, and it's thought through,
I think the result is mistaken.
A 60MHz scope is not a 60 MHz scope only if used with
(say) 3 GHz probes; its a 60 MHz scope if used with the probes as
provided or specified by the maker.

Brian W

It's not mistaken... in fact, it's well documented. Here are some
attributions that elaborate on the effects of a probe on the overall
bandwidth of a scope/probe combination.
http://books.google.com/books?id=xHA...0probe&f=false

http://www.adler-instrumentos.es/ima...%C3%B1al.pd f
pg 3

http://www.freelists.org/post/si-lis...nt-equipment,9

http://www.analog.com/library/analog...cd/vol41n1.pdf pg 13

As you can see from the documents, the scope and probe bandwidths do
interact as the RMS sum of the two. The vertical bandwidth or risetime of
scopes is specified at the scope's input connector. If the bandwidth
specification includes the probe, it will be specified as such. In those
cases, the scope's bandwidth will be specified separately, and will be
higher than the scope/probe combination.
Vertical bandwidth on many high quality scopes will be described in their
manuals or spec sheets when using a variety of probes, and will reflect the
equivalent bandwidth accordingly.

--
David
dgminala at mediacombb dot net

On May 31, 3:13�pm, nobody wrote:
Gary wrote:
On May 30, 3:12 pm, Plasmah77
wrote:

The 60 MHZ specification on your
scope means its vertical amplifier and display will start to degrade
at 60 MHZ or higher in frequency. �

No. It is 3dB Bandwidth. Degrade will start earlier. You will have lost
half power or in voltage around 30% of the signal.

Therefore using a probe with a 60

MHZ rating will allow you to realize all of your scope's capabilities.

There is also a capacitance specification that should match. It is
however unlikely that it should not. Go ahead with the 100MHz probes if
you get them at a fair price.

The question was would a 100 MHZ probe work with a 60 MHZ scope. The
asker claimed to be a beginner. I made a general comment about why it
would. I saw no reason to muddy the waters by talking about half
power points and 3dB bandwidths. Trying to make it simple.

Gary N4AST

"Plasmah77" wrote in message
...

I need to buy a probe for my oscilloscope which is 60 MHZ.

My question is can I buy a probe that rated 100 MHZ or must I make sure
it is rated 60 MHZ the same as my system?

Thanks




--
Plasmah77

You can buy a probe with a higher frequency rating than your scope has and
it will work fine, it just will be more expensive.
Regards,
Bob

"Bob Spooner" wrote in message
...

"Plasmah77" wrote in message
...

I need to buy a probe for my oscilloscope which is 60 MHZ.

My question is can I buy a probe that rated 100 MHZ or must I make sure
it is rated 60 MHZ the same as my system?

Thanks




--
Plasmah77

You can buy a probe with a higher frequency rating than your scope has and
it will work fine, it just will be more expensive.
Regards,
Bob
Actually, it will also work "better."

Pete