[Boatanchors] Inexpensive Scope Probes

[Bob Macklin]

At my age $100 for another scope is a luxury! I can do most of what I need 
to with the 35MHz scopes. And I can use a RF probe on the VHF/UHF stuff 
because I am not really interested in the RF waveform.

And the way ham radio seems to be going here I really need to find something 
else to occupy my time.

Bob Macklin
K5MYJ
Seattle, Wa.
"Real Radios Glow In The Dark"
----- Original Message ----- 
From: "Carl" <km1h at jeremy.mv.com>
To: "Bob Macklin" <macklinbob at msn.com>; "rbethman" <rbethman at comcast.net>; 
"BOATANCHORS" <boatanchors at mailman.qth.net>
Sent: Wednesday, February 09, 2011 9:42 AM
Subject: Re: [Boatanchors] Inexpensive Scope Probes


> With a 465 available for $100 these days why bother? Bench and rack analog 
> models to 300-400MHz are now selling for less than the probes.
>
> Carl
> KM1H
>
> ----- Original Message ----- 
> From: "Bob Macklin" <macklinbob at msn.com>
> To: "rbethman" <rbethman at comcast.net>; "BOATANCHORS" 
> <boatanchors at mailman.qth.net>
> Sent: Wednesday, February 09, 2011 11:45 AM
> Subject: Re: [Boatanchors] Inexpensive Scope Probes
>
>
>>I bought mine from Pomona. since I only have 35MHz scopes they work very
>> well.
>>
>> I have been thinking of making a VHF/UHF converter to use ahead of the 
>> 35MHz
>> scopes so I use the scopes on  VHF and UHF gear.
>>
>> Bob Macklin
>> K5MYJ
>> Seattle, Wa.
>> "Real Radios Glow In The Dark"
>>
>>
>> ----- Original Message ----- 
>> From: "rbethman" <rbethman at comcast.net>
>> To: "BOATANCHORS" <boatanchors at mailman.qth.net>
>> Sent: Wednesday, February 09, 2011 8:36 AM
>> Subject: Re: [Boatanchors] Inexpensive Scope Probes
>>
>>
>>>I don't know how long it has been since you were in the Navy.  If you
>>> are like a large number of us, it has been a couple or more decades
>>> since we left the military.
>>>
>>> I would "normally" agree that non-spec items are to be shied away from.
>>>
>>> I went ahead and bought the same ones that are being offered currently.
>>> (It is 2011 now....)
>>>
>>> I attached these new ones to the dual channel inputs, along with an
>>> Honest to goodness Tektronix Probe.
>>>
>>> Both got fed a 38.8 MHz PLL circuit test point.
>>>
>>> I swapped them back and forth from ch1 to ch2.  Running my hands over
>>> them, and even twisting them around each other resulted NO CHANGE in
>>> waveform.  The same result even when wrapped under the chassis of the
>>> mainframe of the Tek 5440.
>>>
>>> They also compensate very well.
>>>
>>> Since I'm savings significantly, I'll go ahead an use them.  *IF* there
>>> is an "unseen" difference on traces, when one is laid over the other, it
>>> has got to be about 1% or less.
>>>
>>> I think they are more than usable for Amateur Radio.  The larger number
>>> of us are working on our own equipment.  We don't have a need for NIST
>>> traceability.
>>>
>>> You'll find the nuts and bolts you buy are loaded with "forgeries", and
>>> that they will NOT hold the same torques.  I worry more about that when
>>> I start to bolt together 400 pound or greater pieces of gear.
>>>
>>> YMMV.
>>>
>>> Enjoy,
>>> Bob - N0DGN
>>>
>>> On 2/8/2011 11:25 PM, Glenn Little WB4UIV wrote:
>>>> While in the navy, we ordered a Tektronix scope probe.
>>>> Due to competitive bids and "specs" we received a knock off probe.
>>>> When I attempted to measure a clock waveform in a computer with the
>>>> prescribed scope and this probe, the waveform would change depending
>>>> on where along the lead you placed your hand or the position of the
>>>> lead relative to the chassis of the computer.
>>>> The next order was specified "do not substitute" and we did receive a
>>>> genuine Tektronix probe.
>>>> There was no problem measuring the clock waveform with this probe.
>>>>
>>>> Buyer be ware with cheap probes.
>>>> Probably useable for audio, but very questionable above a few 
>>>> MegaHertz.
>>>>
>>>> It all depends on how much you want to trust the waveform displayed
>>>> on the scope to be an accurate representation of the measured circuit.
>>>>
>>>> Just my experience.
>>>> I will only use quality probes.
>>>>
>>>> 73
>>>> Glenn
>>>> WB4UIV
>>>
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>>
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