Look who's all grown up! Finally able to pull the trigger and get an oscilloscope

[nickb]

I meant to use the 1X probe to connect between the attenuator output and the scope. If the voltage at the output of the atternuator is 3kV then somethings really amiss and you can't hook it to the scope input with a wire anyway.

Ah Tom. - thanks - you made me realise I was answering the question of what to put between the attenuator and the equipment and not the one Cory asked i.e what put between the attenuator and the scope. Duh!

The answer is much the same but without the HV restriction and capacitance is less critical.

[SoulFetish]

Or you could just buy a used Tektronix Model P6007 100X Probe. If you are patient, you can get one for a really reasonable price. Here is a link to a completed eBay sale for $20 including shipping. ( Tektronix Probe 2883619. P6007, BNC, 6, 100X~ 2.2pf. 10M? | eBay )

The P6007 is the model I posted about in the thread at http://music-electronics-forum.com/t31492/. It's design is such that it attenuates both the AC and the DC voltage. Therefore, the P6007 does not exhibit the problem that allows the capacitor inside the scope to charge to the full un-attenuated DC voltage being probed. The MEF thread I referenced already explains this and contains the Tek Probe circuit so I won't repeat the info here. The designs and performance of commercial 100X probes vary. One needs to check the specifications and read the operating manuals to determine if the probe will work for your application.

HTH,
Tom

Thanks for the heads up on the Tek P6007. I've been weary of some of the really cheap probes on the market today, particularly when no datasheet is presented.
Sometimes I have to remind myself that it just makes sense to spend the money and buy something, vs making it or finding a way around it.
I don't know what the hell my problem is; I spent over an hour and a half researching solvent dyes for polyvinyl chloride because I have a surplus of white 18AWG UL1015 wire and didn't want to buy more to have different colors. Actually, I do no what my problem is. I'm the perfect storm of cheap, broke, and hubristic. I finally snapped out of it and said to myself "Dude, just pay the $6 a piece for a couple of 25' rolls and pull your head out of your ass".

[Chuck H]

FWIW I spend the extra buck a roll on "irradiated" PVC now. It's far tougher and shrinks about 20% of what standard PVC does under the iron. So worth it. It's certainly cheap enough and the results after soldering and construction are better. Heads up though... DO check for voltage rating on the jacket. When you start looking at irradiated PVC you get into the realm of real pro's that know how to spec. So none of the dunderhead work is done for you. The rating on the material might be strictly AC. I had this problem once and had to shotgun change an order to get lead wire appropriate for the DC voltages we use. The vendor got a little grumpy about it and I had to point out that they hadn't specified AC or DC on the voltage rating!!! Sorry I can't remember where I bought it. It was a few years ago and I've barely cracked into the 600 yard rolls But irradiated IS what you want. Offered for our consideration. And irradiated PVC highly recommended by this guy.

[Justin Thomas]

I remember my first roll of Teflon wire from Belden. I panicked when I saw the 300V rating AFTER I had punched out the center label and couldn't read it entirely. I called the store I bought it at and they said, "that's when you are using it submerged in gasoline; it's 600V." Huh, never woulda thunk it...

Wow, what a relief... I think.

Justin

[Chuck H]

Yeah.?. All kinds of oddness WRT voltage ratings. Why in the hell would they expect anyone to read a spec. and just KNOW "when submerged in gasoline"??? That's just the sort of thing that comes up when you order wire IME. You do learn what to look for, but that doesn't mean it's always represented in completed statements Like we all have extra dough for finding out what we ordered isn't quite right!?! Lazy product descriptions bother the $h!t out of me.

[SoulFetish]

...irradiated PVC highly recommended by this guy.

I dunno' Chuck... Think I can dye that sh*t?

[The Dude]

Yeah.?. All kinds of oddness WRT voltage ratings. Why in the hell would they expect anyone to read a spec. and just KNOW "when submerged in gasoline"??? That's just the sort of thing that comes up when you order wire IME. You do learn what to look for, but that doesn't mean it's always represented in completed statements Like we all have extra dough for finding out what we ordered isn't quite right!?! Lazy product descriptions bother the $h!t out of me.

You just never know when someone might spill a "flammable liquid" inside an amp.

[SoulFetish]

Yeah.?. All kinds of oddness WRT voltage ratings. Why in the hell would they expect anyone to read a spec. and just KNOW "when submerged in gasoline"??? That's just the sort of thing that comes up when you order wire IME.

No doubt. Voltage rating is a moving target anyways. A withstand voltage rating depends on things like temperature, time/duration, frequency, etc. I try and be as thorough as possible when it comes to component data and look at as much graphical detail as is relevant to me. Plus, you have standards like UL and MIL type W which have their own criteria which has to be met in order to get approved for certain classifications.

[SoulFetish]

on a side note, you guys ever read something wrong the first time and whenever you see it again after that you keep pronouncing it wrong in you head even though you know better?
The first time I came across the term "irradiated PVC" wire, I read it "irradated". Like, irradating was a mysterious new technique for processing PVC used by manufacturers.