Some truely insane diy

[kevin gilmore]

So for various reasons that i won't exactly go into, i'm about to

have a bunch of surplus stuff looking for an application.

A bunch of programmed test sources signal generators. computer controllable.

All phase coherent to the master reference source.

http://www.programmedtest.com/pts500.html

3 x 1 mhz to 500 mhz generators

1 x 1 mhz to 620 mhz generator with dual outputs that can be inter-modulated

3 x 1 mhz to 300 mhz generators one with dual outputs that can be inter-modulated

And some CW capable class A RF power amps

2 x 200mhz to 500mhz 50 watts

3 x 10mhz to 200mhz 300 watts

As i said, looking for an application. So i contacted craig who is one of the

few people that i can think of who can come up with something creative.

(knowing full well that he knows where i got the stuff)

So we decided on setting up the stuff in tyll's house. (someone tell tyll)

Lots of copper screening on the walls, floors and ceiling all soldered together

to make a very nice and radiation proof screen room. I mean tyll clearly needs

his demo room to be fully shielded anyway so the aliens don't mess with his brain...

The idea is to test all the claims of various manufacturers of cables with respect

to their supposed ability to remove RF due to (insert techno babble here).

All i need now, are some standard antenna's, and a local oscillator/mixer box

(actually already have it) and we can bring it down to baseband, and then tyll's

audio precision can measure it directly.

Probably don't want to be in the same room at the same time if we are running

the amps at full blast.

So what do people think?

[chinsettawong]

Insane!

[Dusty Chalk]

By 'radiation', I presume you mean RF radiation? Because I don't see anything in there that merits nuclear radiation symbols, nor do I think the screening would help in that case.

Are you going to the point of microwaves and photo-electric effect? Because if so, I want pitchers. You'll have to figure out a way to do that too without destroying the camera.

Yes, I said that while resisting the temptation to include the words "arcy" and "sparky" in there.

[DouglasQuaid]

Because if so, I want pitchers.

Screw pictures, I want videos of people breaking into Tyll's house.

[spritzer]

Like I just told Kevin, sometimes I really glad that a good part of the northern Atlantic sits between us. I'd live in constant fear of crazy shit like this showing up...

[Currawong]

I can't wait to see the "after" pics if you do blow anything up.

[Tyll Hertsens]

Suweet! Does that mean I can cook the brat while Im eating it?

[kevin gilmore]

Suweet! Does that mean I can cook the brat while Im eating it?

Actually this is possible. I have done demo's on this already.

30 mhz at a couple hundred watts into 3 turns of a coil.

Stick tube steak in one end, and it cooks as you push it thru.

Bump it up to 3kw and you get burning argon gas.

And by radiation i mean broadband RF, 1 mhz to say 1ghz.

None of the cable companies are advertising anything related to

nuclear radiation.

More practical is a desktop lindgreen screen room, and i think

i know where to get one of those.

Now how to convince all the cable manufacturers who obviously

don't want their claims actually tested to fork over some demo

material.

Edited January 29, 2011 by kevin gilmore

[Craig Sawyers]

Now how to convince all the cable manufacturers who obviously

don't want their claims actually tested to fork over some demo

material.

You stand a pretty good chance with Kimber - Ray Kimber was a recording engineer before he set up the company, and developed the woven speaker cable to stop thyristor light dimmer crud from getting back up the PA amps, getting into the feedback loop and then coming back down to the speakers as a buzz.

He'd be pretty keen to get immunity measurements as a quantitative selling point for his cables. Cardas too, I would think, MIT, Nordost and others.

Martin Colloms (HiFi Critic) has been trying to get a cables consortium together, part of the aim of which is to substantiate subjective claims with real-world measurements.

[kevin gilmore]

Lets come up with a standardized testing method

How many watts at how many feet.

I guess you would have to the same thing in free-field

which is more like the real world.

[Craig Sawyers]

Lets come up with a standardized testing method

How many watts at how many feet.

I guess you would have to the same thing in free-field

which is more like the real world.

Usually an anechoic chamber is used with conductive or ferrite loaded wedges which looks like an infinitely large environment - so trying to simulate free field, especially when the anechoic is big so you can get a good distance between antenna and DUT.

I've tried finding stuff on alternatives using rf reflective walls (ie bare copper), and drawn a bit of a blank.

[spritzer]

I can donate some Kimber cables for testing if somebody is up for it. I'm going to rip a KS3033 apart tonight to make some truly insane interconnects...

[Tyll Hertsens]

Well Kevin, lemme know if you're really serious about something like this. I would consider housing such a tester. Not sure it's really quite up my "personal audio" ally, but I'd certainly think about it.

[kevin gilmore]

You know i'm serious. You have seen the basement in my house.

The whole setup in a half high rack on wheels should end up

weighing about 300 lbs. Probably less. Generators are about

40 lbs, and the amps are about 85.

Looking for standards antenna's now... But i'll probably make

them, as the new price on those things is silly.

Edited January 29, 2011 by kevin gilmore

[Pars]

I'd think this would make you popular with many of Stereophile's advertisers

[Fitz]

This is going to be awesome on so many levels. I'd gladly donate some of my own cables for testing, which I make no claims of having any benefits.

[wink]

3 x 1 mhz to 500 mhz generators

1 x 1 mhz to 620 mhz generator with dual outputs that can be inter-modulated

3 x 1 mhz to 300 mhz generators one with dual outputs that can be inter-modulated

And some CW capable class A RF power amps

2 x 200mhz to 500mhz 50 watts

3 x 10mhz to 200mhz 300 watts

Hate to be a pedant, but shouldn't the mhz be MHz?

It just had me going for a split second, but knowing some of the exotic and esoteric stuff Kevin (note the capital?) plays with, it seemed plausible that generators with such a slow frequency response would be used.

Upon delving further into this post, I realised my mistake.

Consider the Agilent 33250A:

Sine 1 μHz to 80 MHz

Square 1 μHz to 80 MHz

Pulse 500 μHz to 50 MHz

Arb 1 μHz to 25 MHz

Ramp 1 μHz to 1 MHz

White noise 50 MHz bandwidth

Resolution 1 μHz;

except pulse, 5 digits

Accuracy (1 year) 2 ppm, 18°C to 28°C

I know capitals can be a pain, but it sure helps comprehension sometimes.........

[grawk]

fuck off

[mypasswordis]

if you were a real pedant, you would say mhz isn't a unit of measure. if you had any sort of common sense, you wouldn't have posted.

[Fitz]

Hate to be a pedant, but does anybody really give a fuck?

We all knew what he meant, you knew what he meant, so what's it matter? Somehow I don't think it really necessitates acting like a smartass about it.

[Craig Sawyers]

We all knew what he meant, you knew what he meant, so what's it matter? Somehow I don't think it really necessitates acting like a smartass about it.

Yup - as Richard Feynman once said when a student knit-picked during a lecture "Don't listen to what I said - listen to what I meant"

[wink]

mypasswordis posted:-

"if you were a real pedant, you would say mhz isn't a unit of measure. if you had any sort of common sense, you wouldn't have posted."

You are right, and I apologise unreservedly.

Upon reflection, I realise that my post was out of line.

Thank you for the correction.

[Tyll Hertsens]

OOooooo! Nice shovel-duck.

And whats with all this "pendant" talk?

Edited January 31, 2011 by Tyll Hertsens