electric fencer

Does this fit?

yes. I've worked with people like that, and it isn't pleasant. They'll give a hundred reasons why something can't be done, then tell you it was 'Dumb luck' when proven wrong. One would spend up to seven hours testing and certifying a single board. He insisted that an improved test fixture that reduced the average time to 17 minutes couldn't possibly be turning out any good boards. He, and several others couldn't be convinced of SRF in resistors and capacitors threw a hissy fit when I designed a broadband DC block to replace the pile of unlabeled junk that was in use. It consisted of a stack of surface mount caps. I use .33 uF. .033 uF .0033 uF 330 pF and 33 pF. It was assembled in a rectangular bras box with BNC connectors on each end, and I sued 1/8" brass tubing that was soldered over the center pins of the BNC connectors, then the caps were soldered to the tubes. They were flat from 100 KHz to 1400 MHz on a network analyzer with under .5 dB insertion loss. He, and others insisted that it couldn't possibly work without a way to switch the individual caps. I even caught one of the engineers off guard with the design. That design was the first test fixture to be assigned a part number at Microdyne, and to have the sketches turned into a detailed CAD drawing and have a B.O.M in the database. :)

Like most I learned capacitors as ideal components. It was an eye-opener to sweep them with a network analyzer and see how much they deviated, especially the high-Q MLC ones at high frequencies. The design rule at Mitre (where DC was defined as below 1 GHz) was to do as you did even with bypass caps, like 0.1uF in parallel with 1000pF, sometimes stacked on the same pads.

As an experiment I attached a .1uF MLC to a capacitance meter and heated it with a hot air gun. The capacitance dropped to ~ 1/10th of its room-temp value. A silver-mica changed almost too little to detect. jsw

Unfortunately, capacitors are the weakest link in most electronics.

Some engineers swear by that idea, and others ridicule them. I worked with very low noise RF gear, and you had to keep all the crap you could out of the power rails. Any noise, in any rail including ground would cause excessive phase noise in the wide band synthesizer. It was band switched with forward biased diodes to reduce the length of the inductor in the VCO. I've had idiots try to tell me that that method doesn't work, or that a fraction of a mA is enough to turn it on. You need enough current to turn it on hard, without damaging the silicon to keep the RF from modulating the current through the diode. I just missed buying one of the modules on Ebay by a few bucks, when my browser crashed 30 seconds before the auction ended.

You should have seen the huge, uncased silver mica caps used in RCA UHF TV transmitters. They were over $600 each, in the '70s. They were in the interstage RF coupling, at 1 KW.

Can you do that heat test with any NPO/COG ceramic caps?

Even with no grass that will happen due to line capacitance or line impedence.

HOT

No, it isn't. And it sounds like most of the Demonrat party fits that description, too.

You got the clap doing that, Mikey.

Kudos, BTW.

Not in my experience but I'll check it in the morning.

The Boonton cap meter I have at home was surplus because it no longer functions well at low capacitance values. I could try but the results wouldn't mean much. jsw

It sure does with 2 miles of fence. Or at least it always did when I was back on the farm. With the Bowman Weed Chopper.

Rats turn on each other when the free food runs out.

Never tell me something is impossible, unless you can prove it. :)

Great!

Hmm ... without checking mine out, I think that it could be possible to set up a stack of cutters on the arbor of a horizontal spindle mill, and make the necessary shape in one pass with long stock. Then you *might* need to flip it over and mill the inside cavities.

I forget whether there is perforated metal in holes through the rails. If so -- a bit more milling after flipping it over, and CNC would be the winner there.

And of course, it could all be done with CNC. But with enough of them to be made I think that a horizontal mill would win hands down, at least for the bottom profile.

Enjoy, DoN.

For only 20 sets, the custom cutter stack for a horizontal mill would probably not be worth the time and the custom grinding..

I used the horizontal mill and an index head to make a replacement gear for use inside a differential vertical plugin. I think that I posted a web page about the project a couple of years ago. :-)

If he is stripping a frame to make each, he probably would need the front and rear panels too. The front is likely an injection molding, but the rear is pretty simple sheet metal work, IIRC.

Well ... the QA stamp could be forged, too. :-)

The empty chassis for the TM-500 plugins would be a nice starting point, except that they are not long enough. (I considered using one (which I have) to make a test extender for the 'scope mainframe, and this is how I know this.

Custom machined parts would offer him a better choice of mounting certain parts -- such as those which need heat-sinking.

Enjoy, DoN.

Page 144 of this manual shows the way they are made. Without one in hand, it's the best reference that I can give you right now.

Are you a member of the Yahoo TekScopes group? Some of the people there were engineers at Tektronix.

Here is a Wiki about tektronix products:

Here is a nice collection of Tektronix manuals.

snipped-for-privacy@snyder.on.ca on Thu, 13 Jun 2013 17:25:37 -0400 typed in rec.crafts.metalworking the following:

A hot hat? Must have been a fireman's hat. B-)

-- pyotr filipivich "With Age comes Wisdom. Although more often, Age travels alone."

"Michael A. Terrell" on Thu, 13 Jun 2013

He did say a "good hat" - so a Stetson, maybe?

-- pyotr filipivich "With Age comes Wisdom. Although more often, Age travels alone."

"Michael A. Terrell" on Thu, 13 Jun 2013

And after you sued the 1/8" brass tubing, too.

-- pyotr filipivich "With Age comes Wisdom. Although more often, Age travels alone."

Techs do what engineers can only dream of.