Caps caps caps...

Sounds to me like Cap' Atrick needs a tester ran on him.

I recall octal-based, plugin electrolytic caps.

--

John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom timing and laser controllers 
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VME  analog, thermocouple, LVDT, synchro, tachometer 
Multichannel arbitrary waveform generators

Jan Panteltje a écrit :

wrote in :

Bollocks...

(roasted bollocks, of course)

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Thanks, 
Fred.

Nope. The problem is that the authors of the various tin foil hat articles fail to recognize the difference between an RF reflector and an RF absorber. A tin foil hat will only reflect RF. With tin foil, the RF is not destroyed and can do damage elsewhere, which the above URL demonstrates. (Presumably rampaging electrons emit RF). What is required is an RF absorbant hat, made from any material that will absorb RF such as a carbon doped foam hat, water bottle, or even a wet towel.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Don't remember those. I do remember octal-base mercury relays that looked like tubes.

They were used in some W.W II military radios.

snipped-for-privacy@yahoo.com a écrit :

Just did the measurement again as I couldn't find it back...

That one:

I misremembered and it was rather one 1uF/16V-X5R-0402 that I measured

Measurements done @10kHz DC bias Value

0V 808nF 2V 705nF 4V 475nF 6V 320nF 8V 230nF 10V 180nF 15V 110nF 20V 80nF

It also show a pretty high dependency on frequency:

Freq @0V DC bias @6V DC bias

10K 803n 310n 20K 765n 295n 40K 735n 284n 100K 700n 275n 200K 680n 270n 400K 670n 268n

I can't measure at the 1kHz specified frequency right now, but IIRC the value was spot on at that frequency...

Also, at 3 to 7ohm depending on conditions, ESR surely is not something to brag about.

I finally resorted to use 470nF caps which behaved better at the wanted working voltage...

Time to order some and see how the 100uF ones behave... Maybe not so bright a solution as it first seemed :-(

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Thanks, 
Fred.

No, I thought it was actually quite funny! Ohhh, a return to the vacuum tube days, wouldn't that be WONDERFUL!!!

Jon

I have some very old tube power amplifiers that have them. Back in the

70's I needed replacements and found an old electronics store that still had some on the shelf. I bought all of them he had. I have not fired up those amps in years, but still got them.

I have fond memories of going to the corner drug store with my dad and testing tubes. I was very young, and dad would ahve them all in a bag, and it was my job to read the numbers to him so he could look them up on the chart. (usually a wheel turned to expose the rolled up list).

That's sort of what got me started in electronics as a hobby and an old tube tester was one of the first instruments I bought. I still have thatr old tester too.

These days that closeness of family doing things together is lost. Everything involves calling in some specialist or dropping the tv off as some place where you never see the repair guy, just a salesman with a repair book and later a bill.

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Those are pretty ugly--looks almost like Z5U.

*That* sounds impossible--ESR should be milliohms. I couldn't find a spec, but the datasheet boasts:

"Owing to their low ESR and excellent frequency characteristics, these products are optimally suited for high frequency and high-density type power supplies."

I measured a range of caps, up to about 10uF. I think the smallest was 0603, best (and biggest) was 0805.

I'm afraid my notes are buried, but the upshot (and mfr's application data) was that high C/volume implies ultra hi-k materials, which are responsible for the high dC/dV coefficient.

--
Cheers, 
James Arthur

There's always sports.

--

John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
http://www.highlandtechnology.com 

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom laser drivers and controllers 
Photonics and fiberoptic TTL data links 
VME thermocouple, LVDT, synchro   acquisition and simulation

24/24,

I wonder if you could make an oscillator using the cap as a sort of negative resistor.

--

John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
http://www.highlandtechnology.com 

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom laser drivers and controllers 
Photonics and fiberoptic TTL data links 
VME thermocouple, LVDT, synchro   acquisition and simulation

ESR is normally specified at 100KHz, which might explain the higher ESR at lower frequencies. Note the frequencies.

This is for a similar (but not identical) TDK X7R ceramic 1uf 16v cap: Looks like 1.5 ohms at 100KHz.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

You want tubes? See a shrink.

Him? He can go buy an enema bag if he "wants tubes".

You? You could sit on a 180 kV X-Ray tube, and the 9 inch by 4 inch diameter tube would disappear up your fat, sloppy ass instantly.

then learn electronics, buy all the test equipment & manuals. Then spend $50,000 to stock some parts to fix a $200 TV without waiting weeks for a mail order parts house to ship you the wrong parts. I, like a few others here did my time in a TV shop in the vacuum tube days. Bad tube sockets & other connectors were the bane of every tech. Equipment trashed by 'clever' DIY types were the worst, because they knew everything and screwed up everything they touched. I saw lots of radios & TVs where 'Mr. Fixed it' had put the tubes in the wrong sockets, and one fool who ripped an electrolytic can capacitor out of a solid state car radio, along with part of the circuit board and insisted it was a vibrator.

If you want family activities play games, do woodworking, or remodel the house by yourselves.

Then you better reform them before you fire up the amps.

Sockets are just another component that can fail, and typically cost more than the components they secure.

RL