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Author Topic: Why Orange Drops?  (Read 50033 times)
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W2WDX
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« Reply #50 on: January 03, 2012, 03:45:09 PM »


For your viewing pleasure in case you don't have these committed to memory, the codes for ceramic capacitor temperature characteristics.

I don't know what this has to do with orange drops.  You study this stuff when selecting caps for loading in an output pi network, DC blocking on PA anodes and h.v. choke bypass.   It matters when the cap has to handle a lot of current on a low frequency like 1800 kc and you don't want a value drift but you don't want to use a big tx mica.  so you have the temp codes for the dielectric; the other factor though is the environmental heating which is of concern if the caps are near the tubes (DC blocking caps).   you have two classes, class I and Class II dielectric and IIRC, Class II is what you want for RF ceramic caps.   

What page are you on? We are not talking about high voltage, DC blocking applications or anything like that. The thread is about ... oh well.
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K6JEK
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« Reply #51 on: January 03, 2012, 03:54:58 PM »

Maybe Im a bit denser than usual today but Ive no idea what those charts mean Shocked

Its no wonder TC is such a black art
Carl

Sorry about that.  An explanation is in order.  Here's a longer quote from the article  ( http://en.wikipedia.org/wiki/Ceramic_capacitor )


* CapTempCodes.png (175.58 KB, 1121x1044 - viewed 605 times.)
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K5UJ
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« Reply #52 on: January 03, 2012, 09:57:37 PM »


What page are you on? We are not talking about high voltage, DC blocking applications or anything like that. The thread is about ... oh well.

"Oh well" is right.  Go back and do some more reading.  Read closely.
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k6jca
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« Reply #53 on: January 04, 2012, 10:44:58 AM »

Just some random notes echoing what others have said...

1.  In the SP-600 Hammarlund seemed to have moved from Black Beauties to ceramic disks.  A friend has an SP-600 that (he claims) was capped at the factory with ceramic disks in place of all of the Black Beauties used in earlier builds.

2.  I don't know about ceramic disks, but surface-mount ceramic caps are certainly microphonic (i.e. piezoelectric effect).  However, in my experience with SMT caps the amount of energy generated via mechanical coupling has been negligable with respect to overall signal levels.  If you're worried about a cap's possible piezoelectric effects in a receiver, just tap the cap-in-question with a pencil (or something non-conductive).  Tap around it, too, in case the piezoelectric effect is due to something else.  But I'd think that mechanical coupling to a leaded cap (rather than an SMT cap) would be minimal, as the leads themselves ought to attenuate the mechanical energy.

3.  In the SMT world, I never use Z5U caps -- the dielectric layer is very thin, and they can more easily develop resistive leakage via micro-cracks.  Been there, bit by that.

4.  The Director of Operations at one of the companies I worked at insisted that we use electrolytics rated to 100 degrees C in lieu of the cheaper 85 degree C equivalent parts, because, he claimed they're more reliable.  Don't know if this is true, or not, but to this day I prefer to use the higher-temp-rated parts when I can get them, and it certainly isn't a bad idea in tube gear, where the temperatures can be higher than temps in solid-state equipment.

5.  For replacing RF bypass caps in a tube receiver I'd naturally opt for ceramic disks in lieu of larger "rolled" caps (with their larger inductance and larger surface area (i.e. stray capacitive coupling)).  In audio applications...depends on what capacitance is needed, and at what voltage (and what is in the junkbox).  Also, when bypassing, a larger capacitance value will almost always work just as well (and perhaps better) than the original value (so I use whatever is in my junkbox that's close).  But pay attention to the cap's purpose in the circuit, as sometimes you don't want to change the capacitance value.

6.  Silver-Mica caps can develop resistive leakage -- this seems to be a problem in the CE-100V phase network, where certain mica caps in the circuit can start to leak and throw off the phase-shift properties of the network (it was a problem in mine, and if I recall correctly others have experienced it, too).  Probably due to the high-voltage across the caps-in-question intensifying silver migration, so I'd recommend caution when using micas in applications with large DC voltages across them.

7.  I have no problem replacing drifting carbon comp resistors with more modern film resistors.  But pay attention to package power and voltage ratings versus application power and voltage.  If voltage rating is marginal, use two (or more) resistors of the same value in series.

(Jon -- if you're ever curious about a cap's ESR, resonant frequency, or other parasitic effects, bring it by the house sometime and we'll put it on the network analyzer.)

- Jeff, k6jca

www.k6jca.blogspot.com
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KM1H
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« Reply #54 on: January 04, 2012, 10:52:37 AM »

Quote
2.  I don't know about ceramic disks, but surface-mount ceramic caps are certainly microphonic (i.e. piezoelectric effect).  However, in my experience with SMT caps the amount of energy generated via mechanical coupling has been negligable with respect to overall signal levels.  If you're worried about a cap's possible piezoelectric effects in a receiver, just tap the cap-in-question with a pencil (or something non-conductive).  Tap around it, too, in case the piezoelectric effect is due to something else.  But I'd think that mechanical coupling to a leaded cap (rather than an SMT cap) would be minimal, as the leads themselves ought to attenuate the mechanical energy.


Early 50's high value discs were microphonic at times but also had leakage. The only pencil tapping effect I can think of in over 50 years of repairing radios is those damn Centralab and other brand "Couplates" and they are automatically replaced these days.

Carl
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WA1GFZ
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« Reply #55 on: January 04, 2012, 11:55:55 AM »

Jeff, We have had a lot of issues with SM electrolytics so going to a higher rating is a good idea. We derated the voltage rating.
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W4AMV
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« Reply #56 on: January 04, 2012, 12:35:19 PM »




(Jon -- if you're ever curious about a cap's ESR, resonant frequency, or other parasitic effects, bring it by the house sometime and we'll put it on the network analyzer.)

- Jeff, k6jca

www.k6jca.blogspot.com


This post is way out of line from the original thread, but what the heck. One note of caution... Although the VNA is great for measurements of most run of the mill caps, its not an easy or accurate measurement if you want to measure a really GOOD cap. Incidently, I returned to the original 100 WV Sprague OD that I posted at reply #2 and remeaured it on an LCR Bridge. The measurement was at 120 Hz and 1 kHz. The DF gave a reading of .003 at 1 kHz implying a Q for the cap of 330 and therefore an Rs of 10 ohms. Not to shabby and in the ball park of my original post. I agree on RF bypassing. I think I would rather use a CD or some other form of suitably HV cap whose self resonant frequency is as high as possible and with as high a Q as possible in the RF deck of any tube radio.
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k6jca
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« Reply #57 on: January 04, 2012, 01:09:29 PM »

Since the topic of Q has been mentioned, let me digress even further from the original topic and mention that Dick, W1QG, has an interesting method of measuring Q using a VNA, which you can find described on his website: http://home.comcast.net/~w1qg/

- Jeff, k6jca

www.k6jca.blogspot.com
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« Reply #58 on: January 04, 2012, 03:48:00 PM »

Good read and thanks Jeff!

Alan
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« Reply #59 on: January 04, 2012, 04:27:08 PM »

Because they look so good in point to point work! All this talk about induction and impedance but the real key to Orange Drops is there appearance. Maybe if you're doing strip line or microwave but on my 160 meter AM transmitter they rule.
RF


* rcamoddrv.JPG (115.7 KB, 909x682 - viewed 624 times.)
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AF9J
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« Reply #60 on: January 04, 2012, 04:46:41 PM »

Well there are always silk capacitors with oxygen free copper leads you could use to

"relieve the music's vibration energy"
and to "decrease the peak feeling sound at high compass and rough quality sound at middle compass"

http://www.thlaudio.com/elnaitme.htm

 Smiley  Huh  Roll Eyes  Grin
Or I could buy Black Beauties prized by guitar amp builders.

Actually it's the orange drops, and waxed paper capacitors they prefer.  If I had a dime for every audiophool musician and "boutique" amp builder, I've gotten in a discussion/argument about how orange drops, and waxed paper capacitors make your amps, and your guitars "sound better", I'd be a millionare!  You know what's the worst?, when you tell them that at audio ferquencies, there really is no difference in their reactance frequency/tone-wise, and they respond to you that "there really is a difference - you just have to have a trained ear to hear it."    Roll Eyes
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K6JEK
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RF in the shack


« Reply #61 on: January 04, 2012, 09:51:04 PM »

Since the topic of Q has been mentioned, let me digress even further from the original topic and mention that Dick, W1QG, has an interesting method of measuring Q using a VNA, which you can find described on his website: http://home.comcast.net/~w1qg/

- Jeff, k6jca

www.k6jca.blogspot.com
Very interesting read from Dick on the VNA technique for measuring Q.
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KM1H
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« Reply #62 on: January 05, 2012, 02:42:39 PM »

What I miss most about retiring was access to MATLAB and Microwave Office plus several other specialized engineering programs not available to mere mortals at any price.
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k6jca
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« Reply #63 on: January 05, 2012, 03:40:25 PM »

What I miss most about retiring was access to MATLAB and Microwave Office plus several other specialized engineering programs not available to mere mortals at any price.


Or even just an affordable version of Orcad!
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KM1H
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« Reply #64 on: January 05, 2012, 06:29:32 PM »

I had a copy of Orcad until that PC blew up and I still dont understand why the backup copy on another PC in the home network wouldnt work.
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k6jca
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« Reply #65 on: January 05, 2012, 06:47:32 PM »

I had a copy of Orcad until that PC blew up and I still dont understand why the backup copy on another PC in the home network wouldnt work.

The exact same thing happened to me about two months ago!  My PC with Orcad died a sudden death, and I didn't have a backup copy.  I've since downloaded their free copy, but it is a pitiful replacement, allowing only a small number of components and nets to a design.

Looks like I'll be parsing out new designs onto A-size sheets for the foreseeable future!

- Jeff
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« Reply #66 on: January 05, 2012, 08:46:12 PM »

I managed to grab a light table that was no longer needed at a past employer. It still comes in handy but the only place I can fit it now is in an unheated attic.
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WA1GFZ
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« Reply #67 on: January 06, 2012, 08:35:00 AM »

Jeff, Go to LTC and download LT SpiceIV. It is great for simulations and drawing schematics. Similar to orcad.
I can't help you with matlab.
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« Reply #68 on: January 06, 2012, 09:13:55 AM »

Frank,

    Would you consider chip caps suitable for screen R.F. bypass service? Should they be de-rated?

TIA.
Dave.
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« Reply #69 on: January 06, 2012, 02:25:52 PM »

Hope for American made caps fades. 

ASC caps apparently are made in the US but are very pricey at least at Allied.  For example, a .01 400V polypropylene costs $3.01.  How many do you want to buy at three bucks a pop?

And I received this response from EFC/Wesco

Hi Jon,
 
Thank you for the inquiry.  I don’t believe any of our distributors do internet retail business.  Are business focus is OEM and we do not typically sell retail to individuals.  Our distributors do not stock our product as it is all made to order.
 
Regards,
Bob
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N7CTF
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« Reply #70 on: January 11, 2012, 01:15:52 PM »

 Wink

Hi Folks,

So here's me.. I've referbed a few radios, a ZTO being the last.  I used the yellow metalized Poly caps.

In looking at the comparisons from one of the suppliers I don't see a whole lot of diff between the yellow and the orange.

Yellow come in:
Metalized Polypropylene Film and Metalized Polyester Film.
The later have self healing properties.

The Yellow polyprop:
# Rated Voltage 630 Volts & 1000 Volts
# Wrapped & Filled, Tubular. Axial
# Available in "hard to find" tube radio mfd/uF sizes such as 0.0005 mfd, 0.002 mfd, 0.005 mfd, etc.
# Excellent for use in tube radios, amps and hi-fi audio equipment where low dissipation / high insulation resistance and excellent long-term stability are desirable.
# Capacitance tolerance of +/- 10%.
# Superior replacement for paper/wax capacitors in tube electronics.
# Made by ISO 9002 & 9001 certified manufacturer / OEM supplier with major customers: CDE, Sony, National, Canon, APC, LG, LEO, Bosch, B&D, Askey and HP.

The Yellow polyester:
# Rated Voltage 630 Volts & 1000 Volts
# Wrapped and Filled, Tubular Axial
# Self-healing property
# Available in "hard to find" pre WWII sizes such as 0.02 MFD, 0.03 MFD, 0.04 MFD, 0.05 MFD, etc.
# Excellent for use in tube radios, amps, hi-fi, etc, where a premium quality capacitor with high stability and reliability are required. Also ideal for telecommunications, industrial and general electronics equipment.
# Made by ISO 9002 & 9001 certified manufacturer / OEM supplier with major customers: CDE, Sony, National, Canon, APC, LG, LEO, Bosch, B&D, Askey and HP.

And lastly the Orange drops which come in two exciting flavors:
Metal-Foil Polypropylene Film and Metalized Polyester Film.  The later has the "self healing trait too.

The orange polyprop:
# Rated Voltage 630 and 1600 Volts
# Orange epoxy coated for superior heat, solvent and moisture resistance.
# Extra long radial leads for easy under chassis installation.
# Superb replacement for old paper/wax capacitors in tube radios, hi-fi and amplifiers, where high stability and high insulation resistance are desirable.
# Excellent stability for High Current / High Frequency / Temp. Compensation Applications.
# Made by ISO 9002 & 9001 certified manufacturer / OEM supplier with major customers: CDE, Sony, National, Canon, APC, LG, LEO, Bosch, B&D, Askey and HP.

The orange polyester:
# Rated Voltage 630 Volts
# Dipped in Orange epoxy for superior heat, humidity and solvent resistance.
# Highly reliable with "self-healing" performance
# Extra long radial leads for easy under chassis installation.
# Excellent for DC blocking, coupling, filtering and by-pass in tube radios, hi-fi, amps and communications equipment.
# Made by ISO 9002 & 9001 certified manufacturer / OEM supplier with major customers: CDE, Sony, National, Canon, APC, LG, LEO, Bosch, B&D, Askey and HP

This info is from the "JUST Radios" website.  Wink

So I have to decide what to order.  (for my NC-183D)  Not that great of difference in the cash output.  humm... I like the way the Yellows go in..  The leads are Axial.  How long does one last compared to the other?  humm...

Reading this tread.. I lean this way for a bit the flop over to the other side.  I just don't know.
Help me Obewan..  Roll Eyes Me confused... Grin

Tnx, Scotty

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KM1H
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« Reply #71 on: January 12, 2012, 12:41:39 PM »

I have NOS mylar caps from the 60's that are still perfect.

Since the OD's and the no name yellow axials are from China you take your chances and I NEVER buy anything from garage operations. Just Mouser and industrial surplus dealers. I dont want any of my gear crapping out or customer returns just cuz I was too cheap to stick with known quality.

Carl
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The Slab Bacon
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« Reply #72 on: January 12, 2012, 12:51:43 PM »

I have NOS mylar caps from the 60's that are still perfect.

Since the OD's and the no name yellow axials are from China you take your chances and I NEVER buy anything from garage operations. Just Mouser and industrial surplus dealers. I dont want any of my gear crapping out or customer returns just cuz I was too cheap to stick with known quality.

Carl


YOU DA MAN! ! ! ! ! ! ! ! ! ! ! ! !

I feel pretty much the same way!
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N7CTF
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« Reply #73 on: January 12, 2012, 01:32:20 PM »

 Smiley

Good Morning!

Well that would be nice.  But I think many of the manufactures like Cornel Dubilier are a large conglomerate.  Here's an excerpt from there web page.. Don't get me wrong, they have great stuff! 

Quote id from this page:  http://www.cde.com/about/

and I quote  "A global company, Cornell Dubilier has ISO-9001 certified manufacturing and distribution facilities in Liberty, SC; New Bedford, MA; Mexicali, Mexico; and Shenzhen, China to serve customers worldwide. Cornell Dubilier products are recognized by DESC, as well as safety agencies UL and CSA. "  End Quote.

The companies I found on the Mouser web page for Capacitors are :
AVX
Cornel Dubilier
Dielectric Labs
Icoxris
Elpac
Kemet.. this on is an open DNS now??
Maxwel Tech.
Murata
Nichicon
Novacap
NTE
Susumu
TDK
Vishay
Wima
Xicon

Look at any of these manufactures and I think you'll find they had to build out of the States.. Just to do what they do with out breaking Environmental Laws.  They can pollute in China and others.. but not here in the States...(well not too much GRIN) Smiley

So say at Digi Key or Mouser for instance... which brand name do you go for?

I like buying from that little ma and pop site.  They have fresh stock.. and do a great job!  IMO Plus they give you free shrink wrap with every order.  Nice!  Oh. their fast too. I don't work for them by the way.. nor have any interest or ties with them in anyway.  Smiley

I'm making a list of the caps I need.. and checking it twice!  Roll Eyes

Scotty
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KM1H
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« Reply #74 on: January 13, 2012, 12:38:17 PM »

There is a big difference from buying say Nichicon in China and some no name crap with no paper trail.
The major players have their own factories in China with the same standards as the US, Japan, Taiwan, etc.

For HV 'lytics as used in amps I use only CDE 381LX series made in South Carolina, never had a bad one or any reported failures and Ive been using them since they were first stocked at Mouser maybe 25 years ago.

BTW, you left United Chemi-Con off that Mouser list.

Carl
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