EMRFD Message Archive 8150

Message Date From Subject
8150 2013-01-22 13:55:56 Stephen Farthing component values in EMRFD schematics?
Hi guys,

Is there a standard for the values of the caps in the schematics in EMRFD?
Over here we suffix cap values with pF, mF, F etc.

73s Steve


[Non-text portions of this message have been removed]
8151 2013-01-22 15:07:24 Steve, G4GXL Re: component values in EMRFD schematics?
Steve

I'm looking at the 1st edition 2003

Chapter 1, section 1.14 describes the capacitor values -

Basically, microfarads if electrolytic or have decimal values less than 1.

If greater than unity (and not electrolytic) then picofarads

There's also a note which days "in some applications we will use C values
in nF"

Hope this helps, sorry about the scrappy note - I'm using my phone

73
Steve, G4GXL
On 22 Jan 2013 21:55, "Stephen Farthing" <squirrox@gmail.com> wrote:

> **
>
>
> Hi guys,
>
> Is there a standard for the values of the caps in the schematics in EMRFD?
> Over here we suffix cap values with pF, mF, F etc.
>
> 73s Steve
>
> [Non-text portions of this message have been removed]
>
>
>


[Non-text portions of this message have been removed]
8152 2013-01-22 21:55:10 Todd F. Carney Re: component values in EMRFD schematics?
Usually: pF, nF (not used much in the States anymore), and uF. The "u" is
used in place of the Greek letter "mu" (for "*m*icro") because it's a
oddball symbol not usually at people's fingertips. It would look like this:
𝜇F.
*
*
73,

Todd
------------------------------------------------------------------------------------
K7TFC / Medford, Oregon, USA / CN82ni / UTC-8
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QRP (CW & SSB) / EmComm / SOTA / Homebrew / Design


8153 2013-01-23 06:14:58 David LeVan Re: component values in EMRFD schematics?
actually electrolytics can come in any value of microfaras, I have seen 2200 microfarads. which is far greater than 1. as far as nano farads, they are quite rare but are becoming more accepted here in the USA. often you will see nano farads represented  as thousands of pico farads. this by no means defines pico farads as only in the thousands.




________________________________
8154 2013-01-23 10:07:57 Andy Re: component values in EMRFD schematics?
> actually electrolytics can come in any value of microfaras,
> I have seen 2200 microfarads. which is far greater than 1.

I think that was Steve's point. In fact I can't recall seeing
electrolytics less than 1 microfarad (though I suppose they might
exist). The point was, if the value of the capacitance shown is >=1
AND it is an electrolytic, then the value is in uF; if not an
electrolytic then the value is in pF.

> as far as nano farads, they are quite rare but are becoming
> more accepted here in the USA.

Actually, I use nanofarads quite often, for decades, probably more
often than uF or pF. As I do a lot of digital circuits, a healthy
sprinkling of capacitors in the whole nanofarads range, and drawn on
the schematic as such (e.g., 10nF), is probably the most common
capacitor range I see and use on schematics. So it is not rare at
all, here in the States. But it depends on your background and the
standards of the schematics you use.

My preference is to always fully specify the values on schematics.
Never leave it up to the reader to guess whether you mean uF or nF or
pF. To me that's just sloppy.

Andy
8155 2013-01-23 14:04:47 Dave Re: component values in EMRFD schematics?
Andy:
In my own schematic drawings, I always indicate uF, nF, or pF.
Electrolytics also have a + for the polarity. I often use 10uF ceramic
caps that are not polarized. Resisters have no units(if under 1K)_, K,
or M. Of course here in the states, 1.5K is 1500 ohms. In Europe that
would be 1,5K.

Dave - WB6DHW
<http://wb6dhw.com>

8156 2013-01-23 14:08:44 Thomas S. Knutsen Re: component values in EMRFD schematics?
To be more corect, over here in most of EU 1.5K would be 1K5...


2013/1/23 Dave <dave@wb6dhw.com>

> **
>
>
> Andy:
> In my own schematic drawings, I always indicate uF, nF, or pF.
> Electrolytics also have a + for the polarity. I often use 10uF ceramic
> caps that are not polarized. Resisters have no units(if under 1K)_, K,
> or M. Of course here in the states, 1.5K is 1500 ohms. In Europe that
> would be 1,5K.
>
> Dave - WB6DHW
> http://wb6dhw.com>
>
>
>
8157 2013-01-23 21:11:26 Leonard Meek Re: component values in EMRFD schematics?
Just to add my $0.02, I have a box full of 10,000uF and larger
electrolytics. Some of the surplus places are selling caps in the FARAD
range. I'm seeing the term, "nano farad" used more frequently for values
between 1 and 0.001uF. The notation, "mmF" has gone out of style but I still
have a lot of NOS micas with markings like "10,000mmF" for example. If you
have a junk box like I do, a cap checker is essential. It's often the only
way to tell if a cap marked "180" is actually 180pF or if it says the value
is "one, eight, and no zeros." And don't even start with the color dot
system.

Leonard


----- Original Message -----
8158 2013-01-23 21:11:33 William Re: component values in EMRFD schematics?
Hello to the Group,

I miss the old days when we called it micromicrofarads. Then we also had megacycles.

Bill
N7EU
8159 2013-01-23 21:23:22 William Carver Re: component values in EMRFD schematics?
And "micky mikes"

On Wed, 2013-01-23 at 22:21 +0000, William wrote:
>
> Hello to the Group,
>
> I miss the old days when we called it micromicrofarads. Then we also
> had megacycles.
>
> Bill
> N7EU
>
>
>
>
>
8160 2013-01-23 22:05:48 Don Hackler Re: component values in EMRFD schematics?
They were called "condensers" back then, too.

8161 2013-01-24 04:34:17 NeilDouglas Re: component values in EMRFD schematics?
The electrical units we use today are all expressed in terms of The
International System of (SI) Units. These are defined in terms of metric
units and the common metric prefixes are:-






Multiplication Factor

Prefix Name

Prefix Symbol


1 000 000 000 000 = 1012

tera

T


1 000 000 000 = 109

giga

G


1 000 000 = 106

mega

M


1 000 = 103

kilo

k


100 = 102

hecto

h


10 = 101

deka

da


0.1 = 10-1

deci

d


0.01 = 10-2

centi

c


0.001 = 10-3

milli

m


0.000 001 = 10-6

micro






0.000 000 001 = 10-9

nano

n


0.000 000 000 001 = 10-12

pico

p





Prefixes produce units that are of an appropriate size for the application,
e.g., millimeter for measurement of the dimensions of small screws, or
kilometer for the measurement of distances on maps. Examples that show
reasonable choices of multiples and submultiples for many practical
applications are given in Section 5. While all combinations are technically
correct, many are not used in practice. The prefixes deci, deka, and hecto
are rarely used; prefixes that are multiples or submultiples of 1000 are
generally preferred. When the unit name is written in full, the prefix is
written in full: megahertz, not Mhertz. When the unit symbol is used, the
prefix symbol is used: MHz, not megaHz. Only one prefix should be used in
forming a multiple of an SI unit, e.g., �V, not mmV. Prefix symbols for
multiples of a million or greater are capitalized, and those for less than a
million are written in lower case.



When describing an electrical component it is now common practice to replace
the . (dot) or , (comma) in the described value with the prefix symbol. This
helps with legibility as a dot or comma character can be lost during the
printing or photocopying process, it is much less likely that all of the
pixels of a larger alphanumeric character would disappear.



Most CAD systems will accept component descriptions of the form 2p2 or 2k2
or 100n. The type of unit is inferred from the graphical character.



When writing them in text then they may be of the form 0.47uF or 2R2, then
the type of component has to be included in the description.





Perhaps we should revert to expressing capacitance in jars (look up Layden)
as used in early spark transmitters, 1 jar is 1n111F or 1.111nF.

My 20m atu capacitor is set to about a quarter of a jar.



NeilD

G4SHJ





















_____

8162 2013-01-24 05:06:57 dx11 Re: component values in EMRFD schematics?
And all units that have their name based on real person (Hertz, Ampere,
Watt, Newton, Farad, Ohm etc.) start with a capital letter, all others are
completely lower case. Anyway that's what I've been told. So: kHz, km, MOhm,
kW, mW and MW.

Cor Beijersbergen
8163 2013-01-24 08:46:50 Alberto I2PHD Re: component values in EMRFD schematics?
8164 2013-01-24 11:41:27 Lasse Moell Re: component values in EMRFD schematics?
I bet most of the times it is MS Word spell checker that "corrects" the
MHz to mHz... :(

/Lasse SM5GLC
On 24 jan 2013 17:46 "Alberto I2PHD" <i2phd@weaksignals.com> wrote:

>
8166 2013-01-26 08:26:30 iam74@rocketmail.... Re: component values in EMRFD schematics?
8167 2013-01-26 13:17:20 John Levreault Re: component values in EMRFD schematics?
8168 2013-01-26 13:30:47 William Carver Re: component values in EMRFD schematics?
I agree with John, "1n" for a 0.1 uF capacitor, "1K5" for a 1.5K
resistor both seem to be reasonable alternatives to the nomenclature we
traditionally use in this country, and less likely to be misread.

I grew up with 47 uuF capacitors and once briefly wondered what "pF
meant when I first saw it 50+ years ago. That's now old hat, and I don't
get flustered when I see just "47p" alongside a capacitor on a schematic
created elsewhere.

Schematics are very close to a universal language.

W7AAZ



On Sat, 2013-01-26 at 16:17 -0500, John Levreault wrote:
>
>
8169 2013-01-26 13:58:34 dx11 Re: component values in EMRFD schematics?
>>>I agree with John, "1n" for a 0.1 uF capacitor<<<

I hope you meant 100n, because that is what 0.1uF is.

Cor Beijersbergen
8170 2013-01-26 14:19:58 William Carver Re: component values in EMRFD schematics?
Heh heh..........right Cor, I meant 100n!
W7AAZ


On Sat, 2013-01-26 at 22:58 +0100, dx11 wrote:
>
>
> >>>I agree with John, "1n" for a 0.1 uF capacitor<<<
>
> I hope you meant 100n, because that is what 0.1uF is.
>
> Cor Beijersbergen
>
>
>
>
>