Low Frequency Radio Transmission for long distance.

Your intelligence would be represented by negative infinity. Alwayswrong is once again wrong.

[I'm having a bad day. About 2 weeks ago, I had 2 stents installed. I'm not doing as well I might expect, especially dealing with the side effects of assorted expensive drugs. As part of my therapy and recovery plan, I need someone upon which I can unload my frustrations. You'll suffice. I hope you don't mind.]

Speak for yourself. Literally every one of your mini-rants start and end with an insult. No only are you pathologically incapable of delivering compliments, praise, thanks, recognition, or a sane technical answer, but you also can't seem to write anything without insulting someone in the process. The only problem for me is that finding fault in your comments is far too easy and lacks much in the way of a challenge. I'm here to learn. In trade, I offer my time, experience, analysis, advice, and guesswork in areas where I have some knowledge. All you seem to be able to deliver are insults.

Incidentally, I've noticed that many of your recent posts include numerous comparisons with Donald Trump. What I find interesting is the manner in which Trump treated his prospective understudies in the TV show "The Apprentice" closely resembles the way you treat people in this group whom you find offensive or disagreeable. All that's missing is Trump's tag line "You're fired" and his excellent speech writers. Are you perhaps trying to emulate your hero?

--
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 didn't read my previous comments very well. 0 dBm is 1 milliwatt into 50 ohms. Other impedances are possible, such as 75 ohms for CATV: I'm not sure why you dragged BlueGoof into a discussion on GPS noise margin, except possibly to distract the reader from your previous error(s).

Incidentally, BlueGoof Class 3 1mW radios are intended to operate at up to 10 meter range but rarely do so because of the lack of decent antennas. Most cell phones and associated headsets are Class 2 at 2.5 mW and 10 meter target range. Like Class 3, they usually don't work that far. If you Google for the various BlueGoof classes and associated ranges, you'll see a wide variety of science fiction and "typical" ranges for each class.

--
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

On Mon, 02 May 2016 20:20:44 -0700, Jeff Liebermann Gave us:

It is not an error, idiot. It is an example of one product that operates at the specified level.

You need common sense training, twerp.

Nobody dragged anything anywhere except you dragging your pathetic attitude into the thread.

I will correct one thing. When you are measuring watts, it does not matter what the impedance is. 1 mW into 50 ohms is 0 dBm and the same as 1 mW into 75 ohms which is also 0 dBm. It is only when you are measuring voltage and expressing it as dBm that the impedance matters, P=V^2/R. dB is *always* a power ratio. So if you measure something other than power you have to convert to power to use dB. That is when impedance matters.

--

Rick C

In another group, we had some goof from the cable TV world who believed that dBm means "dB over 1 millivolt"...

While I have seen the unit dB?V used to express dB over 1 microvolt (in some specified impedance), and I could understand the usage of dBmV for a similar dB over 1 millivolt, I have never seen "dBmV" shortened to "dBm", as he was claiming he was using all day as a cable man, and was supposed to be "dB over 1 millivolt".

(his discussion style was similar to mr AlwaysWrong)

But then, those are not scientists, they are field engineers with a box that shows some number and it does not really matter what it means as long as they know the limits it should be in.

0 dBm refers to signal levels compared to 1 mW.

To achieve this, RF people needs about 0.22 V into 50 ohms, while telephone people need about 0.77 V into 600 ohms.

(cable)TV people use 0 dBu as a _voltage_ standard into 75 ohms based

I see I mistyped at one point. I said, "It is only when you are measuring voltage and expressing it as dBm that the impedance matters", I should have said, "It is only when you are measuring voltage and expressing it as dB that the impedance matters". As you say, dBm is

*always* relative to 1 mW and impedance is not an issue. Using a voltage level as the reference would be expressed at dBV or some other similar form to show the reference is a particular voltage level and the impedance has to be specified or assumed by convention.

I literally was out sick the day dB was discussed in college and so did not properly understand the use of dB then. I took me some time to understand what the heck was going on with all the different dB usages (some labeled properly as dBm or whatever and many just using dB with the reference assumed by convention). Then one day the light bulb came on and I got it. lol

--

Rick C

On Tue, 3 May 2016 07:23:14 -0700 (PDT), snipped-for-privacy@ieee.org Gave us:

Funny, since there is no such animal. The terms "Trump supporter" and "advanced" are mutually exclusive. :-)

On Tue, 3 May 2016 01:12:17 -0400, rickman Gave us:

True. When I measure RF power with most (not all) of the wattmeters that I have at my disposal, the instrument is actually measuring voltage, which requires that the impedance is known in order to indicate watts. Those that measure temperature rise from a termination (bolometer or calorimeter) also require that the impedance of the termination be known. Since I live in both the 50 and 75 ohm worlds, specifying the characteristic impedance of the system for power measurements has become a habit so that I know which instrument to use, which cables to use, and if a 50/75 ohm minimum loss pad is required[1]. However, for sake of this discussion and global harmony, I stand corrected.

[1]

--
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

On Tue, 3 May 2016 11:38:35 -0400, Phil Hobbs Gave us:

You got that wrong. John Fields has never done any such thing to anyone here, including me.

On Tue, 3 May 2016 11:38:35 -0400, Phil Hobbs Gave us:

Every one had the same base ID and were easily identifiable.

And posts made were about a specific mood, not an attempt at circumnavigating some retard's filtration childishness.

So yore off a bit today.

On Tue, 3 May 2016 11:38:35 -0400, Phil Hobbs Gave us:

The insults were directed at the asswipes who obviously knew what was meant, but still posted their petty little immature jabs. It was, after all SPELLED OUT right there on the same line.

I didn't say he had, although he has. (He usually tries it on JL.) I said he was the target of that sometimes, which he is. (IIRC it's usually a three-cornered let's-you-and-him-fight approach.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

Of course they did--that's one way Mike T kept score. I don't really want to go into it all--that remark was actually a sincere compliment, believe it or not. AFAICT you've dialled it back by about 85% in the last decade or so, which has improved things round here a fair amount.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

Yeah I totally agree, things have almost become civil here on SED. Well done DLUNU, I find your participation here an asset now rather than a distraction... Keep it up, and don't let those others bait you.) (I do kinda miss when Phil A. would cut loose on someone... but only in a morbid way.)

There is this tendency with males, that we have to always be right.

George H.

Honestly, I didn't know what you meant, and still don't.

--

John Larkin         Highland Technology, Inc 
picosecond timing   precision measurement  

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com

snip

One Bel is just an order of magnitude (x10). You can use it with any measure, but the deci-Bel is often more useful. It's often used with power, but it could just as easily be voltage, kilometers or weeks.

Clifford Heath.