Talk:DBm

message: The very first sentence in the article is misleading by use of the word 'ratio' and I'll change it and see the reaction. Regards,  -- Steve --  (talk) 15:56, 13 November 2020 (UTC)
thread_title:  Opening sentence 

message: There were some edits regarding dBm being a dimensionless or dimensioned quantity. I am going to change the article to state that dBm is a dimensionless quantity for the following reasons
* There are multiple examples of dimensionless physical quantities defined as a ratio between a dimensioned quantity and a constant, dimensioned reference value, e.g.  Relative atomic mass / atomic weight. The mere fact that the reference value is fixed does not render the ratio dimensioned.
* It is only allowed to take the logarithm of a dimensionless quantity. Logarithm of a dimensionless quantity is itself dimensionless.
* If dBm value had a dimension of power then following the rules of Dimensional analysis it should be allowed to mix and match dBm and mW units. As in x = x_0\ \text{mW} + x_1\ \text{dBm} + x_2\ \text{dBm} + \cdots
* I will add references that name dBm as a dimensionless quantity.
mnkp (talk) 00:20, 1 February 2022 (UTC)
thread_title:  dBm as a dimensionless vs. dimensioned quantity 

message: The dBm is still a ratio between two quantities, as are all decibel measurements, this on relative to 1 mW, so shouldn't it also have no units, simular to Sound intensity level? --LeakeyJee 14:57, 31 May 2006 (UTC)
replies: text: I think what he means is that this unit should be dBmW, as it appears like someone just forgot to add the final W. The "dBm" is just a multiplier (an exponent and 1/1000), without actual unit. Technically "dBm" is dimensionless. The missing W is the unit. It appears as if dBm is more like some shorthand for dBmW that have been adopted by the industry and wide public. (Just because EVERYONE is repeating a mistake does not make it right. It's still a mistake.) — Preceding unsigned comment added by 98.128.172.177 (talk) 09:30, 29 October 2020 (UTC)
thread_title:  Untitled 

message: The typical power of an FM broadcast transmitter is given in the article as 100kW.  While this is true for a transmitter with a desired range of 30-40 miles, many local radio stations have an Effective radiated power (ERP) of 1kW or less, since this is enough to cover an area a few miles across.  Also, FM transmitters with mixed polarization may have an ERP higher than this.  The wording has been altered to reflect this. See also . --♦IanMacM♦ (talk to me) 09:30, 11 November 2007 (UTC)
thread_title: "Typical power"

message: The 802.11a power levels (at least) are wrong. According to the standard at http://standards.ieee.org/getieee802/download/802.11a-1999.pdf it is (Maximum output power with up to 6 dBi antenna gain(mW))
5.15–5.25 GHz: 40 (2.5 mW/MHz)
5.25–5.35 GHz: 200 (12.5 mW/MHz)
5.725–5.825 GHz: 800 (50 mW/MHz)
ntg (talk) 09:41, 21 June 2012 (UTC)
thread_title:  Standards 

message: All of this sounds very nice for those who are in the know. But for me, as one of the ignorant masses, it doesn't explain how -50dbm relates to the strength of my Wi-Fi connection. My gratitude goes to anyone who cares to elaborate on a Grade 1-2 level. — Ineuw talk 18:00, 21 May 2017 (UTC)
thread_title:  Explanation is sought 

message: Article states:  "203 dBm | 2.1×10^17 W | Upper estimate for total power output of the Tsar Bomba"
I am removing this row from the table because it makes no physical sense.  
The number 2.1×10^17 W is unsourced, and it does not appear in the text of the wiki article about Tsar Bomba.  
A number of 209-243 Petajoules is mentioned, but that's energy, not power -- 2.1x10^17 joules fits  very nicely into the lower end of that estimate range, but Joules and Watts are not interchangeable.
The total energy output of a bomb is measured in Joules.  "total power output" implies a sustained rate of power transfer which is not consistent with an energy impulse like a detonation.  Power (Watts) is energy over a period of time.  What time period is to be assumed?  One could say that "2.1×10^17 W is the average power output of the bomb if all its energy is assumed to be delivered uniformly over a period of one second after detonation" but that really becomes arbitrary.
Happy to have a discussion and put a revised version back in, but as written I think it misunderstands the relationship of energy and power. Twredfish (talk) 03:36, 14 July 2021 (UTC)
thread_title:  Tsar Bomba comparison