We've beaten this subject to death with lots of good info.
Thread now closed in the interest of improving list SNR :-)
73,
Eric
You're intrepid Elecraft list moderator, who is waiting for his flight home at
Heathrow. I hate jet lag..
elecraft.com
---
Sent from my iPhone 5S
One way to quantitatively evaluate power versus probability of
communicating is to use the VOACAP Online tool:
http://www.voacap.com/prediction.html
The tool includes transmitter power at several steps, 1, 5, 10, 50, 100,
etc. Set the transmitter at your location and the receiver about 1300
miles
Vic K2VCO-2 wrote
This argument will never die.
But remember the last time you called CQ and a station came back that you
could hear, but
not copy. (I'm thinking CW, but it also applies to SSB).
You know he is in there, but despite struggling with the narrowest
possible bandwidth and
I was curious to determine what a 3 db increase in power output might
mean in terms of total number of possible contacts. So I set up my K3
to run WSPR on 20 meters for a while today:
At regular intervals over the course of 9 hours the power output was
toggled back and forth between 5 and 10
One BIG problem which I should have mentioned before is that while you
might get away with it on CW, doing this would increase IMD for SSB or
digital modes a great deal.
On 9/28/13 7:19 PM, drewko wrote:
I was curious to determine what a 3 db increase in power output might
mean in terms of
Message-
From: elecraft-boun...@mailman.qth.net
[mailto:elecraft-boun...@mailman.qth.net] On Behalf Of drewko
Sent: Saturday, September 28, 2013 7:19 PM
To: Elecraft@mailman.qth.net
Subject: Re: [Elecraft] mods to K2
I was curious to determine what a 3 db increase in power output might mean
in terms
-Original Message-
From: elecraft-boun...@mailman.qth.net
[mailto:elecraft-boun...@mailman.qth.net] On Behalf Of drewko
Sent: Saturday, September 28, 2013 7:19 PM
To: Elecraft@mailman.qth.net
Subject: Re: [Elecraft] mods to K2
I was curious to determine what a 3 db increase in power output
It seems that a K2 is not the Radio for you and your intended purpose.
73 Milverton.
From: Allan Taylor k7gt...@gmail.com
To: Elecraft elecraft@mailman.qth.net
Sent: Friday, September 27, 2013 8:35 AM
Subject: [Elecraft] mods to K2
I unask the
My first thought on the audio was to get some efficient earbuds. Lightweight
and cheap.
Over on the KX3 list, people like the Chill Pill powered speakers.
I know it is a second box, but the Hardrock 50 amp has been getting good
reviews. You would not need to get it out except in an emergency,
Quite true on HF.
3dB often matters doing weak signal work on 6 meters and up, and sometimes
on 10 meters, but on HF there are too many other variables, QSB, etc.
Back in the 30's and 40's the Radio Engineering texts used to list 6 dB as
the minimum change one might expect to detect by ear on
I think there is a lot of evidence that 3dB does not matter. 10dB
matters. 6dB might matter.
My thoughts on this are that if 3 dB mattered much, then QRP, down 13
dB from 100w and 23 dB from a KW, would not work at all, or at least
not often. But we all know that QRP does work.
Now . . .
This argument will never die.
But remember the last time you called CQ and a station came back that you could hear, but
not copy. (I'm thinking CW, but it also applies to SSB).
You know he is in there, but despite struggling with the narrowest possible bandwidth and
every trick your receiver
On 9/27/2013 12:37 PM, Vic K2VCO wrote:
This argument will never die.
As long as some of those doing the talking are ignorant of the facts,
yes. :)
I maintain that even ONE dB matters in this situation.
And you are correct. Here are the FACTS. The 6dB and 10 dB rules of
thumb are based
The original question was increasing power from 10W to 20W on a K2 used as an
emergency communication source for serious backcountry trips (multi-day
wilderness whitewater rafting, etc.) That is not very similar to DXing or
contesting. In that situation, you get a few dB by throwing your wire
You are right Vic - it's an old discussion. I was only quoting what the
engineers of ancient times thought was correct.
For myself, I have done tests adding QRN (white noise) to a weak signal
using a noise generator and calibrated attenuator. Bring it up to where I
can almost but not quite copy,
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