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Author Topic: How much power do you need?  (Read 3090 times)

cockpitbob

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Re: How much power do you need?
« Reply #15 on: August 27, 2017, 10:47:09 AM »
swxx, since he heard you, and I'm assuming you were 100W or less, that tells me his 10kW was unnecessary and all he was doing with the extra 9.9KW was QRMing everything out to the Van Allen belt.
Big antennas (and their towers) are much more expensive than amplifiers, but amplifiers don't help you hear the other guy.  I suppose if you are trying to QSO with someone who's QTH as S9 background noise more power will help, but aside from that, more antenna is where it's at.

swxx

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Re: How much power do you need?
« Reply #16 on: August 27, 2017, 11:01:46 AM »
Well I agree of course! Yes the 7ele Yagi was doing the heavy lifting to hear my 100 Mega Micro Watts :-) but believe me if you live out in a remote part of the world on the other side to Europe where you don't often hear strong CW signals, hearing 599 from Europe on a quiet band was NICE :-) and I'm not the type of person who needs nor chases 599 signals, I enjoy picking CW from -13dB SNR! The fact he was 599 with 10kW, means with 100W he would have been 569 to 579 with that 7-ele Yagi, and that's likely how strong I was over there. I got "5NN" but don't believe that, this was a contest stations, most contesters know only 5NN and can't send anything else. Of course the 10kW would be illegal, he was honest enough to give an honest answer, and we all know most amateur radio contests these days are all about cheating.

It is of course the fact that the antenna is the first thing you need to optimise, and while power is another way, rather inefficient as you get higher and higher as each time doubling your power gives only 3dB gain (or half an S meter point in theory, though manufacturers cheat by making it 3 or 4 dB sometimes so that signals look stronger on their radios -- everything now is about cheating). But we are about making batteries or alternative power sources last longer, and about getting away with as little power and consumption as we can. I DO get that. I was just saying, I liked hearing a real 599 from the other side of the world, it reminded me of the days of the powerful coastal stations.

cockpitbob

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Re: How much power do you need?
« Reply #17 on: August 27, 2017, 12:10:59 PM »
swxx, several times you've mentioned knowing the SNR of the signal.  It's cool you know that.  What do you have that tells you the SNR? 

swxx

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Re: How much power do you need?
« Reply #18 on: August 27, 2017, 12:41:55 PM »
What i mean by that is CW can be copied by most at 10dB below noise, and some of us can copy at 13dB below noise after many years of training,