[Elecraft] OT: For New Hams, How to Tell What an Amp Will Do For Your Signal

Sat Mar 23 12:13:36 EDT 2013

I can agree with all of that Ron, and in fact it may surprise many that 
I really enjoy working QRP myself.  I have a K3 and a KW amp but I hang 
on to both my K1 and my old TS-130V for exactly those reasons.

73,
Dave   AB7E

On 3/23/2013 8:27 AM, Ron D'Eau Claire wrote:
> No argument Dave.
>
> You wrote, "If you are competing against other hams, such as calling CQ in a
> contest or calling DX from within a pileup,.."
>
> Of course that's a different situation from listening to a signal on a clear
> frequency.
>
> That's why I don't join pileups calling DX and you'll find me on the WARC
> bands during contests.
>
> And I know a lot of other Hams who operate just as I do, transmitting only
> on clear frequencies. Our sort of operation eliminates the need to have a
> big signal that can be copied through someone else's big signal.
>
> The beacons demonstrate just how little power is necessary to work the world
> on a clear frequency.
>
> 73, Ron AC7AC
>
>   
>
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of David Gilbert
> Sent: Friday, March 22, 2013 11:43 PM
> To: elecraft at mailman.qth.net
> Subject: Re: [Elecraft] OT: For New Hams, How to Tell What an Amp Will Do
> For Your Signal
>
>
> I guess I wasn't particularly clear, or maybe I just didn't say it often
> enough.  If you are competing against other hams, such as calling CQ in a
> contest or calling DX from within a pileup, EVERY db counts no matter how
> good the propagation is.  An amplifier will often win the day for you even
> if you can hear the other guy while he's running QRP.
>
> The same situation exists if it is noisy on the other end of the path, where
> as little as two db will make the difference between clear copy and no copy.
> Check the files on my website if you don't agree.  The problem is ... the
> noise level on the other end may be significantly different than the noise
> level on your end.  Just because you can hear him doesn't mean he can hear
> you.
>
> More importantly, propagation doesn't open up to the same path loss each day
> ... some days 5 watts gets the job done and some days even 1500 won't cut
> it.  And just because you can hear F5XXX running 5 watts doesn't mean that
> you can hear PA3YYY unless he's running 1500 watts.
>
> My point is that EVERYTHING is situational and generalizations don't do
> newcomers many favors.
>
> Dave   AB7E
>
>
>
>
> On 3/22/2013 8:34 PM, Ron D'Eau Claire wrote:
>> Yes. An amp that takes you up 10:1 in power, e.g. 20 watts to 200
>> watts or
>> 100 watts to 1,000 watts, makes a 10 dB difference in signal -- just a
>> bit over one S-unit.
>>
>> I pointed out the beacon resource as a good example of how often that
>> extra power is not needed on H.F., especially for narrow bandwidth modes.
>> Otherwise we would not have QRP enthusiasts using simple verticals
>> with DXCC awards.
>>
>> I liked the idea that new Hams can listen to the beacons themselves
>> and decide whether the power difference is all that important.
>>
>> 73, Ron AC7AC
>>
>>
>> -----Original Message-----
>> That's a good resource but it doesn't tell the whole story.  An
>> amplifier will give you around 10 db improvement in signal on the
>> other end.  That's more than the difference between a dipole and a
>> five element monobander.  As little as 3 or 4 db will make a
>> significant difference when competing against others in a pileup, and
>> of course as little as 2 db can make the difference between no copy
>> and clear copy if your signal is right at the noise level.
>>
>> http://www.ab7e.com/weak_signal/mdd.html
>>
>> Hams have turned their noses up at amplifiers for decades, but the
>> reality is that an amplifier and a decent vertical is often a more
>> cost effective way to put out a good signal than is low power to a
>> tower and big antenna ... especially if you live in a low noise area
>> where you don't need lots of discrimination to hear DX (and even then
>> there are compact receive loops that make possible alternatives).
>>
>> Dave   AB7En 3/22/2013 12:49 PM, Ron D'Eau Claire wrote:
>>> For the newer hams, here's an interesting resource that will
>>> demonstrate to you what a DX signal sounds like at 100 watts, 10
>>> watts, 1 watt and 0.1 watt. All you have to do it tune into the
>>> beacon frequency of 14.100, 18.110, 21.150, 24.930, 28.200 using CW
>>> mode and listen. The beacon stations in 18 countries take turns
>>> sending call signs and 4 dashes, each dash in descending power level.
>>> You might be amazed at how often you can hear 10 watts or less
>>> clearly from half way
>> around the world when the band is open.
>>> When the band is not open, a kilowatt doesn't get through.
>>>
>>> A complete list of the stations, locations and the transmission
>>> sequence is
>>> at:
>>>
>>> http://www.ncdxf.org/beacon/beaconSchedule.html
>>>
>>> IIRC, all of the stations use a simple 1/4 wave vertical antenna.
>>>
>>> I'm not saying that an amplifier isn't useful, but this helps put the
>>> advantage of having one in perspective.
>>>
>>> 73, Ron AC7AC
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