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

[Bob K6UJ]

Ron,

I agree 100% Ron.   I am elmering new hams and use the beacons as a 
good tool to explain the difference in signal strength with increase of power
and relation to db's.  Cant think of a better way to demonstrate. 
It gives credence  to our explaining that they need to focus on the antenna
system first, not an amp.  

Bob
K6UJ



On Mar 22, 2013, at 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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