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Radio => Propagation => Topic started by: Quiet1 on December 29, 2013, 09:20:03 AM

Title: Thinking about a QRP go rig?
Post by: Quiet1 on December 29, 2013, 09:20:03 AM
Here's some food for thought.  The question "is a QRP rig enough?" keeps popping up on this and some other forums.  Here are two 'good' scenarios from the "Prop Modeling for Weekly Roundtable" thread (http://www.preparedham.com/forums/propagation/propagation-modeling-for-weekly-roundtable/ (http://www.preparedham.com/forums/propagation/propagation-modeling-for-weekly-roundtable/)) modeled at 100 and 5 watts.  (You can find the online modeling program at http://www.voacap.com/coverage.html (http://www.voacap.com/coverage.html))  Everything's the same except for input power.

Evening propagation on 40 meters at 100 watts:
(http://i1215.photobucket.com/albums/cc502/AlanGeorges/m40-1utc-100w.png) (http://s1215.photobucket.com/user/AlanGeorges/media/m40-1utc-100w.png.html)
and at 5 watts:
(http://i1215.photobucket.com/albums/cc502/AlanGeorges/m40-1utc-5w.png) (http://s1215.photobucket.com/user/AlanGeorges/media/m40-1utc-5w.png.html)


Mid-day propagation on 20 meters at 100 watts:
(http://i1215.photobucket.com/albums/cc502/AlanGeorges/m20-18utc-100w.png) (http://s1215.photobucket.com/user/AlanGeorges/media/m20-18utc-100w.png.html)
and at 5 watts:
(http://i1215.photobucket.com/albums/cc502/AlanGeorges/m20-18utc-5w.png) (http://s1215.photobucket.com/user/AlanGeorges/media/m20-18utc-5w.png.html)


These four plots don't give all the angles on the "is a QRP rig enough?" question, but they do show the main differences in a likely scenario, in a fair apples-to-apples comparison.  Make of it what you will.
Title: Re: Thinking about a QRP go rig?
Post by: DragoSapien on December 29, 2013, 09:36:07 AM
Thanks for this thread. Been wanting to learn more about this.
Title: Re: Thinking about a QRP go rig?
Post by: AD on December 29, 2013, 09:39:44 AM
Good info and shows actual usable data
Title: Re: Thinking about a QRP go rig?
Post by: Tevin on January 08, 2014, 05:35:27 PM
Wow, thanks! That is very insightful.

The takeaway I get is that QRP would be useful for "almost-DX" ranges of, say, a few hundred miles. And that's going to be more than you really need anyway.

I subscribe to the theory that DX is not a "must have" for prepping purposes. When the S hits the F, some dude in the middle of Iowa is not going to care about what some dude in Africa has to say. Yes, I know there are some rare scenarios where DX would be needed...but 99% of necessary prepping comms is within 50 miles, and in many cases not even that far. 

If you can reliably go 20 miles you are waayyy ahead of all the unprepped dingbats out there.
Title: Re: Thinking about a QRP go rig?
Post by: BTPost on January 08, 2014, 05:48:21 PM
Prep'ed Comms come in multiple varieties... Local, Extended Neighborhood, State, Region, National and Worldwide. You start with local and Family, and then build out, as you find Like Minded Folk,s that share not only Prep'ing, but Comms, as well....
Title: Re: Thinking about a QRP go rig?
Post by: spacecase0 on January 08, 2014, 09:03:34 PM
I like the QRP radios and an amplifier if I need it,
it gives me the best efficiency and the ability to make the long contacts if needed.