Friday, August 24, 2018

Ham Radio HT 2m Antenna Comparison

AQRP 8KHz to 440MHz Vector Impedance Analyzer kit #25
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An OFC Dipole antenna was recently paid-forward to me.  My Elmer friend let me borrow an antenna analyzer to check it out.  I soon learned that the analyzer was actually put together from a kit.  It is a very nice package with a sturdy case, touch screen interface, and an easy to understand user interface.  Go to this page and see the AQRP 8KHz to 440MHz Vector Impedance Analyzer kit #25 for more details.  It's well documented and a very slick package. 
 
 
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Right away I wanted to play with the analyzer and decided to sweep a few 2m hand held radio antennas as a test (results below). 
It's interesting how much flatter the VSWR curve is with the Nogoya NA-771 VHF/UHF aftermarket duckie.  Also, I never tuned the DIY 2m Tape Measure Yagi but just following the build instructions carefully seemed to yield good results.
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And, just for grins we swept a DIY simple wire dipole that was cut for 20m which is only use for Rx with a SDRPlay RSP1A. Our placement for the dipole is marginal and it works equally marginal on 20m and 40m.   FWIW, here are the results:

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Monday, August 20, 2018

Morse Code Practice Oscillator (eBay Kit)

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When learning Morse code (referred to as CW in ham radio circles) a practice oscillator can be helpful.  It lets you practice your sending without transmitting.  Also, if can be useful if you are wanting to practice sending/receiving CW with another ham through a Skype channel without waiting for propagation conditions.  A voice channel like Skype also allows immediate voice feedback for effective Elmering.
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We shelled out $10US on eBay and a few days later we got the practice oscillator pictured above in kit form from  Electroresales with some good instructions.  After about 30 minutes we had a working (and very loud if you crank the volume) practice oscillator.   We made one small mod by adding a JST connector in parallel to the power barrel jack.  This made it easier (for us anyway) to connect a 9VDC battery without having to find the right size barrel jack connector to supply the power.
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The result:
73!
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