Thursday, March 17, 2016

BLT+ Tuner portable Test

A shot in the dark

I wanted to test the BLT+ Tuner portable with a ladder line fed Doublet but my time has been limited.  After getting home from work one night I assembled a 40m Doublet fed by 450 Ohm ladder line in my driveway.

I pushed the Doublet up on my Jacktite pole and attached the ladder line to the BLT+ and attached the BLT to the KX3.  I had the KX3 sitting on the deck table running on internal batteries.

BLT+ tuning the balanced line antenna
By the time I began my test it was quite dark except for the moon.  My headlamp was out of batteries and I was operating by a floodlight up on the eve but I was determined to know how the tuner worked with my portable doublet.

Doublet on Push up pole.  Moon in the background.
40m and 30m tuned up 1.0:1 using the high capacitance setting.  Tuning was fast for each band using the SWR indicator LED.  After tuning on 7030 and sending my call then again on 10110, I tried 14060. Although tuning 14m was a bit touchy it tuned using the low capacitance setting to around 1.5:1 SWR.  After tuning I sent my call on 20m.  Immediately I received a call from K7JHM, a QRP station in Utah (about 1700 miles away).  We exchanged signal reports and station information although copy was a bit rough.  I'd neglected to bring my earbuds out and the speaker on the KX3 is pretty poor.

However, the QRP to contact was a success on a portable antenna, tuned with the BLT+ driven by a rig running on internal double A batteries. 

I didn't try higher bands because it was so late in the evening so I packed it all up declaring success.

Balanced line tuner doing it's job

Tuning 20m was a bit touchy because my total length of one leg of the doublet plus the feedline is too near a 1/2 wavelength on 20m.  I need to add about 7 feet of ladderline to keep it from being near odd 1/8 wavelengths of the bands I want to tune. Or I could add 7 feet to each leg of the antenna.  I will need to do that before the next test.

That's all for now

So lower your power and raise your expectations

Rich AA4OO

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