Building my own balun, part 2: measuring the 'old' balun / 2018-04-04

Fritzel balun SWR scan 1-60 MHz 20180325

Fritzel balun SWR scan 10 meter band 20180325

Fritzel balun SWR scan 20 meter band 20180325

Since I want to replace a balun that has been up there for ages I want to be able to compare the two. So I used the antenna analyzer to get graphs of the SWR over the whole possible range (1-60 MHz) and on the amateur bands it was built for: the 10 meter band and the 20 meter band.

There was a very interesting difference with the earlier results on the 10 meter band when I first tested the SARK100 antenna analyzer from Linux. The 10 meter band dipole probably moved a bit or something else changed.

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Fritzel balun SWR scan 1-60 MHz 20180404

Fritzel balun SWR scan 10 meter band 20180404

Fritzel balun SWR scan 20 meter band 20180404

So I diverted from my original plan of just documenting the current state and checked and fastened all the wires and screws on the attic dipole. This helped! The difference on the 20 meter band is minimal, the difference on the 10 meter band is serious. So now the correct current state is documented, back to building the new balun.

Other parts:

• Building my own balun, part 1: idea and parts needed
• Building my own balun, part 3: First work on the case
• Building my own balun, part 4: Deciding on where to put dipole ends and finishing it
• Building my own balun, part 5: First tests of the result
• Building my own balun, part 6: Redo and some success: a working antenna again
• Building my own balun, part 7: Better measurements of the result