Friday, October 29, 2010

Dual-band "fan dipole" for 40 and 30m

I've been having great success with 40m WSPR with my 1W going right around the world (at certain times of the day) but much of the WSPR activity is on 30m.

Today I ran a second wire dipole cut for 30m below the main dipole suspended with strings cut for 30m and connected to the same coax.

VNA_101030_103640.jpg

It worked out pretty well and I'm keen to see how it goes over night. That plot is from a MiniVNA which makes it very easy to get everything adjusted.

There's a half G5RV on it's way and I'm looking forward to getting more bands but it's unlikely that I'll see the exceptionally low SWR I get with my simple wire dipoles.

Looks like it's working nicely:

Screen shot 2010-10-30 at 5.37.36 PM.png

As the "grey zone" approaches it gets better:

Screen shot 2010-10-30 at 6.59.06 PM.png

A nice balance of hearing and being heard. I'm running 1W here and have just been spotted by W1BW 16,209Km away. (The earth's circumference is 40,000Km, so I'm on the way to the other side).

Screen shot 2010-10-31 at 6.19.07 PM.png

I'm using a new centre connection with screws so I can switch wires more easily.

centre.png

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