Bruce vs. Bobtail

As it turns out, the space I have for a 40M Curtain Array is great for a Bruce Array, but problematic for a Bobtail Curtain

The width of the Bobtail Curtain is 140′, and there are two problems in my back yard:

  1. The feedpoint would be in a really bad location – too close to the house
  2. The farthest element would require that I cut down trees next to my creek

Luckily, A Bruce Array – with 4 elements happens to have the same gain and pattern as the 3 element Bobtail, and is 1/4 wavelength less in width. This means it is 105′ wide, which will fit perfectly in my small and odd shaped property.

The feedpoint (shown as the blue circle) ends up being in the perfect position – it’s where my DX Engineering DV-40P feed and control wires are routed to my 2 element 40M vertical array (today). It also would end up being a perfect place to insert the Collins 180S-1 L tuner at the feedpoint of the array. I would have everything I need – the control wires would control the Stepper motors. In fact, I could even do an A-B test between the DV-40P by leaving that array alone and hanging the Bruce from two trees that would support the 40-ish foot high (elevated Bruce). I could feed it at a 50 ohm point for the comparison test – and that coax would be at 90 degree angle away from the antenna to the remote RatPack antenna switch that I run all antenna coax into – and then just one line into the shack.

I could even feed it using what is my 80M feed and control wires – because the Bruce can be used for 75M local phone nets that I check into – since it would be a perfect NVIS antenna

It turns out that the funny Bruce pattern avoids trees in each “bay” almost perfectly. The third element is closer to the house (and shack) than I would like it, but all of the elements end up in the clear – which is a real feat given all the trees and my creek and my house.

Before I “fell into” the Collins Gold Dust Twins late last year, I had a $50 deposit on a new Yaesu 200 watt rig at DX Engineering – so I just switched that deposit towards 300 feet of their excellent 14 gauge antenna wire (same as Flexweave – which I think is trademarked by Davis).

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