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Robb, since you have received a warning of sorts, why not try setting the beam up with a better bandwidth if possible. I use to run my 4 element Wilson with a bandwidth well over 2.0 mhz <2.0:1 by using a 54" spacing for Dr/D1. It didn't like going much below 26.965, but it worked at 28.000, with about 1.6 SWR or less and centered at the top end of the CB band.

The Sirio 3 element shows 1.8 mhz BW and the 4 element shows .6 mhz. The difference is 48" of spacing between Dr/D1 on the 3 element and the 4 shows about 40" inches. If you can move the driven element back toward the reflector a bit you might see some increase in bandwidth, and if you're lucky you may not need to adjust and tune much. The wider spacing is a bit more forgiving. The narrow spacing they use is primarily used for max gain at the expense of BW and rejection. You may find that a little less here and a little more there will work both frequency ranges best in your case without a noticeable loss. But, if it don't work out, then you can always try to get it perfect on 27.555.

I never found going for max gain to be the best setup. I always settled on a well balanced setup rather than the optimized ideas. In other words, I like the old Moonraker 4 setup...with almost equal spacing across the boom. I saw good gain, with great BW, rejection, and was very directional.

Some of the optimized designs I found to be almost omni-directional when on-the-air.

<blockquote data-quote="Marconi" data-source="post: 256809" data-attributes="member: 903">Robb, since you have received a warning of sorts, why not try setting the beam up with a better bandwidth if possible. I use to run my 4 element Wilson with a bandwidth well over 2.0 mhz &lt;2.0:1 by using a 54&quot; spacing for Dr/D1. It didn&#039;t like going much below 26.965, but it worked at 28.000, with about 1.6 SWR or less and centered at the top end of the CB band.&nbsp;The Sirio 3 element shows 1.8 mhz BW and the 4 element shows .6 mhz. The difference is 48&quot; of spacing between Dr/D1 on the 3 element and the 4 shows about 40&quot; inches. If you can move the driven element back toward the reflector a bit you might see some increase in bandwidth, and if you&#039;re lucky you may not need to adjust and tune much. The wider spacing is a bit more forgiving. The narrow spacing they use is primarily used for max gain at the expense of BW and rejection. You may find that a little less here and a little more there will work both frequency ranges best in your case without a noticeable loss. But, if it don&#039;t work out, then you can always try to get it perfect on 27.555. &nbsp;I never found going for max gain to be the best setup. I always settled on a well balanced setup rather than the optimized ideas. In other words, I like the old Moonraker 4 setup...with almost equal spacing across the boom. I saw good gain, with great BW, rejection, and was very directional. &nbsp;Some of the optimized designs I found to be almost omni-directional when on-the-air.</blockquote>

[QUOTE="Marconi, post: 256809, member: 903"] Robb, since you have received a warning of sorts, why not try setting the beam up with a better bandwidth if possible. I use to run my 4 element Wilson with a bandwidth well over 2.0 mhz <2.0:1 by using a 54" spacing for Dr/D1. It didn't like going much below 26.965, but it worked at 28.000, with about 1.6 SWR or less and centered at the top end of the CB band. The Sirio 3 element shows 1.8 mhz BW and the 4 element shows .6 mhz. The difference is 48" of spacing between Dr/D1 on the 3 element and the 4 shows about 40" inches. If you can move the driven element back toward the reflector a bit you might see some increase in bandwidth, and if you're lucky you may not need to adjust and tune much. The wider spacing is a bit more forgiving. The narrow spacing they use is primarily used for max gain at the expense of BW and rejection. You may find that a little less here and a little more there will work both frequency ranges best in your case without a noticeable loss. But, if it don't work out, then you can always try to get it perfect on 27.555. I never found going for max gain to be the best setup. I always settled on a well balanced setup rather than the optimized ideas. In other words, I like the old Moonraker 4 setup...with almost equal spacing across the boom. I saw good gain, with great BW, rejection, and was very directional. Some of the optimized designs I found to be almost omni-directional when on-the-air. [/QUOTE]

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