Needing design informantion of the SB-II

I have been wanting to buy a SB-II but they are no longer in production. So I was wondering that if someone that may have one down or in the attic would post the size and spacing of the elements and boom length along with pictures. I will be greatly appreciative and I am sure others will be as well.

What is an SB-II? Did you mean an AntennaCraft ST-2?

popnokick said:

What is an SB-II?

Click to expand...

https://www.scannermaster.com/SB_2_Scanner_Beam_II_Antenna_p/34-541847.htm

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the boom length is listed in the link, looking at the picture in the instruction pdf on the link, you can see 4 distinct band lengths of the elements, the short ones look like 2m, that should be easy to get off the multitude of diy plans out there, along with the other bands if you look up plans. I bet you have enough info to extrapolate a copy if no one responds with actuals...if you do, please post for the rest of us!

Main boom 4' 10" Longest element 8’ 4” Number of elements: 14
GAIN:
30-50 MHz, 0 dBd (unity);

100-200 MHz, 4-6 dBd;

400-500 MHz, 6-8 dBd;

800- 1100 MHz+, 10-12 dBd.

Here are a couple resources that may help you in your project:

Log‑PeriodicÂ*DipoleÂ*Array Calculator

Designing Log Periodic Antennas: i1wqrlinkradio.com

No more than an old time VHF-UHF TV antenna mounted to provide vertical polarization.

The SB-II Scanner Beam II Antenna is VHF/UHF 30-1000 MHz

Thanks

It's a log-periodic antenna optimized for three bands. Do a google search on log-periodic antennas, and you'll probably find detailed construction plans for something that would work for you.

I beleive Jacob wanted some anwers to a couple of questions when he saw the picture.

1. Are there a critical distance between the sections of the different bands?
2. There seem to be some sort of parallell elements arrangement for the two lowest bands?
3. The coax seems to go twisted around the boom to indicate some sort of phase adaption?
4. Logperiodic antennas are coax feed from the front but this ones seems to be at the middle or from the back?
5. How to mount the boom without disturbing the antenna characteristics or shortciruit it?

I use logperiodic TV antennas that are dualband with two sections of elements, 175MHz-250MHz and 470MHz-700MHz.
I was thinking about doing it more scanner dedicated by drilling new holes and only design it for 120MHz-175MHz and 400MHz-470MHz
so I am interested in any comments to the questions.

/Ubbe

I have a ham friend that has one of these antennas,he say they work very well.....