The picture below will tell thousands words. The narrower bandwidth is not a problem since the usage at 10m band is intended for CW portion only. This method of feeding will results of an easy-to-construct-and-feed dualband yagi antenna at the expense of narrower bandwidth at the higher band. The idea behind it is simple We construct a 2-elements Yagi antenna for 15m band, then add 10m band 2 elements yagi into it so the driven element for the 10m band is open-sleeve-coupled from the 15m band driven element. Then re-tune the antenna by moving the gamma-match.10/15m Band Portable Yagi Antenna | Portable-Yagi-10-15-2E Portable-Yagi-10-15-2E Dualband portable 2 elements yagi antenna for 15m and 10m CW View on GitHub 10/15m Band Portable Yagi Antennaĭualband portable 2 elements yagi antenna for 10m and 15m CW. If the antenna doesn't work well then you can also try to rescale the spacingīetween elements (using the same formula above) Using a ros-meter (I can't help you now the new position is not prevedible) Possible problems) and verify the correct electrical working.Īfter the rescale you must to tune the antenna moving the gamma-match and Initially, I suggest to not rescale spacing between elements (only for To work at 27.555MHz you must to RESCALE all lengths using this formula:įinal_length = (27.2 / 27.555) x Initial_length = 0.9871 x Initial_length However, if you really want to try to change the work freq. Substitutions and doesn't guarantee the correct working of altered products. SY 27-4 is not a tunable antenna and SIRIO ANTENNE doesn't effect +39-0376-801515 fax Antenne - High Performance Antenna But I would double check my math to be sure that it is correct before you commit to cut or change anything. That is the same info the Mr Mezzadrelli sent me concerning re-tuning the beam for a different freq center. This part is speculation but if you must you might try to contact Sirio and ask for the details. Which I suspect means that some engineers at Sirio used some EZNEC program to make it work on a short boom length. This Sirio beam beam was 'computer optimized'. Having said that, the way to change the beam for 10m is to scale it using the formula above for the element and spacing between the elements. The boom length on the Sirio is about~13 ft long whereas the standard boom is about~16 ft for a 4 element Yagi. The only problem I see with using standard beam dimensions with the Sirio beam, is that the Sirio beam doesn't use a standard length boom.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
January 2023
Categories |