Thread: DIY Db8
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Old 19-May-2015, 1:16 PM   #38
rabbit73
Retired A/V Tech
 
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,516
Quote:
Originally Posted by kojo View Post
I have a db8 from Antennas Direct.it can yesterday in the mail. I haven't done much with it. But I guess it's different then yours and it will only get UHF signal and not vhf. I might have to start from scratch and build one like yours.
The new bowtie antennas don't pick up VHF as well as the older bowtie antennas because the baluns (4:1 matching transformers) now being used by the manufacturers are printed circuit board baluns. The older bowtie antennas used ferrite core baluns that were good for UHF and VHF signals.

Quote:
DB4e and DB8e use PCB (Printed Circuit Board) Baluns, which are VERY lossy in Hi-VHF Band
http://www.digitalhome.ca/forum/show...10&postcount=3

Quote:
To use this antenna for VHF, I recommend replacing the feed harness with two baluns and a splitter (in reverse as a combiner).
http://www.hdtvprimer.com/antennas/temporarypage.html
scroll down about 1/3 of the page to just before The 4228HD balun images.

When you use two baluns, one for each 4-bay, you must reverse the wire leads on one of the baluns as a test, to see which way is better. This is so that the two 4-bays are fed in phase so that the signals from each are added together.
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Last edited by rabbit73; 19-May-2015 at 1:42 PM.
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