Originally Posted by uhfyagi
hey chuck you said that you make your own balun for 91xg, is it optimize only for UHF, unlike the 91xg balun that is wideband. i took off balun on 91xg and looks like it needs to be soldered on? Can you explain what you did dude, txs. hope your at sfgiants parade 😂
Originally Posted by ADTech
He made a coax balun which is inherently a narrow band balun, just like the standard UHF PCB balun that has been in use for a while. However, he could tune it for a specific frequency if he chose to do so.
If you want a wideband balun, just remove the PCB and install a standard wire-wound balun. That's what was standard on the driven element for our Yagi series up until 3 or 4 or 5 years ago.
First I need to define what I think is narrowband and broadband because I found different people have different ideas about this. To me narrowband is one or two channels wide and wideband would be the the entire UHF or high VHF TV band.
I replaced the 91XG baluns with wideband coaxial baluns.
Referring to the attachments:
1) Loss of the original 91XG balun on UHF. Two baluns measured back-to-back. Divide the loss by 2 to get the loss of one balun. Max loss is 1.6 dB. Min loss about 1.1 dB.
2) Loss of the 91XG PWB balun on UHF. Two baluns measured back-to-back. Divide the loss by 2 to get the loss of one balun. Max loss is 1.4 dB. Min loss about 0.5 dB.
3) Loss of the coaxial balun on UHF. Two baluns measured back-to-back. Divide the loss by 2 to get the loss of one balun. Max loss is 0.6 dB. Min loss <0.1 dB.
4) Image of the coaxial balun without ferrite beads over the center coax.
5) A not very good image of the balun installed on a 91XG.
The loss of the coaxial balun includes about 4' of RG-6 where the loss of the other baluns has no RG-6 so the coaxial baluns are actual slightly lower loss.
If someone wants to build one I can provide I can provide P/Ns for the coax used and ferrite beads.