Thread: 91 XG Modified
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Old 11-Jun-2020, 10:07 PM   #11
bobsgarage
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Join Date: Mar 2016
Location: Beach Park IL
Posts: 318
Great information, thanks Tripleo

Tripleo, thank you for your detailed information. It's exactly what I need. Again as you see I have an eye for detail and I will report each and every change I make. Not just for my benefit or yours but for anybody who may try this. I know it sounds simple but for me it's like working on a new brand of car with new tools and a new scanner.

For now I plan to just try the two antenna stacking side by side. I want to do two 91XGs with the 300 ohm twin lead separate from two 30 - 2476 VHF antennas with a similar. I mean side by side and using the twin lead.


When I am done and I am satisfied I have made good progress , I hope to join them at a combining preamp. I've got a good friend making a low noise VHF UHF combo amp.

So, to stack each array antennas I believe I have ordered the correct ferrite cores. I have 10 of each number, which are Fair-Rite "Ferrite cable cores 61 Z= 280 ohm at 250 megahertz. I believe those are for UHF.

The other ones are the Fair-Rite "Ferrite cable core 43 round cable cores Z = 280 ohms at 100 megahertz". I think those are for VHF.

The plan was to put four on the RG6 coax of the VHF array and four on the RG6 coax of the UHF array with six leftover of each. I'm 100% sure I should have no problem soldering the twin lead to the coax.

Hey, a question came up should I be using dual Shield or quad Shield RG6?

Another friend Sev, is going to do with the similar or the same. The plan was to twist the cable 1 twist per foot or was it two? I'll check my notes. Then put it inside 1/2 " CPVC tubing to keep the rain off of it.

That's the plan I would like to hear any input that you or anyone else has. This is new to me, and I am just learning how to do this.

Oh, and I like your idea of spreading out the ferrite cores. I don't know what the distance would be when you say 1/4 wave, I don't know the calculations. If it's easy for you, I'd like to hear your input on the lengths I need to work with.

I don't mind learning all these calculations but math isn't my strong point. Sure, I know decimals fractions and multiplication / division. But I don't know formulas math and I parted ways at algebra and trigonometry..

Thanks, hope to hear back from you before the weekend when I plan to do this. We're supposed to have some beautiful cooler weather perfect rooftop weather. I'll start with my scans to make sure the two antennas are equal. Which I'm sure will take me several scans to perform an average.

Last edited by bobsgarage; 11-Jun-2020 at 10:16 PM.
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