I have a project that will require a single feedline to the top of the antenna structure (175') for a UHF and a 900 repeater system. A second feedline is not an option. There will be two antennas.
I know there's a host of designs, but, I'd like to hear the net.wisdom on the best.
My performance criteria are reliability, performance, cost, size and maintainability in that order.
Rob
NE Massachusetts
UHF/900 Repeater Systems on a Single Feedline
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Re: UHF/900 Repeater Systems on a Single Feedline
I think what your looking for is a cable diplexer as some call it. They use band pass filters to combine the different bands. You will need a unit for both the top and bottom of the feedline. Only problem is I don't know of any company that makes a weatherproof unit.
Several companies make them. It has been a long time since I had to look up this type of unit, so don't remember the company names right now. Maybe someone else on here may have the names. Austin seems to stick in my mind. but would have to check.
Jim
Several companies make them. It has been a long time since I had to look up this type of unit, so don't remember the company names right now. Maybe someone else on here may have the names. Austin seems to stick in my mind. but would have to check.
Jim
rodell wrote:I have a project that will require a single feedline to the top of the antenna structure (175') for a UHF and a 900 repeater system. A second feedline is not an option. There will be two antennas.
I know there's a host of designs, but, I'd like to hear the net.wisdom on the best.
My performance criteria are reliability, performance, cost, size and maintainability in that order.
Rob
NE Massachusetts
The EMR 6051/CKS model is .7 dB loss, with 60 dB of isolation, and lists for $300 without the enclosure. They want another $285 for the waterproof enclosure. Ouch. The 1.4 dB isn't helpful, either.
The Telewave 4680 is .15 dB per pair - much better in the loss department. It is also lists around $300, something over $200 from Tessco. The 4690 is the right one, but, they don't list the loss. Likely it would be better than the EMR. It is a sealed unit.
The ham units are about .3 dB each. with 45 dB isolation. I can't see using them in this application.
I've also considered window filters, which might work on only one end.
Rob
The Telewave 4680 is .15 dB per pair - much better in the loss department. It is also lists around $300, something over $200 from Tessco. The 4690 is the right one, but, they don't list the loss. Likely it would be better than the EMR. It is a sealed unit.
The ham units are about .3 dB each. with 45 dB isolation. I can't see using them in this application.
I've also considered window filters, which might work on only one end.
Rob
Personally, if you have a budget to make this happen, I'd be calling RFSCelwave on Monday. Tell them what you have and what you're trying to do and have them put a quote together on a system for you.
I'd never even *think* of putting anything ham-grade on a real site.
Unfortunately, you may as well figure on 1-2dB of insertion loss... part of the game.
I'd never even *think* of putting anything ham-grade on a real site.
Unfortunately, you may as well figure on 1-2dB of insertion loss... part of the game.