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BridgeCom Systems Guide to Repeater Systems, With An Emphasis On Duplexers.

BridgeCom Systems Guide to Repeater Systems, With An Emphasis On Duplexers.

Have you ever wondered what makes a repeater system? Or interested in setting up your own system? This article will explain all the components of a repeater system. With an emphasis on duplexers and why a person would get one.

Parts of a repeater system

A repeater systems contains 5 core parts. They are the power supply, Repeater, duplexer(optional), feed line, and a antenna(s). We will breakdown all of the parts in the next few paragraphs

Power Supply.

Most electronic devices require DC(Direct current) Power. The electricity that comes out of your wall socket is in fact AC (alternating current). Your power supply is responsible for converting the AC into DC. It is also responsible for getting the correct power to the device. Your power supply will regulate the current and prevent surges from destroying your equipment. Duracomm Power supplies work fantastically for any radio application.

You can find them at the bottom of the article.


The purpose of a repeater is to extend the range of other radios. Think of it as a signal amplifier. For example; A handheld or mobile radio in a vehicle will transmit to the the repeater. The repeater will then receive that signal and then immediately transmit it over a much larger area. Repeaters are generally mounted on high altitude locations relative to the surrounding area.


A duplexer is a tunable pass, pass/notch, or notch filter. It separates the transmit and receive signals. A repeater With a duplexer can transmit and receive simultaneously.  Using a duplexer allows you to use only one antenna instead of two. And thus half the feed line. The advantage of using only one antenna saves money but also is quite helpful on congested tower sites. Where it may not be possible to get two antenna locations.

Feed Line

Feed line is simply a specialized wire that transmits signal from the repeater to the antenna and back.


The antenna is where the signals go in and out. If you have a duplexer, only one antenna is required. If not, two are required. One for transmit, and one for recieve.

Why A Duplexer:

Cost Savings - Use only 1 antenna and feed line.

Using a duplexers enables the use of only one antenna and feed line. Eliminating the second antenna and feedline set. This can save hundreds if not thousands of dollars in equipment!

Convenience - Do half the work.

By only having to mount 1 antenna. You are cutting the amount of work in half. This gets the system up faster and leaves more time to talk on the system.

Now you only need one antenna location. If you have a tower you can now use the top instead of having to use the top and a lower location on the tower. Using the top enables maximum coverage.

Accessibility - Only secure one tower spot.

In a lot of areas tower space is in high demand, very limited, and expensive. It can be hard to get a spot to mount 1 antenna, let alone 2. Having a duplexer makes getting a tower slot much easier and a lot cheaper. Leasing a slot for one antenna on a commercial site could cost $5000 a month! Double that or more for 2 antenas. If that isn't enough to convince you I don’t know what will.

Good news. -BridgeCom Systems has everything you need.

BridgeCom Systems Supplies all of those components, and will help find what you need.  Not only is having a duplexer convenient. Getting an all included repeater system package from BridgeCom Systems is even more convenient! Please call us at 816-532-8451, send us an email at or visit our product selection.

Our Repeaters and Duplexers have been tried and tested all over the world.

Check out our testimonials page for proof






Power Supplies


Rack Mount:

Feed line:





If you don’t find what you looking for. Call us at 816-532-8451 or send us an email at

If you have any input on the article, please leave a coment below. 

Previous article Discover the Power of DMR with BridgeCom Systems at Hamvention® 2023


Thomas - February 24, 2020

I have not review any thing yet. I’m due into surgery in few days from now. After surgery I get plenty of time to review every thing.
We thing of repeater for portable usage during emergency operations and Search & Rescue which I was trained in Arizona. I’m trying for same type of operations in Texas. There is 3 of us that is limited duty do to injury we received in military duty.

Brian Corty - July 4, 2019

I ready for the repeater 190foot tower 4 bay at the top with 7/8th In to it

David Tatem - July 3, 2019

This is good basic info! However there is one more thing you need to put with it, well two, grounding and lightning protection.
Grounding the feed line top (antenna end) to bottom on the tower.
Lightning arrester before entering the building on the feed line. And good founding of the repeater components to a good ground as well.
De vp9iv, David

Jason Walker - June 23, 2019

I love to win something

HErmon WInch - June 5, 2019

Here in Newhampshire we have set up a harp net with communication with hospitals around our state with ares networks. Here in Exeter NH we have only local hams to volunteer there time working emergency calls when needed. Another repeater site with more power could help provide more communications to reach others who can’t here calls from farther operators. We do a lot of relay work and it does get the job done. Hope I get drawn and with the club members I think it would fly on setup… thanks. KA1OPS….

Gary Wisner - May 27, 2019

Good quality

Michael Marcier - May 17, 2019

Our Amateur Radio Club, Iroquois County Amateur Radio Club, has a UHF and VHF Repeater (call sign AD9L) covering Iroquois County Illinois and a number of other counties in East Central IL and West Central Indiana we are looking to upgrade these sites but are not able to afford it yet.. Winning this system would help us to do that and even link with other repeaters to the north of us for SKYWARN operations. Please select us for the award.
Mike Marcier – KC9HHT

Gary Edward Brewer - March 20, 2019

H, there is no 220 NHS. Repearter here in Vernon parish so I want so much to put up a 220 repearter but the cost is the mean thing I am only a poor amateur radio operator that wants one here for others to be able to use. De k5geb. Gary Edward brewer

J MCDermott - March 20, 2019

We’re fortunate. We already have space available on the same tower we currently utilize. I spent 18 years installing systems overseas for VHF & UHF and taught personnel how to tune Duplexer systems should the need arise.

Reuel de Egurrola - January 31, 2019

Got it. Bookmarked this. Thank you. 73!

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