Gamma Electronics’ 2021 Wrap Up

Gamma Electronics Blog

Gamma Electronics’ 2021 Wrap Up

With the holiday season now upon us we wanted to take a moment and wish you the happiest and healthiest of holidays!  As we do every year, we like to take a step back around this time and reflect on the year that we will soon leave behind us.

Without a doubt, 2021 will be remembered as a unique year.  All of us have had to make adjustments in how we work and how we live and I’m sure you’ll agree that we all hope that these adjustments will make us better and healthier going forward.  Here at Gamma Electronics, we are pleased with what we’ve accomplished in 2021 while simultaneously feeling excited and optimistic about 2022, and the future in general.

Below we have highlighted some of the news from 2021 as well as some things we are looking forward to in the future.

Highlights from 2021

New Products for 2021

We released some exciting new products this year, most notably our Rugged, Ultra Low Loss Coaxial Cables and our RF Suppressor Boots.  In addition to these products we also made new options available for our Custom, RF Coaxial Cable Assemblies, and we added new variations to some of our most popular RF Weatherproofing products.  You can learn more about these product releases and updates by clicking on the images/links below.

Rugged, Ultra Low Loss Cables
RF Suppressor Boots
Clear Cold Shrink
2.2-5 Weatherproof Boots

10 New AT&T Product Approvals

AT&T Approved 10 More Gamma Electronics Products

During 2021 we were fortunate to further our relationship with AT&T as they approved and issued CEQ numbers for 10 more of our products.  AT&T continues to utilize Gamma Electronics as their go-to for RF tower weatherproofing products, having approved 5 additional models of Gamma cold shrink in 2021 alone.  Beyond weatherproofing however, we have been fortunate to have our 5G/Small Cell Adapter Kit approved by AT&T as well.  You can learn more about each of these approvals and products by clicking on the image/link below.

AT&T Approves Gamma Clear Cold Shrink
Gamma Adapter Kit Approved by AT&T

Gamma’s Next Chapter

In recent months we have promoted several individuals to better meet the needs of our growing company.  As an organization we are thrilled, as we have been able to promote individuals within our own ranks, helping these individuals better realize their own potential while helping Gamma Electronics reach greater heights.  Beyond on what it means for us internally however, we’re very excited as these changes will allow us to better meet the needs of our customers.

Peter Weyhreter

Vice President of Sales & Operations

Peter has been with Gamma since its inception, and had spent more than a decade as Gamma’s National Sales Manager.  As Gamma’s longest tenured employee Peter has also worked extensively with our operations teams and he will now over oversee both Sales & Operations from a more macro level.

Nathan Street

National Sales Manager

Nathan has spent over 20 years in various sales and management roles and has spent close to 2 years with us here at Gamma Electronics as a Regional Account Manager. In his new role as the National Sales Manager, Nathan will oversee our sales team while further fostering relationships with our distributors and resellers.

Lisa Schlaeg

Production & Logistics Manager

Lisa has been with Gamma Electronics for more than 6 years, serving in production/operations, sales, and customer service roles.  Given her wealth of experience, Lisa’s promotion to the Production & Logistics manager was a natural next step for both her and for Gamma Electronics.


Gamma Brand Ambassador

Bella has been with Gamma Electronics for 6 plus years, or nearly half of her lifetime.  In her time with Gamma she has epitomized what it means to be a good listener and she exemplifies discipline, by not barking while people are on the phone and always going outdoors to use the restroom.  Frankly, Bella’s promotion was long overdue.

In addition to the changes taking place at our organization, we also have new products that we are preparing for release in early 2022.  So make sure to sign up for our newsletter and to follow our blog to stay in the know!

Thank You

Most importantly, we want to take a moment to thank our customers and partners for your continued support.  Our goal is to earn the trust of our customers and partners by providing top notch products alongside top notch service.  We’re gratfeul that so many of you have come to trust Gamma Electronics’ products over the years, and our hope is to build upon that trust in the years to come.

If you’re not already a Gamma love customer we would to have the opportunity to showcase the quality of our products and service.  Please take advantage of our 3 for Free promotion, in which we offer 3 of our RF Weatherproofing products to you, for free, (through the end of the month/year).  Click on the button below to take advantage of this limited time offer.

On behalf of the entire Gamma Electronics team please allow me to say thank you once more and we sincerely hope you have the happiest and healthiest holiday season.

Warmest Wishes,

Cameron Lanier
Director of Marketing and Media Communications

Happy Holidays from Gamma Electronics


AT&T Approves Gamma Clear Cold Shrink

Gamma Electronics Blog

AT&T Approves Gamma Clear Cold Shrink

AT&T has further expanded their use of Gamma Tower & RF Weatherproofing products, adding 2 new models of our clear, silicone cold shrink to a growing list of approved products.  CEQ numbers have been issued for each of these new models, which have been designed to cover 2-10 AWG wires.

Just like our black, silicone cold shrink, these new clear versions are pre-expanded, rubber tubes that do not require heat to shrink.  These models of clear, silicone cold shrink deliver the same incredible results that our customers have come to expect from our popular, black, silicone cold shrink, including incredible shrink ratios and amazing weather resistance.  Gamma cold shrink is easy to install and is ideal for organizations like AT&T who like to use our cold shrink on cell phone towers to weather protect connections on antennas and remote radio units.

Below, you will find the exact models and AT&T issued CEQ numbers.

Newly Approved Cold Shrink Models

AT&T Approved Clear Cold Shrink

Want to read more about our AT&T approved products? Visit our AT&T Buying Guide for more information.

Key Features

  • Protect connectors from weather, moisture, UV, ozone, dust, and fungus.
  • Provides excellent physical protection and moisture sealing for Telecom Connectors and Cables.
  • Corrosion protection for fittings and couplings.
  • Cold Shrink reaches shrink ratios as high as 5:1.
  • Perfect Application for Antenna & Remote Radio Unit Connections.

Visit our Cold Shrink Tubing Page to find out more about our products.





More Information

Interested in buying Clear Cold Shrink? You’re at the right place! Our clear cold shrink is available to purchase through our website or in smaller quantities through our authorized distributors and/or resellers. Find out more information on Where to Buy.

If you are interested in purchasing in higher volumes/quantities please don’t hesitate to contact a Gamma sales team member.


Gamma Cold Shrink
Gamma Slide Lock
Gamma Cold Shrink
Gamma Cold Shrink

New: Rugged, Ultra Low Loss, Coax Cables

Gamma Electronics Blog

New: Rugged, Ultra Low Loss, Coax Cables

The Gamma Electronics team is happy to announce a new addition to our cable line of products: Rugged, Ultra Low Loss, RF Coaxial Cables. 

Below we provide answers to, (what we assume will be), common questions and we provide some test data as well.

Reduce RF Interference with the Gamma Suppressor Boot

What does “Ultra Low Loss” Mean?

These new cables are an upgrade over braided shield cables, (i.e. LMR 195 & 400), which are often referred to as low loss cables.  While it’s true that braided shield cables tend to produce good low loss results, our new Ultra Low Loss cables significantly improve both the VSWR and insertion loss results over low loss cables, hence the name, “Ultra Low Loss.”

The Test Results

We’ve compared our cables against LMR 195 & 400 cables to find improved VSWR results, as well as up to a 25% improvement on insertion loss results.  Our Rugged, Ultra Low Loss Cables will make it so that more of your signal gets to the desired destination.  You can see the test results in the chart below, where we compared these new cables, (labeled as S-FLEX 1/4″), against both LMR 400 and LMR 195.

Ultra Low Loss Coax Cables Test Results

It’s important to note that a drop of 1 dB amounts to about a 26% improvement.  For those who might not be familiar, measurements like dB are not done on a linear scale but instead utilize a logarithmic scale.  Logarithmic scales are intentionally used to make numbers that would be spaced apart from one another on an exponential level, easier to read on a single chart.   So, for example, in the Insertion Loss test results above, a 1 dB improvement may seem like “only 1 dB,” but it is actually around a 25% improvement.

What Makes these Cables Different?

The single biggest difference between our Rugged, Ultra Low Loss Cables, compared to cables like LMR 195 & 400, is the cable’s outer shield.  The outer shield, (sometimes also referred to as the outer conductor), is the part of the cable that sits just inside the cable jacket.  It’s called a shield as it rejects outside interference, but it also acts as a conductor that helps propogate the signal through the cable.

Low Loss cables use a braided shield, which are made up of many small, woven, metallic fibers.  Those fibers create a shield to help block external, electromagnetic interference.  Low Loss cables also require a foil conductor, that sits just inside the braided shield, to act as a conductor, which helps conduct and propogate signal through the cable.  Low Loss cables need this two piece solution that produces good, but not great results. 

Our Ultra Low Loss cables on the other hand, utilize a spiraled, corrugated copper design, which accomplishes both the rejection of outside interference as well as conducting signal within the cable, with great results.

SDL-SMA-60 Dimensions

Ultra Low Loss Coaxial Cable Interior

SDL-SMA-60 Dimensions

Braided Shield Cable Interior

A braided shield is, simply put, an inferior outer shield/conductor compared to the spiraled, corrugated copper used on the Ultra Low Loss coaxial cables.  A simple bend or twist in the cable could easily introduce a gap in the braided shield, which is not going to happen on a corrugated copper cable, unless there is a noticeable break in the cable, (also unlikely to happen).  Additionally, the braided shield is not as durable, which we’ll go into more below.

What Makes these Cables Rugged?

Ultra Low Loss cables are far better suited to withstand the wear and tear that comes with being deployed on cell phone, WISP, or fixed wireless applications.  Braided shield cables, as a comparison, can be easily knicked or cut, resulting in a gap in the outer shield/conductor, that leaks signal while also allowing for outside interference to work its way into the cable.  In addition, that knick/cut in the cable has introduced an entry point for moisture into the cable.

Ultra Low Loss cables, on the other hand, have that superior outer shield that will better withstand knicks and cuts.  It’s a single piece of copper as compared to a bunch of braided metal fibers, making it tougher and more durable.  Even if the cable jacket were to be knicked or cut it’s unlikely the cable’s outer shield would be cut as well.

Lastly, the Ultra Low Loss cables are soldered instead of being crimped.  Not only does this give better test results, but in simple pull tests we found that braided shield cables needed far less pull to come apart than the Rugged, Ultra Low Loss Cables.  A strong enough tug and the connector on braided shield cables would pop off, but not so with the Ultra Low Loss cables.  The Rugged, Ultra Low Loss coaxial cables required one side to be held in place and far more pounds of pressure to be applied in order to come apart.

Are the Rugged, Ultra Low Loss Cables Flexible?

Yes, very.  The Rugged, Ultra Low Loss cables are actually Superflex, quarter inch cables.  These cables do have more rigidity to them than you will find with LMR cables, but they are far more flexible than something like a 1/2″ annular and/or standard coaxial cable.  These cables are able to be flexible because, (unlike annular or standard cables), their outer shield is spiraled.

What Connectors Can I Get on the Rugged, Ultra Low Loss, Coaxial Cable?

We currently offer this cable in three connector varations: RPSMA to RPSMA, RPSMA to Type N, and Type N to Type N.

We also offer different length cables in these different connector variations, so make sure to check out their individual pages for more details.

Do You Offer the Rugged, Ultra Low Loss Cable with Weatherproofing?

Absolutely.  We offer all variations of the Rugged, Ultra Low Loss cable with our industry leading, silicone cold shrink tubing.  We have cold shrink tubing designed to perfectly match RPSMA connections, (SDL-SMA-60) and Type N connections, (SDL-TNS-65), all while creating a watertight seal on a 1/4″ superflex cable.  Our cold shrink tubing provides an IP68 rated, watertight seal that simply cannot be matched.


Our new, Rugged, Ultra Low Loss Coaxial Cables are a solution we chose to bring to the market as we saw an increasing demand, (specifically from the WISP industry), for cables that outperformed braided shield/low loss cables, while not having to be quite as high-end as Low PIM cables.  We were able to utilize some of the technology from our Low PIM cables in this new offering, while providing a better price point for our customers.

Assuming you don’t need low PIM cables, the Rugged, Ultra Low Loss coaxial cable is the “best value for your money” cable on the market, especially when you consider the perfectly matched cold shrink tubing included with the cable.

Get our Rugged, Ultra Low Loss Cables

Ready to improve your VSWR and Insertion Loss Results?  It’s time to upgrade to Gamma’s Ultra Low Loss Cables.


Gamma Cold Shrink
Gamma Slide Lock
Gamma Cold Shrink
Gamma Cold Shrink

What is Cold Shrink Tubing?

Gamma Electronics Blog

What is Cold Shrink Tubing?

Most people are familiar with heat shrink tubing but many have not heard of cold shrink tubing.  So what is cold shrink and when and where does it get used?

We answer these questions and more below.

Reduce RF Interference with the Gamma Suppressor Boot

What is Cold Shrink?

Cold Shrink is a rubber tube or sleeve that can shrink down many times smaller than its original size.  Unlike heat shrink it does not require any type of heat in order to shrink in size, which is what earned it the name “cold shrink.”   If you’re familiar with heat shrink don’t let the “cold shrink” name confuse you.  Heat shrink requires heat to shrink but cold shrink does not require cold to shrink.  The term “cold” is simply used to reference that no heat is required.

Gamma Electronics cold shrink ratio

Watch “What is Cold Shrink?”

How Does Cold Shrink, Shrink?

Cold Shrink Tubing wants to shrink down but it is held in place by an inner, plastic core, that keeps it from doing so.  That plastic core is perforated, with a piece of the tube ready to pull, (we call this piece the rip cord), to make removing it very easy.  As soon as you start to pull the inner core out of the way the tubing immediately shrinks.

Below is an example of the before and after sizing of one of our models of cold shrink tubing.  On the left side of the image is the “before”, or the pre-shrunk version of the cold shrink, with the plastic core in place.  That core is removed in the “after” portion of the photo, (shown on the right), where you can see the size the tubing has shrunk down to.

How Do I Install Cold Shrink?

Cold shrink tubing is incredibly easy to install and can typically be installed in less than a minute.  We made a step-by-step guide for those who are new to cold shrink installation, as well as a short video, (below), where we install cold shrink on an RF coaxial cable/conneciton to make it as clear as possible.

What is Cold Shrink Made Of?

Cold Shrink is typically manufactured from one of two types of rubber: EPDM or Silicone.  You can easily find cold shrink manufactured from both materials and they both have their perks.  EPDM tends to be more rugged and capable of taking a beating, making it ideal for when the cold shrink is likely to be in contact with other materials, like inside machinery for example.  Silicone on the other hand will shrink down to a much smaller and tighter size than EPDM, and is ideal for applications like cell tower weatherproofing.

We have an entire post dedicated to the differences between EPDM and Silicone Cold Shrink, which you can read here.

Where Would I Use Cold Shrink Tubing?

One of the most popular uses for cold shrink is on cell phone towers, where it is used to protect electrical cables/connections from water ingress and weather in general.  Cold shrink tubing is also used for various types of cable protection including splicing joints, cable trench applications, and in very confined or dangerous spaces where heat guns and/or blow torches are more difficult to use.  Cold shrink tubing is very popular in the telecommunications market, as well as in the oil, energy, cable television, satellite, and WISP industries.

What are the Key Benefits of Cold Shrink Tubing?

There are many key reasons that someone should choose cold shrink over other options.  We identify 7 of those reasons below.

1.  Incredible Sealing Properties

Cold Shrink Tubing, and specifically silicone cold shrink, offers incredible shrink ratios that make it easy to seal cables and/or connections from the outside elements.  The high shrink ratios make it so that the cold shrink can get around cables and connections and still seal down tight to not allow anything, water, dust, or otherwise, into the cable and/or connection.

2.  Fast & Easy Installation

Cold Shrink can literally be installed in seconds, and it creates a watertight seal while doing so.  Solutions like tape & butyl might be able to create a watertight seal, (initially), but it can take anywhere from five to twenty minutes to install per connection.  We did a time analysis which highlights the time cold shrink saves you versus tape and butyl, check it out here.

Similarly, cold shrink is much faster, (and safer), to install when compared to heat shrink as well.  Because Cold Shrink does not require a heat gun and/or blow torch it means installation becomes much faster, easier, and (again), safer.

3.  No Tools Required for Installation

This is similar to the last point, but we felt it was worthy to be mentioned on its own.  No tools means that there’s no additional tool cost when you choose to go with cold shrink.  It also massively reduces the hassle and cost of having to make sure you have batteries charged for heat guns, or propane/gas for blow torches.

4.  Cold Shrink is Safer

We have spoken to numerous companies who have made the switch to cold shrink tubing specifically because of how much safer it is, specifically in high fire danger areas.  Too often fires have been started by contractors who didn’t have a choice but to use heat guns and/or blow torches in high fire danger areas.  Cold Shrink tubing eliminates the need for those tools to be used in those areas.

Cold Shrink also has a far higher voltage rating than heat shrink tubing, which makes it a much-improved form of cable protection against power surges and arcing.

5.  Longevity

Cold Shrink tubing will outlast nearly all other forms of weatherproofing.  The tape and butyl method of weatherproofing, for example, is unlikely to last more than a year as it is unable to handle both high and low temperatures.  Butyl specifically is likely to melt in high temperatures and become brittle in lower temperatures. The adhesive on tapes will also not hold up to high and low temperatures, resulting in the tape coming loose over time.

Silicone cold shrink has incredible temperature resistance, going as low as -76° Fahrenheit, (-60° Celsius), and up to 446°  Fahrenheit, (230° Celsius), before showing signs of degradation.  In other words, you don’t have to worry about the cold shrink coming loose in either extreme hot or cold, in large part thanks to the fact that it has no adhesive, (more on that below).

Silicone cold shrink also comes with all the incredible properties that silicone offers in terms of weather protection, including UV resistance, and protection against Ozone and fungus.  We are so confident about the abilities of our silicone cold shrink that we guarantee it for the life of the cable.

6.  No Adhesive

When it comes to outdoor weatherproofing you typically want to avoid adhesive as a rule, which is one of the many reasons cold shrink tubing is such a fantastic weatherproofing option.  As mentioned previously, adhesives tend to melt in hotter weather, and they can prove ineffective in colder weather.  In other words, adhesive in weatherproofing can easily lead to your weatherproofing not working the way it should.  Adhesive can also melt and work its way into connections, causing issues in your cables.  At that point your weatherproofing is more problematic than it is helpful.

The other reason however, for mentioning the lack of adhesive being a great cold shrink feature is because it means removing cold shrink is far cleaner and easier than it is to remove tape or adhesive lined heat shrink.  If you want to remove weatherproofing from a connection and not have to replace the connection, then you should probably go with a solution like cold shrink.

7. Quality Control

A key benefit that customers like AT&T have told us, is that cold shrink tubing makes it easy to ensure consistent installation results.  Experienced and inexperienced installers alike can get the same results with Gamma Cold Shrink Tubing, which becomes especially important when a single location can require dozens upon dozens of connections needing weather protection.

Does Cold Shrink Come in Different Sizes?

Yes, absolutely.  In our cold shrink sizing chart, (below), you can see the model of cold shrink we have matched with various cable and connector combinations.  We have tested our cold shrink with these various combinations to ensure that they are watertight, with IP68 rated weather protection.

Each model of cold shrink shown above has been designed for and tested with the connectors and cables shown in the chart.  We test by installing the cold shrink on a cable/connection and then dunking the cold shrink and connection into a water tank more than a meter deep.  After about 45 minutes to an hour we remove the cold shrink/connection from the tank and check for any signs of water getting into the connection.  All of the cold shrink models shown above have passed testing, numerous times, with the cable and connector combinations shown next to them.

What Does Shrink Ratio Mean?

Shrink Ratio refers to the size the cold shrink starts at compared to the size it shrinks down to.  This difference between where the cold shrink starts versus where it ends up is expressed mathematically in a ratio format.  For example, our SDL-1A-125 cold shrink tubing starts more than 4 times larger than what it ends up shrinking down to.  To make it easy we say it has a 4 to 1 shrink ratio, or 4:1, (technically it is closer to 4.5 to 1).

Most of our silicone cold shrink is around a 4 to 1 (4:1) shrink ratio, although some of our smaller cold shrink models are closer to around 3.5 to 1, (3.5:1).

Watch EPDM vs Silicone Cold Shrink: Shrink Ratio Comparison

Does All Cold Shrink Tubing Shrink Down to the Same Size?

No.  Different models of cold shrink tubing have different shrink ratios.  Each model of cold shrink tubing shrinks down to a unique size and you will want to make sure that you have the right model that starts large enough to get around your cable, connector, etc., and is still able to shrink down small enough to give you the watertight seal you need.  In our cold shrink sizing chart you can see the cold shrink models that we have tested and that we recommend to match with popular cable and connector combinations.

Below we have images of two of our models of cold shrink, to demonstrate the contrast.  The SDL-1A-125 is larger with a higher shrink ratio, while the SDL-SMA-60 is smaller with a still very impressive 3:1 shrink ratio, (click on the photos to enlarge).

SDL-SMA-60 Dimensions

On our Silicone Cold Shrink page you can also find images like those above, where we show the exact dimensions that each of our cold shrink models start at, and shrink down to.  We made these graphics to make it easier for our customers to visualize if our cold shrink can work for the cable, connector, etc. that they are trying to protect.

How Do I Choose the Right Size Cold Shrink?

There are three things to consider when trying to choose the right cold shrink size, (in no particular order): the starting size, (or pre-shrink size), the length, and the shrunk down size of the cold shrink.

You can start by looking at the largest thing that the cold shrink needs to fit over, (usually the connector).  You need to make sure the cold shrink starting size can fit over that size, plus a little bit of wiggle room for the plastic core of the cold shrink to have enough room to be removed.  If the fit between the cold shrink and the connector, cable, or whatever you’re trying to protect, is too tight, then the inner core won’t be able to be removed and you won’t be able to install the cold shrink.

Next, make sure the cold shrink is long enough to fully cover what you want protected, plus a little extra.  You don’t want the cold shrink tubing to be too short in case you miss the mark ever so slightly.

Lastly, you need to make sure the cold shrink can shrink down small and tight enough to create a water tight seal.  For example, our SDL-1A-125 model shrinks down to 0.4 inches, making it ideal for shrinking onto half inch, (0.5″), cables.  The fact that the SDL-1A-125 will shrink down smaller than 0.5 inches mean you get an even tighter seal with your cold shrink on half inch cables.

If you’re unsure about what size cold shrink tubing you might need feel free to Contact Us, and a member of the Gamma team will gladly help you find the right model for your application.

Can You Make Cold Shrink in Custom Sizes?

Absolutely.  We have made custom sized cold shrink for varying customers and we can make it in different colors, (including clear).  If you need custom sized cold shrink just reach out to our sales team and they will help figure out the specifics.


Cold Shrink Tubing is an incredible cable protection tool that holds up better to weather and environmental factors than all of its competitors.  We consider silicone cold shrink tubing to be the ultimate outdoor, “set it and forget it” weatherproofing solution.  We also have customers using it indoors in very moist situations where other solutions just have not measuresd up.

Cold Shrink Tubing also has the added benefit of being far easier and safer to install than its competitors.  Say goodbye to heat guns, blow torches, while saying hello to higher voltage ratings and installation consistency.    Our customers have seen install times improve and maintenance costs go down when using Gamma Cold Shrink.  It is for these reasons that Gamma Silicone Cold Shrink has become a top choice for the telecommunications industry, as exemplified by AT&T approving 5 different models of Gamma Cold Shrink.

You will be hard pressed to find a better weatherproofing solution than Gamma Cold Shrink, and you will see the results almost immediately upon using it.

Try Gamma Cold Shrink

Ready to improve your weatherproofing?  Give Gamma Cold Shrink a shot.  Reach out to our sales team at (909) 860-1479, or Contact Us by clicking on the button below.

Learn More About Cold Shrink
Save Time & Money with Gamma RF Weatherproofing
Maintenance is RF Weatherproofing's Problem
Gamma Cold shrink Frequently Asked Questions
Why Gamma Electronics cold shrink is the best cable protection


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Reduce RF Interference with the Gamma Suppressor Boot

Gamma Electronics Blog

Reduce RF Interference with the Gamma Suppressor Boot

“What if we made a boot that could reduce RF interference?”  That was the question our engineering team set out to answer.  We’ve been making boots that provide IP68 level weather protection for coaxial cable connections for years, but what if we took it a step further?  What if we made a boot that provides weather protection and reduces RF (Radio Frequency) interference?
Reduce RF Interference with the Gamma Suppressor Boot


Immediately the ideas began to flow on how we might accomplish this.  The overall boot design was already in place as our engineering team has created boots for coaxial connectors ranging from NEX10 to 7/16 DIN.  The more pressing question became “what would the boot be made from?”  All our weatherproof boots up to this point have been designed from silicone because of silicone’s incredible weather protection properties and resistance to environmental exposure.  Pure silicone rubber does not however block RF signal that could easily find it’s way into nearby antennas from loose leaking connectors.

So the next question became, what material would block or reduce outside RF interference, and could a rubber style boot be manufactured from such a material?  Those were the two key criteria that would have to be met for this to work and, needless to say, this brought about quite a bit of testing. Our team started by testing samples of different silicone rubber composite materials to see which ones would effectively attenuate, (or reduce), undesired RF egress, while still providing the level of weather protection our customers have come to expect from our boots.

To find the right material we had to put it through rigorous testing, which, (to vastly oversimplify the process), can be stated in a few steps.  First, we would transmit an RF signal.  Next, we would receive and measure the intensity of that RF signal. Lastly, we would place different materials in between where the signal was generated and where it was measured to see if the material made any noticeable difference to the RF signal, (i.e., block and/or reduce signal levels).  The basic premise of this test is illustrated below.

This process sounds basic but there are so many different ways to do it that we had to be sure we were using methods that would produce trustworthy test results.  One way we found success in testing material was by generating the RF signals with a PIM tester which sent two RF signals (via cable) to a small antenna unit.  The antenna unit would transmit the RF signals to be picked up by a field probe (receiver), with the results being shown on a spectrum analyzer, (illustrated below).

Below you can see some of the real-world equipment we utilized during the material testing phase of this process.

PIM Testing Equipment

Small Antenna Unit (Transmitter)

Magnetic Near-Field Probe (Receiver)

Spectrum Analyzer

We tested a number of different materials with this type of testing with some variations.  As can be seen in the spectrum analyzer below we were able to pick up the two test frequencies, (1805 and 1880 MHz), quite clearly with this testing method.

Spectrum analyzer read out of RF signal with no boot material

The next step was to test out different materials and see if those materials would impact the strength of those transmitted frequencies.  Typically, we would take the material and place it over the antenna unit and check the spectrum analyzer for a difference in the strength of the signal.

Antenna covered with material

We tested several materials, some of which had zero impact on the strength of the RF signal with others having negligible results.  However, after going through several different iterations of materials we found a silicone rubber composite material that significantly attenuated the RF signals, as can be seen in the image below.

Spectrum Analyzer Read-Out of RF Signal with Boot Material in use

When compared to the earlier photo you can see that this composite material resulted in a reduction (or attenuation) of about 15-20 dB, a massive reduction.  This led us to believe we had found the composite material that could be molded into a boot and realistically reduce RF interference.  Here are the before and after results side by side.

We should note that these are proof-of-concept results and that a drop this significant, while fantastic, is not what would be expected in real-world results.  In these tests we were looking for an effective material, but there is almost no real-world scenario where we would take that material and wrap it around the front of an antenna,  (as we did in these early tests).  Once we found a material that worked, wrapping it around the front of the antenna unit should have drastic results, but not the same results as would be produced by a boot made of the same material over a connector.

Truth be told, what is shown above is only a fraction of the amount of testing that took place to choose the right material.  Furthermore, the more testing we did the more refined our testing process became, (which can be seen in the actual boot testing below).  These proof-of-concept tests were simply to make it easy for us to identify the right material that we would attempt to make a boot out of and, (of course), to see if our concept could work.

From Theory to Practice

It was time to take the material and put it into boot form. Luckily, we are well versed on manufacturing weatherproof boots and we were able to produce them with ease.  We were very pleased that the boots did in fact have the elasticty we were looking for, and that the install/uninstall experience is essentially identical to our normal weatherproofing boots.  In fact, if you were going by the feel of the boot alone you might find it difficult to tell the difference between our normal weatherproof boots compared to the Suppressor Boot.  So we had now met one of the 2 needed criteria.

Gamma 7/16 DIN Suppressor Boot

Gamma Suppressor Boot

Antenna Unit

Once the boots were made, we knew we had to test them again and that the testing process would look a bit different.  We improved upon the testing process for the actual boot while utilizing the basic idea used in the proof of concept tests.

First, like the proof-of-concept test, we generated RF signal from our PIM tester and sent the signals, (via cable), to the antenna unit.  This time we took all the testing outdoors to help eliminate any wall reflections.

Next, we aimed the antenna at a horn antenna designed to receive the RF frequencies being transmitted much like water going into a funnel.

RF Signal Radiated by a Waveguide Antenna and Collected by a Horn Antenna

Inside the horn antenna cavity is a dipole feed element measuring the intensity of the RF frequencies being transmitted to it.  The signal intensities are then measured by our trusty spectrum analyzer.

Feed inside of Horn Antenna Cavity

PIM Testing Equipment next to Spectrum Analyzer

Like before, the spectrum analyzer would tell us how much of the transmited signals  were being picked up and how much was attenuated by the suppressor boot.  Note, in the photo above that we covered the spectrum in two different boxes, one of which is covered in foil, to shield it from any outside interference. We did this despite the fact that it should only being showing frequencies coming via the cable from the horn antenna, but we wanted to make sure we were eliminating any potential interference.

Testing the Boot

In order to know how much RF signal was or was not being affected by the boot we first had to measure how much the transmitted frequencies were being picked up by this testing setup.  The first image below shows the results with no boot over the feed (unattenuated).

Like the proof-of-concept testing we can clearly see two frequencies being transmitted: 1805 and 1880 MHz.

Next, we placed the Suppressor Boot over the feed inside the horn antenna, (click photo to enlarge).  As soon as we placed the boot over the feed there was an immediate signal drop shown on the spectrum analyzer.  You can see the before & after photos below.

With the suppressor boot over the feed we saw an immediate drop of at least 10 dB.  Don’t let the spectrum analyzer fool you, a 10 dB drop is huge.  Decibels (dB) are not charted on a linear scale, instead the spectrum analyzer is giving us a logarithmic reading.  In other words, a drop of 10 dB is not simply a loss of 10 units but amounts to a 90% reduction in signal intensity.

If the Suppressor Boot were to reduce the signal by 3 dB that would mean it effectively reduced the original signal’s power by half.  A 10 dB reduction means the Suppressor Boot has effectively reduced the RF signal to 1/10 of the original signal.  It doesn’t quite look that way in the test result but that’s the nature of a logarithmic scale: the logarithmic scale is designed to make numbers that are greatly spaced apart easier to read on a graph.

Testing for Real-World Scenarios

Next, we performed a test that was more like a real-world scenario.  Instead of using a waveguide antenna to transmit the frequencies we instead created a “leaky connector” scenario by sending the signal from the PIM tester to a 50 Ohm dummy load, (commonly used when testing RF cables).  We used a Type N connector and only hand tightened the connector to the load.  We then placed this leaky connection in front of the horn antenna.

In essence, the leaky connection is replacing the antenna as the transmitter in this test.  As can be seen in the photo below the cable did have the Suppressor Boot on it, (in preparation for the next step in the test), but the boot was not covering the connection.

For this test, the RF power of each frequency from the PIM generator was 43 dBm versus 33 dBm, (which is what we used in the previous test with the waveguide antenna). This increase in power was to compensate for the reduced radiating efficiency of the leaking connector compared to that of the waveguide antenna.  In other words, the leaky connector doesn’t radiate signal the way the waveguide antenna does and we wanted to make the signal clearly visible when seen on the spectrum analyzer.  If you compare the photo to below to earlier tests above you can see the change in power on the spectrum analyzer.  Each horizontal line on the spectrum analyzer represents a division of 10 dB, and the results in the leaky connector test do show up as 10 dB higher than previous tests due to this power change.

The reduced radiating efficiency also resulted in a larger signal-to-noise ratio. As opposed to previous tests with the waveguide antenna where we really only saw the 1805 and 1880 MHz frequencies, we are now seeing more noise showing up alongside the signal on the spectrum analyzer.  Again, the results from a leaky connector were not going to be as clean and clear as results from the waveguide antenna.  As a result of this larger signal-to-noise ratio, the spectrum analyzer was operated with a much larger gain setting to help separate the signal from the noise.  The noise at zero-frequency and frequencies greater than 1880 MHz is comparable to the signal itself as seen in the pictures below. However, in each test, the gain was set to a fixed value before the Suppressor Boot was applied so the before-and-after signals are apples-to-apples comparisons.

Long story short, we made some adjustments to make the results more clearly visible but those adjustments had no bearing in determining how effectively the boot would work.

The only thing left to do now was to cover the leaky connection with the Suppressor Boot and see if there was a drop in intensity of any significance on the spectrum analyzer.

It was the moment of truth.  Months of work came down to this test.

Just as we saw in the previous test, there is at least 10 dB in attenuation/reduction.  A massive reduction.  Again the 10 dB reduction indicates that the frequency intensity has been reduced to 1/10 of its original intensity.  Here’s the results without and with the boot side by side.

We’ve tested the Suppressor Boot time and time again and each time it produces the same results: at least 10 dB attenuation.  We had achieved what we set out to do.  We had successfully found the right material and manufactured it into a great RF interference attenuation/reduction solution.

What It All Means

A reduction of about 10 dB is impressive, but what does it really mean?

Anyone with familiarity of cell phone towers or fixed wireless in general is aware of the often dozens of cables being utilized at a single site, all of them carrying RF signal.  With that much electromagnetic signal flowing any type of egress or leakage can quickly become a major problem as those signals can interfere with one another, resulting in poor service and/or cross talk.  In some cases, interfering with the wrong frequencies can even result in being fined.

Over the past ten years, the problem of CATV, 4G LTE and now 5G signal interfering with each other is compounding. RF interference is a huge problem for Cable TV providers as they are strictly regulated by the FCC and run the risk of getting fined if their RF networks are leaking. In fact, it is well known that when they leak RF signal into the air AT&T, Verizon or T-mobile will come knocking on their door letting them know that they their CATV network is interfering in their network. If the cable TV provider is unresponsive, it can lead to significant fines. It all has to do with a hierarchy and who has the rights to the frequencies transmitted. The shared frequencies of 600 MHZ and 700 to 800 MHZ is especially problematic.  The Gamma Suppressor Boot was designed largely with these problems in mind.

The testing above shows that if a single connection were to be leaking signal that the Gamma Suppressor Boot would greatly help contain that RF leakage.  The boot is designed to simply reduce and/or block RF frequency from getting through and possibly finding its way into an antenna, which would introduce Passive Intermodulation, (PIM), to the system.  Add to this that the Gamma Suppressor Boot also provides IP68 rated weather protection and the incredibly fast install/uninstall process, and you have an easy-to-use solution providing multiple layers of protection.

Available to Order Now

The Gamma Suppressor Boot is now available in 4 different variations:

NEX10 to 1/4 inch superflex Suppressor Boot

4.3-10 to 1/4 inch superflex Suppressor Boot

4.3-10 to 1/2 inch annular Suppressor Boot

7/16 DIN to 1/2 inch annular Suppressor Boot

For those interested we’re also happy to manufacture custom sized Suppressor Boots to your specifications.  You can connect with a Gamma representative by clicking here to learn more about customization options.

For more information regarding our testing process check out the documentation put together by our engineering team.  You can also get more details about the Suppressor Boots by clicking here.

To purchase, click here or speak to a Gamma sales representative.


Gamma Cold Shrink
Gamma Slide Lock
Gamma Cold Shrink
Gamma Cold Shrink

2 New Weatherproofing Product Variations

Gamma Electronics Blog

2 New Weatherproofing Product Variations

The Gamma Electronics team is excited to share the addition of 2 new product variations to our RF weatherproofing line of products: Clear Cold Shrink tubing and 2.2-5 Weatherproof Boots.

With the addition of these products we continue to add to and lead the fixed wireless industry in terms of RF weatherproofing options and solutions.

New Weatherproofing Product Variations from Gamma Electronics
Gamma Clear Cold Shrink Tubing

In recent months we’ve received numerous requests for cold shrink tubing that would allow installers to see cables and connections after the cold shrink had been installed.  Our new, clear cold shrink tubing has been designed to do just that and has been specifically designed for wires 2-10 AWG sized wires often in use for power on radios.  Finally it’s easier to give those power connections an IP68 rated seal while still being able to see the connection beneath it.

We have 2 variations of the clear silicone cold shrink.  The SDL-134-50-CLR, which is 50mm (1.96 inches) in length, shrinks down to 4mm, and is designed specifically for 8-10 AWG wires.  The SDL-245-65-CLR is 65 mm in length (2.56 inches), shrinks down to 5mm, and is designed for 2-6 AWG wires.

Gamma 2.2-5 Weatherproof Boot
Gamma 2.2-5 Weatherproof Boot

Another request we’ve received in recent months has been for a weatherproof boot specific to 2.2-5 connectors.  The BT-225-COAX25 is made of silicone and provides IP68 rated protection for 2.2-5 connections that are installed on quarter inch sized cables.  This boot marks the first time Gamma Electronics has made a boot designed for 2.2-5 connections, or any type of RF weatherproofing designed specifically with 2.2-5 connections in mind.

Gamma Electronics’ new Clear Cold Shrink Tubing as well as the 2.2-5 Weatherproof Boot are already available to purchase.


Gamma Cold Shrink
Gamma Slide Lock
Gamma Cold Shrink
Gamma Cold Shrink