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Cudy 4G LTE Router (LT15, LT18) External Antenna Guide

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Looking to get the best possible data rates from your Cudy 4G LTE LT15 or LT18 Router?

You’ll want to purchase and connect external MIMO antennas to the device’s four SMA cellular antenna ports.

In this guide, we'll:

  • Recommend the best external antennas to use.
  • Show where the SMA ports are located.
  • Explain how to aim the antennas for best results.

In this guide

The Best External Antennas for the Cudy 4G LT15 and LT18 Routers

Using a MIMO antenna outside your building, pointed towards you best incoming cell service, can help provide you with the fastest LTE data rates possible.

The Cudy 4G LT 15 and LT18 have four SMA cellular antenna ports on the back, which allow for a 4x4 MIMO antenna to be connected to the device.

Which of the two different 4x4 MIMO External Antenna Kit options to use depends primarily on how much time you're willing to spend on aiming.

The easiest antenna choice for the Cudy 4G LTE Router is our QuadMini Antenna Kit. With up to 5.2 dBi of omnidirectional gain and multiple mounting options, it is designed to be extremely simple to install outdoors or indoors, at home or in an RV.

Easy install, no aiming

Upgrade your 5G in minutes with no aiming, and four easy mounting options.

However, if you're willing to spend a little bit of time aiming, our QuadPro Antenna Kit will generally get you the fastest data speeds, thanks to its 9.1 dBi of directional gain. This is particularly important if you're on the edge of coverage, or have very weak signal.

Best performance, requires aiming

Aim QuadPro at your nearest tower for blazing data, even at the edges of cellular coverage.

Why External Antennas Are Critical for Improving Data Rates

Most people think that external antennas primarily help you increase your data rates by increasing the signal strength. But that's not the case.

An increase in signal strength is often less important than other ways that external antennas help.

Here are the three main ways that external antennas help you increase your data rates:

1.They Improve Signal Quality

In 4G LTE networks, signal quality is measured as SINR (Signal to Interference plus Noise Ratio) or sometimes as RSRQ (Reference Signal Received Quality).

Improving signal quality has a huge impact on your data rates.

Higher data rates allow your hotspot to communicate using "higher order modulation schemes." That means they can use the same wireless spectrum to send more data per second.

However, there's one big caveat: In order to improve your signal quality, you need to both aim and shield your outdoor antenna properly. We talk more about this in the next section.

2.They Allow You To Connect On More Bands

Cellular Routers like the Cudy 4G LT15 and LT18 support an LTE feature called "carrier aggregation."

Carrier aggregation allows for the ability to connect on multiple cellular bands simultaneously.

The more bands you're connected on, the greater the bandwidth, and the higher your data rates.

However, many of the higher frequency bands aren't able to penetrate into buildings. Using external antennas allows you to access higher frequency bands, which are often less congested and offer higher speeds than lower frequency bands.

3.MIMO Isolation

MIMO (Multiple Input Multiple Output) technology uses signals travelling along multiple paths simultaneously, increasing both bandwidth and reliability in wireless connections.

MIMO isolation is the antenna's ability to handle several data streams at once, cleanly and without interference, leading to quicker data speeds and steadier connections

Our external antennas are specifically designed for superior MIMO isolation, and dramatically outperform standard built-in antennas found in most home devices.

This means you'll see a more reliable connection with enhanced bandwidth, ensuring smoother streaming, gaming, and browsing with minimal interruptions.

Installing External Antennas to the Cudy 4G LT15 or LT18 Router

Before getting started, it's always a good idea to run a couple of speed tests indoors from a device connected to the Wifi of your Cudy 4G LT15 or LT18. The results will fluctuate a little, but this is the baseline you're trying to improve.

Once you've tested your baseline internet speeds, you're ready to install external antennas.

The Cudy 4G LT15 and LT18 have four SMA cellular antenna ports grouped on the back of the device; they are labeled Cellular DIV, Cellular MIMO 2, Cellular MAIN, and Cellular MIMO 1 and would be used to connect to MIMO external antenna(s).

In the next section of this guide, we'll show you how to best connect adapters for external antennas to the Cudy 4G LT15 or LT18.

Step-by-Step Guide to Installing Adapters for External Antennas

Step 1: Disconnect the standard paddle antennas that are connected to all of the "Cellular" antenna ports.

Step 2: Connect the external MIMO antennas to the newly available cellular SMA ports on your Cudy 4G LT15 or LT18 Router in the order shown below:

device ports
antenna ports

Congrats! Your Cudy 4G LT15 or LT18 Router is now connected to your more powerful MIMO External Antennas. You are now ready to go outside and test your system!

Positioning and Aiming MIMO Antennas

Correctly positioning and aiming MIMO antennas is crucial to getting the best performance to your Cudy 4G LT15 or LT18 Router, or indeed any other router.

We've actually compiled detailed instruction manuals for our 4x4 MIMO antennas, mainly the QuadMini Manual and QuadPro Manual, where we go into depth on the best ways to aim each antenna.

The goal is to find the best location and direction for the antenna(s), to maximize data rates to the Cudy 4G LT15 and LT18. It can take a little patience, but can have a huge impact – it’s worth a bit of extra effort!

Once you've got your external MIMO antennas connected, you're ready to go outside with your "test-rig".

With each location and direction you try, run a couple speed tests, and make a note of the results. Here are all the locations and directions where we recommend testing your MIMO antenna:

Where to test your signal

Where to test your signal

Pro tip: Don’t just go to the highest point of the roof! While signal is generally stronger the higher you go, there’s also often more interference. We’ve found it’s often better to mount the antenna(s) on the side of the building where the structure can shield the antennas from interference.

Once you've found the position which gets you the highest data rates to the Cudy 4G LT15 or LT18 Router, that's where you'll want to install the MIMO antenna. Go ahead and mount the antenna, run cables inside, connect everything up, and enjoy superior data rates!

Advanced Optimization

If you've gone through the trouble of installing and accurately aiming a MIMO Antenna Kit, you're likely already getting excellent data rates from your Cudy 4G LT18.

That said, there's always more that can be done!

Band locking is a great way to optimize data rates through an LTE router or hotspot. The idea is that you test every different frequency band being received by your device, and lock it onto the band that results in the best data rates.

The Cudy 4G LT15 and LT18 are one of few routers to allow manual band locking in their web interface - here's a step by step guide of how to do it.

Band Locking the Cudy 4G LT15 or LT18

The reason this works so well, is because different frequency bands transmit with different bandwidths.

Generally speaking, higher frequency bands (like 1900 MHz and 2100 MHz) offer more bandwidth but travel less far and penetrate building materials less well than lower frequency bands (like 700 MHz and 800 MHz).

As a result of travelling less far, higher frequency bands tend to be less “congested” - they have fewer users connected to them, and data rates are often faster.

This isn’t always the case though, sometimes a lower frequency band may have better data rates, depending on your location.

This can be quite time consuming, but often results in significant improvements to data rates.

We'll keep the steps below as simple and concise as possible!

Step 1: Access the Cudy's web interface

  • Use a laptop to connect to your Cudy's WiFi network, and open a web browser.
  • Enter "http://cudy.net/" (or "http://192.168.10.1/") into the URL bar to log into the Cudy's web interface.
  • Login to the interface with your username and password - default password is "admin".

There's a fair amount of useful and interesting information to be found in the web interface. For now, we're only interested in the band locking feature.

Step 2: Lock the Cudy 4G LT15 and LT 18 to a frequency band

  • In the top menu, navigate to "General Settings" -> "4G" -> "APN".
  • Select the button next to "Band Select" and to turn it to the "ON" position.
  • From the list, select the band you'd like your Cudy 4G LT15 or LT18 to lock to.
Cudy 4G LT15 and LT18 Band Selection Screen

Once you hit "Save & Apply" to select a new frequency band, the Cudy 4G LT15 or LT18 will take a few minutes to reboot. Once it's back up and running, connect to it's WiFi network again.

Now, lets test each available band in your area, to determine which band(s) will result in the best data rates.

Step 3: Test and select the best tower and frequency band

  • Look up your nearby towers. This can be time consuming and accuracy is often questionable - we've listed our suggestions in an article on the Best Ways to Locate Nearby Cell Towers.
  • Aim your external MIMO antenna(s) at each nearby tower and band lock the Cudy 4G LT15 or LT18 to each band that the tower transmits.
  • Run 3 to 4 speed tests on each band to find the fastest bands. Speedtest.net is a great tool for this.
  • Repeat this for every tower in your area, and make notes of the speed test results you get from each band and tower combination.

Once you've identified the best tower and band combination, lock your MoFi to that band(s), and make sure your outdoor antenna is secured so that it doesn't move in the wind.

Note: Since the Cudy 4G LT15 and LT18 have the ability to carrier aggregate (i.e. combine the service of multiple different frequency bands into one), it may be worthwhile to bandlock to more than one band.

Cudy 4G LT15 and LT18 Technical Specifications

Cudy 4G LT15 Technical Specs

Supported 4G LTE bands

  • AT&T: B2, B4, B5, B12, B14, B17, B29, B30, B66
  • Verizon: B2, B4, B5, B13, B66
  • T-Mobile: B2, B4, B5, B12, B25, B41, B66, B71
  • Other: B7, B26

Cellular Modem

  • Modem Chipset: Quectel EG120K
  • MIMO Support: 4x4 w/ external antennas
  • LTE-A Carrier Aggregation: 3x Download
  • LTE Performance Category: Cat 12
  • Max Theoretical Speeds: 600 Mbps Download, 150 Mbps Upload

Wi-Fi

  • Wi-Fi Version: Wi-Fi 6
  • Technologies: 802.11 b/g/n/ax (2.4 GHz); 802.11a/n/ac/ax (5.0 GHz)
  • Bands: Simultaneous 2.4 GHz and 5.0 GHz bands

Ports

  • Cellular Antenna Ports: 4x SMA-Female
  • SIM Ports: 2x SIM (1x Redundant SIM slot)
  • Other Ports: 1x GbE WAN/LAN, 3x GbE LAN

Other

  • CPU: Mediatek Dual Core 880MHz
  • Power: 10V-30V DC power (no internal battery)

Cudy 4G LT18 Technical Specs

Supported 4G LTE bands

  • AT&T: B2, B4, B5, B12, B14, B17, B29, B30, B66
  • Verizon: B2, B4, B5, B13, B66
  • T-Mobile: B2, B4, B5, B12, B25, B41, B66, B71
  • Other: B7, B26

Cellular Modem

  • Modem Chipset: Quectel EG18
  • MIMO Support: 4x4 w/ external antennas
  • LTE-A Carrier Aggregation: 5x Download, 3x Upload
  • LTE Performance Category: Cat 18
  • Max Theoretical Speeds: 1.2 Gbps Download, 150 Mbps Upload

Wi-Fi

  • Wi-Fi Version: Wi-Fi 6
  • Technologies: 802.11 b/g/n/ax (2.4 GHz); 802.11a/n/ac/ax (5.0 GHz)
  • Bands: Simultaneous 2.4 GHz and 5.0 GHz bands

Ports

  • Cellular Antenna Ports: 4x SMA-Female
  • SIM Ports: 2x SIM (1x Redundant SIM slot)
  • Other Ports: 1x GbE WAN/LAN, 3x GbE LAN

Other

  • CPU: Mediatek Dual Core 880MHz
  • Power: 10V-30V DC power (no internal battery)

Other Helpful Resources

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