Tag: Vhf

CB and 2-Way Radios – Why the Technology of the 50’s Is Still Relevant Today

If the world goes down a dark and bleak spiral, the people of the future are going to ask: “What’s a radio?” But not if we have anything to say about it. With the rise and domination of Smartphones and streaming media, radio is becoming less and less relevant to the people of today. Or so it seems.

You see, 2-Way and CB radios are still relevant to the average person as much as it might not seem like it is. Why? Well a radio can communicate with another person from a distance.

But so can a Smartphone…

You can contact emergency services in case of an emergency.

But so can a Smartphone!

You can quickly find out information about storms and other hazardous weather.

There’s an app for that!

This is all true. But let me ask you this, how long does the battery last on your cell phone? How many times have you dropped a call or found yourself in an area where your data doesn’t work? How many times have you had to ask “Can you hear me now,” because of the static in the poor connection? Ahhh…. Starting to make some more sense now?

Here’s the deal, cell phone companies don’t like to put towers up in places like mountains, or the middle of nowhere or in the middle of the ocean because it would cost more money to them than its worth (and possibly because they want to inconvenience us). If you’re someone who likes to hike, climb, boat or explore abandoned places, it’s a very good possibility that your phone isn’t going to work very well in those places and doing those things.  Do you want to rely on your cell phone if you get your arm caught in a rock like the guy from 127 Hours? Didn’t think so.

If only I had a 2-way radiooooo!!!!!!

Radios are designed to be used in that kind of environment, your phone isn’t. Not to mention, if you’re biking and hiking, or on a boat, do you really want to risk dropping and breaking your phone or losing it in the water? A radio is like an insurance policy for your cell phone; small investment, big payoff.

A cell phone might be good for a 3 hour tour... But not for 3 year long TV series

Plus, you get some cool features like the one touch NOAA broadcast. With the push of one button you get access to the emergency weather station and can find out if you need get your skipper back to shore because a storm. If only Gilligan and his crew had one…

And, the Cobra CXR925 has a Rewind-Say-Again feature that will record the last 20 seconds of a transmission so you can play it back. Never miss an important detail again.

And think about this, if you’re tailgating, it’s lame to have to call someone in the car ahead of you, wait for them to answer and then try to hear them over your Hands Free kit because you shouldn’t be talking on the phone while driving, and then have a conversation. Just press a button on your radio and start talking. Simple. And have you tried making a phone call at an amusement park with all the screaming kids and roller coaster noises in the background? It’s something out of a nightmare. A radio is meant for noisy environments so you know you’ll hear the other person.

So, still think they’re irrelevant? If so then you let me know how it goes trying to dial the nearest coast guard or ranger station when you get stranded in the ocean or on top of a mountain. An ounce of prevention is worth a pound of cure so why take a chance that you don’t have to take? Be prepared all the time, every time with a 2-way radio.

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Wireless Microphones: UHF and VHF


EW100ENG-G3

The benefit of wireless microphones

Wireless microphones free you from being tethered to cumbersome audio equipment giving you the ability to move about during a performance or engage your audience in a way that otherwise would take a very long microphone cable. Wireless microphones also eliminate tripping hazards as well as simplify set up and tear down as there are no cables to wrangle and detangle. You may find wireless microphones in a number of different designs in fact there are just as many wireless microphone designs as there are wired mics as almost all wired microphones can be converted into a wireless system with the implementation of a transmitter such as the SKP 100 G3 plug-on transmitter which can be found in the Sennheiser EW100ENG G3 wireless microphone pack pictured above.

How They Work

Wireless microphones use two major components. The first being a transmitter which operates like a little radio station transmitting anything the microphone picks up. The Second being a receiver which just like the radio in your car receives the radio signals from the transmitter and converts them into a line level audio signal to be amplified or recorded.
The radio signals are broadcast using frequency modulation (FM) which is a process of encoding the audio being transmitted in a carrier frequency using phase variance. This is exactly the way the FM dial on your car radio works. There is another process used less often for this application called amplitude modulation (AM) which uses varying levels of signal strength or amplitude to encode the audio. If that sounds familiar it’s because that’s exactly how your AM dial on your cars radio works. Depending on the manufactures design the transmitter and receiver may have only a fixed carrier frequency on which they operate or variable frequencies that can be selected based on the available of frequencies in a particular area.


In order to truly understand this process it’s important to understand how radio signals are broadcast. Radio waves are waves of electromagnetic radiation that oscillate or vibrate back and forth a number of times in a second. The term “frequency” simply states how “frequently” the electromagnet wave vibrates in a second. We use Hertz (Hz) as a standardized unit of measurement for all broadcast applications. This is named after Heinrich Rudolf Hertz, the German physicist that first demonstrated the existence of electromagnetic radiation in the mid 19th century.
That being said there is only a finite amount of “bandwidth” which wireless microphones can operate on. Bandwidth is a term used to describe the range of carrier frequencies the transmitters and receivers can use i.e. the amount of information that can be transmitted.


Freq Spectrum

The range of the available bandwidth can be seen in this image of the electromagnetic spectrum where youll notice the two classifications of available bandwidth VHF (very-high frequency) and UHF (ultra-high frequency). VHF ranges from 30 MHz to 300 MHz meaning 30 million oscillations per second to 300 million oscillations per second. UHF ranges from 300 MHz and 3 GHz meaning 300 million oscillations per second to 3 billion oscillations per second.

UHF vs. VHF

Due to the higher frequencies UHF equipment use physically smaller waveforms meaning the receiver anteni can me much smaller making UHF receivers much more compact. The downside is the smaller waveform carries less energy so the operating range of the system may not be as great as a VHF system. For this very reason the FCC (Federal Communications Commission) allows for UHF transmitters to be more powerful. This is great but as a side effect battery life may be sacrificed. The FCC limits transmitter power of UHF equipment to 250mW compared to VHF 50mW limit. Given the larger VHF wave these systems have more ability to punch through walls and their designs typically yield longer battery life.
So what does this all boil down to? UHF systems are typically the choice of professionals for higher fidelity and operating range due to power regulations. VHF is often chosen as an option for situations where direct line of sight isn’t an option as the waves can punch through obstacles.

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