Why AM Listening is Better at Night

If you listen to AM radio stations at night that are just impossible to pick up during the day, chances are you’re benefiting from sky-wave propagation. Propagation is just the technical word for how radio signals travel through the air. Sky-wave propagation is the specific name given to radio waves that travel through the sky. Sky-wave propagation takes place between sunset and sunrise. It’s the flip side to the ground wave propagation used to transmit during the day.

During the day, ground wave propagation is preferable because the radiation from the sun causes so much ionization that radio signals sent into the air are absorbed into the atmosphere. When atoms in the D region of the ionosphere are ionized, you end up with free electrons and ions floating around in the air. It’s kind of like trying to walk through a room filled with dancing couples. When in pairs, there’s more room to walk through, but when they’re not paired, it’s easier to get stuck in a conversation with someone. That’s kind of how the ions and electrons in the D region work. When they’re not combined they look for something else to combine with and that’s how they absorb radio waves. At night, however, once the sun begins to set, the electrons and ions in the D region recombine rapidly – leaving more room for the radio waves to travel a little farther up. Above the D region, the F1 and F2 regions are also recombining, but much more slowly than the D region. When the radio waves hit those regions of the ionosphere, they have a chance to be reflected or bent (some prefer refracted) back toward the earth.

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What that means for AM radio listeners is that they’ve experienced the remarkable ability of AM radio signals to travel hundreds of miles farther than during the day. Listening to AM, and scanning the AM dial between sunrise and sunset is a fun way to discover how far a sky-wave signal can travel to reach you. During the baseball season, you can use the sky-wave to tune in some night games played in different parts of the country. In Northern California (where C. Crane is based), as in other places around the country (even up into Alaska), people use the sky-wave to listen to stations like KGO which is a 50,000 watt station located in San Francisco. If a signal reflects off the ionosphere and then bounces off the earth and then reflects off the ionosphere again, it can travel even farther than with just a single reflection. So, as you can see, sky-wave propagation makes it possible to tune in stations that you might not even know about when tuning your radio during the day.

If you ever come across a DX website, or even a shortwave radio website, where someone is really happy about intense solar activity (or lots of sun spots), it’s because more ionization during the day makes for better sky-wave propagation during the night.

If you want to make the most of sky-wave propagation, we’d suggest the CCRadio-2E and if you’re into shortwave, our CCRadio-SW is also an excellent choice. Since these radios have fine tuning capabilities, thanks to the built-in Twin Coil Ferrite® AM Antenna, you may be able to find a new station almost every night. A smaller version that works great for portability would be the CC Skywave. It’s a lot more fun than you might realize, with something as simple as a radio. Here’s a sample personal station log you can use to keep track of what you hear.

We’d love to hear how far away you’ve received an AM signal from its source, and on what radio!

Happy DXing

Gift Guide for Dads and Grads

giftguidedadsandgradsShopping is supposed to be fun, but when it comes time for Father’s Day or Graduation Day, we know even the most savvy shoppers are often left wondering “What the heck do I buy this person?” C. Crane is here to give you some suggestions for the man in your life who might seem to have everything or the graduate who seems to need everything. 

Ideas for Dad

CC Skywave – Great for the traveler. It’s small and portable, with excellent overall performance, an intuitive layout and great sound for the size. Easy to stash in a carry on or take to the ball game. Covers AM, FM, Shortwave, Weather (with weather alert) and Aviation Band.

CCRadio-EP – Perfect for when less is more. Larger radio with a flip up handle. Analog tuning dial, great AM and FM reception, clear sound from the large speaker with separate wide and narrow audio control. No clock to set or memories to program, just turn it on, tune the dial and listen. External AM antenna jack.

CCRadio 2E – For the man who wants it all. The top of the line digital radio with extra bells and whistles. This is the best radio we have for AM Reception and it also has really good FM reception as well. Audio tuned for clear voice. 5 one touch memory presets per band, clock, alarm, sleep timer, programmable timer, separate bass and treble. Weather band with WX alert. External AM antenna jack. 2 Meter HAM band for emergency listening. 

CC Pocket – For the man on the go. Small, lightweight pocket radio with excellent reception for its size. Your dad can listen through earbuds or the built-in speaker. AM/FM and Weather with Alert.

Garden Noise Reduction Headphones and Radio Kit – For the man who does it all and wants to listen to his radio while he does! Kit includes the CC Pocket Radio above along with Noise Reduction Headphones and a made in the USA harness is also available to keep the radio in place while working around the house or weed eating in the yard.

Pillow Speaker – This may be more for your Mom :). Allows your dad to listen to his favorite radio show at a volume level that doesn’t disturb the whole house (sorry we can’t help with snoring).

Ideas for Graduates

Senta 40 Headphones – Awesome set of headphones that are a great value for the money. If your graduate is more interested in sound than in a brand name these are the right set of headphones for them.

VOZ Wooden Earbuds – A favorite among staff and their families. Great sound, comfortable to wear and the no tangle wires are such a relief.

Senta ALLY Portable Bluetooth Speaker – Great for listening to a favorite smartphone app using Bluetooth. Whether working out or sitting by the pool, it makes listening to any audio from a Bluetooth device so much better. Also works with SD cards, USB or direct line input. Bonus – it has a replaceable battery!

Super WiFi Repeater Kit – May come in handy in the apartment or dorm room. Allows you to pull distant WiFi signals into your computer, smartphone, tablet and more. The best part is there are no drivers to install!

If all else fails a gift certificate is pretty safe. Our C. Crane Amazon store has a lot of stuff and depending on your recipient, it may make more sense to give them one from there. Especially if they have a Prime Membership, they can take advantage of their Prime Shipping options if they are enrolled. 

No matter what you choose, we hope all of you have a fantastic Father’s Day!

For those of you with loved ones or acquaintances who are graduating – Congratulations! What a fantastic way to kick off summer. 

Wireless Audio Demystified

WirelessAudio-ThenNowWe’re living in a world full of contraptions that were once considered futuristic concepts. For audio lovers, this is a particularly exciting time. With the development of digital audio technologies, we’ve experienced incredible reductions in physical device sizes, while data storage capacities have increased greatly. More recently, wireless technologies have enabled audio to be transmitted from source to speakers without cables; however, many of us may be confused by the many wireless audio options that are available. This article will hopefully help clarify the differences among the various technologies and may serve well as a platform for further research.

Wireless Audio- The Basics

Despite many differences, all wireless audio systems share some common components: an audio source (this can be a Radio, a television, a stereo receiver, a smartphone, really anything that has an audio out or headphone jack), a transmitter, a receiver, and an audio amplifier. The audio source is the device that contains the audio signal. The transmitter receives the audio signal from the source and then transmits the signal wirelessly. The receiver picks up this wireless signal and passes it to the audio playback device which plays the signal back as audible sound.

WirelessAudio-SignalChainKeep in mind that wireless audio technologies deliver audio signals, not power, wirelessly. Depending on the design, wireless audio devices may be powered with batteries or with a power cable.

FM Transmitters

FM transmitters are great devices that serve a wide variety of applications. These devices are typically connected to the headphone jack (or audio output jack) of an audio source and are able to transmit the audio on vacant FM frequencies. These wireless FM broadcasts can then be received by any FM radio.

WirelessAudio-FMTransmitter

FM transmitters are very popular due to their ease of use and wide compatibility. The audio quality provided by FM transmitters is limited compared to other technologies. Top-notch FM transmitters may offer a frequency response of 30Hz to 15kHz. The operational range (i.e. broadcast distance) of FM transmitters varies. Some are low powered and will only transmit audio a few yards, while others may be able to transmit a signal 50 feet. The FCC places limits on the output power for these devices to prevent interference with licensed FM radio stations. The FCC output power limit is 250 Micro Volts at three Meters.

FM transmitters are often used to transmit audio from source devices like MP3 players, satellite radio receivers, etc. to car stereos, home theaters, or portable radios. Many times they can be found in gyms or fitness centers where they are used to transmit audio from televisions. People who are exercising simply tune their radios to the FM frequency listed below each T.V. to hear the audio. One point of confusion that often exists, is transmitting an AM signal over FM. The transmitter doesn’t “care” what is on the audio signal, it just uses the FM frequency band to send that signal to other devices on that same frequency.

One of the greatest benefits of FM transmitters is the fact that the transmitted audio signal may be received by any and all FM radios within range. As far as the radios are concerned, they are receiving an FM signal just like a normal FM radio station.

Bluetooth®

Bluetooth is a wireless technology that uses radio signals in the 2.4GHz band to transfer small amounts of data wirelessly over short distances. While Bluetooth can transmit various types of data, we will focus on its usefulness for wireless audio.

Many new mobile devices like tablets, smartphones, MP3 players (etc.), may already have Bluetooth communication technology built in. These devices are also capable of storing music or audio files, thus making them “audio source devices”. These Bluetooth devices may actually perform two functions of our wireless audio chain: the source and the transmitter. There are also Bluetooth transmitter devices which may be connected to the headphone jack of an audio source to transmit audio to a Bluetooth receiving device.

Bluetooth audio receivers are available in various forms. They may be devices which can be connected to input jacks on (non-Bluetooth) playback devices like home stereos, amplified speakers or headphones. Other times, they may be devices which are consolidations of Bluetooth audio receiver and playback device. These are typically stereos, amplified speakers, headphones, radios (etc.) which have integrated Bluetooth audio receivers.

WirelessAudio-Bluetooth

Providing 20Hz-20kHz frequency response, wireless Bluetooth audio offers better audio quality than FM transmitters. The operational range is about 30 feet with clear line of sight. A neat feature about Bluetooth is that because it can transmit data other than audio signals, it is possible for Bluetooth receiving devices to offer control of audio content such as fast-forwarding/rewinding, song skipping, pausing etc.

Most people familiar with Bluetooth may have seen the technology used in wireless earpieces for cell phone calls. (Some of us may just wonder why so many people seem to be talking to themselves nowadays.) Bluetooth is also used for mobile or home speakers systems. Since many new audio source devices (smartphones, MP3 players, tablets, etc.) feature Bluetooth technology, Bluetooth speakers offer a convenient and widely compatible way to playback audio without requiring special (proprietary) adapters, connectors, or docking mechanisms. This is one of the greatest strengths of Bluetooth technology in regards to audio. Due to the 30ft range of Bluetooth, audio products using this technology are typically optimized for single room (close range) environments.

WiFi

If you’re not familiar with the term “WiFi”, please click the link above to learn more. In regards to audio, WiFi offers the same provisions as Bluetooth, but the operational range is usually about 250 feet with clear line of sight. Compared to the mobile benefits of Bluetooth, WiFi is typically more of a home-based technology that is able to connect multiple devices together to form a network. This networking ability works out great for setting up wireless audio systems to serve entire buildings.

Many people may already have wireless networks in their homes. In these home WiFi networks, multiple computers, laptops, wireless printers, tablets, smartphones, etc. may all connect to a single WiFi router to share data between the devices. Music (or audio files) stored on one device may be shared via the WiFi network with the other connected devices.

WirelessAudio-WiFi-1

WiFi audio products follow the same basic signal chain as the other wireless audio technologies. WiFi audio source devices, WiFi audio transmitters, WiFi audio receivers, and WiFi audio playback devices are all available. Generally speaking, WiFi source devices are typically also transmitters. WiFi enabled playback devices (speakers etc.) are typically also receivers.

As with Bluetooth, there are also separate WiFi transmitter or receiver adapters which can be connected to external sources or playback devices.

WirelessAudio-WiFi-2

Proprietary

Some audio companies make wireless audio products which only work with other compatible products made by the same company. These wireless audio products are usually sold as transmitter and receiver kits. Often times, multiple receivers may be used to receive a wireless audio signal from a single transmitter or source. Products like these, which are only compatible with other products made by the same company, are considered “proprietary”. The benefit of proprietary products is convenience. Since the products are designed to work together, setting up and using the systems is typically an easy process.

Keep it Simple!

All of these mentioned wireless audio technologies provide great methods for sharing audio without requiring cables. No matter which type of wireless audio set up you’re considering, the easiest way to understand the system is to consider the signal chain.

WirelessAudio-SignalChain

Original article written for C. Crane by James Adams