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EAA AirVenture Oshkosh RSS FeedSporty's new SP-400 is four radios in one
The new handheld performs the functions of a pile of different boxes
By J. Mac McClellan

Sporty’s new SP-400 handheld radio is a com transceiver, of course, allowing you to communicate across the entire ATC frequency band. It also can receive and display VOR radials, and ILS guidance, including the glideslope. And it can also receive NOAA’s dedicated weather channels.

Do you realize what a technological achievement that is? Those tasks represent four distinct receiver functions, and there is also the transmitter to send your words to the controllers. To deliver so much capability in a compact handheld transceiver that costs only $399 blows me away.

Consider that ATC communications operate across a section of the VHF radio band, and so do the VOR/LOC signals and the broadcasts from the NOAA weather stations. Sounds like a single receiver function, right? Wrong. These are four different operations.
First, the com part of the SP-400 operates on AM, which is unique to aviation. Virtually all other radio communications use FM techniques. So the AM broadcast and reception from the controllers is one function. But the NOAA weather channels broadcast in FM, so the SP-400 needs to be able to perform as an FM receiver.

We usually lump VOR and localizer functions together because those signals are adjacent to each other on the VHF band. But once the signals are received something called a VOR/LOC conversion needs to happen so that the different modulations of the VOR versus the localizer and be presented as either a radial to or from the station, or as the single center line guidance of a localizer. Not long ago a VOR/LOC converter was a separate avionics box that you had to buy, and then mount in your airplane.

Finally, the glideslope signal is in the UHF band and that requires still another receiver technology. Glideslope receivers have stood alone for decades, and many a well-equipped airplane had only one even though there were two VOR/LOC receivers. To get a glideslope receiver in a little handheld, and for so little money, is astonishing.

So, with the SP-400 you have complete IFR backup capability that is independent from the airplane electrical system and its antennas. You can talk to the controllers, track a radial to or from a VOR, and then in an emergency have ILS guidance to the runway.

The flat screen display on the SP-400 measures about two inches by two inches allowing plenty of room to show frequencies, radials and other information large enough that I don’t need my reading glasses to see them.

A vertical bar moves left or right to show course deviation from a selected radial or the localizer. A horizontal bar moves up or down to show glideslope deviation. In other words, it’s a conventional ILS display – except it is in a handheld navcom.

Despite the complexity of its multi-receiver functions using the SP-400 is as intuitive as any piece of avionics that I have encountered. To select a frequency simply key in the numbers using the telephone style keypad. The only trick here is to fill out all of the numbers. So, to enter 126.4, you would key in 126.400. You can also use keys marked “DWN” and “UP” to step through frequencies. Press and hold the button marked 121.5 and up comes the emergency frequency. The recall key displays a list of frequencies you have stored in memory.
When a VOR is received you see your bearing to the station. To enter a radial you hold down the OBS button. The SP-400 recognizes a localizer frequency, and the paired glideslope if there is one, without any special action other than entering the frequency.

Somehow the SP-400 receives the nav signals with good accuracy using only a “rubber ducky” type of antenna that looks much like that used on an ordinary handheld com. Obviously there is a lot going on inside that antenna, and the receiver itself, to perform all of the functions that require their own dedicated antennas on an airplane.

Standard power for the SP-400 is eight AA alkaline batteries though rechargeable batteries are an option, or you can connect to aircraft power. I like alkaline batteries for the emergency standby radio because their shelf life is years while the rechargeable batteries fade even when not in use. Also, it’s easy to carry along a spare set of alkaline batteries without worry they will discharge while waiting for you to really need them. A battery life indicator continuously displays how much power you have left.

An option that I would want is the $26 headset adapter so you can plug in your standard headset. The speaker volume of the SP-400 is good enough to hear in a noisy cockpit, but in a true emergency loss of primary avionics I would want the advantage of the normal headset.

Finally, Sporty’s SP-400 comes with a five-year warranty.

You can find Sporty’s Pilot Shop here at the show in Building D, booth numbers 4128 to 4130. For more information see sportys.com.

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