Operating D-STAR You’ve seen the ads, now find out how it works and what it does. Gary Pearce, KN4AQ ou’ve probably heard or read about D-STAR, the system for VHF/UHF digital voice and data Y being promoted by ICOM. At the very least you’ve seen the ads. But very few hams have actually used a D-STAR radio through a D-STAR repeater system. Since AUTHOR THE BY PHOTOS ALL this could be the leading edge of “the future Figure 1 — A complete system, an ICOM D-STAR repeater and controller, along with the of Amateur Radio,” you might be curious what ID-800 mobile and IC-91AD handheld, getting ready for operation on the K4ITL repeater that future sounds like and how it works. system in Raleigh, North Carolina. Digital Telephony is Here to Stay Out there in real life (that is, outside of Broadcast radio, both AM and FM, are fairly inexpensive add-ons to your existing HF Amateur Radio), the transition from analog to in their digital infancy. It’s a troubled birth. and VHF radios. Even so, they have a relatively digital communications is happening all around I wouldn’t blame you if you didn’t know small (but enthusiastic) number of users. With us, though each industry has its own pace. there is a digital AM and FM, even few exceptions, digital voice is still an expen- From the everyday user’s perspective, cell though there are more than a few stations sive and rare HF add-on.3 phones are way out front. Try to buy an ana- broadcasting that way now and there have been log cell phone today — you’re going to have a few fairly recent QST articles on the topic.1,2 Enter D-STAR to look hard. The cell phone industry had to Digital AM yields “FM quality” sound, and Digital voice for VHF-UHF, such as with embrace digital quickly, even though it had digital FM is “CD quality.” Some of the sta- D-STAR, requires whole new, and fairly a huge analog infrastructure. Digital let cell tions call themselves “High Definition Radio.” expensive radios. There have to be some big systems more than quadruple the number of They don’t have the same pressure their TV advantages to get us to go there. Will the D- calls they could handle in a given amount siblings do, since digital radio is done “on- STAR digital voice system provide the advan- of time and spectrum, two elements in very channel” along with the analog signal. It uses tages that will spur a VHF/UHF version of the limited supply. no extra spectrum, and there’s no deadline switch we saw from AM to SSB on HF in the Digital landline telephony may seem in looming for switching off the analog signals. ’50s and ’60s? It might. It offers clearer sig- its infancy, but behind the scenes the good Broadcast satellite radio is breathing down nals with less bandwidth than analog FM, and old phone company has been digital for their necks, though, and they’ve been digital a more elegant and targeted form of network- years. The copper wire carrying your analog from the start (Sirius and XM Radio are the ing than IRLP or EchoLink (amateur voice voice probably doesn’t go more than a mile two satellite radio broadcasters in the US). over the Internet with radio links) do today. or two before the signal is converted to digi- Business and public-safety two-way radio My first experience with D-STAR came in tal for transport to anywhere on the globe. are slowly making the transition. They are Huntsville, Alabama last October at a D-STAR Sykpe, Vonage and other VoIP phone sys- required to reduce their channel space over training seminar. Here several D-STAR pio- tems are just the new kids on the block. the next few years, but they can do that with neers gave talks to help the next wave of early Digital audio and video on the Internet are either analog or digital modes. adopters understand how this system works. booming. Just ask your kids. This is new stuff, And then there’s ham radio, where digital These seminars are intended for repeater own- with no old analog infrastructure to push out voice is still just a novelty. Hams are happily ers and the most dedicated users. You can of the way, though it seems as if my computer using voice modes that were developed in the get really deep into this stuff. It reminds me is prodding me to install an update to one of first half of the previous century — AM, FM, of both the enthusiasm and complexity that the many media programs every few days. SSB — and the equipment we use today is still packet network sysops experienced in the mid compatible with the earliest products devel- ’90s. Everyday users, you and I, won’t need Digital Voice over Radio oped for those modes more than 50 years ago. to get this deep into it. At the most basic level, Broadcast television is teetering on the For hams, the transition to digital is going to we’ll be able to operate digital voice through edge of its digital revolution. Almost every be bumpy, for many reasons. We have to spend repeaters almost as easily as we use analog TV station now has a digital transmitter going, our own money to upgrade and, except for the repeaters today — you’ll need to enter your and most have at least some high-definition change from spark to CW, we’ve never been call sign in a menu in your radio before you use programming. In February 2009, just after the told we have to. SSTV, RTTY, packet, PACTOR any repeaters. After that, just key up and talk. Super Bowl, all US analog TV transmitters get and the other TORs, PSK and the newer, nar- To go beyond that, to talk to a ham on a net- turned off for good. Public safety and business row text/data modes are niche modes that are worked repeater in a distant town, the D-STAR radio users sit poised to jump on the spectrum system makes you poke and prod inside your that will then open up in the 700 MHz band. 1Notes appear on page 33. radio’s menus a bit to enter more call signs From September 2007 QST © ARRL (your local repeater, the distant repeater, or the (PTT) switch. No courtesy beeps (though there like? If you have a cell phone, you’ve probably ham you want to talk to) and set options. If you is a beep of sorts generated by your radio that heard lots of digital voice audio. My cell phone are a ham who finds programming your radio you hear at the end of a transmission some- is one of the increasingly rare models that will for CTCSS (continuous tone coded squelch times). No autopatch. ICOM’s controller has do both digital and analog. When I’m in very system) so you can use a tone access repeater no provision for Morse tone (MCW) or voice rural areas (such as the middle of Death Valley, too big a challenge, I’m afraid you might be identification announcements or other canned as I was recently when my phone surprised left in the digital dust. At least for now. messages. the heck out of me by ringing), I get only an But fear not — this change will happen You hear a user’s voice, or you hear nothing. analog signal, and I find the background noise slowly. That analog-only handheld you got You can see something, however. Whenever and picket-fencing to be unusual, even though for Christmas will have a place for a long, you receive a signal, you see the transmitting I’m used to hearing all that on ham repeaters. long time. station’s call sign on your radio display. You In digital mode, the cell phone audio is usu- might also see a short text message, such as ally perfectly clear. When the signal gets very D-STAR Needs Repeaters, Too “Hello from Gary.” And S-meters still work. weak, the voice I’m listening to begins to gar- D-STAR repeaters are special. Because of When someone else is talking you can see how ble a little. Syllables or whole words just dis- the narrower D-STAR bandwidth and special strong the repeater is, even if your ears aren’t appear, but there is no noise. It’s actually kind requirement to allow decoding of the modu- giving you any of the usual clues. of irritating, because intelligibility begins to lating signals, D-STAR repeaters don’t work Otherwise, routine operation on a local suffer before you know what’s happening. You between analog radios, nor can analog repeat- repeater is, well, routine. You push-to-talk miss words, but you don’t know you’ve missed ers handle D-STAR signals. and release-to-listen. One exception — you them. With a noisy analog signal you know Repeater coverage is reported to be just have to program your call sign into the radio when you’re losing pieces of a transmission. a little better with D-STAR than we’re used before you can talk through a repeater. You Most of the time the digital signal is prefer- to, thanks to the narrower bandwidth. I’ve do that with the front-panel buttons and menus. able to a noisy analog signal.