The Perfect Radio

So as anyone who’s seen me in person will surely know, I have a lot of radios. I’ve sold a few lately, but I’ve owned a wide variety. I have the VX-2R, one of the smallest radios ever produced. It’s got an incredible frequency range, too. I have the ASTRO Saber, one of the biggest radios ever made, capable of APCO25 digital voice, trunking, and MDC ID decoding. I’ve owned police scanners and mid-range radios.

Perhaps unsurprisingly, I’ve found that there are big differences between a tiny, $200 radio and a gigantic, $5,000-new ($250 on eBay a decade later) radio. But the huge expensive one doesn’t always win out. If I were designing a radio (which I’d like to!), here’s what it would be like….

  • Medium size. The tiny radio is handy, but it ‘feels’ crappy just because it’s small. The Saber and ASTRO Saber feel like some of the most solid radios ever built, but they’re almost comically large. I want something in the middle: solid, with controls big enough to use, but something that I can put in my pocket.
  • A good speaker. I can turn my Saber / ASTRO Saber up halfway and hear it more or less throughout the house. By comparison, if it’s noisy, I can’t hear my VX-2 unless it’s pressed against my ear. And turned up all the way, it’s heavily distorted. This is probably true of the Saber-based radios, but you’d probably blow out your eardrums before you noticed the distortion.
    • The sound quality is just as important as volume. The Motorola radios have a nice ‘deep’ sound, whereas most other radios sound somewhat tinny.
    • It probably costs $5 more to include the best speaker ever put in a radio in. I’d gladly pay $50 to upgrade to a radio with substantially better audio quality. Why don’t more people include good speakers?!
  • Notch filter or similar. There’s lots of extraneous noise on most signals. It’s actually pretty easy to filter it out, and ‘base’ HF ham rigs have been very good at it for a long time. Something as simple as a notch filter would eliminate a lot of the nuisance noises and make listening much more pleasant. (You could do a lot with DSP and make audio sound much better, but someone should at least do the minimum…) This is also the place to mention that I’d really like it if your radio would do some volume normalization.
  • A good microphone. For normal ham radio stuff, this doesn’t really matter and any 19-cent microphone can be soldered in and work just fine. But ‘real-world’ stuff doesn’t work that way.
    • At work, I can almost never hear the mechanics when they’re out back trying to talk to me. They could be telling me that they’d like me to ask the snack bar to cook them a hamburger, or they could be telling me to shut down the machine because they have their arm stuck in the gears. I think a good directional microphone would be a big help here, in only picking up what’s directly in front of the radio and not the (very loud!) ambient noise. (I remain convinced that another microphone on the back of the radio, ‘subtracted’ from what’s coming into the front micrphone, could produce amazing results.)
    • Campus Police responds to a lot of fire alarm activations. The fire alarms are extremely loud, to the point that it’s literally painful if you’re there in person. You can only hear what they’re saying between the buzzing of the alarm, and even then it’s hard because it echoes. I don’t know that this can be solved easily, but I’m sure a good design could at least help.
  • A nice big screen. In ham radio, giving me eight characters is considered amazing. Many commercial radios just give you a numbered readout of what channel you’re on. The ASTRO Saber has an incredible 14 (I think…) characters. But even then, fitting “Boston PD Channel 4 – Area ‘E’ – West Roxbury, Jamaica Plain, and Hyde Park” is a chore. You end up with something like”BPD4EWRX-JP-HP,” which is not that helpful until you get very familiar with it. At which point you’ll probably know what Channel 4 means without the label anyway.
  • A sane way of organizing channels. Motorola gives you 16 ‘zones’ of 16 channels each for 256(ish) channels. (This is technically not true but it’s a practical limit.) Many ham radios just give you 200 channels. Some of the better ones (and some scanners) let you use ‘banks,’ which are sort of like ‘folders’ of channels. But there are almost always limits: a bank can almost always store 40-50 channels max, and you usually can’t assign a channel to more than one bank. In my mind, it’s idiotic to still have these limits. What if I want 60 channels in one bank? What if I want to have 72 banks? What if I want Campus Police in a “School” bank and a “Waltham” bank and a “Waltham – Active Emergency” bank?
  • Nuisance Delete! Motorola got this a long time ago, but until I bought the ASTRO Saber, I’d never heard of it since it seems like nothing else supports it. When you’re scanning a range of channels (which is, you know, what scanners are for), there’ll sometimes be one that you don’t want to scan. Maybe you have the police, fire, and the local ham repeater, and there’s a big fire going on. The police are scrambling to get someone out of the building while the fire department is attacking the flames. And then the scanner stops as someone on the local ham repeater discusses how he doesn’t really care for Taco Bell that much these days. Most scanners have a “Lockout” which will ‘permanently’ delete the channel from the list of channels it scans. Nuisance Delete is temporary and gets wiped out once you stop the scanning ‘session.’
  • Recording! Really, I can’t believe there’s almost nothing on the market that does this. I want to leave the radio ‘off’ (let’s call it “Standby Mode’) on the charger all day. And when I see five police cars go speeding by, I want to jump out of my seat, pick up the radio, and hear what the police dispatcher said two minute ago. I’m not aware of any radio that will do this. The thing is, voice takes up very little space. 64kbps MP3 would be plenty. Probably overkill. And a 1GB flash storage card is about $20. And I bet you could get it for a quarter of that if you were buying them OEM to embed as opposed to a consumer buying SD card. You could store weeks of audio. And how many times are you listening but you miss a key detail. (When I’m listening to try to figure out why the emergency vehicles went by, I’ll almost always hear, “We’ll be on scene with a –” “Hey Matt, do you know what’s up with that fire truck?”) It’d be great to just replay it.
  • Digital mode support. This is kind of vague, and could involve a lot of licensing / royalties. But public safety (law enforcement in particular) is very quickly moving to the APCO Project 25 Common Air Interface (generally “IMBE,” “P25,” or Motorola ASTRO). There are three scanners, out of probably 50, that do this mode, and their audio quality doesn’t compare to the genuine radios. There’s also trunking which is very common in cities. The ability to monitor paging networks (POCSAG/FLEX) is handy, but raises a lot of legal issues. (Intercepting other peoples’ pages is explicitly illegal and it’d be hard to design a radio that could decode the protocols without allowing people to see other peoples’ pages.) There are other experimental digital modes, too.
    • The best solution, IMHO, is to make the device run Linux (or any other common embedded OS) and release an SDK so people can write their own digital modes.
  • Muting of various junk, such as digital modes. These days I’m using the VX-2, and I really miss the ASTRO Saber’s “DOS [Data-Operated Squelch] Muting,” which would detect MDC1200 data traffic and mute the speaker. All too often what comes out of the speaker isn’t voice, but just various noise that gets transmitted over the air. It’s really not that hard to detect it.
  • A good battery. I should be able to use it all day, including periodic transmission, without recharging. (Motorola famously offers a 4,000 mAh battery for their flagship line of radios.)
  • A very readable display. Not just big as I said earlier. One of my radios is hard to see if I look down at the LCD. Another is hard to see if I look up at the display. Another is kind of washed out if the backlight is on. Anything with a graphic LCD (very few radios) is almost impossible to see in direct sunlight. (Frankly, I’m very impressed with e-ink displays like the Sony Reader, and would be obliged to buy a radio, no matter the price, that had one as an LCD.)
  • A frequency counter, to detect what frequency something is on. Generally you have to buy an external device to do this. The VX-2 is (as far as I know) the only radio ever made with a neat feature which is basically a ‘ghetto’ frequency counter: it’ll kick in a 100 dB attenuator and see what frequencies it can find, good for locating very close transmitters. But it’s not a real frequency counter. It seems pretty obvious to me that frequency counters and radios are generally used together, so it’s really kind of surprising that so few people have thought to blend the two.
  • Durability. I drop things. Public safety radios get it ten times worse. You’ll read stories about people dropping their high-end Motorola radios into the ocean, or someone dropping it and then backing over it in the fire truck. And they pick it up, dust it off, and realize it sustained almost no damage. There seems to be more of a focus on making things cheap than on making them durable these days, though. But we want durability! At the very least, I should be able to stand on top of the machines at work and drop your radio eight feet (or so) onto the concrete floor and just have to put the battery back on.
  • Scratch-resistance. Especially the LCD. For some reasons radios don’t seem to scratch as bad as cell phones and iPods, maybe because not many people put their radio in a pocket with their keys. But a lot of watches have faces made out of things like sapphire or crystal that are basically impossible to scratch. I’m sure this adds to the cost (watches like this aren’t exactly cheap), but I also bet much of that stuff could be grown in a lab. People do care when it’s for a wedding ring, but I’m pretty certain no one cares when it’s for a radio display covering.
  • Intuitive controls. I shouldn’t have to press ‘shift’ and then something else to perform basic functions. When it’s -10 out and my hands are almost numb, I should still be able to operate the radio. (And when I wise up and put gloves on, I should still be able to use it.)
  • Wide frequency range. I’d be interested in working the 6-meter ham band (50-54 MHz), the 2-meter ham band (144-148 MHz), VHF ‘commercial’ (136-174), the 220 MHz ham band, the 70 centimeter ham band (420-450 MHz), the enormous UHF commercial split (403-520 MHz), the 700-800 MHz public safety band, and the 900 MHz ham band. If I were to cover all of these, I’d probably need eleven radios. My little VX-2, smaller than a deck of cards, will happily receive all of them. There’s been one commercial radio that would let you transmit on more than one ham band, and that was discontinued a long time ago. (Many ham radios support several bands.)
  • Simple programming. I like FPP (front-panel programmable) radios, but there are legal issues on commercial radios that usually prevent this. It’s also handy to be able to program radios on a computer, especially if you have a lot of channels or want to program a lot of radios the same way. (Aside: why can’t radios share data over the air? There could be an ‘over-the-air cloning’ mode that uses something like spread spectrum to avoid interference, which could make programming a fleet of radios much easier.) And it’s also neat to share frequencies with other radio users. As far as the computer programming, though…
    • The interface has to be intuitive. Motorola’s RSS, somewhat of a standard (until their Windows-based CPS replaced it), is probably the least intuitive piece of software I’ve ever used. Programming the ASTRO Saber, I had a huge sheet of paper. On one screen, I’d input a “personality,” which was the frequency for a given channel. Then I’d have to map that personality into a zone, hence the big sheet of paper keeping track of what went there.
    • The software should be free, or at least included with the radio. (It should really be open-source, in my opinion, so people can enhance it.)
    • Programming should be quick. USB 2 allows 480 Mbps. Why are people still designing connectors that use serial ports? The last few computers I’ve owned haven’t even had a serial port. Not only is it obscure, but it’s so slow!
    • As long as the device is Linux-based, why not just have an /etc/channels.xml file or something? Using an open standard like XML, and making it just a file that anything can read/write over USB, would make programming ten times easier.
  • GPS. Ham radio has APRS. And frankly, I’m very surprised that there’s no public safety equivalent, especially as they all go digital. (Random aside: LTR trunking uses “subaudible data” to pass the relevant control information: they pass the data in the ‘audio’ range outside of human hearing, so it’s there as part of a signal but not reproduce as audio, so it’s basically ‘hidden’ in the analog voice signal. This is ingenious. In the 20 years or so since that began, I’m surprised that no one has ever thought to embed PTT-ID/ANI (e.g., a way of identifying which radio is which) data that way. And now you could embed GPS coordinates that way… But I’ve still never heard of it even being attempted.)
  • Tones and a vibrate function. Cheap “bubble-pack” radios have a “call” function that transmits a ringing sound. It’s actually very useful at work for getting one’s attention. High-end radios have things like “Private Call” that send a digital signal to a particular radio telling them to sound a bell to get the user’s attention. This is also handy. A vibrate function on phones is common for quiet areas but many will agree that the vibrate feature is actually most useful in very loud areas where you’ll rarely even hear your phone ring. I want the same on a radio.
  • Remote control. This isn’t useful for individuals, but is actually fairly common already in fleets of radios. Some existing uses:
    • Motorola’s OTACS: Over-The-Air Channel Steering. You could want all the firefighters at a given call to switch over to a fireground channel. Why not let the firefighters tend to the fire instead of their radios, and just send their radios a command to switch over?
    • OTAR: You can push out a new encryption key to all the radios in a fleet. (As inherently insecure as this sounded at first, it’s actually a complex process that’s incredibly secure.) This is important since, in a really secure setup, the key should be rotated every few days. It’s not practical to pull in all the radios for reprogramming every few days.
    • Remote inhibit. When a radio goes missing, dispatch can send an inhibit/stun command, which basically renders the radio a brick: a brick that silently keeps listening for an uninhibit/restore command. This means that if someone steals a radio, and it’s detected, they won’t be able to monitor you, much less interfere.
    • Remote transmit. Usually in response to an officer transmitting an emergency call or just not responding. Dispatch can send a command to the radio instructing it to begin transmitting audio, so they can hear what’s going on.
    • General reprogramming: I’ve never heard of this! It could be extraordinarily useful, though!
    • This whole thing needs to be encrypted/authenticated. The current implementations are not, which means that anyone with access to a dispatch console (rare, but they show up on eBay periodically) could, say, start sending inhibit commands to radios in the field. This could be really, really bad if it ever fell into nefarious hands.
  • A clock. Just a simple clock shown on the radio. (For bonus points, the radio should be capable of receiving the time over the air anyway from various atomic clocks, so you could have a very accurate clock if you were willing to take the time to program it.)
  • RSSI: I want to be able to see how strong the received signal is. Almost all ham radios do this. Very few commercial radios do. (RSSI stands for “Received Signal Strength Indicator.” Hams generally call it an S-Meter.)
  • Text messaging. A lot of departments will give their officers pagers, too, to send supplemental information. Why not just do it over the air in text form? Some of the newest Motorola radios support this, actually.

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