Railfan Technology > NXDN Consumer Radio Status, 2016 edition

Welcome to my fourth annual NXDN report from the Dayton Hamvention.  The Hamvention is the largest “trade show” for the Amateur Radio (Ham Radio) hobby.  The attendance last year was just under 26,000 and probably a few more this year.  All major manufacturers of Amateur equipment and some of the smaller ones are represented.  

The news for this year, there is the good, the bad, and the ugly.  Let me start out with a little good news.  NXDN will be available on "consumer grade" hand held scanners by the end of this year.  Another bit of good news, a factory rep from Kenwood that is very knowledgeable about the rail industry says he doesn’t expect the class 1s to use NXDN on the main lines for 5, or maybe even 10 years.  He said that some of the short lines are using it and some non-main line functions are using it but that’s about it for now.  He said NXDN seems to be the best protocol for the industry but the NXDN committee is working on some needed enhancements.  So, those old scanners you bought 5 years ago and still going to be usable along most railroads for several years.  The other good news is that there will be at least two NXDN compatible handheld scanners available by the end of the year.
 
Now for a little bit of bad news.  It’s not really all that bad.  Both Bearcat and Whistler will have either a new scanner or a software upgrade available this year.  The bad part is that there are no dates available for when it will happen.  I ask Whistler and they said, “By the end of the year.”  I ask, “You mean June, July, maybe October?  The answer was the same, “By the end of the year.”  There was no budging on the answer.  The radio is already available but NXDN will be a software update.  No word on the cost of the update, if any.  Bearcat was about the same.  Their scanner is available but there will be a software update “By the end of the year.”  This is a big improvement over the first year I ask about NXDN.  Some of them didn't even know what I was talking about.
 
OK, time for the ugly.  I saw the AOR “AR-DV1” scanner that came out about a year ago.  Nice looking radio and it will copy just about anything from AM to NBFM, WBFM, NXDN, DMR APCO P25, and several others.  Here’s the bad part.   MSRP is a little over $1300 and the street price is around $1200.  The Whistler and Bearcat products will be a bit less expensive.   Still, the “less expensive” isn’t cheap.  Both will be in the $600 range.  Neither could give me the exact price since they are still in development and on their way to the market.  Both said “$600-ish.”  In a world of Bearcat and Radio Shack scanners around $100, Yaesu, Kenwood, and Icom ham radios at less than $150, and the Chinese “Baofeng” radios for $50 (I actually saw them for sale, new, in the box for $27.95) it’s hard for most of us to think about $600 for a radio.    For that price you can by a new Icom NXDN radio, programmed for the railroad frequencies. 
 
Now let me add a bit of mystery.  During the past year, Alinco introduced a UHF version of an NXDN radio but there was no word about VHF (161 MHz) version.  A year ago they were waiting for the FCC to approve the radio and then they would work on the VHF model.  I didn’t find their rep this year.  Alinco is usually a little less expensive than some of the other brands.  I just don’t have anything that I can report, good or bad. 
 
Now for a personal observation.  As a ham I recently upgraded part of my station to include digital voice.  I am using the Yaesu “System Fusion.”  In the Yaesu forum at the Hamvention the speaker ask if anyone had used any other digital format that sounded better than the Yaesu system.  The only comment was someone that had used NXDN.  I would guess that part of the difference would be because the NXDN radio was commercial grade and probably had a slightly better or slightly larger speaker.   The Yaesu system and NXDN both use C4FM (Constant Envelope 4 level Frequency Modulation) but use different vocorders (voice coder-decoder, or A to D and D to A conversions).  That’s just a bunch of technical jargon to say that the two are similar.  C4FM is about the latest and greatest available.  My personal experience with the consumer grade Yaesu radio is that it really does sound quite decent.  It sounds better talking to someone across town than analog FM sounds when the person you are talking to is in the next room.  With GPS on both radios, I get a display of how far it is and what direction to the other person.  When they transmit it displays their call sign.  There is the capability of transmitting voice and data at the same time.  The system also allows some addressing capabilities to limit who you talk to or who you want to hear.  NXDN has similar capabilities.  It’s just a matter of what the users want to include in the system.  Those are the things the NXDN committee is working on.

 
I’m not the authority on this subject.  I just happen to attend the Hamvention and ask a few question.  I’ll try to keep my ear to the ground and listen for any developments.  There are a few others on Trainorders that may know more and I welcome their comments.  After all, “We’re all in this together.” 
 
John
 



Edited 1 time(s). Last edit at 05/22/16 22:34 by wa4umr.

Thanks for the report, John.

With 3-4 mfrs all giving the same "by the end of the year" do you think they are all waiting for the same new NXDN chip from the same mfr?

Posted from iPhone

Thanks for the report.  There's some interesting info in it.

KG

John, thanks for the report.  I don't know whether to get an NXDN radio or not now.  I like to ride the Cumbres and Toltec and I understand that they are now using NXDN, so if I can, I may go ahead a get a radio if I it is a bargan.
Also thanks for the info on the scanners, kind of expensive for my retirement income, especially since it can't transmit.
Lots of other good info.  Hope that you had a good time at the event.  Maybe one day I will attend.

73's
Pat
WA5VRO

I use NXDN--the voice quality is very good--better than most any analog.  One of the essential differences between analog and digital is that analog signal strength tends to degrade along a fairly straight downward line as distance increases, and the voice quality degrades similarly.  With digital, one usually will get crystal clear audio until right near the very end of the radio's receiving distance where, at that point, the audio simply cuts off. As noted, digital radios, and NXDN is a great example, offer a plethora of data transmission, group calling, emergency call, and other features that analog just doesn't have.  There are a lot of those capabilities that the railroads may never use, but there are a bunch that they undoubtedly will use.

I personally think that the railroads' cutover to NXDN will happen in less than 10 years.  Most all of the moblie, portable, and locomotive equipment  will be NXDN-capable long before then.  The bigger challenge is changing out all the base radio, relay radio, and repeater equipment.  There is a lot of that, and it's more expensive than the other mobile, portable, etc. equipment, though NXDN bases, repeaters, etc. cost a fraction of what Motorola's digital base stations, etc. cost.  Also, since NXDN is based on an open architecture platform, it is a lot easier to modify and enhance.  I've been around NXDN for about five years now, and there have already been a lot of features added to it in just that time.

As to the NXDN scanners, at the prices that have been quoted above, they're a non-starter--there are first-rate commerical NXDN radios available for less than those prices that  are on the market right now.



Edited 1 time(s). Last edit at 05/23/16 19:43 by WW.

With the description of analog vs. digital reception, how does effective range compare under similar analog tx/rx characteristics?   Will you still be able to receive a digital transmission where you might still be able to understand a weak analog signal?  Railroads have a number of considerations when looking at terrain, length of trains and so forth.  Canyons, tunnels and other obstacles can make life difficult even from a mile away.   The change over to narrow band VHF presented some challenges to longer distance communications from engine to "pack set" was we called them.

sphogger

I frequently hear the complaint, "Digital doesn't perform as well over long distances as analog did."  When I dig a little deeper into the comment, though, I usually find out that the comparison that is being made is between digital and the old wide-band analog.  In my experience, NXDN reception distance is pretty close to that of narrow-band analog.  Also, in my experience, narrow-banding shortened reception distance by about 10%-20%.  NXDN gained a little bit of that distance back, but certainly not all of it.  Both analog and NXDN are susceptible to RF interference, though it usually has to be pretty bad to mess up digital signals.  There is no doubt, however, that a "dirty" digital RF interference source will cause problems to NXDN (and, usually, to analog, too). The one quirk of NXDN that I've discovered is that if two NXDN radios are trying to talk to each other over a very short distance, say, less than  300 feet, they may not be able to hear each other.  It isn't a consistent issue, but does happen, and I have seen it happen with analog radios, too, on occasion.

When it comes to portable radios ("pack sets"), they will always be at a disadvantage.  The radio receiver hardware found in a portable radio is essentially the same as that found in a comparable mobile radio model.  For example, the hardware and firmware in the Icom IC-F5061D mobile is so nearly identical to the IC-F3261D portable that the same software program is used to program both.  The difference in reception lies with the portable antenna and where the radio is carried.  A "rubber ducky" antenna--even the best quality ones--are extremely inefficient at receiving signals.  Carry the radio on your belt and your body can absorb up to a third or more of an incoming radio signal before it even gets to the antenna--especially if your body is between the portable radio and the transmitting radio's antenna.  Put the portable radio inside a metal container like a vehicle interior or passenger train car and the incoming signal can be degraded by another 50% or more.  Portable radios are essentially good for one major purpose--to carry when you are not in proximity of a mobile radio--as in the case of being out in the field away from your vehicle.  That is why I use mobile radios mounted in the vehicles that I drive and I keep a portable to strap on if I'm going to be away from that vehicle.  Though not applicable to railfanning, transmit is self-explanatory.  Do you want to transmit with 5 watts of transmit power using an inefficient, poorly located portable antenna, or would you rather use  30W, 50W, or 100W of transmit power of a mobile radio using a very efficient antenna?

Finally, all of the same caveats still apply when purchasing, installing, and using NXDN equipment.  Good quality radios, good quality antennas, good installations (in vehicles) will get one the best reception.  Skimp on any one of those, and the setup will not work very well. There is no free lunch.



Edited 1 time(s). Last edit at 05/25/16 18:19 by WW.

Thanks, very interesting thread.  Sphogger. 

sphogger Wrote:
-------------------------------------------------------
>
> ... how does effective range compare under
> similar analog tx/rx characteristics?   Will you
> still be able to receive a digital transmission
> where you might still be able to understand a weak
> analog signal?  

There's a video on YouTube you might want to check out.  It's not very exciting.  It's a couple of hams testing a couple of digital formats to analog and digital to digital.  They do not test NXDN but the results should be similar.  The Yaesu System Fusion and NXDN both use C4FM for transmission but different vocorders.  The results should be similar.  You can find it if you search "hamradionow episode 161".  You can skip the first 20 minutes.  They are just comments about the Yaesu radio system.  This is a pretty good real world demonstration.  It's not exciting at all.  They guys drive down the road until the analog signal gets pretty noisy and they stop and do the testing.  No slick production or exciting dialog, just analog to analog and then digital to digital communications and then comparing different digital modes.   D-Star is GMSK and not a good comparison to NXDN.  Did I say it's not exciting?

John