Dstar Blog

November 23, 2010 Dave has fixed the problem with the spontaneous unlinking.  There is a feature in the hotspot software that commands the hotspot to relink if it gets booted off.  So far today that has happened twice and on both occasions it has immediately relinked.  This is the same feature that Monlink performs on the repeater.  Thanks Dave, looks like we’re back in ‘Fine Business”.

November 21, 2010 We are continuing to experience spontaneous unlinking of the St Helena hotspot. It happens at irregular intervals so it is being difficult to troubleshoot.  The only thing I can tell for sure is it is happening immediately after a gateway data update.  Once per hour, at approximately 3 minutes after the hour, the databases are updated with fresh user tables and gateways.  This is necessary because new systems and users come on-line everyday around the clock.  The update does not take very long, just a few seconds, but for some reason every now and then it is causing the link between the hotspot and the repeater gateway to stall and time out.  Upvalley users should ker-chunk  it now and then, sometime around 10 minutes after the hour and see if it is linked.  If not, link it up. (unless you like the peace and quiet.)

On another note, I was experimenting with the echo feature.  I got to thinking about the usefulness of a hotspot that is not linked to anything.  An analogy might be a working telephone that is “on-hook” in other words, not being used.  Unlike a repeater, a hotspot is a simplex device and when it is not linked to anything it can’t pass traffic.

Or can it?  Using E in my urcall, I made a rather lengthy transmission to nobody in particular.  When I unkeyed, what I had said played back to me.  If someone in, say, Calistoga needed to be heard in Napa, that would be one way to do it.  And by the way, I did this from the multi-purpose building in Kennedy park using my handheld with a rubber duck.  Keep it in mind.

In another experiment (from my shack) I set up D-rats and sent a number of Data transmissions to the unlinked hotspot using E in my URcall.  Each transmission was echoed back and repeated back to my computer but unfortunately it contained a lot of overhead  and then only the first 30 characters of what I sent was correctly received.  Not very useful but it does look like data will pass through the hotspot into the network when it is properly linked.  Anyone want to try it?

November 19, 2010 Some good news for those interested in building their own DVAR Hotspot.  Mark Phillips, builder of the Mini Hot Spot and the NQSMHS has put up his own website where you can see his product and order them as well as accessories.  Go to http://www.gmskhotspot.com/ to see or order.  Click on the photo of the enclosure above what looks like a link “Click for embeDiSTAR appliance” or just Click here to see something really interesting!   Mark is beta testing a small board that will support a remote hotspot without the need for a computer! A lot of hams have the same thoughts that I do: If it will support a hotspot, what else will it do?  Mark has answered that question.  It will perform a lot of functions that are today performed by laptops and desktops but not all because it has no provisions for a PCI bus. This means you can’t plug in things like sound cards and such.  But the path forward is clear and began with the introduction of Mini-ATX, Micro-ATX and even smaller boards.  It won’t be long before fully functional computers about the size of a paper back book will be commonly available.

November 3, 2010 Anatomy of a Black Hole

If anything kills Dstar as a viable mode of communication it will be the dreaded “black hole.”  This is the name given to the circumstance  where one party makes a transmission and the other party fails to hear it.  Human nature being what it is, the party making the transmission usually steps up and accepts the blame.  (And will usually be blameless.)  A third party, we’ll call him the referee can monitor the conversation and keep score as I have done for the past two days.  Listening to numerous conversations I was able to note quite a few black holes and I found it interesting that in most cases, the transmitting party  made a successful transmission but the receiving party failed to receive it.  On a few transmissions, I, the referee, was a victim of a black hole when I failed to receive the transmission.  But, I was watching the on-line Dplus log and was able, in every case to determine if a transmission was successfully made and if there was any packet loss.

So this leads me to a couple of inescapable conclusions:
1:  If someone calls “black hole” on you, don’t be too quick to accept the blame.  If he failed to hear you the problem is more than likely on his end.

2:  If you are in a QSO and are failing to receive someone’s transmission, look around; are there lots of nearby hills or masonry buildings?  If so you may be experiencing multi-path distortion, not signal blocking.  Icom recognized the problem of multi-path distortion (MPD) when they designed the IC-2820H.  They built it with dual receiver ports (PL-259).  By using two antennas separated by several feet, MPD can be reduced or eliminated.  MPD also affects analog transmissions but we hear it and call it “picket fencing”.  Occasionally you will also notice rapid fading if you live under a commercial air flight path.  On a FM receiver you will hear very deep fading going in and out very rapidly but changing as the aircraft passes over, much like the Doppler effect.  The same condition affects Dstar signals only you don’t hear fading – you hear a “black hole.”

It seems that black holes are more common in mobile operation but they happen all to often in base locations where there are many nearby hills as in my case.

Collisions. It’s believed that if someone keys up too soon after someone unkeys, a collision will result and all will be lost, resulting in a black hole.  Makes sense I guess but explain this:  Listening to a longish transmission I can disconnect my antenna and let the signal drop.  The receiver will beep indicating it thinks the transmission is finished.  I can then reconnect my antenna and the conversation will resume almost immediately.  The conclusion is there is more than one destination header in every transmission and a collision will only clip the first part of the transmission.  Seems like some experimentation is in order.

November 3, 2010 The KI6SZE-Hotspot is ready to use.

What’s it do? It’s sort of like a remote base in that it extends your signal; not quite like a repeater because it operates on a simplex frequency.  Unlike an ordinary remote base though, the hotspot provides nearly all the features of a Dstar repeater.

How do you access it? The hotspot should be accessible, using a handheld, anywhere from Oakville to Calistoga and from Highway 29 past the Silverado Trail to the East.  Future testing will determine the exact limits.  Use a Dstar capable radio, either a handheld or a mobile and use no more power than required for solid communication.  Set your frequency to 438.500*, plus or minus offset with an offset frequency of 0.000.  You read that right.  Some programming software will balk at an offset of 0.000 so you may have to do this manually.  Set your callsigns as follows:

MY Your own callsign

When you transmit you will be heard on whatever node is linked.  Right now the hotspot is linked to Reflector 14C and since there are currently 13 repeaters also linked to Reflector 14C, you will be heard on all of them.  When you release your PTT, you will hear a beep and the link status will scroll across your display.  The callsign of the hotspot and the link status will also scroll across every 7 minutes.

Commands. You can unlink any current connection by changing your UR to “U”  Be sure the U is in the 8th position and don’t use the quotation marks, please.  Just a plain U in position 8 of the UR field.  Please don’t leave it unlinked because an unlinked hotspot is not very useful.  You can now link to any valid dstar repeater or Reflector.  This connection will show up on dashboards and dplus logs as a “dongle”, but will work just as if it were a complete Dstar repeater.  For a complete list of available reflectors visit This Link. For a complete list of Dstar repeaters, visit http://dstarusers.org/

To link to any reflector change your UR to REFnnnxL  nnn=001 through 036 and x=A,B, or C.

To link to any repeater (use W6CO as an example) change your UR to W6CO  BL  be sure the L is in position 8.  For repeaters other than W6CO use the same format.  Once linked to either a reflector or repeater, change your UR back to CQCQCQ.

Long term linking strategy. Not decided yet but we favor two:

1:  Linked full time to Reflector 14C with W6CO B also linked full time to Reflector 14C.  This gives you two benefits; usually someone around to talk to, and solid communication to Napa via the Mt Veeder system.  The downside of this strategy is if you want to talk to someone in Napa you will be heard everywhere…not necessarily a bad thing.

2:  Linked full time to W6CO B with W6CO B either linked to a reflector or not.  The benefit of this configuration is solid communication to Napa via Mt Veeder.  For use during events and emergencies, this would be the preferred configuration with no link between W6CO B and anything other than the hotspot.  An example would be the NV Marathon.  Using Dstar we would have “armchair copy” between any checkpoint upvalley and Vintage. Same with various bicycle events.  Another benefit to this configuration and yet to be explored is the ability to use D-rats for message traffic.  We will be experimenting with this very soon.

Please send questions, comments, or reception reports to me a n6xn at arrl dot net.

*438.500 is set aside for ATV repeaters and repeater links.  If you experience interference or complaints please let me know and we will look for other frequency options.

November 2, 2010 Dave, Ki6SZE turned up his Hotspot today at his facility in St. Helena.  I was surprised to hear it so strong here at my QTH and even more surprised that I could “hit” it with only 15 Watts from my IC-880H.  The antenna on this radio is at the end of 100 feet of LMR-400 but is only 10 feet in the air.  This is a deliberate placement to reduce interference from the voter transmitter.
While I was making a couple of test transmissions, I was called by an old friend, KA6DFP, and we were able to chat for a few minutes.  This was an interesting contact as Jim was running 50 Watts into an Elk beam on a 60 foot tower.  He was going through K6MDD-C, while I was passing him mid-stream going into the system in St. Helena.  Jim is located in a little valley about midway between I-80 at Weimar and the American River on a dirt road to Iowa Hill.

Later in the day I was able to get into the Hotspot from several places in Napa including from in front of the Library on Division street.  Dave plans to keep the Hotspot linked to Reflector 14C or whatever W6CO-B is linked to, but is available to the users to be linked in other configurations.  More information to follow as testing proceeds.

October 27, 2010 You may have noticed an article in the SARS Newsletter (Nov-10) concerning the ARRL publishing a position paper on the narrowband study. Read it Here
This is especially pertinent because for the past two years there has been pressure brought to bear on our NARCC organization to make more room on the 2-meter band to accommodate new Dstar repeaters.  There was so much resistance to this pressure (from the membership) that a moratorium on the subject was voted in at a meeting last year.  This moratorium is to last 3 years, at which time a renewal of the moratorium will undoubtedly be floated.  The latest proposal will be coming from the petition circulated by K6BIV, which many of you signed asking NARCC to provide additional pairs.  The details of this proposal have not yet been released but they do not propose narrowbanding.

Now this from the Yahoo forum:  I wouldn’t normally reprint someone else’s letter but this, coming from Jim Moen, K6JM, is so well thought out and so well written I don’t want to paraphrase.

The quotes are taken from DOC-26

“In the commercial communications world, digital technology is ascendant.  It is attractive for a number of reasons, not the least of which is the ability to share voice and data information simultaneously.  This creates a ‘rich’ communications environment that is otherwise impossible or impractical with analog technology.”

“There is a certain market incentive for Amateur Radio to adopt 12.5 kHz channels as this would ensure our continued compatibility with commercial equipment manufacturers.  A willingness to keep in step with the prevailing spectrum usage, whether is is for analog or digital communication, would also cast Amateur Radio in a more favorable light.  In addition, broader adoption of digital technologies, which would be possible through the additional spectrum made available with 6.25 kHz or 12.5 kHz channels, would also enhance the image of Amateur Radio as a service keeping pace with modern technology.”   “FM repeater coordination in the US and Canada is managed through a diverse collection of volunteer groups.  Some groups welcome digital technology and recognize the benefits of narrowband allocations while others vehemently reject both.”   “Like the coordinating groups themselves, repeater operators tend to be fiercely independent. Historically, attempts by coordinator groups to implement various changes have often been met with resistance by the operator community.”   “The ARRL focus needs to be on consensus building and important that we not advocate one approach over another (analog vs. digital) or one digital technology over another (such as D-STAR over APCO-25).” <end quotes>   Speaking personally, though I started in amateur radio in 1959, focused on HF, it was only in the last 5 years that I came to realize the extensive knowledge and skills needed to set up and manage a VHF/UHF repeater.  I have great respect for the many repeater owners and administrators in northern California.   But in looking at Part 97, I’m struck how vague it is about frequency coordination. See attached.  I think the way our NARCC (Northern Amateur Relay Council of California) is organized is typical.  In their bylaws, voting (regular) members must have a valid FCC amateur radio license and be the designated representative of an organization that already has a coordinated repeater pair, or at least has applied for a coordination.  The Board, elected by voting members, approves the Policy & Procedures Guidelines. This is the only document that identifies the purpose and objectives of the organization.  It says the NARCC recommends channels “in order to avoid or minimize potential interference.”  “In addition, NARCC provide band planning as described herein. NARCC represents its members’ interest while formulating regional band plans, working coorperatively with other amateurs representing different operating modes.”    Nowhere is there an objective to optimize the use of the spectrum for the good of the community at large or all amateur radio operators in the region.  The focus is to represent only the members’ interest — that is, those who are repeater representatives with coordinations or waiting for coordination.   So the system is constructed to favor the status quo, and to favor what’s best for those operating current repeaters as opposed to all amateur radio operators.  Since a majority of these people are sponsoring existing wideband repeaters, it is not surprising they do not look favorably at the narrowband ideas in the ARRL report.   The good news is that in some regions, the leaders of the frequency coordinating organizations are working to educate their members about narrowband, and to find ways to accommodate both wideband and narrowband usage.  As these regions begin to demonstrate that both wide and narrowband requirements can coexist, and that optimizing the use of our scarce spectrum can be a valid objective for their organization, perhaps other regions will begin to think about this approach.   It may take a long time, depending on the region, but somehow I suspect that some of our young new hams will someday benefit from the changes being recommended by the ARRL Report on Narrowbanding.    Jim – K6JM   Part 97 references to frequency coodination:   Part 97.3a21 says: ” Frequency coordinator. An entity, recognized in a local or regional area by amateur operators whose stations are eligible to be auxiliary or repeater stations, that recommends transmit/receive channels and associated operating and technical parameters for such stations in order to avoid or minimize potential interference.”   Part 97.205c says “Where the transmissions of a repeater cause harmful interference to another repeater, the two station licensees are equally and fully responsible for resolving the interference unless the operation of one station is recommended by a frequency coordinator and the operation of the other station is not. In that case, the licensee of the non-coordinated repeater has primary responsibility to resolve the interference. ”  97.201 has something similar for an auxiliary station.

October 24, 2010 Lots of discussion on the Forums these past few days about “remote RF” interfacing the Dstar system.  There seems to be numerous interpretations of just what this would entail, as one writer refers to only receiving, not transmitting.  Others are looking for a way to interface analog (FM) to the Dstar system.  Many, perhaps most Dstar users are opposed to this on the grounds that it would introduce inferior signals into a world of “pure” audio.  Pretty much bunkum, actually, since a goodly number of Dstar QSOs contain gobs o’ R2D2, black holes, and mind numbing jibber jabber.  Dstar, as it stands today, is far from a perfect medium.  Call it a “medium” medium.
I guess my biggest objection to this concept is not the sound of FM but all of the ancillary noise that goes along with it.  Wind noise from mobiles, road noise, background music from the car stereo, not to mention the various boops, beeps and IDs from a typical analog repeater.  Then you have the tendency of FM users to create their own noise from excessive deviation, too much (or too little) mic gain, and improper use of the mic resulting in popping audio. Hello check, check, check.  You get the idea.
One contributor brought up a really good point about the above:  A typical amateur may not have the expertise to open up his radio and make repairs and adjustments, but we all have a responsibility to produce the best signal possible.  if that requires a taller mast, a different antenna, a better feedline, whatever, that’s what needs to be done.  I listen to the local nets and some folks have barely intelligible signals week after week and you have to wonder “is he aware of this?”  If so, why not do something about it?

Echolink as a pipe. Here’s a thought:  Say we have a remote facility with a Hotspot feeding a dual band antenna.  The digital radio is on UHF leaving the VHF section free for other uses.  Now say we wanted to control a bunch of things in the remote facility.  By installing a DTMF decoder such as an Uddle DTMF-2, we could install echolink on the same PC that is controlling the Hotspot.  The echolink node is then set to receive connects only from a select list of callsigns.  Once connected, DTMF controls could be sent to the decoder using the echolink internal DTMF pad.  Hooking the echolink system to the antenna would require a VHF radio and a diplexer, plus a simple sound card interface.  This would provide a nifty remote base, accessible from anywhere.  Just a thought…

October 23, 2010 Got a chance to try chirp today.  If you are not familiar with this program, it’s another fine product from Dan Smith KK7DS, creator of D-Rats.  If you have problems with the crude programming software from Icom, this is a possible solution.  It allows you to export your radio’s memory to Chirp, then transfer it to a spreadsheet program such as Excel where you can massage it more easily.  Probably only useful if you have a lot of data.  Chirp also lets you convert your program data to a CSV file where you can then input it to a different model of radio.  Most of the popular models are supported.  See it at http://chirp.danplanet.com

October 21, 2010 One of the current topics on the Yahoo forums concerns the difficulty of learning to operate the current crop of Dstar radios.  Anyone who has tried to struggle thorough the Icom manual can testify to the difficulty.  So even after reading the manual one often has problems figuring out certain features.  The DR mode in the IC80 handheld and the IC880H mobile area cases in point.  So imagine my surprise when reading today’s forum mail, the writer describing the purpose of the CQ button on the dial of the IC91AD.  “Say what? What CQ button?”  So a careful investigation of the dial reveals the letters CQ on the zero button of the keypad.  What’s it do?  Seems you press and hold it while you twirl the knob until the URcall you want comes up. (smack forehead with palm of hand)  Wow that makes changing URcalls pretty easy, funny I don’t remember seeing that in the manual.  Now be honest: did you know this?

October 18, 2010 Kristoff Bonne presents an interesting proposal to facilitate creation of audio messages.  His solution is to connect a DV dongle to the gateway and use the messaging/recording feature to create the files.  That plays right into another proposal to have someone write an application for the iPhone for Dstar just as there are now applications for iPhone and Droid into Echolink.  It’s a little different proposition since a Dstar contact is not created in a link but rather IP to IP.  Anyway, have a look at this blog and set your imagination racing! Blogspot

So where do we draw the line?  It is now possible for two hams to communicate, over Echolink, using nothing but iPhones.  This was demonstrated at the Codger palace not long ago.  Is this ham radio?  Supposing the Dstar application is written.  A ham in Napa, with nothing but an iPhone can talk to a ham in Europe also on an iPhone.  Wouldn’t it just be simpler to get the guy’s phone number?

October 18, 2010 Wracking my brain trying to remember where I saw something…  Oh yes, the script shop.  A while back Brian Roode NJ6N and Darren, G7LWT developed a number of scripts that would cause the Dstar gateway to do something when executed.  I installed all of the scripts that were available at that time.  Since then, several of the features provided by these scripts have been provided by other programs or updates.  For example, the script IX is no longer relevant since Monlink provides that information.  See the entire list here or here .

October 17, 2010 Last day of Pacificon.  We had a very pleasant visit with Tim Barrett K6BIV who is building a petition to be submitted to NARCC (spectrum management group) to act to provide additional frequencies for Dstar repeaters in Northern California.  If you are a registered DStar user within the W6CO group you should be receiving a copy of Tim’s petition request via email.  Please sign and send it on to Tim ASAP as the proposed action will be happening very soon.

October 16, 2010 First day of Pacificon (Saturday).  We attended a 2 hour Dstar forum and it was very interesting.  The forum demonstrated DVAPs, Dongles, DVARs and other node adaptors.  The last presenter was David Lake who wrote the software for NI-Star (Non Icom Dstar) which permits enterprising hams to build fairly low cost D-Star repeaters.  The newest NI-Star repeater to come on line is WW6BAY, part of the Bay-Com system in Palo Alto.  Have a look at their website for interesting details: http://bay-net.org The presentation slides are also available here.

Part of the overall presentation was geared for newcomers and unfortunately the programming data shown was out of date and did not reflect the changes made by Dplus 2.2g. Below is a sample of the programming on a IC2820H showing 2.2f vs 2.2g.

Here is the most salient part of the 2.2g update concerning programming:

Up until now, several Dplus commands required prefixing by a repeater callsign in the UR field.  For example, if you wanted to do an echotest on the W6CO repeater you needed the UR to look like this:

W6CO   E

Similarly, all other commands needed the callsign in the UR preceding the command.  As a result you needed to use a separate memory line for each repeater/command in your program memory.  If you used several repeaters on a regular basis, this added up to quite a large number of memories.  Now, with Dplus 2.2g, any command will work without a callsign in the UR.  All you need is the command in the 8th position.  As a result, you only need to dedicate 4 or 5 memory lines to commands, and as you switch repeaters, simply adjust your URCall accordingly. If you operate either an IC80 handheld or an IC880H you will find this vaguely similar to the DR mode of operation.

If this is still not clear, please drop me an email and I will try to clarify or elaborate.

October 15, 2010 Listening to Reflector 014 this morning, around 9 AM I heard Robin, AA6RC come on frequency announce he was doing “something” to the reflector.  Being mobile I couldn’t quite hear what he said he was doing.  When I got home later I took a look at the reflector dashboard and it immediately came clear.  He has modified the code to display the data from the dplus log (see below).  Have a look – it still needs work, but if you click on any callsign that is colored orange you will be taken to a map page showing the location of that callsign.
Find any dashboard: Click here

October 13, 20100 A Monlink. Written by Ken Adkisson, WB4FAY.  This program has 2 main features we use on the W6CO gateway: First, it announces the link status of the repeater.  If the frequency is not busy, you will hear “Linked to reflector fourteen C”  (or whatever) The second feature is it automatically relinks the repeater in case it gets dropped due to a DSL problem.  A couple of other things it does are not apparent to the end-users:  Every Sunday morning it cleans up the logs and archives them so as to not clutter up the log files.  It also performs a restart to all the gateway programs.  If you went to bed Saturday and the repeater was linked, you will find it unlinked the next morning.

Incidently, if you are one of the people who find the Monlink announcement annoying, be aware that it is not carved in stone.  There are a number of options:

1:  Turn the damn thing off.
2:  Lengthen the interval to say, every hour or two.
3:  Record a new announcement using a pleasant voice.  I’m not kidding, if you are blessed with dulcet tones, drop me an emai and I’ll tell you how you can immortalize your voice for the betterment of the Dstar world.

DStarMonitor. Written by Pete Loveall AE5PL.  This adjunct provides the information needed to populate the “Last Heard” tables as well as that needed to interface the various GPS location services such as www.aprs.fifi

Dplus is the name of the adjunct that provides most of the features we use today,  Features such as reflector or repeater linking, repeater control by the end-user etc.. We are currently running version 2.2g which provides some enhancements:  See http://napasars.org/news/Oct10/dplus2gfeatures.htm for more details.


About n6xn

It all started in 1968 at a small 100 Watt radio station in Napa California. Looks like I finally got my priorities straight: the career is on the back burner and the K3 is getting some air time.
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