Field Day 2020, APRS, Updates, and Civil Unrest

June 26, 2020

Well like many things in 2020, Field Day 2020 is going to be different this year.

I actually think it’s a good thing. For many groups Field Day has become way too much of Yet Another Contest (YAC) and a reset would be healthy.  I remember hearing some guys fussing last year about how Field Day just wasn’t as fun as it used to be and too much work to pull off. Sorry guys, but Field Day is like Christmas. If you’re tired, stressed out, and sort of glad that it is over with then you’re doing it wrong.

While the ARRL has hinted along these lines, consider doing something different this year. Maybe do something more off-grid EMCOMM realistic than YAC (Yet Another Contest) like operation. Maybe pack your gear up and go operate off battery or generator somewhere where you have to improvise more. This could be nothing more than going out in the back yard, a park, mobile on a high point, activating your favorite camping spot, etc etc.

Maybe do more than the usual SSB/CW stuff and also test your digital/packet modes off-grid.  Maybe pass some P2P traffic/messages over digital.  Maybe see if your state STM will guard some HF frequencies on a schedule for incoming P2P traffic. Try getting that message and acks/replies from point A to B without ANY internet transport while operating off backup/emergency power.

I often come across EMCOMM operators that constantly pick the lazy way of doing things commenting “well if power is out and internet is down I’ll just do this or that.”  Sorry but talk is cheap so go out and do it. See if you can actually do it fully off-grid during the optimal conditions of “normal” times.  Those that have worked a few real world disasters will tell you that if you haven’t actually tested things under realistic conditions then you are just asking for “I didn’t think about that” gotchas and quality time with Uncle Murphy later on when you really need things to work.


Summer Plans?

Well I’ve been bachelor’ing it for over a week now. Ah man it’s freakin’ amazing what one can get done when left alone for more than an hour! LOL The XYL went back to work on a long trip that will end in Denver. From there she’s taking a rental down to her family’s place in Iowa to visit with them till I get several items wrapped up here and head west in a few weeks.

Given what is going on now all our plans are “soft” this year but we both are suffering from serious mountain-time withdrawal LOL. Given the Festival de Crazyville going on lately it looks like a really good summer to go disappear into the mountains where it’s easy to unplug from it all.

Fall will equal a lot of work helping with harvests on both family farms. So a couple months of Summer is about all the break I think we’ll probably get this year LOL.


My Field Day 2020 Plans?

Well last evening’s shop project was replacing the coax on my 6m slim jim style antenna (300 ohm twinlead design) from where I made the mistake of originally using solid center conductor RG-58 for the feeder on a roll-up antenna.  After a few years of being packed around and used a lot you can figure out what happened inside that coax. Hey it was all I had handy at the time, but lesson learned. Ah those things you learn from actually using/testing your gear under real usage scenarios LOL.

If weather allows I plan on going 1-B portable QRP back at a hilltop camping site on the EM78PP/EM78PQ line. Hopefully I can get some on-air validating of the repaired antenna on 6m SSB and probably work some packet too.

Right now the weather forecast doesn’t look too promising as rain is fine, but I’m allergic to lightning LOL. Unless one is looking for a Darwin Award nomination it’s a bad idea to be on top of a hill, under a tree with an antenna hoisted up into it when lightning is around 😉


Ham Radio Time?

Well between work and playing wannabee farmer and helping with three gardens I haven’t had as much spare time for ham radio stuff as I would prefer. Still managing to get some projects done and have some fun on 6 meters SSB and packet.  If you haven’t been on the 6m weak signal modes this Spring then you are missing out on a lot of fun.

Yes even some 6m packet/APRS DX has been flying around lately with the Conway, AR node and VA 6m APRS stations popping in at times.  Some asked if K4AF-6 is down. Judging by APRS-IS it appears to have been down since the first of the year. I also didn’t note it on the air a few months ago when visiting family in Haymarket, VA. We had a nice strong opening to that area of VA on Father’s Day (June 21st) and it was not heard but the Calverton VA digi was ripping in at times.

I worked the CQ 160m Contest on remote from my sister’s place in SC. 160m is a band that is growing on me. No VHF contesting so far this year. I know, I know but just too many other conflicting priorities so far. Kind of hoping to maybe work part of the CQ VHF Contest from the mountains, but will probably be busy keeping some fly line wet if you know what I mean 😉

Been working on upgrading station grounds and installing some outside antenna disconnect boxes for the 4-land gear. I wanted to make it easy for my neighbor hook-up or disconnect the main lightning rod HF antennas here for me while we’re gone. Normally my cousin will handle that for me on his daily visit to check on things and feed the animals for us, but wise to have a Plan B. I have considerable lightning protection in place, but the best protection is always physically unplugging things.

Another project completed this winter was to build an identical hamshack desk for the 7-land QTH and then another frame to allow mounting the gear stacked “vertically” to allow easy tear down or moving it around. The first desk I built was originally for the 7-land QTH, but it became part of the 4-land home office/hamshack.

We’ll be looking at some land this summer and considering getting an RV to live in for awhile if we find a place we buy and want to get started building. Thus a perk of keeping the radio gear in an easily moveable frame makes it easy to move things from the shack to the RV as needed. Like any good ham I have my ideas for the ultimate hamshack/geek-cave layout when we settle down and I build the “last hamshack” I’ll probably build.  For now this approach works fine and provides consistency between the shacks.

I’m also enjoying getting back in SWL’ing which was my original radio enjoyments that led me to some of my career and hobby choices. Enjoying chasing NDBs, DXing the lower bands, and chasing mediumwave DX when time allows.  Spare time project has been installing a couple nice beverage antennas for VLF and mediumwave DXing.

Having some fun on 80/60/30/17/10m robust packet at times. Yes 17m is open at times. I worked the 4-land BBS via the KY Gateway on 17m several times from WY a few months back.

One of the Spring robust packet connections ended with a surprise tail-end connection from a friend /P in Haiti that got a nice DR-7400 modem for Christmas. That link up turned into a 24 minute 10m/17m crossband chat session via the Jonesville and my home home nodes…..gotta love BPQ32 + RP LOL. Was neat to hear what was really going on Brazil (his home country) weeks before it showed up in our news here stateside.

I even worked the KY Gateway on 15m (yes 21 mhz) RP from Iowa (usually a 30/40m path) on a short skip opening. Always fun to see hat you can do with “5 watts and wire” QRP.

Yeah 40 and 30m have been the workhorse bands for a couple years now, but the higher bands are so much less crowded. So even at the bottom of a solar cycle it’s a good idea to keep an ear out for short/e-skip propagation indicators.


APRS Stuff

On the 2m APRS front I helped an old packet friend over in SE Indiana work on resurrecting the Dearborn County 2m APRS Digipeater.  KB9GYO-2 is online from his office in a low power configuration till he can acquire the needed gear better suited for installation back at the old original tower site.  Even the temp installation has helped improve 2m APRS coverage in NKY. 

The BPQ32 Jonesville node can technically provide APRS digi/gate functions on any or all ports just like it does on the 6m 1.2k port. Over the past few months we’ve done some testing of alternate-QRG APRS on the 2m 1.2k and UHF 9.6k ports and found that approach could work very well if needed. Since we have done some APRS on UHF simplex in the past we may test enabling APRS on the node’s UHF 9.6k port this Fall to have handy if needed. That said, the existing 6m APRS and groundwave into K4KPN-10 should cover most anything we really need.

It’s also been an interesting tool for seeing what the real world mobile coverage of the system is on UHF, 2m, and 6m using APRS setups. I need to take a 220 radio out sometime and see how well it plays across the area, but suspect it will beat UHF and slightly outperform 2m even with half the TX power as that’s what we observe on classic packet uses.

When time allows I’ll do a more detailed posting on what was observed while doing mid-day (to minimize inversion enhancement) during heavy foliage loss season. Basically reasonably solid mobile coverage (modest mobile setup) for 30+miles on 6m, 25 on 2m, 20 or so on 70cm. Note that is mobile packet coverage, not voice coverage. Takes a decent signal level to get 1200 baud packet to decode a moving mobile station, even more so for the UHF 9600 signals. So basically some worst case mobile-to-base range testing.

Even had a little 6m/10m packet groundwave DX fun the other morning while in Richmond. There’s a couple spots down there that we can hit our dispatch repeaters if the band is in decent shape while down at the academy. While eating breakfast at one of them, for giggles, I tried the 10m RP port and got in fine. So I swapped in the 6m whip and worked the BBS via both ports at 64 miles mobile to base. I had to make a meeting so I didn’t have time to try the other ports but 6 and 10 meters were getting it done that morning.


Is W4VPN Still on 80m RP?

Since some have asked….yes it is still there. I got into it from a pit-stop in southern Kentucky the other day as I came back from SC.


While I can tell the 80m antenna works better on the truck than the car, it’s always fun to see what a few watts of robust packet can do. S3-4 on the mobile and I was most likely at the NF (noise floor) on the other end but still linked up.  #GottaLoveRobustPacket

Admittedly I was unable to get into it from SC, but I only had my 40/30m end fed wire antenna available there. Only had some mid-afternoon downtime available and that’s a poor time for that 80m path even with a better antenna. Plus he may of had it offline due to local weather or testing other things.

PS – John KX4O sysop’s that system. Please contact him if you have questions regarding it.


Protests, Riots, Crazyville?

Several interesting exchanges in the inbox lately from friends in my LE and non-LE circles. I could write a multi-volume novel on things and several aspects few consider.

My soundbite answer is summed up as “I stand with the peaceful and innocent.”

Longer version…..

As someone with an LE background whose work sometimes has him on the grounds of three different LE academies, I would offer up a caution. Many of your large police agencies are increasingly struggling with recruiting new officers. Policing now pays a heck of a lot better than it did back in my day, yet fewer and fewer folks want to pursue that career. It’s a growing problem in law enforcement across several major metro areas.

This recruiting problem has resulted in more than a few of these agencies lowering the bar on their recruiting standards. More than a few instructor friends have commented that agencies are increasingly hiring folks that they would of never hired just 10-15 years ago. Don’t get me wrong, with a good FTO and adequate supervision most of these recruits will become good officers. Unfortunately some will be walking liability time bombs poorly suited to the challenges of modern law enforcement.

Note:  We have over three quarter million police officers in this country. Most do an exceptional job of keeping our communities safe by reasonable enforcement of our laws. Are there bad apples out there? Sure there are, just like any other large group, but I think the fair minded will understand a few exceptions do not equal the rule.


As far as the riots go?  Well unfortunately well intended peaceful demonstrations tend to get invaded by certain criminal elements. It’s also pretty clear there’s both money and organized support feeding a lot of the criminal element.

While keeping in mind this is a few weeks old, some good food for thought within. For the hams I know Jon is a ham and think the other two are also hams. For those looking to be offended and upset by the “Roof Korean” comment, its a term they don’t mind and you need to brush up on your history studies.


Are there some serious problems with policing today? Yes. Are some changes needed? Yes, but a lot of what I’m hearing is not going to help. Why not? To fix a problem you have to gather all the facts and then actually identify the root problems versus just repeatedly playing politics with the symptoms and exploiting people.

Unfortunately instead “take a breath, wait for all the facts” rational problem solvers we now get an ever increasing deluge of “we gotta look like we did something” political pandering, camera whores, and frankly insulting levels of virtue signaling. Too many politicians playing distraction from their own failures while acting like they had nothing to do with the collapsing conditions in their area.

Of course our shameful political media complex is a more than willing participant in a lot of this. Hate, fear, lies, and division sells. It’s now all they have to sell. Business is good and thus they see no need to change. It is now all about ratings, views, and clicks. The full truth is increasingly the first casualty of every incident. Real journalism in the national media is increasingly rare and usually only by accident. Sad, but it is what it is.

Most of what I’ve seen offered up lately is just going to make the jobs of the “good” officers out there even more difficult. This will cause more recruiting difficulties, increase the number of officers leaving large metro agencies for other careers or smaller agencies, and add to a flood of early retirements. That’s not theoretical, it’s already happening. Several of my old LE friends comment “glad I’m retired” and others can’t wait to retire or seriously considering relocating or retiring early.

One of our newer deputies out west is from a large SoCal agency and oh the stories of political insanity he can tell. He now enjoys working a low crime area full of good hard working people that for the most part we all get along just fine. Works where he feels welcome, supported by his bosses, supported by the community, gets to be more peacekeeper than revenue generator, and doesn’t even have to be careful about where he grabs lunch or a cup of coffee while on patrol. His comment of “we should of left that sh#%2hole 10 years ago” speaks volumes.


The Seattle Mess?

Thankfully all my Seattle family moved out into the distant suburbs years ago.

Seattle is a good example of a once great city (one of several) that has been “circling the drain” for years now. A city in dire need of productive policy changes versus all the political denial and distraction blame games. The ongoing neutering of law enforcement is ultimately just making things worse for everyone there.

I recognize the following is a long video, but it is a rare piece of actual journalism. Worthy of at least watching the first 30 minutes of if you want some insight into what is going so wrong in several of our major cities. Warning, you are going to see some things that not easy to watch if you care about your fellow man.

To be fair to the good people of Seattle, you could replace Seattle with the name of several other cities in our country.

That’s enough for now.




6 Meter APRS will be Supporting the USMC Marathon this Sunday, Fall Update

October 25, 2019

October 25, 2019:

Six meter APRS (50.6200 MHz 1200 baud) will again be used my ham radio in support of the Marine Corps Marathon this Sunday in the Washington DC area.

Looks like Bruce (K7BC) and crew have deployed the temp/backup digi MCM-14 today and been testing several of the trackers earlier this week.  This is in addition to the existing full-time K4AF-6 6m APRS digipeater at the Pentagon MARS station.

While it may need some last minute revisions, this link should provide a decent live view of the network’s performance.  (Link updated 0759 local Sunday)

For giggles, KYPN will be putting our K4KPN-6 6m BPQ32 based APRS Digipeater/I-Gate’s best receiver (Jonesville “east” site) on a 5 element beam aimed east sometime late on Saturday. This time of the year an eskip opening – especially one strong enough to support that short VA<>KY path – is unlikely.  That said, we are just on the downside of the Orionids peak so there’s a decent chance of some meteor scatter reception with all those packets flying around there starting during the early morning hours.

On another note, I just noticed the summer KYPN Summer Update just expired off the K4KPN-1 packet BBS and I should do a Fall update soon. I’ll probably post the Fall Update here before we head off for the holiday season.




K4KPN-6 6 Meter APRS Digi / I-Gate Full Availability

August 10, 2018

Observing a need for a 6 meter APRS I-Gate in this region, KYPN realized the K4KPN-4 BPQ32 node could probably meet this need without any additional hardware investment. Recent versions of the BPQ32 node software have considerable built-in APRS digi/gate capabilities that only need to be configured and enabled.

The past few months showed that the past trend of most activity on the node being on the UHF 9.6k, 220 1.2k, and 10m RP ports was still holding true today. Thus we pondered could the APRS features on the 6m port be enabled and would they coexist with the existing Node and its BBS, Chat, and RMS functions? If both could coexist then it was frankly a no-brainer to do it.  The 6m port puts out a stout signal that penetrates well into the valleys and hilly terrain common to the area.

The 6 meter APRS scene has seen bursts of activity over the years, but good 24x7x365 digi/gate infrastructure is very rare outside of a few pockets of activity. The rest has been more of  what I’d call seasonal activity of folks firing up on frequency to listen for packet/APRS DX during the late Spring and Summer e-skip seasons. Others use it as a less congested alternative to the mess that 2m APRS can be in some areas.

At one time there was a push to build up packet infrastructure on 50.620 across the country for the PropNet network. The WSPR mode and network came on the scene and its many advantages stagnated PropNET growth. What remains of PropNet seems mostly focused on PSK31 operations on HF. No PropNET packet operations have been noted on 50.620 for over a decade now. This means 50.6200 MHz is an underutilized frequency begging to be put to good uses.

Testing showed both APRS and conventional packet should coexist fine on the Jonesville BPQ32 node’s 6m port. Thus on the afternoon of July 9, 2018 KYPN spun up K4KPN-6 on 50.6200 MHz 1200 baud AFSK packet mode. K4KPN-6 offers both full WIDEn-n compliant digipeating and basic R-I-R (2-way) I-Gate messaging functions.

The current plans are to run K4KPN-6 24×7. The 6m port beacons an APRS compatible beacon every 5 minutes to help detect DX openings. Beaconing faster would provide a better chance of catching meteor burns, but 5 minutes was felt to be a good compromise value for a mixed use port.

The advanced APRS digipeater functions available in BPQ32 are downright slick and one can tell John gave them some thought. The I-Gate side has some cosmetic issues, but it is plenty usable from a functionality standpoint. I’ll try to run some changes/improvements past John (G8BPQ) this winter. He is busy sailing/traveling during the Summer months. Thus I avoid bugging him with non-critical feature requests and minor bug reports that can wait. John should be deemed a Saint for his patience with his user base and his willingness to continually improve BPQ32/LinBPQ.

So far K4KPN-6 looks like a valuable asset both locally and for the 6m APRS DX folks. Best of all with our existing 6m port on the Jonesville BPQ32 system there was no need to buy anything else. Just enable and configure the functions you want in the bpq32 config file and restart the node. Obviously you’ll need an APRS-IS login and password if you want to use the I-Gate functionality.

Node and application stack (BBS, Chat, RMS) remain available on the 6m port. The APRS functions are just another application running on the node.


6m APRS Path Recommendations?

Making use of the K4KPN-6 6m APRS digi/I-gate functions is no different than operating on 2m APRS. Paths of WIDE1-1 or WIDE1-1,WIDE2-1 are good choices for 1-hop and 2-hop paths.


6m APRS Beacon Rate Recommendations?

The 6 meter APRS frequency is not overloaded like the 2m APRS is in so many areas of the country. There is plenty of spare airtime on the channel. Thus the use of aggressive beacon rates is unlikely to be an issue. 5 or 10 minute rates for infrastructure sites should be fine in most areas.

Temporary use of even faster rates for testing or during meteor shower peak times should not be an issue and would increase the odds of snagging a burn. Mobiles can probably dial things down to 1 or 2 minute rates.


6m APRS Biggest Range Challenge? Noise Floor

The 50 MHz band propagates locally just like the 30-50 MHz VHF-Low band that you may be familiar with. Not so great in a pure urban environment. So so in a suburban environment, but ultimately best suited to rural environments where its range and terrain penetration qualities can shine.

Note:  There’s a reason why a surprising number of users remain active in the VHF-Low Band spectrum even though it doesn’t get much press. Current marketing/sales efforts are geared towards selling more expensive and complex systems on the higher bands. The range and simplicity of VHF-Low systems are still a good fit for some users.

Don’t laugh at Low band. VHF….  I know of a 46 MHz system installed in the early 1980’s that is still in use. Now that’s serious ROI. Also note that the VHF/UHF Part 90 narrowbanding mandate did NOT apply to VHF-Low systems.

Back on topic….

All things being equal 6 meters has more range potential than 2m. Problem is in the real world of RF all things are rarely equal. On 6m you are probably using a lower gain base antenna and most likely a less efficient mobile antenna system compared to say 2 meters. In most real world installs some of this will be offset by higher standard transmit powers, less free space losses, lower feedline losses, and better terrain penetration. All that aside, the main range limiter for 6m operators today is the higher local noise floor (NF) compared to the higher bands.

The old enemy of power line noise remains, but it is now joined by a wide variety of noise spewing consumer electronics clobbering both HF and the lower VHF spectrum. Sadly this is a problem that will only get worse unless the FCC cracks down on a lot of the cheap poorly designed/filtered junk behind so much of the problem. Even then it would take ages for device attrition to clean up the spectrum much. Plus we’ve become a society that expects everything to be super cheap versus paying for higher quality equipment.

Where you live and operate can make a huge difference and must be factored in unless you like surprises. I was stunned at the NF differences between the old KY QTH and our temp place here. Living out in farm country most of my life definitely spoiled me. I wouldn’t call this “urban” by any means, but having several neighbors nearby = a lot more noise on the bands. I was initially worried about the big power distribution lines a few hundred yards away out back. Turns out they are actually the least of the NF problems here LOL.

Every amateur radio band has it’s pros, cons, and unique propagation characteristics. Six meters is no exception to that rule. It remains a local workhorse of a band that also offers some fun DXing at times. It is called the Magic Band for a good reason.


6 Meter APRS Lives

June 21, 2018

Update:  Dale N0KQX has joined in from SW Kansas as of June 24th. N0KQX-6 has already been heard several times at K4KPN-4 in KY.  The K7BC-6 Virginia I-gate appears offline since the 21st. A few more I-gates on frequency would be nice. I believe I can enable gating on K4KPN-4’s 6m port (ah the flexibility of BPQ32) without impacting general packet operations on that port. I plan to test that option on my next trip back thru 4-land.

It’s not every day you hear and “digi” off the 50 MHz APRS digipeater at the Pentagon.


Map showing location of the K4AF-6 six meter digipeater at the Pentagon. I believe this is part of the MARS radio station located there. Frequency is 50.620 MHz using 1200 baud AFSK packet.


June 19th 2018 a nice strong opening into NE Virginia revealed that the 50.6200 MHz 1200 baud 6 meter APRS and long time 6m packet “calling” frequency still has some action on it.


The monitor for the 6m (50.620 1.2k) and 10m packet/robust packet ports at the K4KPN-4 N. Kentucky node. K4AF-6 is at the Pentagon. K7BC-6 is a few miles to the SW. Both are just over 400 miles away. Opening was very brief. June 20th would produce a stronger opening. Times are UTC.


On June 20th things would liven up even more with the Conway AR node “CON50” W5AUU-6 (likely bleed-over from 50.615 MHz) coming in. There was also an extended and strong e-skip opening to Wash DC with APRS packets bouncing around and being digipeated like it was 2m APRS at times. Several K4KPN-4’s beacons were getting digipeated and I-gated into APRS-IS via K7BC-6 in Springfield VA.



The June 20th 6 meter APRS opening into the Wash DC area lasted for over an hour. K4AF-6 was even audible at times on a HT (Yaesu VX-8DR) setting on my desk. Gotta love the Magic Band of 50 MHz!

Distances involved where about 410 miles from Kentucky to DC. So I wouldn’t call it really short skip, but definitely shorter than normal. General rule of thumb is when 6 meter e-skip shortens up to 250-300 miles then it’s time to start checking 144 MHz for possible e-skip on that band.

Good to see there is still some life on 6m APRS. Band openings can make things interesting, even on VHF packet. Also nice to see there is some packet radio gear at the Pentagon MARS / AR station(s).

K4KPN-4’s 10m port beacons every 10 minutes and the 6m port beacons every 5 minutes with APRS compatible beacons to help detect band openings. The 50.620 MHz 1200 baud port on K4KPN-4 also supports WIDE1-1 digipeating in addition to normal packet radio connects.




K4KPN-10 Robust Packet I-Gate / Digipeater Update and APRS-IS Gotchas

May 26, 2018

K4KPN-10 has clearly benefited from the combination of antenna system repairs and noise floor (NF) reduction work at the site last Fall. Performance is back to what one would expect from it.

For those that ask why Robust Packet? One word….performance. Below is a screencap of what the 30m RP APRS world looks like from the Kentucky gate’s perspective over a few days.


K4KPN-10’s view of the 30m Robust Packet APRS world. Why RP? One word….Performance.

Around 25 to 30 of those stations on there have been heard direct on RF at some point. Single hop stateside coverage is easy. Europe is in to some degree nearly every evening and EU mobiles are often heard. Even the challenging polar path over to RT9K-15 is in there at times.

I’m hesitant to use APRS-IS for serious coverage analysis since it doesn’t begin to reflect everything heard on RF, especially on HF. Regardless K4KPN-10’s “heard” and “heard by” data is interesting:


APRS-IS perspective on RP HF APRS stations heard by K4KPN-10 so far this month.


APRS-IS perspective on RP HF APRS stations that have heard K4KPN-10 direct so far this month.

Yes some of the soundcard modems will do good work on 300 baud AFSK for single hop HF APRS and some occasional DX can get through. Some can do even better with bit fixing. The problem with bit fixing (guessing) is it breaks spec and can easily cause corruption if done too aggressively even on APRS. Thus why we so often trace corruption on the VHF APRS feeds back to soundcard modem equipped gates. Even with bit fixing the limitations of 300 baud AFSK become apparent over long haul DX paths.

Where Robust Packet shines is it uses Pactor-III like modulation that allows error correction without breaking spec. RP offers good noise immunity and deals with the multi-path on long haul DX packets better than a typical AFSK modem can.  Since RP uses space and power efficient dedicated hardware it is also well suited to stand-alone portable/mobile tracker uses without the need for a PC/laptop.

Robust packet is a mode and hardware built from the ground up for improved performance on HF and well suited to HF APRS. DX reception is not occasional, it is commonplace. I admit to sort of taking 4,000+ mile APRS DX as NBD till one of the HF AFSK guys sent me a “holy $#@$ what are you using that hears across the pond nightly” email LOL.

For those asking “where is K4KPN-10 hearing RT9K-15? Oh it is in there on RF, but due to his gate configuration it’s going to be difficult for stations other than a few lucky EU gates to ever get credit (APRS-IS perspective) for hearing him.


RT9K-15 being heard direct at K4KPN-10.

Well here is an opportunity for a good lesson on the flaws of assuming APRS-IS gives a complete picture of what is going on at the RF level.

It is important to realize that APRS-IS does dupe checking. If I-Gate A and I-Gate B hear the same packet only one of them can get credit for it from the APRS-IS perspective. Which one gets credit? The first one that gets that packet to APRS-IS. The one with the lowest latency to the APRS-IS system.

If you run an I-Gate or home APRS system on both IP and RF you can easily screw yourself with bad timing values. The RT9K-15 I-gate is doing something that will make it very hard for coverage analysis via APRS-IS. It appears to be aggressively beaconing to APRS-IS every few minutes? I’m told that it is heard often in EU, but rarely does an EU gate get credit for it in the eyes of APRS-IS. This tells me it is probably making the 2nd mistake of beaconing to APRS-IS and RF at the same time. This means even if another gate hears his packet on RF then it’s unlikely outside of internet congestion on his link that another gate can decode that packet off RF and inject it into APRS-IS before his internet beacon gets into APRS-IS.

Another problem this creates for APRS-IS analysis is it throws the packet counts off on the above pages. A good example is it shows a monthly total of 5 packets for DF1CHB /AM.  He was in direct on the eastern USA I-gates for hours earlier this morning, but also hitting EU gates so NOAM will only get occasional credit for gating him even after dozens of packets gated in. Tonight he is airborne over Serbia and K4KPN-10 is hearing him direct like clockwork on 30 meters:


DF1CHB /AM over Serbia and coming in on 30m robust packet almost as if he’s a local on VHF LOL.

Don’t get me wrong, this is not a complaint towards APRS-IS. It’s just how the system works and how it has to work. It’s just important for APRS operators to understand that APRS-IS doesn’t give you the full RF picture due to the necessary dupe checking going on. This is especially true on HF where the same packet can easily be heard by multiple I-Gates hundreds or thousands of miles apart.

Also noteworthy that some stations run beacons marked “RFONLY” or “NOGATE” paths. A properly configured I-Gate will not gate those beacons into APRS-IS. This is another gotcha if you’re trying to get a full picture of RF level activity via APRS-IS based systems and apps.

Recommendations based upon lessons learned here if you are interested in getting decent coverage analysis via APRS-IS?

  1. There is normally no need for an APRS station to position beacon on their internet port (APRS-IS) more than once or twice an hour unless it is moving. Serves no useful purpose for fixed stations and it only adds to the cumulative load on the APRS-IS system.
  2.  I-gates should consider beaconing on their internet port at a rate of just under 60 minutes.
  3.  Avoid beaconing via RF and internet ports at the same time.
  4.  If you are not moving, then you don’t need to be pounding the heck out of the RF side either. 2-3 RF beacons an hour from a fixed station is more than enough to keep you on most maps and fresh in APRS-IS for messaging/gating purposes if you are in range of an I-Gate.