9.6k Packet Myths – 9600 baud packet is not much faster than 1200 baud

July 16, 2019

Claim:  9600 baud packet is not much faster than 1200 baud.

Fact Check:  Not true. Well that is unless you have a strange definition of “not much faster.”

9600 baud packet may not be 8 times faster, but 5+ times faster throughput can be easily obtained off a user port if decent radios are used. If backbone grade radios are used then you can make 9600 go faster. Use backbone grade radios on a full duplex link then it will really push some bits along.

Real world example? After completing some project work at a client’s location down on the river I ran some quick tests off our 2m 1200 baud and 70cm 9600 baud user ports. Same client radio, same antenna, same software, same modem, linking to the same RMS.

Not a lab grade test, but a very “real world” and fair test. Both ports used on the remote RMS are user ports configured as they have been for years. The 2m port is ran about as aggressive as you would want on a 1200 baud port with a variety of client radios connecting. This also includes some users running soundcard interfaces that are often a bit slower on TX<>RX turnaround/recovery times. The 9600 baud port is also running somewhat restrained due to some users having slower radios.

Tests were from my FT-818 based portable HF Robust Packet, 1200 baud, and 9600 baud station using just a mobile antenna on the car in a parking lot. Just shy of a 15 mile mobile to base non-LOS link. It was 92F down on the river and I’d venture to say the “hot humid sunny afternoon effect” was in full effect. Trees are fully leafed out after a very wet spring so foliage losses are high. flat bands, elevated path losses, and some multi-path through the hills all equal a near worst case non-LOS link scenario for that path. Perfect for a real world test.

Could this be done in a more perfect lab like environment? Sure and those results would have value as long as one keeps in mind that the lab is not the real world. Nothing against lab tests, but we don’t operate in a lab here. Thus we prefer to see how things actually work out in the real world 😉

The TNC used on my end was a SCS Tracker DSP TNC running version 1.7m firmware. The RMS gateway was running as one of several applications on top of a BPQ32 node.  TNCs at the RMS Gateway are a KPC-9612+ for the 1200 baud port (so much for the myth that the Tracker is not compatible with Kantronics modems LOL) and a PacComm Spirit-2 TNC for the 9600 baud port. Both running in XKISS mode. Both those TNCs are arguably the gold standard for their particular uses.

Screen shots of the results speak for themselves….

9600 baud packet radio link test. 17k compressed, 28,791 bytes/min.

 

1200 baud packet radio link test. 17k compressed, 4,537 bytes/min.

Signals on my end were nearly full scale on 2 meters and floating around S9 to one bar over it on UHF. It was the middle of the afternoon on a hot sunny day down on the river with some terrain between my mobile and the site so some multipathing was in there but not severe.

Yes just like the Yaesu FT-817 and many of the VHF/UHF all-mode radios the Yaesu FT-818ND is a good radio for 9600 baud packet. It may be “new version bias” at play but I suspect the 818’s receiver is a bit better at 9600 baud. I would love to see ARRL Lab BER test data for it. Yes they are very similar, but contrary to popular myth there are some design changes in the FT-818 vs the FT-817…..hint take a look at the receiver section.

Nope I didn’t buy the FT-818 instead of another 817 for the extra watt of TX output advertised LOL. It is interesting lately watching how the manufactures have figured out how to market to (and milk) the growing appliance operator crowd in our hobby. I wanted to use my 817 for a remote IF radio in the 7-land shack so I needed a 2nd one for travel and 4-land.. The FT-817ND was out of stock and the 818 was on sale so that’s what I got, no regrets thus far.

Sidebar:  If you have a FT-817ND and are happy with it I don’t see a reason to go out and buy a FT-818. If you are in the market for your first or additional radio with the 817/818 capabilities and packaging then by all means consider the FT-818ND first.

FWIW I suspect the Tracker’s 1200 baud mode could use a bit more optimization to decode weak noisy signals better, but it appears the Tracker’s 9600 baud mode is working extremely well. The Tracker is a hybrid software/hardware TNC that can be firmware flashed (free downloads) with new features, bug fixes, and optimizations so it’s only been getting better over time. SCS has been great to work with on bug fixes and improvements.

Wondering what that binary attachment was? Here you go. A very useful graphic for those that work EmComm in the SE USA this weekend. With 9600 baud packet you can have that downloaded, reviewed, and moved onto other tasks before 1200 baud is halfway done downloading it.

Tropical Storm Barry weather graphic. Well under a minute to pull that down over 9600 baud packet radio versus nearly 4 minutes if you used 1200 baud.

True nearly 4 minutes versus a fraction of that may be NBD in some situations or a huge boost in messaging capacity and turn around time for other situations. Regardless, to claim 9600 baud packet is not much faster than 1200 baud is easily proven to be just another packet radio myth.

In closing I suspect this particular myth is just folks repeating what they heard or read as gospel. Sometimes I think it’s just an excuse to avoid learning something new and making packet radio even more useful. Regardless they obviously have never actually seen or used a properly configured 9600 baud packet system. Trust me once you use 9600 baud packet it will be painful to go back to 1200 baud for all but APRS and the lightest of duty needs.

No the above is not a dissing of 1200 baud packet in any way.  Hey, gotta be careful now that Perpetually Offended by Everything Syndrome seems to be infecting the hobby lately 😉

 

73
WA4ZKO


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.

WA4ZKO /7


K4KPN BBS & RMS Gateway are Available

June 9, 2018

KYPN would like to announce the full availability of the KYPN Dry Ridge BPQ32 based packet radio site as of June 9, 2018.

The following packet radio applications are available:

K4KPN-1    BBS
K4KPN-4    Node
K4KPN-13  Chat/Conference Server
K4KPN-14  RMS Gateway

The above packet radio applications are normally available 24x7x365 to appropriately licensed amateur radio operators on the following frequencies/modes:

SYSTEM PORTS:
441.0500 MHz 9600 baud *
145.6900 MHz 1200 baud
223.6600 MHz 1200 baud *
28.1480 MHz USB dial, 28.1495 CF, Robust Packet “NET10R” *
50.6200 MHz 1200 baud **
* High availability, primary port.
** Dual-use port, both general use & 6m APRS WIDE1-1 Digi

All 5 bands and 3 modes are published to the Winlink channel listing.

Recommended user software:

KYPN recommends Outpost Packet Message Manager version 3.0.0.333 for BBS access. Full installer is available for download here.

KYPN recommends Winlink Express v1.5.12.0 or newer for RMS access. Available for download from here.

More details can be found on the K4KPN-1 packet BBS under messages #1 thru 8.

More details in future blog posts and the work in progress draft KYPN System FAQ.

 

The KYPN team.