AVRT5 Tracker

[Bill Vodall]

The Chinese Radios have met the APRS trackers.

Has anybody any experience with this?

<http://www.radioddity.com/us/avrt5-aprs-tracker-vhf-with-gps-bluetooth-thermometer-tf-card-support-aprsdroid.html>

There is a yahoo group for this device

https://groups.yahoo.com/neo/groups/AP510/info

Perhaps with a small amplifier it will be the general 2 meter packet
radio we've been looking for.

Bill, WA7NWP

[Tom Hayward]

I ordered one and I'll be testing it. I've been waiting for something
like this for SAR use. Bluetooth for smartphone mapping is the killer
feature, and it'll still run standalone for non-nerds.

Unfortunately I ordered from radioddity (China) before realizing it
was available locally:
http://www.amazon.com/dp/B00JLB94IS/

Tom KD7LXL

> --
> You received this message because you are subscribed to the Google Groups "NWAPRS" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to nwaprs+un...@googlegroups.com.
> To post to this group, send email to nwa...@googlegroups.com.
> Visit this group at http://groups.google.com/group/nwaprs.
> For more options, visit https://groups.google.com/d/optout.

[Jeffrey Benedict]

Looks like it might be a good solution in lots of instances. Do report how it works for you!

Jeff KB7AIL CN88

[David Dobbins]

Nice looking little tracker. I ordered one.

[Bill Vodall]

On Thu, Sep 11, 2014 at 9:33 AM, Bill Vodall <wa7...@gmail.com> wrote:

> The Chinese Radios have met the APRS trackers.
>
> Has anybody any experience with this?
>
> <http://www.radioddity.com/us/avrt5-aprs-tracker-vhf-with-gps-bluetooth-thermometer-tf-card-support-aprsdroid.html>

In seconds of looking, I see no mention of a TNC interface or KISS packets.

Bill

[Tim Monk]

I found this last week, looks very interesting but my only concern was that it's only 1watt of output . Looks like it's a Bluetooth serial device similar to the mobilinkd TNC, so if you have Bluetooth on your laptop you "should" be able to use it that way. I so know there is talk in the yahoo group when I skimmed it last week of using it with APRSdroid.

There is a wealth of information on this family of trackers in the ap510 yahoo group.

Tim

[Tom Hayward]

I have some preliminary test results from the AVRT5 (aka SainSonic
AP510) tracker. Conclusion: it works!

1W does not get very far in the QRM of 144.390. When I connect it to
my home antenna, I'm able to get into digipeaters and decode packets
fine. I took it on a mobile trip through Tacoma last night and did not
get any packets out once I was out of line-of-sight of my igate. (I
get similarly disappointing results around Tacoma with 50W from the
D710, so I don't put much blame on this tracker.)

I was able to decode plenty, and they showed up on the APRSdroid map
on my phone via Bluetooth. KISS-over-Bluetooth is very cool. I paired
it with both my phone and laptop for use with APRSdroid and Xastir,
respectively. Setup in Xastir is the same as a Serial KISS TNC @ 9600
bps, very simple.

I got about 22 hours battery life beaconing every 60 seconds.

I don't have the test equipment required for objective testing,
although DK7XE has published some (disappointing) results:
http://dk7xe.blogspot.de/2014/09/ap510-avrt5-aprs-tracker-hf-signal.html

Tom KD7LXL

[K7ADD]

I received mine earlier this week.  My initial impressions, most of which were completely expected:

Packaging:

I purchased from an Amazon reseller with Prime shipping and it arrived on time, with good external packaging, if a bit heavy-handed on the packing tape.

Initial packaging was good, including an appropriately sized corrugated box and surprisingly well translated full color pocket sized "manual."

Build:

I was surprised by the mass of the unit.  That's a big battery, given the size of the case.

Build quality was predictably poor.  The case is effectively a silk-screened project box.

Case, as expected, showed no FCC ID.

Unit came with battery discharged, but contained a surprisingly heavy mini-USB cable.

Setup:

Legit FTDI/Prolific drivers would not work with Windows 8.1, after some fiddling, managed to get an old PICAXE driver to work (dated 2007 http://www.picaxe.com/Software/Drivers/USB010-USB-Adapter-Driver/)

Software is functional, if not polished. Little things that you'd expect from more mature software are just missing, for example trailing zeros are required on frequency field.

Setup was pretty quick, given the YouTube video and info on the Yahoo group.

APRSdroid setup was quick and painless, it's pretty slick and makes me reconsider the utility of that app.

Performance:

Default whip/dummy load is as useless as expected.  Zero igated packets from outdoors in Duvall, WA (top of the hill).  A Nagoya (knockoff) telescoping I purchased in Beijing worked "better."  In the same location, just over 50% of packets were igated.

As expected, 1W in the choppy sea of 144.390 is insufficient, but with 30 second intervals it's enough to map a typical drive.  60-120 seconds for walking.

There's a slight audible whine while it TXs.

Messaging with something other than a DTMF mic on my mobile might be something I'd use!  I wish there were a way to feed APRSdroid external telemetry.

The AVRT5 certainly had successful decodes, including it's own packets digipeated.  Kenwood D700/D710 packets were plentiful, but location packets from my Yaesu FTM-350AR weren't decoding.  Messaging packets decoded, but not location.  A problem with decode might limit it's use as a receive only igate... though the ISS has a Kenwood, iirc.

Battery:

Similar results to Tom's with an initial charge voltage just under 4.0v and decodes stopped at 3.42v.

The unit was still functioning, but not hitting the previous paths (K7ADD-1>APAVT5,WW7RA*,WIDE2-2,qAo,SEDRO being the most common).

Overall impressions: 

Would not recommend, given the plethora of alternatives available.

This falls into roughly the same class as the Trackduino and is much less ham-chic than a homebrew kit.  :) 

For HAB or similar "may end up being a throw away" application, it might find a home.

It'll be interesting to see how the price point finds stasis.  I've seen them listed anywhere from $78-$124.

Any regular use will really need a good lowpass filter (anyone have a good source?), as the results DK7XE published are abysmal.

A Raspberry Pi with a bluetooth dongle and aprx is the next experiment.  I'd love to have APRS data off on our local repeater's health (battery voltage, solar panel stats, COS duty-cycle. etc) and this might be the thing to do it.

Bengt-Erik, K7ADD

[Tom Hayward]

Some comments...

On Fri, Sep 19, 2014 at 9:55 AM, K7ADD <very...@gmail.com> wrote:
> Build:
> I was surprised by the mass of the unit. That's a big battery, given the
> size of the case.
> Build quality was predictably poor. The case is effectively a silk-screened
> project box.

I'm actually pretty happy with the case. It's aluminum, but with a
plastic top to let GPS signal in, and a plastic bottom to let
Bluetooth through. The respective antennas are mounted flush to the
plastic, so I had no trouble getting signal through the case. The GPS
works indoors.

https://dl.dropboxusercontent.com/u/8174/2014-09-18%2015.10.18.jpg
https://dl.dropboxusercontent.com/u/8174/2014-09-18%2015.13.54.jpg

By the way, mine is branded AP510. I think this may be a newer
revision than the AVRT5. My photos of the circuit board definitely
show some changes compared to the photos on the website.

> Unit came with battery discharged, but contained a surprisingly heavy
> mini-USB cable.

My battery arrived at 3.7 volts. The recommended storage level for
Li-Ion is 40% (~3.5 volts).

The mini-USB cable is actually a USB-serial cable with USB connectors.
The bulky part houses the USB-serial chip. The 5V and ground pins on
the cable are standard USB, so any charger with mini-USB will work,
but the data pins have serial data, not USB. (I didn't check levels,
but 5V TTL would not surprise me.)

> Setup:
> Legit FTDI/Prolific drivers would not work with Windows 8.1, after some
> fiddling, managed to get an old PICAXE driver to work (dated 2007
> http://www.picaxe.com/Software/Drivers/USB010-USB-Adapter-Driver/)

I used the driver linked here in the MediaFire download:
https://www.youtube.com/watch?v=qmtVvKav_LU

> Software is functional, if not polished. Little things that you'd expect
> from more mature software are just missing, for example trailing zeros are
> required on frequency field.
> Setup was pretty quick, given the YouTube video and info on the Yahoo group.

As you mentioned, the software has some idiosyncrasies, but this video
does a good job explaining them.

> Overall impressions:
> Would not recommend, given the plethora of alternatives available.
> This falls into roughly the same class as the Trackduino and is much less
> ham-chic than a homebrew kit. :)

I am hoping the AP510 hardware can be flashed with some open source
software like the Truckduino project. I haven't done enough reverse
engineering yet to determine if the tone generation is done in a
compatible way--that's the part I really don't want to reinvent
myself.

I have been waiting for perfect hardware for tracking SAR teams. My
requirements are:
1. Some sort of tracker, not necessarily APRS
2. Built-in VHF transceiver
3. Internal battery with 12+ hours life
4. Built-in GPS
5. Decode / plot on map (GPS or smartphone)
6. Digipeat capability
7. Small / lightweight (SAR teams don't like being told to carry extra stuff)
Bonus:
8. Waterproof
9. Frequency agility in the field (no computer)
10. Bluetooth serial for viewing other teams' location on smartphone.

I have a Kenwood TH-D72 and it comes very close to all these points. I
only get about 6 hours of battery life, which isn't enough for many
SAR missions. It's also complicated and expensive, which isn't an
issue for me because I like playing with radios, but it's not a great
choice to hand to a typical searcher.

For everyone else, the AP510 is a perfect form factor. It's a black
box with one button that fits in the palm of my hand. It hits all
points except #8, and it's cheap. My biggest concern is the low power.
I'm going to try testing it again this weekend in a quiet, wooded
valley typical for SAR.

I should mention the Micro-trak AIO. It's a similar product to the
AP510, though much bigger (with 8x the battery life, naturally) and
lacks a receiver. This eliminates of bunch of the features I want,
like digipeat. With the Micro-trak, I would have to make sure the team
that is searching the ridge is issued an alternative tracker that can
digipeat (so we can hear the other team on the far side of the ridge).
It's also twice the cost of the AP510.

Some other solutions, like Garmin Rinos and Astros come close and I'm
seriously considering writing a grant for a pile of them. If you have
any other suggestions, I'd like to hear them (maybe in a new thread).

> A Raspberry Pi with a bluetooth dongle and aprx is the next experiment. I'd
> love to have APRS data off on our local repeater's health (battery voltage,
> solar panel stats, COS duty-cycle. etc) and this might be the thing to do
> it.

I'm currently testing an RPi igate. Originally, I had the RPi running
two TNCs from the same audio feed: the internal TNC in a Kenwood
TM-D710, and a Dire Wolf soundcard TNC running on the RPi CPU. Dire
Wolf consumes about 50% of the RPi CPU decoding 1200 baud APRS. I've
since moved Dire Wolf to a more powerful PC to see how that affects
decode rates. A typical serial TNC and aprx don't stress the RPi at
all.

Dire Wolf: http://aprs.fi/info/a/KD7LXL-10
Kenwood: http://aprs.fi/info/a/KD7LXL-11

Bottom line: Dire Wolf decodes a lot more packets than the Kenwood TNC.

You might consider sending your repeater telemetry over HamWAN. The
hardware is similarly priced to a VHF transceiver, TNC, and antenna,
but you'll get a lot more bandwidth out of it. If you need the typical
cavities and isolator for VHF, the 5 GHz HamWAN link starts to look a
lot more economical. It would also leave the possibility of fancier
TCP/IP linking and control systems. If you wanted, you could install
both VHF and HamWAN for an igate at the repeater site.
https://www.hamwan.org/t/tiki-index.php

Tom KD7LXL

[Bill Vodall]

> The Chinese Radios have met the APRS trackers.
>

> <http://www.radioddity.com/us/avrt5-aprs-tracker-vhf-with-gps-bluetooth-thermometer-tf-card-support-aprsdroid.html>

So what's the verdict on these little data-radios? Go or no-go?
Every RPI need one?

> Perhaps with a small amplifier it will be the general 2 meter packet radio we've been looking for.

I just realized these might be a good match for the 2-10 Heathkit
HA-201 amplifier. I've had several in a box for years and years
waiting for some use.


Bill

[David Dobbins]

I sure like mine.

[Bill Vodall]

>> > The Chinese Radios have met the APRS trackers.
>> > <http://www.radioddity.com/us/avrt5-aprs-tracker-vhf-with-gps-bluetooth-thermometer-tf-card-support-aprsdroid.html>

On Thu, Oct 30, 2014 at 2:59 PM, David wrote:
> I sure like mine.

Any idea how much current they pull? This might make a solar powered
tracker easy...

http://www.gizmag.com/solar-flight-sunstar/34551/

>

More questions in a bit...

Bill

[David Dobbins]

Hi Bill. No, I don't know the current pull, but I'm sure it's light. It would be worth a try. Dave

Bill

[Bill Vodall]

> I sure like mine.

http://www.amazon.com/gp/product/B00JLB94IS/ref=s9_simh_ot_p422_d2_i1

Price on Amazon has dropped and it's now being fulfilled by Amazon.
Oh so temping. If I hadn't already indulged twice this week
(streaming video at 2400 baud?) I'd jump on it. So now I'll argue
with myself for a couple days before going for it.

Bill

[David Dobbins]

I probably won't have a lot of use for mine over here as the local club isn't much interested in APRS or supporting events with tracking. It is a nice little device.

My indulgence in ham toys got the best of me this past week: NanoNode (Portable IRLP/EchoLink device, probably a r-Pi and 440 radio with a nice display all in one small case)

Dave K7GPS

Bill