Timz
Ham Radio PageTH-D72a APRS / FTM-350R / Yaesu FT-90R
Kenwood TH-D72a
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below is a pic of a TH-D72a with the case removed. Between the volume control and antenna jack is the custom built GPS receiver:
APRS & GPS
Setup for APRS-GPS OperationFor my TH-D72a, the normal/regular use of this radios APRS capabilities will be:* to transmit my location coordinates* No digipeating or messaging (although the digipeat & message functions are cool to play with, I really won't be using those features that often.... and there's battery life concerns when allowing this radio to transmit every 10-15 seconds. Please read "more on this later" at the end of the section).
* have the radio as less-annoying as possible
I can't improve upon the Quick Setup instructions that came with the radio; so will try to cover specifics that the manual didn't cover all that well.
Here are the APRS & GPS Menu fields I altered from the factory settings:
* GPS Track Log "ON" (221) wrap when full.
*APRS-Digipeat "OFF" (3K0) please read "more on this later" at the end.
*APRS-UIcheck "0" (3L0) please read "more on this later" at the end.
*APRS-Inc TNC2 "300" (321) I gave the transmitter an additional 100ms to develope RF before sending data.
*APRS-TX Beacon "Auto" (3D0) in my experience, Smart Beaconing (although looks like a good idea on paper) is a headache to get set to your liking. There will always be an instance where the radio did not transmit your coordinates... but you'd wish it had. If you're like me, you'll start out with Smart Beaconing enabled... but finally switch over to automatic (timed interval) beacon transmit.
*APRS Sound "OFF" (3T0 & 3T1) I don't need the radio BEEPING every 10-15 seconds.
*APRS Display "One Line" (3U0) I wish there was a "no line" selection here.
*APRS Display "3" (3U1) 3 seconds.
FAQ1: are these the ideal settings for everyone?
No. These are just what I settled with. It will be different for a lot of people.APRS Pop-ups on the Screen
The LCD display can become very active when receiving a lot of APRS traffic. Apparently there is not an option to totally turn off popups (but still allow logging); all you can do is limit how much of the total screen the popup APRS data will occupy. In the program software, go to Edit, Menu, APRS, Display tab, and change the "Display Area" field to "one line" (3U0)Unwanted APRS transmitting
I initially configured my TH-D72a using the supplied Quick Setup recomendations, except I had the beacon interval at 1 minute. To my surprise, the radio was transmitting every 10-25 seconds; randomly. That was puzzling to me since I already own a ham radio with built-in APRS-GPS and am familiar with how it should operate with a generic configuration. The first thing I discovered was that the Digipeat function was enabled at the factory, so I turned that off (3K0). That made a difference, but the radio was still sending "something" inbetween the 1 minute beacon interval. I then changed the APRS-UIcheck field to zero (3L0)... and that finally worked. Now, the only time the radio transmitted GPS coordinates was once every 60 seconds.At this point I have my TH-D72a operating exactly like I prefer it to.
Screen Shot
all these icons need be active on the LCD screen in order for the radio to send your geographical coordinates automatically:
and... the iGPS icon needs to be flashing (meaning the GPS has acquired -at least - 3 satellites).
FAQ2: my radio dispay says "packet12" instead of APRS12.
keep repeat toggling (hesitate a few seconds between button pushes) the "TNC" keypad button until APRS appears.FAQ3: my radio display says "iLOG" instead of iGPS.
keep repeat toggling (hesitate a few seconds between sequence repeats) the Function-GPS button sequence until iGPS appears.FAQ4: the "D" symbol is not showing on my radio
then neither should the APRS script as well. Enabling the TNC will cause the "APRS" & "D" to appear.FAQ5: my display does not show "BCON"
press the keypads BCON key to activateFAQ6: what's the easiest way to stop the coordinate beacon transmissions... while still allowing the radio to log received APRS data?
Press the BCON keypad button until the BCON icon disappears.
Turning off the GPS receiver will also accomplish this, but it requires two keypad button pushes.FAQ7: is there a way to mute the APRS receive audio.... without having to adjust the Balance Audio function?
Yes. Program the 144.390 frequency for CTCSS. It must be both encode & decode. Shown below:
With all the APRS functions enabled on this TH-D72a, it will be transmitting "something" every 10-20 seconds. Not only will this deplete your battery quickly, you'll also flood the APRS frequency within your area with RF. Grasp the reality that you're not the only radio beaconing/texting/digipeating. Like other radios, the TH-D72a looks to see if the channel is busy before transmitting data. If everyone in your area with APRS radios also have all the functions enabled as well... there would develop serious channel congestion; yours & others radios may have to wait quite awhile before there's a gap long enough to squeeze-in an APRS dats transmission. My local area has enough digipeaters/iGates already. No need to duplicate something that's not really needed in the first place.Yes, I know that all this technology is super cool. And... I know - as hams we like to "tinker" around with this stuff. But... if the sole reason of running this radio with all the APRS functions enabled (when you really don't need it all at that time) is to boost your ego... I can guarantee the ARRL will not print your picture in QST stating you're "Ham of the Year" just because you purchased this radio and figured out how to turn it on
.
So please, only enable those specific functions needed at that time.
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