New Kenwood TH-D74 HT + APRS ramblings

Airmapper

Inactive Member
Anyone else drooling over this? :drool:

I know this is the opposite end of the spectrum than most of us go with our $30 Baofeng HT's, but if I were to spend good money on an HT, I'm thinking this would be it. And besides I'm a Kenwood fan for no reason at all other than I just like them.

http://qrznow.com/kenwood-th-d74-how-to-do-a-quick-setup-video/

th-d74_vhf.jpg


I have no idea what the price tag is on that, probably costs more than my smartphone, so I'm betting once I see the $$$ my drooling will stop and I'll go back to running cables from a phone or tablet to a Baofeng. (You mean you guys don't do that, and you call yourselves hams.....)


For those of you who don't know what I'm talking about....you are thinking big deal, it's an over complicated HT, why would you want that.

Say you are out in the middle of nowhere hiking. Lets say you can park your vehicle where you have ham radio reception (much further than typical cell phone reception so it's more probable in a rural area to have ham reception vs. cell tower.)

We hams think about using a cross band repeater to get a voice message from our HT out of no mans land, think about it anyway, never do it. But if you did, will anyone hear it? I mean at some point every week I'm in my truck, bored, and I'll make calls on like 4-5 repeaters in a row that are within my range, and don't even hear crickets in response. What if I really needed someone to respond?

Now something else I hear Overlanding hams groan about: What is the point of APRS, it's lame....it's too hard and I don't know what it's for....

Here is where a APRS gets relevant, and why I think it's horribly underrated.

With your vehicle parked in an area it can reach a part of the APRS network (and you can positively confirm this quickly) you can set up your mobile as a "Digipeater" and even target it specifically (so the whole local area is not making your radio transmit) and if you are in HT range of your vehicle, you can send out a burst of data with your exact position, a text message, even an EMERGENCY status that should throw up a red flag on some APRS clients.

Also consider this, data packets are a quick (Like 1 second) burst transmission. If you set a HT to beacon every 30 minutes, how long would it be able to keep that up on a battery vs. a few minutes of voice transmission every hour? You won't have to waste battery unless there is someone on the other end to talk to, because guess what else you can send in that data, the frequency you are monitoring for a response on.

Even for a non-emergency emergency, you can have someone back home, a non ham even, monitoring APRS on the internet for your movements and messages to see if you are okay. Heck you can even send an email using APRS.

Anyway the point of all this is I like seeing new APRS tech available in a form that is easily transported and allows you to use your vehicle as a link in the chain for comms. I like the movement of off road enthusiasts taking ham radio seriously as a form of communication, and if more would get on the APRS bandwagon as well, we could be setting up our own infrastructure to have high quality comms tech for recreation and safety.
 

Hilldweller

SE Expedition Society
I'm afraid of technology that's smarter than I am...
I can barely remember how to program the radios I have already.

$650 at HRO, btw.
 

Airmapper

Inactive Member
I'm afraid of technology that's smarter than I am...
I can barely remember how to program the radios I have already.

$650 at HRO, btw.

The robots are going to rule us all Bill! :yikes:

APRS isn't as hard as you might think, but it's still not a lot of fun for the technologically meek. It can be a lot of button pushing.


Thanks for the HRO tip, I didn't realize they were priced already. (I don't look at HRO much, it's hazardous to my wallet.) Yeah, $650, drooling is drying up. A few cords and I can make my Baofeng do it, just needs extra devices attached. Not radio clipped to your belt friendly.

I see the old model TH-D72A is on sale that does all the APRS functions. No shiny color screen though....and looks plain awful for a HT in my opinion.
 

1Louder

Explorer
Cool gadget. Way too much money. APRS with my mobile Kenwood is fine and other money spent on a Delorme InReach that will work anywhere for emergency communications. APRS doesn't function in Mexico for example. Don't get me wrong I love APRS. There is an app called APRS Pro for iOS that along with a cheap Baofeng radio and a $30 box can give you APRS on a mobile. So cost of entry is much less although less elegant and cool. Maybe the price point will drop in a few years.
 

opg4759

New member
APRS on this radio is great feature, but the big win for the TH-D74 over the TH-D72 would be the inclusion of D-STAR, which has historically been a Icom only protocol.
BTW APRS on a Baofeng is painful at best, while it will work with the right TNC the radio is very noisy and APRS get garbled. I have many APRS setups including a Baofeng and Mobilink.
 

ChadHahn

Adventurer
I just ordered the Icom id-51a plus from Main Trading Company for $250. Looking at the videos it seems like a pretty sweet little radio and the anniversary editions are a lot cheaper than the regular versions.

Chad
 

1Louder

Explorer
APRS on this radio is great feature, but the big win for the TH-D74 over the TH-D72 would be the inclusion of D-STAR, which has historically been a Icom only protocol.
BTW APRS on a Baofeng is painful at best, while it will work with the right TNC the radio is very noisy and APRS get garbled. I have many APRS setups including a Baofeng and Mobilink.

Good to know. Thanks
 

Airmapper

Inactive Member
APRS on this radio is great feature, but the big win for the TH-D74 over the TH-D72 would be the inclusion of D-STAR, which has historically been a Icom only protocol.
BTW APRS on a Baofeng is painful at best, while it will work with the right TNC the radio is very noisy and APRS get garbled. I have many APRS setups including a Baofeng and Mobilink.

It's cool, but D-STAR would not be very useful for me. None of the local repeaters use it to my knowledge. While I think it would be nice to have if I were in a situation where I could use it, for me it wouldn't make a $650 price tag viable. Even nearly $400 for the D72 is ridiculous. I'm thinking about getting a Mobilink. A bit more clumsy but will be interesting to play with using my Baofeng.

What I'm really wanting is a way to display live data from my D710 on a screen. It does APRS great, but it's hard to get position awareness from the stations coming in without a map. I think the Mobilink is overkill as I have no need to TX packets, the radio does that, I just want to see RX packets on a map, even if my cell service is spotty. The issue with a D710 I believe is if I use an audio connection, the squelch open interferes with packet TX, and closed it interferes with proper RX, so I can't win using audio. I DO NOT want APRSdroid to take over any APRS functions or TX, just listen and display packets. I think it's possible but I haven't found any tutorials for making it work in that manner yet.


APRS with my mobile Kenwood is fine and other money spent on a Delorme InReach that will work anywhere for emergency communications.

I agree wholeheartedly, it's not worth sinking that kind of cash into for a HT with APRS, I won't and I think APRS is really cool. It's not nearly utilized enough to accommodate to that level and I agree it's way to expensive for what it is.

I don't want anyone cruising this thread to get confused, they have some similarities, but InReach is not the same as APRS. APRS 'could' be used as an option in an emergency, but if you have heightened need for a rescue device, or making periodic messages to home, an InReach is a better tool for that specific task.

APRS doesn't function in Mexico for example.

It absolutely does function in Mexico. It's not going to work well to reach the internet, not many Mexicans seem keen on building and installing iGates and Digipeaters. If you and your party have APRS devices, you could keep tabs on each other and exchange messages among yourselves as long as you are within RF range. APRS works as it's own independent network with or without additional fixed infrastructure. But, say you do have a cell connection at your vehicle, you could set up an iGate from your mobile to the internet, if such a thing was desired. (Example: You want to hike into a valley with no reception, your phone might do you more good connected at your vehicle than useless in your pocket...)

APRS in Mexico would not be high on my list of concerns though.

I'm not advocating it as some kind of awesome super solution. But if more people used it at group events, or among their personal friend groups, you could get some handy functions out of it in places cell phones don't work.

I just ordered the Icom id-51a plus from Main Trading Company for $250. Looking at the videos it seems like a pretty sweet little radio and the anniversary editions are a lot cheaper than the regular versions.

I can't really tell from the documentation, but it looks like they gave it all the necessary hardware to use APRS, yet replaced the functionality with their own proprietary (D-PRS) protocols to make it so you cannot use it in the standardized APRS system? Thus everyone would need to buy Icom radios to use it. Lame if I understand correctly, I may not.
 

opg4759

New member
What I'm really wanting is a way to display live data from my D710 on a screen. It does APRS great, but it's hard to get position awareness from the stations coming in without a map. I think the Mobilink is overkill as I have no need to TX packets, the radio does that, I just want to see RX packets on a map, even if my cell service is spotty. The issue with a D710 I believe is if I use an audio connection, the squelch open interferes with packet TX, and closed it interferes with proper RX, so I can't win using audio. I DO NOT want APRSdroid to take over any APRS functions or TX, just listen and display packets. I think it's possible but I haven't found any tutorials for making it work in that manner yet.

This is totally possible with APRS Droid, you need to look at Kenwood mode. It will display objects on a map, but the way the D710 works it cannot message or TX that has to be done in the D710.

https://aprsdroid.org/kenwood/
 

opg4759

New member
Also the Kenwood TH-D72 & TH-D74 are more than just APRS data radios, you have the ability to access the full TNC so you can use them for packet data to connect to Packet Bulletin Board Systems (PBBS) and Winlink which the Icom and Yeasu radios lack built in.

The TH-D74 looks like it will be my next HT once the rebates start happening.

Looking at the specs radio is also a HF receiver. The more I read about the specs the more I want it.
http://www.rigpix.com/kenwood/thd74.htm

RECEIVER SECTION
Receiver system: IF-matrix
Sensitivity: AM (10 dB S/N)
0.3-0.52 MHz: 4 uV
0.52-1.8 MHz: 1.59 uV
1.8-54 MHz: 0.63 uV
54-76 MHz: 1.12 uV
118-174 MHz: 0.5 uV
200-250 MHz: 0.63 uV
382-412 MHz: 1.12 uV
415-524 MHz: 1.12 uV
FM (12 dB SINAD)
28-54 MHz: 0.32 uV
54-76 MHz: 0.56 uV
118-144 MHz: 0.36 uV
144-148 MHz: 0.18 uV (Band A), 0.19 uV (Band B)
148-175 MHz: 0.36 uV
200-222 MHz: 0.36 uV
225-250 MHz: 0.36 uV
382-400 MHz: 0.5 uV
400-412 MHz: 0.36 uV
415-430 MHz: 0.36 uV
430-450 MHz: 0.18 uV (Band A), 0.2 uV (Band B)
450-490 MHz: 0.36 uV
490-524 MHz: 0.63 uV
NFM (12 dB SINAD)
144-148 MHz: 0.22 uV (Band A), 0.24 uV (Band B)
430-450 MHz: 0.22 uV (Band A), 0.25 uV (Band B)
WFM (12 dB SINAD)
76-95 MHz: 1.59 uV
95-108 MHz: 2 uV
SSB (10 dB S/N)
1.8-54 MHz: 0.4 uV
54-76 MHz: 0.79 uV
144-148 MHz: 0.16 uV
222-225 MHz: 0.2 uV
430-450 MHz: 0.16 uV
DV (PN9/GMSK, 4.8 kbps, BER 1%)
144-148 MHz: 0.2 uV
430-450 MHz: 0.2 uV
 
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Airmapper

Inactive Member
This is totally possible with APRS Droid, you need to look at Kenwood mode. It will display objects on a map, but the way the D710 works it cannot message or TX that has to be done in the D710.

https://aprsdroid.org/kenwood/

Thanks. I have read that page but what kinda set me off the arrangement is how APRSdroid acts as the units GPS. I have a D710G, my unit has a GPS. I also don't like the idea of the extra stuff on top my dash.

The head unit has another port, referenced here (and detailed in the manual)

http://aprsisce.wikidot.com/port:kenwood-tm-d710 said:
The Kenwood TM-D710 has the ability to push all of the APRS packets heard out the COM port (Menu 604 set to ON) that is found on the back of the control head when it is running in full APRS mode (Use TNC button to set to APRS).

That port should output full packet info and not disrupt or replace the D710's own hardware. Unfortunately, as mentioned, it's on the head unit, on the dash.....

But I held out hope, there is also a TNC data port on the back of the main TX/RX unit under the seat, a more favorable location. Turns out it is disabled when the face plate TNC is active.


I'm not too happy with the idea of more wired up stuff on top my dash. However, should I move the unit down to the base of the dash, it might be a more appealing solution and the extra wire and Mobilink will be out of the way. My phone would have better GPS reception and display the stations.

I think I'll probably get the Mobilink and it will get used in 2-3 different ways until I find where I like it best.
 

opg4759

New member
The problem with the Mobilink is that your phone tablet has to be active and connected for it to work appropriately since it requires your phone for the GPS to work.

What would prevent you from running a cable from the head unit back down with the extension cable to where ever you want your display setup? Just saying.
 
I just got my Tech license a month ago and have been playing around with APRS, put a D710G and it works great to send packets as I move and hear them. As has been said it's the displaying them on some sort of a mapping device that is the problem. I understand using a Garmin Nuvi 350 works well, but only the 350. It will take the Waypoint info from the head unit data port into the 350 and it will show all received packets as waypoints. The 350 is the only one that will let the waypoints expire so they don't blot out the screen. OF course it requires the usual spaghetti mess of cables to adapt the output port of the Kenwood head unit to the input of the Nuvi and also power it. More stuff on the dash, more cables, more ...

Or you could do a similar set up into a laptop/tablet running nav software with offline maps, etc. Maybe convert the serial output of the head unit data port to a Bluetooth then into... More cables, adapters, it doesn't end.

I just got back from a trip down through Lassen and the Owens Valley in CA. While I could hear quite a few packets, there seemed to be a lot of wholes where my packets weren't picked up and forwarded to an i-gate. Not a big deal, but was trying to have it so family and friends could see where we were. And/or being able to text in outlying areas via SMSGTE (which works very cool if you can hit a gate).

All in all APRS is very cool, I typically have it running on road trips no matter what. Having others with APRS you and the ability to map where others are would be a plus. Will probably McGuyver something (i.e. cludge) over the winter unless I can come up with a better diversion...
 

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