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Is the TH-D7 still viable for SOTA APRS?

Let me preface by saying I have no experience with APRS, but seeing a lot of mention of it in conjunction with SOTA, I wanted to look into it. I have access to an old (15+ yrs) TH-D7, which looks like it only needs a new battery. Is this still a viable radio for this, or has technology passed it by? With the current Kenwood and Yaesu APRS HTs in the $350-500 range (not interested in Anytone or similar) I’m hoping this is an option.

If I understood properly the TNC for APRS is external. There is no GPS for position for APRS beacons so most of the SOTA relevant features are missing (at least the one that I highly value).
Dual-RX and CW/SSB support are rare features now so that might be other reasons for getting the TH-D7.

You can self-spot with a simple handheld and an APRS app like Aprsdroid.
See here: APRS spotting on the (very) cheap
This would work with the TH-D7 too.

If you want an ‘all in one’ solution get a modern one. Yaesu is a bit “special” in the ways APRS is integrated in the FT1 to FT3 series.
I have the FT1xde and are okay with it.
Icom seams to have a lot better implementation from what I heard.
But it’s a matter of price.

73 Joe

It’s been a long time since I’ve last used my TH-D7. Yes I did use it to self spot, but I was at the time more interested in using it for Winlink or sending out emails back to my kids from areas without cell svc. It worked OK and I would pair it with an older Ace notebook. Last time I really played with it was 2016 during the NPOTA event. I activated Elk Mtn in Glacier Nat’l Park and was able to spot to SOTA. It has a bit of a learning curve (like trying to remember how to use! :wink: ) for general ham use. I found myself actually carrying two HT’s! One for 2M/440, and the D7 for APRS etc…I think you’ll find out real fast that a newer Kenwood D74 would be more efficient. But like you, I had one laying around and wanted to experiment. I found too that having the Kenwood software that came with it more it a whole lot easier to use…Give it a try…

73, Todd KH2TJ

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A TH-D7 should still be useful for SOTA APRS. It does have a TNC built in. It does not have a GPS built-in, however you can manually input and send positions if you don’t have an external GPS (page 68 of the manual). Besides, you can send APRS messages without having to send your location.

For the battery, instead of sourcing a replacement, consider saving some weight by powering it off your 12V power source with the PG-2W cable. If you want to protect the terminals, an empty AA battery pack would do the trick.

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Doug, I’ll be curious to read what you decide to do, and if you use the TH-D7, what specifically you use it for, and how it works out for you. I’ve considered picking one as a low cost replacement for a TH-D72 I used to have.
73, Peter

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@KH2TJ I’d love to get a D74 or D72. One might be in the cards if I get the APRS bug from trying this.

@K7III I don’t have the PG-2W cable, but that’s a great idea, I’ll need to get one. I have a TH-F6A which it will fit as well.

@KD0YOB I’ll definitely loop back here after I’ve read the manual enough to figure out how to run the radio, and do APRS on it.

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Is that really what you want though? It’s a nice shiny thing and we all like shiny things. But is the performance and usability the best for the quite high cost?

If you use the handy on hilltops and there’s commercial VHF gear on site you want a radio that will work under such conditions. Look at this table Razvan M0HZH/YO9IRF put together and really you want radios from the top of the list. https://qrpblog.com/vhf-uhf-handheld-performance-comparison/

You have a TH-D7 which needs the battery repairing (either with a new complete unit or by you replacing the cells in it). The TH-D7 lacks a GPS receiver so here is a simple design to add a GPS to it. https://www.richardmudhar.com/blog/2015/12/gps-serial-receiver-for-kenwood-th-d7/

So for not a lot of money you can bring your TH-D7 back to be much more APRS-able and have satisfaction of making some of the stuff yourself. Compared against a TH-D74 it doesn’t have D-Star.

A TH-D74 new in the UK including P&P and all sales taxes is $702US. That includes a warranty that may be longer and more inclusive under UK sales laws than the US before your head explodes at the price. That’s a lot of money still. You get a more modern radio but it still has a less than ideal UI.

My view, FWIW, is a better APRS system is to use a Mobilinkd TNC ($120 http://www.mobilinkd.com/ ) with a handy from top of Razvan’s list and use it with the smartphone you already have with you. You get to use the phone for the UI which is going to beat the living daylights out of a compromised handy APRS UI. Yes, needs setting up etc. but the performance, usability and cost should beat a high spec APRS modern handy. You wont have D-Star but I don’t see that as a real loss.

Just my $0.02 to give you something to think about.

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Great comments and suggestions -

Honestly, I don’t know yet. I’ve never played with APRS, but the mention of it here piqued my interest, as I’m always game for learning new things. If it turns out I like APRS a lot, and if a new HT with new capability fits the bill, I don’t mind paying for quality and usefulness. Lot of ifs.

I have to confess, I’m not very good with electronics. It took me a month to build an end fed zep. One of those kits is above my ability level.

As far as using smart phones, with activities like emergency communications, camping & hiking, and as an extension SOTA, I try to get by without using one. With APRS in the radio, it adds one more capability to the hobby.

Nobody was to start with, if you don’t try you’ll never get better!

Join your local radio club or find an electronics or maker group. Get involved and there’ll be plenty of people to help you with building etc.

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It’s a nice shiny thing and we all like shiny things. But is the performance and usability the best for the quite high cost?

Yes, performance and usability are the reasons for the high cost. Spotting with the D72 is as easy as texting with a 20 year old Nokia phone.

If you use the handy on hilltops and there’s commercial VHF gear on site you want a radio that will work under such conditions. Look at this table Razvan M0HZH/YO9IRF put together and really you want radios from the top of the list. https://qrpblog.com/vhf-uhf-handheld-performance-comparison/

The TH-D72 is a wonderful RX. No issues even on DM/SA-001 Brocken (complete list of transmitters, german only). Lots of handies just give up there.

Ahoi
Pom

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My VX-8R works great

Kent K9EZ

Thanks for linking to my list Andy.

I’ve actually owned the TH-D7. Quick breakdown:

  • dual receiver is amazing for satellites
  • nice Kenwood user interface, none of that Yaesu chaos or Icom minimalism
  • big & heavy
  • requires aftermarket batteries & charger (original batteries used outdated NiMH technology, limits output to 2W)
  • no internal GPS, so you need an external unit if you want to send dynamic positioning
  • modest RF performance

An APRS mobile app like APRSdroid will give you significant APRS functionality without even using a radio.

I have owned a TH-D7A for years and I have been using APRS2SOTA on several of my activations. It works pretty well. My only complaint is that typing in all the necessary information is pretty cumbersome on the keypad.

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I’ve gotten mine to receive, but doesn’t seem to be transmitting. At least I’m not seeing myself on aprs.fi. Any suggestions/recommendations?

but doesn’t seem to be transmitting

Have you told it to? If you’re receiving and decoding you have probably got the TNC set up right, in which case hit the bcon button twice, and look for the red TX light and listen on another RX for the bzzrt sound. If you’re receiving but not decoding then you need to set the data band and the TNC on first.

Then go into the menu and set the beacon interval to your preferred setting.

Alternatively compose a message and send it. The UI on the THD7 is beautifully simple and usable, compared to the foul and disgusting mess that Yaesu have made of the FT3DE, where yes, in theory you can compose a message in the field but in practice fuhgeddaboutit. The onboard GPS in the FT3DE makes up for all that :wink:

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I will check the instructions you mentioned. It’s been over a month since I was working on this, so I don’t remember all the steps I did (and didn’t) do. I need to make a comprehensive step by step instruction sheet with all the recommendations I’ve gotten, here and elsewhere, and correct the manual I downloaded with the accurate menu items.

That was the problem. No where did I see to hit [BCON] twice, it always said Press [BCON].

Next problem, In menu 2-4 (My Pos) the second settings for longitude only goes as far as 59, and I’m 71.7128, Close, but not exact, off by 25 miles.

Is the setting in degs mins secs and not decimal degrees? 71.7128 is 71deg 42 mins 46 secs.

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Good point!

It’s degrees and decimal minutes (p68 of the manual). The Bcon command is modal, what you’re actually doing is turn regular beaconing on - look for the BCON icon in the top of the screen. It sends out a beacon at the start of beaconing mode. The second press turns it off, so it’s ready to send out another beacon when you do it again. Else if it was on, turning it off sends out the beacon on the second press, when you turn it on again.

Page 74 and page 75 tell you how to set the beacon TX method. It can be periodic (auto) when you press the beacon button (manual) or after you unkey PTT (PTT). Since you don’t normally have a QSO on the APRS frequency PTT isn’t tremendously useful. If you are entering the location manually then manual is probably what you want. The serial GPS mod works a treat, in which case auto is good. The main bugbear with that is until the GPS locks up the TH-D7 is quite happy to send out beacons with a LL of 0,0 which puts you in the sea a little bit west of Africa, they really should have masked that is the s/w

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