Archive for Transceivers

APRS in my car – TM-D710 or FTM-350

Wow, it’s been a long time since I posted anything here – so sorry for that! I’ve been too busy to think about my hobbies, unfortunately. To sum it up in two words: Work + XYL.

feel that I have to make a little rant about todays APRS-capable transceivers, namely the Kenwood TM-D710 and the Yaesu FTM-350. I just traded in an Icom ID-E880 DSTAR-radio for the FTM-350 (don’t get me started on the ID-E880..). I was hoping that the FTM-350 would be way more user friendly for car use as it has an awesome display and well laid-out user interface. Indeed, in some places the FTM-350 shines like no other radio I’ve used. The display can be customized with colors, text size and other parameters to look at. The buttons and ease of access to common functions is as expected from a Yaesu radio. A bonus is that the display light can be set to match my instrument lights (BMW orange-ish). I also like the fact that you can chose to connect the microphone to either the base or the remote panel – neat! The remote panel also contain two small speakers, but they’re too weak to be of any use in a car. I recommend connecting an external speaker anyway, so I won’t make an issue out of it.

The FTM-350 is marketed as an APRS-capable radio, which it is, but when you start looking at the flaws or

Yaesu FTM-350

Yaesu FTM-350 in car

misunderstood implementation from Yaesu, I think you should think at least twice before you select this one instead of the (older) TM-D710. I might be a semi-advanced user of APRS, so my view on this might be a bit biased compared to people who just want to use a “tracker”. Please see my pros/cons list further down, it’s a lot easier to explain what I mean in a table instead of a huge wall of text.

The TM-D710 has been around some years now and it certainly is a good and


Kenwood TM-D710

capable radio with lots of features. Sadly, it lacks user-friendliness when driving a car. I don’t encourage people to make changes on the radio while driving, but sometimes you just have to change to a different memory channel or take a look at where you’re transmitting. Yep, the display on the TM-D710 could use some tweaking. One major gripe is that the alpha-tag of the memory slot is so small, while the frequency is in huge letters. Why couldn’t it be switched over? You might not agree, but I think some customization would be a good idea so it suits the user. More details in the table further down..


Good Nuissance Minor flaw Major flaw
FTM-350 TM-D710
Many selectable colors Can only select from two eye-straining colors
Can be set to single mode (hide APRS-part) Will always show A and B-side
Very good TX audio Good TX audio, although not as clean as FTM-350
No fan noise Noisy fan, although not Icom-style, but still loud
Integrated GPS (option FGPS1) Have to use external GPS – more clutter
Received beacons only show up ONCE until you delete the station list All received beacons can show up as you want them
Transmitted beacons does not show digipeat-path if heard Transmitted beacons can show all heard digipeaters and their path
NO digipeater functionality! (Severe flaw) Has all functionality to be a proper digipeater
No access to internal TNC so it can be used for packet or external APRS control (although it can send data out to serial) Full access to internal TNC so it can be used for APRS or KISS
Menu-driven squelch adjustment (no pot) Dual physical squelch control
Nice readout of alpha-tags and/or frequency Alpha-tags are very small while frequency is shown as huge numbers
Receiver seems poorer, it can’t decode packets as good as the TM-D710 Receiver can decode packets with lower S/N-ratio then the FTM-350, but nowhere near as good as a TinyTrak4/Yaesu FT-7800 combo
Transmitted beacons seems to hit fewer digipeaters than the Kenwood at the same power level Transmitted beacons is successfully decoded more often than the Yaesu
Wide receiver that also supports AM air-band and broadcast + FM wide broadcast (even has line in) Supports FM a fair bit up in frequency, but no FM or AM broadcast
Microphone can be attached to radio or remote panel Microphone has to be attached to the radio (base) and in 99% of all cases extended to be useful in a car
Speakers built into the front panel (although they are small for car use) Have to use external speaker as the speaker in the radio most often will be tucked away to reduce fan noise
Display can use different colors for different information, customizable Display can only show alternative color for emergency beacon and messages
No profile memory Has profile memories, very smart when you want to use different setups according to the situation

As you see, there’s quite a few differences between the two radios, and I haven’t mentioned them all just yet. Why can’t at least one manufacturer make THE radio for once? Both the Yaesu and Kenwood have their pluses and minuses, but there’s no hands down “best radio” as far as I see it. On top of all this, you have different standards when it comes to digital voice, but the most evolved “standard” is the DSTAR system. I’m currently not too fond of DSTAR, ’nuff said (keyword: Icom).


Wishlist for a mobile dream-rig:

  • Large customizable display (size like the FTM-350)
  • Color LCD or even OLED? You could get rid of the distracting backlight if you used OLED, but it would probably suffer in very bright (sun) light. Not a big problem here in Norway as 75% of all my driving happens when it’s pitch black outside.
  • Discrete TNC that can be used however you want when connected to external devices
  • Built-in digipeater with features like the ArgentData OT3m (options connected to the radio base)
  • Full-blown APRS like the TM-D710
  • Multi-band: 2m, 70cm and hopefully 4m
  • All mode! When was the last mobile 2m all-mode rig produced? Disregard the HF-capable rigs.
  • DSTAR (even though I don’t like it, it would be nice to have it in the same box as APRS)
  • Choose where I connect my microphone (like Yeasu)
  • Capacitive touch-screen if the user interface at least have physical buttons for common “operate-when-not-looking”-functions (VFO, volume, squelch, beacon on/off).
  • Integrated GPS (with external antenna if needed)

I guess I could go on forever, but I might just post a follow-up later..


Kenwood TS-2000 delayed transmission fix

Well, I had to do something to sort this out. I can’t cope with a radio that’s not working as intended, it really

TS-2000 with the control board removed.

TS-2000 with the control board removed.

bothers me 🙁 After some digging around, I found a Yahoo-group where this case was discussed (see it here). To sum it up, it suggests that you put control and PTT over to the sub band and the radio will transmit at full power immediately. I tried this, but didn’t work at all – still the same. Seeing that my radio had a pretty old firmware (F095) I decided to try an update. The update procedure is easy enough and was done in no time. After this update, I could do the PTT/control trick – which works (wicked). This workaround creates a new problem though; the log program will save my contacts as worked on the sub receiver, which isn’t very handy. I could of course edit all those logs, but what a pain! At the very least it makes me able to do the important Winlink-tasks over Winmor.

TS-2000 R708 removal

Removed R708 from the control board.

need a proper solution to this, so had a new look at the bulletin from Kenwood. I could easily do the suggested mod, but I miss the flash-IC (IC508). Can’t exactly see why they have to change that one, unless it was for some other preventive measure.. No idea, so let’s try! Opening up the transceiver is trivial, just remember to be gentle with the flat flex cables (there’s plenty of them). I desoldered R708 and put in a 47kOhm resistor between C705 and C701 per the bulletin. I didn’t have any smaller resistor than an 80’s 1/4W device, but it fits ok. I put it all together and fired it up, anxious to see the results, but (bah!) – it’s still the same.



TS-2000 resistor mod

A new 47kOhm bodge resistor in place.

What now? Should I try to source the flash IC and change it, or would it be a waste of money? I haven’t decided yet.. There’s another “redneck” solution though, making a mike-selector box. Put in a couple of male 8-pin connectors for microphone and interface so I can switch between them. It’s possible, but I don’t like it! It would also require me to feed the interface from the ACC2 or a speaker jack, absolutely not elegant.. A third possibility would be getting a newer control board off ebay, but might have some issues pairing it with the other boards as it could contain different firmwares and of course calibration data. Will consider everything right now. Might also need a new encoder for the multi function wheel as mine is bouncing a bit.

Will come with a new update soon 🙂


Kenwood TS-2000 delayed transmission

So I have my TS-2000 in house, finally! The rig looks super and it feels quite comfortable using it too. Tried it in a few QSO’s on HF and VHF and after some tweaking the sound is superb! As a lot of other people mention, the VHF could use a mast mounted preamp to get sensitivity like a normal VHF-only rig. Will look into that, but that’s not the main dish for me.

As I’m into digital modes, especially PSK and Winmor, I had to connect it to my computer via an interface. I didn’t want a “cowboy” solution, and as audio transformers are hard to get and quite expensive, I went for a ready made box – the TigerTronics Signalink USB. It all hooks up nicely to the TS-2000 and the process is foolproof. When everything was connected and set up, I tried some PSK31 to see if I could have some quick contacts, but things started to look ugly.. When the Signalink is keying the radio, it fades the modulated signal (fading in) and takes about three-four seconds before I have a stable output. At first I thought that the Signalink might be the cause for this, so I checked all connectors and the jumper settings according to the schematic that was provided. Everything looked good. Next up was resetting the radio to see if something was set wrong, then I checked all settings again, but still giving me the same result.

Ok, further investigation was needed, so I opened the Signalink and had it connected while open so I could take out the jumper links while transmitting. I set DM780 to send a PSK31 carrier and took out the audio jumper to the radio. While the radio was transmitting, I put the jumper on to the pin to see if the audio would “fade in” at that point – and it didn’t. Ok, so it might be the PTT, so I tried the other option and lifted the PTT from it’s socket and put the audio jumper back in. Voila! When keying the radio, the audio would slowly fade in. Bugger, this sounds like a radio issue 🙁

After some tedious searching around the net, I stumbled upon this bulletin from Kenwood:

Hmm, ok – I need to get those parts then, but why would I need to change the SRAM* flash? It’s not a problem soldering it (these components are gigantic compared to what I work with on a daily basis), but sourcing them is another league.
* Apparantly this is a flash IC, not SRAM as Kenwood states in the service manual.

While looking around I also found a probable workaround; setting the control to the sub-band while operating the ACC2-jack. I have to try this when I get home..

What am I using?

I don’t think I’m any different to most other radio amateurs, so the equipment flow is varying all the time. Radios in, radios out, antennas up and antennas down – intentionally or not.. Just look at the 2012 field day picture..

A pwerful gust of wind trashed our little camp

A powerful gust of wind trashed our little camp

I’ve had numerous HF rigs, both large and small, good and bad. I still haven’t settled on a specific brand or type of radio (I probably shouldn’t either), but somehow it tends to be Yaesu rigs I end up with. As with women, cars and computers, they have to be swapped for something newer at some point..

Current list of devices is as follows:

HF and combined rigs:



  • LDG S9v31 vertical
  • Longwire connected to an Icom AH-3 tuner
  • Homemade OCF dipole in an inverted vee
  • Random lenghts of wire and dipoles for field use

Other peripherals worth mentioning:

Radial field

Radial field


I will make a new article regarding the setup, descriptions, history and pictures. Meanwhile, have a glimpse at the radial field I put down last summer 😉