Archive for LA1HSA

My APRS setup

Yaesu FT-7800, Kenwood TW-4100E and Raspberry Pi 3

It’s about time I write some more here, the updates have been seriously lacking for a few years 🙁


I have a link to this website in the status text for my digipeater, just in case someone wanted to have a look at what I use and the general setup and configuration for my software and hardware.


I live about 10 km north of Oslo. The location have a nice (radio) view over large parts of Oslo and the surrounding areas, which is ideal for APRS infrastructure. I think we have the highest number of APRS users in this part of Norway, so a working infrastructure is crucial. We also have a fair bit of SAR usage on APRS, so my setup is tailored for both normal APRS and high-rate beacons from lots of trackers.

The TinyTrak4 used to be my “go to” TNC for this use. It’s stable, quick and easy to configure, but unfortunately it lacks some of the more advanced features. After tinkering with the software TNC “Direwolf” for a while, I thought it was time to give it a go under live conditions. As a fill-in digipeater with some extra features, it’s quite straight forward to set up. It currently runs on a Raspberry Pi 3 with a “no name” C-Media USB soundcard and a crude PTT circuit, which is then connected to my trusty old Yaesu FT-7800 (discriminator output). The software TNC also sends data over a TCP KISS-port to APRX (LA1HSA-1), which then i-gates traffic (bidirectional for objects, messages and selectable TCPIP only stations).

The digipeater (LA1HSA-2) will respond to the following unused paths:

  • WIDE1-1
  • TEMP
  • SAR3-3 to SAR1-1
  • LA1HSA-2 (a digi should always respond to its MYCALL!)

Callsign substitution is of course activated, so everything should be traceable.

The antenna is Diamond X-510N on top of a 10m high mast, fed with Ecoflex 10 (changing to Ecoflex 15 when I have time). This antenna provides a high gain and is suitable for my QTH. The TX power is about 10 Watts.

Here’s a little map showing stations heard directly during some months. Note that this only shows stations transmitting full paths, like WIDE1-1 or WIDE2-2. assumes that a path of WIDE2-1 has been digipeated, but not inserted its callsign. There’s also quite vast areas that never sees a person sending a beacon, so the main roads are probably the only places you’ll see someone sending their position.

APRS coverage for LA1HSA

APRS coverage for LA1HSA

This picture is a superimposed stack of pictures from I’ve since improved the reception a fair bit with the use of Direwolf.

Since I run this on a Raspberry Pi 3 and have “loads” of CPU power available, I’m thinking of expanding it a bit further. I have an idea for our SAR usage which involves cross-band digipeating to free up time slots for more trackers in the field. With 40-50 trackers deployed, there will be issues getting all packets when they transmit on the same frequency and perhaps have to be digipeated at the same time. The solution might be a digipeater that receives on one (or perhaps two) 2m-frequencies and digipeats them on 70cm or maybe even 6m. On the other end, I could have an i-gate that receives on the digipeater’s frequency. To make sure the digipeater can keep up, I might use 9600 baud or 2400 baud (Direwolf allows me to do all this). A simple cross-band digipeater could possibly consist of a Raspberry Pi Zero and two soundcards connected to two commercial high quality radios. This is on the to-do list and should be in a test phase during this summer.

Here’s a picture showing the APRS radio, the old repurposed project box that contains the

Yaesu FT-7800, Kenwood TW-4100E and Raspberry Pi 3

Yaesu FT-7800, Kenwood TW-4100E and Raspberry Pi 3

Pi (the box was originally an old stereo amplifier I worked on when I was 12 years or so). It also shows the radio that takes care of my Winlink gateway (70cm 1200 baud packet, LA1HSA-10).

I think I have to revisit this topic a bit later, I have more things to polish and try out before anything is definite. It’s working great though, and the best part is that it’s very easy to reconfigure anything on the go wherever I am in the world (if needed). A mobile phone with SSH is all I need 😉


I was hacked

Oh well, I guess it can happen to anybody..?

I haven’t been too busy with watching this site, at least not making any new posts, so some gremlins in the PHP scripts decided to take on a life of their own. Nearly all my PHP-scripts was injected with some malicious (encrypted) code. Don’t know what kind of hack that was, but it was quite a pain to get rid of it all – and hopefully I did!

Actually, everything seemed fine and dandy here, until I decided to uninstall the plugin “Shareaholic” since they started with some annoying advertising. Right when I uninstalled it, all my plugins were gone from the control panel. After some googling and checking out my scripts, I concluded that I had been hacked.

Hopefully, everything is patched up again – we just have to wait and see. In the meantime, I’m working on some new content for this place. It’s been a while since I posted anything, but some work has been done nevertheless.

73 folks!


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..

QRO you say? Dentron MLA-2500 repair

MLA-2500 front

Front face of the Dentron MLA-2500

We just had our yearly dose of hamfest and swapmeet and I couldn’t leave empty-handed. Well, I got my arms full when I had to carry this vintage Dentron MLA-2500 amplifier back to the car. Heavy means good, right? Let’s hope so. I traded it in for a mobile radio, so no expenses so far, but the seller said it was working, but defective.. Uh, what? Well, it can’t be that bad.


MLA-2500 original capacitors

MLA-2500 original capacitors

First things first; I didn’t attempt to power it up before properly inspecting it, just in case I made things worse. Smart decision! The old electrolytic capacitors in the B+ line was way, way out. One of them had vented and one was shorted. I immediately started tearing it apart and ordered new caps and bleeder-resistors from eBay. Thanks to VE3PVS, Peter, I got a great deal and excellent shipping time for six new Nichicon 150uF/500V caps including six new bleeder resistors.

MLA-2500 HV electrolytics

MLA-2500 HV electrolytics

The new capacitors were of course quite a bit smaller than the original ones, but that shouldn’t matter too much. I just have to figure out a proper way of mounting them. It wouldn’t hurt if it looked original either. I decided to keep the paper insulators that covered the old caps, just had to be liberal with the glue 🙂






I just tacked the paper forms to the chassis with hot melt glue before I inserted the new caps and glued all around, both at top and bottom. See pictures below.

MLA-2500 paper insulators

MLA-2500 paper insulators

MLA-2500 new caps installed

MLA-2500 new caps installed



Next up was wiring them in and confirming everything was correct according to the manual.

MLA-2500 new capacitors wired in

MLA-2500 new capacitors wired in

MLA-2500 band selector flashover

MLA-2500 band selector flashover

After connecting everything, I had to check the rest of the amplifier. I saw that there had been some flashovers in the band selector switch, especially in the 80m and 40m positions. I had to clean that up a bit, but saw no permanent damage.

MLA-2500 band selector flashover

MLA-2500 band selector flashover






Nast nasty, that must have made a nice sound 🙂



MLA-2500 in operation

MLA-2500 in operation

After some gentle cleaning and vacuuming, it was time to power it up. Ideally, I would like to use a variac to slowly increase the voltage, but I don’t have any. Tried to look for a decent 60 or 100W lamp to connect in series, but quickly tossed that idea away (getting eager to try it). I just plugged it in and poked it with a stick. Guess what? No bangs, no circuit breaker blowing! Just a fan starting up and plate voltage meter showing a healthy 2250V+ 🙂

So, will it produce any output? Oh yeah, plenty of it too! I have no problems reaching our legal limit of 1kW on all bands without even being in the danger-zone of the grid current on the expensive 8875’s which lives in this amplifier. Sweet 🙂

Just to be sure my setup was ready for handling the QRO situation, I had to change some coax and secure my windom antenna a bit more. Ok, this is absolutely overkill, but I now use Ecoflex 15 for my HF antenna. This was primarily selected to be my 70cm coax, but as I didn’t want to rip down the mast for that antenna and change out the Ecoflex 10, I keep it this way for now.


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..

New domain


Everything is working now – hopefully!

If you find any links, pictures or articles that points to the old domain, please inform me. I’ve tried to correct the database, but there might be issues I haven’t seen yet.

Testing a gallery..

This plugin might be what I need for a gallery. Not sure, but let’s try it out 🙂

These pictures are from Field day 2010.

We cannot display this gallery



New blog is active

Well, it sure took some time to take this step. I’ve had this site for a number of years, but haven’t really put much into keeping it alive. The site was registered back in 2003, but haven’t been any useful stuff on it since 2004. Earlier this week, I started a big cleanup to remove old content and fix security holes. Yep, the site was hacked and full of dubious links and files – it’s all gone now 🙂

This site should be about one of my hobbies, ham-radio! It’s a fantastic hobby where you can get in touch with people all over the world (and even entities flying around the earth). You do not need any internet connection to achieve this and you’re not relying on any current infrastructure if sh*t hits the fan. Of course, internet, power and other infrastructure is nice to have, but most of us hams are set up to be independant of this if the situation requires it. More on this later, but have a look at if you want to read what ARRL says about the subject.

Anyway, I’m off to complete this install and write some articles about the hobby. Will post lots of pictures when I get around to do it.

73 de LA1HSA