Alinco Advanced Battery Pack

26. Dezember 2014 Keine Kommentare

Five years ago I bought a new battery pack for my Alinco DJ-V5 portable 2m/70cm device. Unfortunately the batteries became dead again during summer. I could revive the batteries with putting them in the freezer for 30 minutes, but they did not last for long. Even two of the eight cells were completely dead, as the voltage dropped from 9.6V to 7.2V.

So I opened the battery pack with a scalpel. It was heavily glued and it took some time. I had to be careful not to destroy the sides where the hinges for mounting the battery pack are located. In the end I found out, that there are some special cells built into this EBP-46N battery pack.

IMG_3142They are way smaller than a standard AA cell. I could probably install 5 AA-eneloop cells rotated by 90º, but then I work with 6V only. This is enough for the TRX, but the output power will reduce from 6W to roughly 3.5W.

I then found out, that there are AAA-eneloop cells with soldering tags available, which I instantly ordered. I wanted to try, if I could put in 8 AAA cells. Then I will have 9.6V again, but the electric charge will drop from around 2Ah with AA-cells to “just” 800mAh. On the other hand, the original battery pack provides 600mAh when it is new. And another advantage of eneloop batteries: they will not loose their charge by not using the device. So I can charge the batteries and keep the device laying around for the moment I want to use it!

IMG_3152I removed the old cells and soldered the eneloops in zig-zag style. The distance between the cells is needed, so that they can fill out the space a little bit better. The pack is too small in height to carry two layers of AAA-cells on top of each other. I also put in some double layered tape in the bottom to keep the cells in place.

IMG_3153It looks a bit ugly, but now the cells fit into the case. I did not glue the case, as I want to use a special battery loader instead of using the built-in charger electronic of the Alinco DJ-V5. I tried it and it works, but I could not find a charger which will properly charge the batteries to their full capacity.

So charging the battery pack looks a bit experimental.


So far I could use the device for roughly 24 hours keeping it on in RX mode without the battery saver enabled. It was switched on all the time and I had some QSOs with high power output. This modification was a success!


WAG Contest 2014

20. Oktober 2014 Keine Kommentare

After I skipped last year’s Worked All Germany (WAG) Contest this year became even better. The Chaoswelle Contest Crew has been offered a new location: DF0MU near Schöppingen in north-west North Rhine-Westphalia.

It’s a former military station from the WWII-era which was later used by the University of Münster. Several years ago some ham radio operators took over the station and refurbished several antennas. Today it is a great spot with a lot of antennas. Many activities are on UHF and VHF bands (or even higher), but they also set up several HF antennas. These are the antennas we use during WAG Contest.

DF0MU Panorama

We had really great weather with up to 22ºC during day (and that in late October!). During night it is so dark that we could see the Milky Way and thousands of stars.

My “shift” was during early morning. From around 5 to 9 A.M. It’s a time where there are not so many QSOs, so I mostly called “CQ Contest DA0CCC” just to reserve the Frequency.

I hope that we can use this location for the next WAG Contest.

Portable IC-7000

20. Juli 2014 Keine Kommentare

I wanted to take part in the Berlin UrbanHamRadio activities with my own equipment. But I did not want to buy a new TRX for portable usage. My iCom IC-7000 is more or less portable – at least it fits in my backpack and can be powered with 12V.

After some research I found out, that I can use it with a standard Lithium-Polymer (LiPo) cell for RC racers. It costs about 50 EUR and if you don’t own a proper charger, you need to buy one as well (and a LiPo carrying bag). It’s a four cell LiPo with 14,4V voltage, which I can directly insert to the IC-7000 (it works best with 13.8V±15%, so from 11.7V up to 15.8V).


The LiPo is equipped with an EC5 plug, so I soldered the proper pins to the power cable for the IC-7000. The good thing about this LiPo: it can release up to 20 times its capacity as current. This is a 5Ah battery, so it can provide up to 100A for a short period of time. With RC racers this is needed for the start-up momentum. But I can also have some advantage during TX, when I want to use up to 100W of the TRX. Although the IC-7000 drains up to 22A at 100W transmit, I’m far away from any unsafe usage.

Talking about battery drains. Unfortunately the IC-7000 is equipped with a bright LCD and a lot of circuits. It’s far away from low power consumption. In idle receive mode it drains about 1.5A. With a battery of 5Ah I can use that for a bit more than 3 hours. Time drops rapidly with every transmit.


But it was time enough for several nice afternoons in the park! The small LEDs on the battery pack signal the remaining capacity. And we were lucky enough to bring a second battery pack just for the single time, when we wanted to end this QSO with Cornwall.

Unfortunately all the needed equipment is not portable enough for climbing on mountains. I need at least the IC-7000 (2.5kg), the battery pack (500g), the power connector (500g), probably the external tuner (700g), antenna and cables (4kg). So already about 10kg of stuff. But it’s okay for the city and carrying around on my bike and having a nice Sunday afternoon in the park!