Participating in the WSPR-challenge



PA3FYM WSPR-challenge receiverThere is buzzing a new phenomenon at PI4RCG (our local HAM club): the WSPR-challenge. One prominent club member, Remco PA3FYM, founded this WSPR-challenge with Richard PE1ITR. Essentially they download the whole WSPR-spot-database once every night and parse it in a top 50. The result changes per day. This challenge only consist of reported spots to So you can sneak peak at site to see your uniques. Since only logs your reported spots, this challenge is actually a RX-only contest.
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Update 23cm trx

23cm TRXDid a lot of work the other night at the 23cm trx. Build in the speaker (drilled a lot of holes!) and did the last mod to do more filtering in the VCO voltage. Also fixed the phantom power for the electret microphone. Modulation and LF-sound are now in an acceptable range. There is always room for improvement, but at least I can leave this little puppy running in the background without scaring up every time some one opens the repeater.
Now I have my ‘reference rig’ I found out the filtering of the 23cm TRX is indeed under average. The reference rig can easily hear repeaters from miles away and doesn’t have a S6 to S7 noise without an signal. I think the UMTS-antenna that is about 50 meters away must have something to do with this. I think the next to do for this trx is building a bandpass filter.

Kenwood TM-241E

TM-241E (RigPix)When trying to improve my 23cm trx I was in desperate need of a reference 23cm rig. I need something that just works and can make a little more power then 400mW. Asking around gave me a Kenwood TM-531E for borrowing. I fell a little in love with this little puppy. On a local eBay-like site I spotted the 2meter brother of the TM-531E: the TM-241E. Actually it is one type newer (the same line should be the TM-231) but they look almost the same. I ordered this puppy, so hopefully (if everything goes well) I can hang him besides his 23cm sister in a few days.

Maybe one of these days I’ll spot the 70cm model too (TM-431E/441E). Who knows I’ll buy that one too 🙂

DRA-818V project

7dc169314a5773a452cdfb58d6b19586For a few years now I tried several radios for VHF and UHF here in the shack. I am unable to find one that really suits my needs. I have used a Yaesu FT-817 (not handy), an Icom IC-910H (more a DX-radio), some surplus (clunky), an Kenwood TM-D710 (way to much options for base station) and many others. Main problem: they are too expensive and have too many options I never use.
Last night I was in QSO with a fellow HAM-operator nearby and I told him about my idea to convert the design of my 23cm transceiver to a VHF and UHF meter version. He liked the idea but pointed me to the DRA-818-module instead. Just connect an Arduino to this module and you have a complete transceiver. Great idea! Immediately my mind starts spinning, I could buy a BGY-module (BGY36 for VHF and BGY22 for UHF) for some more power and put it behind the modules.
Googling around found me SV1AFN who build great looking kits based on the DRA-818 with a low pass filter and small audio amplifier on the same board. I immediately ordered his VHF-version! Very curious to see if this will work with an Arduino attached to it. Now I have myself a full transceiver for around 50 euro’s and I can program is myself. Seems a neath solution!

Will keep you posted on this blog about this new project.

New casing 23cm trx

Lately I have lots of problems with my home made 23cm transceiver. But before I will go hunt for solution I decided it was time to replace the 19-inch casing with something more decent. The 19-inch housing was way to big and not practically because of the thick steel.
So I wanted a somewhat smaller case, preferable made of aluminum. I always liked the cases of MicroHAM so I looked up the dimensions. It could fit in the same dimensions as the USB micro Keyer II.
So I made a design based on those dimensions and cut and fold some aluminum at the club. A lot of drilling and filing had to be done to fit everything. But I’m pleased with the end result. Unfortunately the problems with the transceiver didn’t disappear with the old housing, so I still have to find out what is wrong with it. Since the LF-sound screams when I turn on the volume, I assume it has something to do with the LF-amplifier (LM386) or the radio-chip (MC3362). I tried to reach out to the designer of the transceiver (Bas PE1JPD), hopefully he can help.

Firmware upgrade: 1.13

Icom IC-7300 main shack rigToday I finally found some time to update the firmware of the IC-7300. I noticed 1.13 was out. Didn’t even update from the original 1.11 to 1.12 because my only netbook (MSI WIND U-100) doesn’t recognizes the internal SD-card reader. But a new Asus EeePC found it’s way to the shack. It’s running OpenSuse and does recognize it’s internal SD-reader so I had no arguments to not update the firmware. The procedure is quite simple: download the firmware, unzip and save on SD-card, put SD-card in radio, put on radio, [set] – [SD-card] – [Firmware update] – [click, click, click, yes, click] and after about 10 seconds the radio restarts.
This latest release should improve FM TX audio S/N ratio, first test show a little improvement indeed.