PCB holder kit

I just got this kit in the mail. It is a simple and quite handy PCB holder from Ken WA4MNT. Get more information and buy at http://qrpbuilder.com/ .

Unfinished and ongoing projects 2011

I haven´t posted in a while. I usually have posted when something is more or less done. So the conclusion of that would be that I got a few projects going now that I have not finished. So just to have something to post here on the blog I thought that I could describe a few of them. The main project right now seems to be the remote RX I have online and we are a group of people sharing it. That project deserves a separate post.

These are a few of the projects that I have started and not finished yet. I think I list them in priority order below.

A step attenuator
The first project is a step attenuator. I use 1206 resistors. I have measured the SWR through it (without any attenuation on) and see a rising SWR and at 30 MHz it is 1:13. Quite high? Any readers could give a comment on what could be wrong. Is it just the switches and the zigzag between them that changes the impedance?

I use a box that used to have Mackerel fillet in tomato sauce in it.. :-)

Step attenuator progress

HF Test set
This is a kit that I bought a while ago. It is from the 4 State QRP Group. It will become Frequency Counter, Crystal Oscillator, Wideband Noise Generator, Audio Oscillator, 50 Ohm Dummy Load, RF Probe and Time Domain Reflectometer. I started to build and finished about up to 50% of it and then got diverted into other projects. A got a nice enclosure and a back lit LCD here to be used for the project.

NB6M HF Test Set (not built by me)

Watt meter

AVR with LCD for the AD8307 Watt meter

This project is also finished to about half. The AVR is soldered to the board and LCD is tested as seen in the picture. I was happy that the first time ever I soldered a TQFP32 was success!

I have also done the input part and measured it with the VNA. Next step is the AD8307 IC. I am following the guide here:

http://lategahn.2log.de/index.php?A-minimalistic-500MHz-Wattmeter


10m CW beacon
I got the PCB for the Genesis Radio Q5 transmitter some year ago. What I did not have was the final transistor but I received one of those last month. My idea is to build a beacon for the 10m band. I have built and tested the oscillator. The PA stage is built as can seen on the image, but not tested yet. To be built is the LPF and the beacon keyer. I think I will use an attiny45 together with the code from YACK
I could probably run it on my balcony if I come up with an antenna. Might be a loop.

Genesis Radio Q5 CW transmitter

30m QRSS beacon

QRSS transmitter for 30m

This projects started earlier this year. I bought a few ATTINY13 IC:s and programmed to IC, I thought.   When testing the oscillator it was ok, but no keying from the attiny. I then thought I should get another programmer. I have it here, but I have not got back to the build. It will be later.... Together with this I also started  to build a DCTL antenna after reading about it a  http://draaggolf.blogspot.com/ . I also got some good advice from Joachim but have not finished it either......

MKARS80
I bought the kit quite a while ago and started the build. Then I thought it would be more fun to build simpler things and not necessarily kit. As the build instuctions did not include any testing along the way, everything just felt like a soldering practice. But I have to finish it. Might be good to have a goal set for summer 2012 so I can run it portable.

Softrock Ensemble II VHF

I finally started to build on one of my Softrock kits that I got lying here. My wife and son was away one Friday night and I could start building and continue uninterrupted for a few hours. It went smooth, apart from a problem soldering the Si570 where I thought that all three pads on each side where to be soldered together. No contact from the AVR to the Si570 so I just had to use the wick to remove some solder.  Two build sessions  after that and I could listen to the local repeater! A big thanks of course to Tony KB9YIG for providing the kits and Robby WB5RBZ for excellent build instructions. I still have some tweaking to do as the image rejection is not 100% but for now I consider this project done. I will now start with a Softrock receiver specially aimed for the Broadcast AM band. I will later make the same kind of enclosure to both these receivers.

80m BPF

A band-pass filter for 80 meter band.

The simple direct conversion receiver I built a while ago works great when used daytime but on the evenings it will get overloaded by broadcasters. Maybe I can cure that with a better Band-pass filter. So I built one.  I used the values that I found at W8DIZ site, but with some variation to fit what I had in the junk box. As you can see it is built 'ugly' on a PCB. I am using SMA connectors as I was able to buy a large number that probably will last for many years to come.

Tuning and measuring the band pass filter with the MiniVNA Pro

Now using the miniVNA pro and the VNA/J software a can tune and align the filter as I want to have it. The nice thing is that you run the VNA continuously so I see right away on the screen how to filter looks like. This was the end result: 

VNA/J showing the 80 m BPF curve

Summer 2011

A long time since last entry in this blog. A summer with vacation and nice weather is now behind us. Some radio activity also and other news to mention.

Portable: I have been portable a few times during the summer. I have been participating in the Swedish Flora and Fauna activity. If you activate a Nature Reserve you might get a pile up on you which I now have tried for the first time. I also realized this summer that this contest and dx chasing part of this hobby is not a thing that I find important. It is the technical things and building stuff that is fun! But being portable has of course been a good time to try new antennas. I have built a few and I hope to write about them in later blog posts.

Oscilloscope: Some months ago I bought my first oscilloscope. It is a portable called DSO Quad. I have not used it enough so I can give a review, but according to the support forum it does not deliver according to the specification. Hopefully software patches can solve the problems...

Mini VNA Pro: I got a really nice birthday present some months ago, the Mini VNA Pro. An instrument that can measure on antennas, filters etc. The good thing with this one compared to other offerings is that I can use the VNA/J software in Linux.


Others: I have a few projects running now, like some more SDRs and maybe some rx / trx, but still not enough to tell anything about. I also play around with the Atmel AVR microprocessors, that is fun!