Sunday, 22 May 2016

Portable preparations

I have been really enjoying working with the you kits HB1B and have used it most days to make a QRP CW contact by the bedside station or out portable. So far I've been using a 12v SLAB as a power source but it has proven to be a pain to carry around with such a weight. I emailed you kits to see if I could buy an internal battery pack and was told this is not possible because of shipping issues. What to do? Make my own...

I found lots of great information online and set about making a 18650 lithium battery pack to put inside the rig but the more I learnt about balanced charging the more I felt this should be a consideration so I also purchased a small PCB from an eBay seller that allowed balanced charging and voltage limit on discharge too. It was not hard to make a pack that charged nicely from 12v and allowed me to fit the whole thing internally. 

Please ignore my messy bench but here is the pack and control board as I soldered all the connections up. I did a dry run on the bench and all looked good so I put the pack inside the HB1B and started to make contacts around Europe. The pack can provide as much as 12.6v at full charge. 

All was good but I needed to make going portable easier, I wanted a nice Peli case but couldn't afford to spend that kind of money on a whim so went looking for what I had stored away to "make do." I discovered an old case that once held spares for my aquariums and soon stripped it down to basics and set about looking for any foam I may have laying about. This is naturally where being a hoarder helps and soon enough I found some suitable foam and plastic to make inserts and set about filling the case and making a secure holder for my basic portable station, the radio, key, charger, ear buds, coax, plugs and antenna. 

Here are a few images to show how I managed to cram everything into a small space and keep it secure. All I have to do now is get out portable and enjoy the summer. 
73 - M0TEF

Sunday, 8 May 2016

Video of the working Pixie 2 QRP CW radio on 30m

Below is a copy of the video I made showing how the 30m Pixie behaved in testing and how I modified it for the band. I have yet to test it better as conditions have naturally gone bad since it was complete. I did get a few reverse beacon network spots form Europe last night but nothing worth shouting about. I hope to have a half decent contact with it soon.

Saturday, 7 May 2016

More Pixie fun

I haven't been on my blog recently but that doesn't mean I have not been actively seeking more QRP adventures. I had been enjoying messing about with a Pixie 2 given to me by M0SIY when he almost died laughing at the strange chirping signal it produced. The good news was I was able to get it to play ball and started to modify the little rig to cover more frequencies with switched crystals and a ceramic resonator to allow me to cover more frequencies with the little gem.

The picture shows, left to right,my amplified speaker, 30m, 40m and 20m versions of pixies lined up next to the key. Indications on my meters suggest I'm getting 500-600mW from the rigs with 12v input voltage about 200-300mW with a 9v battery.

So during my trials I was enjoying the fact that the kits are so cheap that you can mess about with them until you can't find anything else to do with them but without adding any stress on the bank balance. I ordered three other boards, some inductors, crystals and variable caps and set about getting a pixie on 80m, 40m, 30m & 20m. I found that changing the crystals and adding a variable capacitor inline with the crystal was enough to get it working but I also needed to changed the pi output filter with differing values of caps and inductance but this is far from hard work and most rewarding for the efforts.

I haven't been able to make any contacts of value and have had a handful of Reverse beacon network spots but the real fun has come from throwing such simple rigs together and the knowledge that has been gained in the process of building VXOs and optimising the rigs.

The best outcome overall is the awesome fun I have had over the last few weeks messing about with the kits, the next stage will be to add an AF narrow filter for the CW reception to improve and to stop me listening to what feels like a whole band at once.