Category / DIY

Irons in the Fire (Projects and upcoming geekery) April 13, 2012 at 12:49

It’s been a grind of a week this past week, so I haven’t had a lot of spare braincells to finish polishing a few post drafts that I’ve got sitting in a holding pattern right now, so it’s been a bit radio silent.

I don’t want to lose posting momentum, it’s what killed me last time, so here’s what I’ve been working on:

Ensemble RX/TX SDR – This is a software defined radio kit project for the amateur radio HF bands that I’ve been working on over the past couple of months.  I’ve got a big post about it coming up soon that I hope to have video and screencaps shot of the unit sometime this weekend.  I’m going to be rewinding coils and hopefully getting the transmit portion of this up and running this weekend.

Following closely on the heels of that, I’ve jumped on the bandwagon and ordered one of the Realtek-chipset based USB DVB-T tuner widgets from an eBay seller that should be arriving any day now.  Apparently the things can be used as 64-1700 MHz software-defined radio receiver radio front-ends.  All I have to say to that is…HELL YES.  So I ordered one.  The prices have gotten jacked up from the $10-15 they were originally selling for, but for $28, if it works half as well as they say it does, it’s still a steal for experimentation purposes.

A Cobweb antenna for the house – Living in a narrow urban lot, with power and telecom lines running liberally through the backyard (I have to contend with my power lines as well as my neighbors), putting up a decent HF antenna can be problematic.  Given that ham radio operators in the UK have to deal with gardens that are in similar situations (or smaller!), I went hunting for solutions that UK hams have come up with, and ran across this antenna design.  I have all the electrical parts required, I still need to pull the trigger on ordering the fiberglass from Max-Gain (My original source doesn’t stock what I want any longer).

Near future projects:

Building a Pennywhistle HF amplifier kit from TAPR.  Giving the Ensemble a little more transmit oomph, 1W probably won’t end up cutting it.

A switchable low-pass filter for the amplifier kit and the Ensemble RX/TX – I’m probably going to go with something like the LPF-100 R3A  from HF Projects, just so I don’t have to source all the parts and gin up a PCB, I don’t have a ton of time and my layout skills kinda suck.

A Z-Match QRP antenna tuner for tuning up antennas to the radios – This one may get supplanted by finding a good deal on a QRP tuner at a hamfest.