Video – Introduction to Termination Insensitive Amplifiers

As I’ve alluded to previously, I’m currently working on a BITX-style transceiver, using bi-directional termination insensitive amplifiers in the vein of N6QWs ZIA rig and N2CQR’s BITX DIGI-TIA, with the added challenge of implementing a variable-bandwidth crystal filter. In the process of putting this thing together, I’ve been learning about and experimenting with these so-called termination insensitive amplifiers, and I’ve put together a little video about their characteristics and uses:

This is my first foray into video-making, and I had a great time putting it together. Looking forward to making a few more down the road.

See you on the air!

73

BITX40 Module & ARRL SSB Sweepstakes 2016

A few weeks ago, I participated in the ARRL Fall Sweepstakes SSB Contest, and succeeded in making my first voice contacts from home. It’s incredible what you can do with 5 Watts and a simple antenna!

Over the course of about an hour on Saturday night and another hour after work on Sunday, I made fourteen total contacts all across the US, including Colorado, Illinois, Kentucky, Manitoba Canada, Maryland/DC, Michigan, Minnesota, New Jersey, New York, Ohio, Ontario Canada, Texas, and Virginia. Several stations clearly had to reach way down into the muck to pull me out of the noise, which was very much appreciated.

Part of the exchange for the SSB Sweepstakes is a “precedence,” which is based on your power level, among other things. I was handing out “Q’s,” which denotes a QRP power level of 5W or less. A couple stations, after a minute or more of trying to pull me out of the noise and finally getting it, “OH, QRP, that explains it…”

I worked the entirety of  my contest activity through a new rig in my shack, one of the new BIX40 modules out of India. Afshar Farhan, originator of the BITX Transceiver, has recently rallied together some resources to start producing a “kit” version of that radio for the 40m band. I say kit only lightly, since the main board (which is mostly SMD components) comes fully assembled and tested, and you merely need to solder on the provided external controls (tuning and volume pots, speaker/headphone connectors, etc.) It only took about 20 minutes from unboxing the package to having everything installed. But there was an issue lurking on the horizon…


I’ll save that story for another post though. Hear you on the air!