I’ve been keeping my eye out for a mic for the hw-101 for since I got it. I’ve been partial to the Astatic D-104’s, but the prices for them have been too high for my taste. I recently found one on ebay that seemed to be in good condition for a reasonable buy it now price, so I picked it up. The listing didn’t outright say that the mic worked, but I was under the assumption that it did.

I recently got a new truck and the stock stereo doesn’t have an aux input. I mostly listen to audio books in the car and instead of buying a new stereo, I was able to add a 3.5mm socket that is directly connected to the audio amp in the stereo. This is what I started with. Its a stock GM Delco stereo. Inside, I found that it had a saa7706h dsp chip (datasheet).

I’ve been working on a 2 meter aprs digipeter/i-gate (more on that later) and was having trouble picking anything up with my ht antennas, so I put together a copper pipe j-pole this weekend. The parts that I used were: 2x 5 foot sections of 1/2″ copper pipe 1x 1/2″ elbow 1x 1.2″ T junction 3x 1/2 end caps There is a pretty good calculator here for finding the correct lengths for the antenna sections.

I’ve been reading some older qrp circuit design books and wanted to play around with some of the oscillators. With the audio amp from a recent post, I may have the start of a little qrp receiver or possibly a transceiver. I started with a simple colpitts oscillator. The schematic below is what I used. For the capacitors, you can see the capacitive reactance to the right. Using the formula at the bottom, you can calculate the capacitor values for the desired frequency.

We’ve got a new store that opened up in town, and from what I gather, it sells merchandise that either has damaged boxes or were customer returns from other stores including Amazon. They’ve got a lot of cool stuff. They had about ten of the monoprice select mini 3d printers for about half the price that they are online. I was hesitant at first, thinking that there may be something wrong with them, but the store has a good return policy so picked one up.

Over the weekend I put together an audio amp using a schematic from N6QW. It is from his simpleceiver project. Since my bitx project fizzled out ( I will try to get it working one day.) I figured I would start on another transceiver in my free time. I’ve got some packaged mixers instead of using plain diodes and I may buy a crystal filter instead of trying to make one myself.