Sunday, January 26, 2003

Day 3 Build: RM-20

Jan 26, 2003 - I woke up at 03:30 local thinking about the RM-20. I could not get the radio off my mind. What could be wrong with the RM and how do I fix it. The schematics floated through my head as I thought. Finally I got up and started looking over the schematics. I pulled out my meter and began testing points. I checked the resistors, and transistors, following the path from beginning to end to make sure I had made all the proper connections and placed all the parts correctly with no solder joints. Everything looked good. The RM-20 should work. A little breakfast and then back to work. Double checking all the work I had done. I was sure that the RM was working but with out a watt meter at the time I had no way to know for sure. I fired up the rig one more time before church and called CQ. And what to my surprise did I hear but "?? DE N1OGL K". Was the operator calling me. I responded "N1OGL DE KE4QDM K". N1OGL then came back with my call. We attempted to converse for about 10 minutes. My code is still slow and I was able to get N1OGL's call and that the operator wanted to know my QTH. N1OGL had my name right and was copying me just fine. I still had trouble copying. Need to work on the Code, but nevertheless, I had finally had my first contact. My first contact with the Rock-Mite Expedition.
I obtained a Power/SWR/Field Strenght Meter from a friend latter that evening and was able to confirm with the meter that I was definitely getting a signal out. I was putting 100mW into a Dipole with a 1.4/1 SWR at 18 ft. Is that right. I need to do further checks to make sure the meter is reading accurately. Well, that's all for now. Hope to hear you on the bands, 73, KE4QDM.

Saturday, January 25, 2003

Day 2 Build: RM-20

Jan 25, 2003 - Now that the board has been assembled it's time to put the package together. I've chosen a tin that used to house a Timex watch called the Expedition. This is where I get the name Rock-Mite Expedition. The tin measures 5 1/4" x 4 1/4", just the right size to install the radio, power regulator and some batteries. To start I will just install the radio and connections to the outside world. I purchased all my parts from Mouser Electronics. See the supplemental guide for a list of parts.

The hardest part of the whole project so far was drilling the holes in the thin metal. I used standard drill bits and slow speed on a hand drill. The tin bent a little and I messed up one hole a little bit. All in all the final product looks good. Just don't look to close (Picture 4).

The board is mounted with 40-4 x 3/4" Bolts with Nuts and 1/4 Long nylon spacers to mount the board inside the tin. The nuts, bolts and spacers were purchases at Home Depot for $2.09. With everything mounted and wired I was ready to smoke test the unit.

Friday, January 24, 2003

Day 1 Build: RM-20

Jan 24, 2003 - My Rock-Mite 20 arrived in the mail today, and I'm already to go. After having read numerous articles on The Rock-Mite Files I've decide to build my RM-20 Stock with just one modification. I'm putting in the machined pins from an IC socket for Q6 (2N2222A) so that I can experiment with the final. This will also allow me the ability to easily replace Q6 in the event that I try to send smoke signals instead of code.

After reading the instructions thoroughly and checking for all the parts (Picture 0) I began assembling the circuit board. I started with the surface mount first as suggested in the supplement. A very good suggestion. When the project is done it looks like a small house in the midst of a bunch of high rises. There'd be no way to get that in there after you put any other components in around it (Picture 1). From there I worked towards the closest edges and then down and across the rest of the board (Picture 2). Identification and installation of the components was straight forward and the hairpin style mounting made for compact construction (Picture 3).

In about three hours I had completed the circuit board and was ready to go to bed. I would mount the board in the tin in the morning (Day 2).

Thursday, January 23, 2003

Rock-Mite Radio

Now for a little Rock-Mite Expedition history. As I was wandering through World Radio Magazine back in December 2002 I ran across an article on the Rock-Mite. My curiosity was peeked instantly as I realized that this would be the perfect homebrew project to start me off on a wonderful journey. The price was just right ($25) and I would be forced to put that Morse Code practice into actual use. I ordered the Rock-Mite on the 24th of December with the hopes that it would get to me by my birthday on the 25th of January. I then began to read everything I could find on the Rock-Mite. As my education continued I realized that I would need to order a few parts, so with a quick trip to Mouser Electronics I quickly ordered that parts I would need to mount and connect the Rock-Mite to the outside world. Now for the enclosure; I wanted something different than the standard Altoids Can (not that I have anything against Altoids mind you.) What I found was the perfect tin. The Timex Expedition watch that I received from my wife for Christmas came in a tin that was considerably larger than the Altoids tin, there would be plenty of room for the Rock-Mite and a battery and voltage regulator to power the Rock-Mite Expedition. I finally had all the pieces in place, well, I was still waiting on the Rock-Mite itself. I check each day to see what the current shipping status was and then on the 21st of January I finally saw my name. My Rock-Mite had been shipped. So let the fun Begin.