Originally Posted by fuzzoli
...maybe I will
post a bit more of 'status' here....
The goal of this project is to make as close of an exact duplicate of the original Transroc as possible. The links in my previous post have more technical details, but here's a summary:
The boards are done. Unless you need a board "today", it's almost not worth it these days to etch your own boards. It is so cheap that you can get dozens made for literally a few dollars. In fact, shipping from China cost more than the boards.
^-- sorry for the out-of-focus photo.
The modulator section has been breadboarded and is working. I'm working on the RF section now.
The coils have been wound based on the data in the manual.
If you were hinting at the $250 price tag for the Microphone kit on ebay, I seriously doubt it will sell at that price. In fact, just a couple of months ago the Microphone and Spin Rate kits sold for $39/$52 respectively. Most of the manuals are posted over at transroc.org.
So things are moving along...
Oh, no, I had no particular price in mind (and I haven't yet looked at the Transroc items on Ebay). I was hinting that if you'd like to produce Transroc beacon transmitter clones (possibly including the add-on instrument modules, such as the roll-rate sensor, microphone, temperature sensor, etc. [see: http://www.ninfinger.org/rockets/ca...74/74est52.html
]) in some quantity, a lot of people--myself included--would be interested in buying them. (Your pictures of the already-printed PCBs, and the inductor assemblies, look like a small Transroc production batch.) Also:
Regarding the custom PCBs' low cost, I read on a ham radio website (after posting my message here late last night) that local PCB printing houses, like local printing houses (they're like small POD--Print-On-Demand--publishers), can print multiple, custom-layout printed circuit boards for quite low per-PCB costs, even if only about five copies of the PCB are needed. Amateur radio clubs often make up batches of soldering practice kits, Morse Code oscillator kits [for code practice], simple radio receiver kits [such as Short Wave Xtal sets <crystal radio receiver kits>], and QRP [low-power] transmitters and/or transceivers that utilize custom-printed PCBs, for amateur radio clubs in schools, Scout troops, and 4-H clubs, and:
At the school in the isolated town of Eagle, Alaska, Professor Neal Brown--a long-time ham radio operator and a former Director of the Poker Flat Research Range [our sounding rocket launch site, 30 miles north of Fairbanks]--teaches the "Middle School grades" kids at the Eagle Community School how to solder connections properly and build radios, using such kits that he (in concert with the local Arctic Amateur Radio Club) has made up in small batches; he teaches the lessons via a Skype audio and video connection. It is very effective; each year, several of the kids earn their FCC Technician class amateur radio licenses (and when the Novice class licenses were still offered in previous years, the children earned those). Even those who choose not to become amateur radio operators learn useful--and marketable--skills in proper soldering of electronic circuits, how to read resistor color band codes, how to test transistors and other electronic components to determine whether they're still in working order (transistors' wave forms on an oscilloscope screen yield such information), and so on; plus:
The Transroc clones that you're making might also interest them and their teacher, Marlys House (she also has a long-running model rocketry STEM--Science, Technology, Engineering, and Mathematics--courses enrichment program, and over the years Neal and I have located and donated model rocketry equipment to her program). She and Neal might prefer the Transroc kits, as they could combine the electronics & radio lessons with the model rocketry STEM courses enrichment program. Also, the Transroc would be useful in R/C model sailplanes, as a "model-finding beacon," and the temperature sensor module would probably be useful in such models for finding thermals (bubbles or columns of warm, rising air, which sailplanes--full-scale as well as model ones [even F/F--Free-Flight--model ones]--ride in order to gain altitude, over Sun-heated darker ground areas).