FM Radio Station Testing Part 7

The 9-volt powered mini radio station is set to broadcast on the FM band near 102 MHz with more tests using a tiny 1.75-inch circular loop antenna. Today's tests include a harmonic and range study, along with orientation reviews. A very sensitive Chinese multi band radio is at the receiving end. The photo does not show the actual test range distance. In this second day "on the air" test, a small script will be sent out over the "air waves." Stay tuned to this project and the radio station just keeps growing and growing.

FM RADIO STATION TRANSMITTER TESTING PART 7
The next phase of the radio station is testing and calibration of the transmitter and equipment, and running more experiments to pace the radio station and see what works best.

* Range
* Transmitter Signature Footprint
* Detail & Extent of Harmonics
* Quality with Microphone
* Background Pickup Determination
* Orientation Positioning Effects
* Results of interchangeable Antenna
* Results with Different Antenna Designs 
* Signature of Transmissions with Antenna Position
* Effects of Antenna Blockage
* Types of Material and the Effects on Wireless
* Results of Direct Audio Feed Bypassing Mic
* Results of Varied Lower Power Voltage
* Instrumentation Add On 
* Mute Circuit Resistor Determination 
* Power Determinations

FM Radio Station Part 5 Index
http://humanoidolabs.blogspot.tw/2013/12/fm-radio-station-part-5-index.html

FM Radio Station Part 2 Assembly

Flipped reverse side photo to match component side

MINI FM RADIO STATION  Note top side component placement. Top two holes are for the 9-volt battery clip leads with ground on the left side. The left bottom hole and the bottom right hole are for the antenna connection.

Connections are easily seen when the printed circuit board is back lit, showing the circuit board traces on the reverse side. This makes it easier to match component locations to the schematic diagram.

Schematic diagram for a two stage transistor FM transmitter. Features microphone driven audio input, with tunable frequency range with L1. Operates on a 9-volt battery. Range tests are yet to be determined but the frequency appears to be around 100MHz on the FM band.

BUILD YOUR OWN FM RADIO STATION TRANSMITTER
IN-HOUSE DIY RADIO STATION PART 2

Rotated left to right view for component placement

Work is progressing on the electronic construction of the Lab's two stage exampling FM radio station. Stay tuned to this series of blogs as we supply the details of going on the air, as well as technical info so you can roll your own in-house radio station for fun.

The test transmitter printed circuit board has 17 components mounted and ready for soldering. This blog details the component placement and the circuit traces on the printed circuit board and includes transistor placement guides and a schematic for assembly. Note the two transistor identifications in the illustration showing keyed emitter, base and collector locations. 

The power board uses two transistors, a C1675 K6YC at the right side of the board (see photo above) and a C9013 H049 nearest the microphone. The circuit has one electret microphone input for voice operations and includes one coil, two transistors, two electrolytic capacitors, five ceramic disc capacitors, and five resistors. Not shown is a 9-volt battery clip and the antenna.

Verified leg identification ok

The antenna is only a few inches of wire which minimizes the range for initial testing, and limits use and range of reception to inside the lab room. The electronic project goal is an exampling in-house educational fully functional radio station. More tests will determine the range characteristics more precisely.
Note that some countries and municipalities allow short range transmitters of this type and some do not. Be sure to first check local laws and regulations before proceeding with the project.

The copper printed circuit side of the board with through hole leads ready for hot soldering

Ok to Use: MICRO Data/Japan data

The coil in combination with the parallel capacitor tunes the circuit to a frequency within the FM band.

Frequency trimming is accomplished by stretching or compressing the coil or modifying the value of the ceramic parallel 10 pF capacitor.

Initially the frequency should be in the range of 88 to 108 mHz on the FM band.

Warning - do NOT use USHA India/LGE leg positions

The radio station will have an identical twin backup system for service or parts to remain up and running as necessary.

The cost of the first set of parts is NT$132 (US$4.42) and the backup duplicate parts are NT$120 (US$4.00). Thus far, combined cost is US$8.42 for the hardware.

The transistor leg identification does not agree from one data sheet to the next. See diagrams.

Careful with data sheets for the 2sc1675 transistor as there are discrepancies between the TO92 and TO92b case versions. For example, the equivalent Panasonic 2sc 829 equal to 2sc 1675 as a substitute is in agreement with the transistor placement of emitter, collector, base, therefore this is the arrangement to use.

FM Radio Station Part 5 Index
http://humanoidolabs.blogspot.tw/2013/12/fm-radio-station-part-5-index.html

FM Radio Station Part 1 Announcement

Preliminary Radio Station Design

FM RADIO STATION TRANSMITTER
PART 1 ANNOUNCEMENT
Coming to a station near you!

The Big Brain machine is developing a radio station for programs dealing with Big Brain topics and schedules. Programming detail is yet to be determined as the design of the station is in the works.

It could include the sounds of the local SETI program, downloadable serial sounds for direct reception of Parallax Propeller chip software, special music, details of the powerful telescopes observing schedules at the Humanoido Observatory, Lab schedules and updates, various projects, educational programs, ESL language programs, special weather reports, planet and solar casts, Brain Cortex news, etc.

The science Laboratory station includes a fully electronic radio station transmitter capable of reaching your home if your location is within the range of the electromagnetic signal.

Scheduling
Programming schedules may appear in this blogger ahead of time, and transcripts may be available before or after the broadcasts. There is always the surprise and unannounced broadcast with special information.

It is not determined if the Big Brain machine will narrate all or many of the broadcasts and programs using its machine voice.

The idea for the station was hatched long ago, and now resources are available to make it happen. The location sites of the transmitters are currently undisclosed. Stay tuned for more information.

Web Version
Along with the radio version, a web version radio may appear for those individuals not within the electromagnetic signal range. A static web version could feed text transcripts of various broadcast programs about science and technology.

FM Radio Station Part 5 Index
http://humanoidolabs.blogspot.tw/2013/12/fm-radio-station-part-5-index.html

Temporary Satellite TSAT

BIG BRAIN INVENTS THE TEMPORARY SERVICE SPACE SATELLITE TSAT

A space satellite can hold a space telescope with 3-inch or smaller optics and observe lunar terrain above the blurring effects of Earth's atmosphere for more clear imaging and study. Having your own Amateur Satellite is mind expanding learning experience that can raise the know-how level of your technology.

Large TSATs could adapt QuadLyzer BASIC Stamp
Homework boards or similar components

DEFINITION
A satellite is defined as an artificial body placed in orbit around the earth or another planet in order to collect information or for communication. The Big Brain has extended this definition to include suborbital path.

SATELLITES
One aspect in the Big Brain Space Program Initiative that could use more development is that of satellites. Years ago, the author's Amateur Space Telescope was developed as a satellite to be hoisted into orbit by the US Space Shuttle with the NASA GetAway Special Program. Satellites are expensive to create, launch, and maintain in orbit. Big Brain has found a way to bypass these complexities and cost, by introducing the temporary service satellite or TSAT.

Solar study with TSAT is possible

TSAT TYPES
There are two types of Big Brain invented TSATs. One is lofted during the Next Space Program and provides data and services during the loft. The next type is the Dropped TSAT. This will provide data and services during the trip from space to the Earth.

TSAT FLIGHT
The TSAT is launched from space and allowed free flight. TSATS can be free fall, gliding, resistive, or have powered flight.

SUBORBITAL
The difference of a TSAT and an orbital satellite is the TSAT is mainly suborbital at this time.

TIME IN SPACE
The amount of time the TSAT remains in space for use is based on a number of conditions, such as the amount of time of free fall, wind resistance, height of release, air pressure, atmospheric re-entry parameters, etc.

LAUNCHING DOMAINS
TSATS are currently capable of launching two space domains - both Micro Space and Next Space.

TSAT APPS
TSATS have use for exploring space, understanding the conditions of atmosphere in lower space, and it can serve to bounce signals or act as a launch platform for other space craft. A TSAT can hold special payloads like a Temporary Space Telescope or TST.

WORLD RECORDS
The TSAT may indeed have the smallest suborbital flight in history. For Micro Space, the suborbital position down-range can be measured by a few feet. For Next Space, based on conditions, the distance can range to several city blocks. Anything launched higher is dependent on additional conditions and the satellite can end up considerably farther down range.

TRAJECTORY
TSATs can go up by various means and drop back to the Earth. Part of the TSAT project is to maximize the satellite's time spent in space. This may include lofting based on the Jet Stream, slow lofting through special gliders in Near Space where a tenuous atmosphere exists and a slowed reentry based on a parachute, streamer or other aerodynamic means.


TSAT FUNCTION
TSATs are generally lofted and dropped in Micro Space and Next Space, providing a temporary service during their reentry trip to the ground.

LOFTED TSATS
Another type of TSAT is one that only goes up and records data and provides services within this range. Thus far, the Lofted TSAT service is provided during the Next Space Program.

TSAT COST
TSATs are relatively inexpensive. Consider, the Big Brain space exploration initiative is many things and always growing and expanding in knowledge, design, and discovery. On aspect is the creation and invention of new designs and crafts that function in space. Being a bare bones cost space exploration program, the Big Brain can offer a ride into space from a cost range of free in Micro Space, to $12 for Next Space, and $5.53 per pound of payload to go up into Near Space.