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Oregon Coast Repeater Group |
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Antennas |
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The following links and files contain information for various antennas. |
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916.5 MHz Receiving Antenna for Wireless Weather Stations |
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The 916.5 MHz receiving antenna for wireless weather stations is used to improve the reception of remotely located weather sensing units. The antenna is built on a PVC schedule 40 boom using copper wire elements cut from #14 copper house wire. The insulation is stripped off of the copper wire elements. Element lengths and spacings are shown in the following picture/diagrams: |
| 916.5 MHz Antenna |
Design/build information for the 916.5 MHz Receiving Antenna. |
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| Quagi_916MHz_Rev2.zip |
Design file for the 916.5 MHz Receiving Antenna. |
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Miscellaneous Functions |
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The following links and files contain information for miscellaneous functions. |
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Watchdog Power Cycler |
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The WDPC - Watchdog Power Cycler is an activity monitor for remote sites. Upon the loss of a heartbeat signal, the WDPC will produce a power down/power up cycle and wait for the remote equipment to reboot and then again start looking for the "I'm Alive" heartbeat signal. If the signal is again not present the power cycle will be repeated until the "I'm Alive" heartbeat returns. |
| WDPC.zip |
Design files for the Watchdog Power Cycler. Includes schematics, micro-controller firmware source code, firmware hex image file, photos and mechanical details. |
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Packet Radio Telemetry |
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The following links and files contain information for packet radio telemetry. |
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KPC Telemetry |
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Sending remote site telemetry data using the KPC TNC. |
| KPC_Telemetry.zip |
Design files for a KPC TNC Telemetry Adapter and Monitored Voltage Signal Attenuator. Includes schematics, PCB layout, and photos. |
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Radios |
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The following links and files contain information for various radio upgrades. |
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Yaesu FT-301D Replacement Display Yaesu FT-301D Replacement Display Document |
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The Yaesu FT-301D transceiver's digital readout display used TIL-306 and TIL-308 LED display devices that have long gone obsolete. Those display devices ran hotter than blazes and frequently failed due to a lack of cooling. This paper and accompanying files (see below) contain the documentation for a new, directly plug in compatible, digital display for the Yaesu FT-301D transceiver. |
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!!! Updated !!! |
Nov. 30, 2012: Includes firmware update A03 that displays dashes in the display when an unpopulated crystal channel is selected, or if an external VFO is selected and it is not powered on or it is not attached. Also shows a fixed "5.000.0" value for the JJY/WWV switch position. This firmware update is compatible with all circuit board versions of the "FT-301D Replacement Display."
Dec. 6, 2012:
- - - - - - - - - - - - - - - - - - - - |
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Radio Accessories |
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The following links and files contain information for various radio accessories. |
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DigiVFO/DigiBrain Upgrade DigiVFO/DigiBrain Upgrade Document |
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An upgrade for the DigiVFO/DigiBrain. This Direct Digital Synthesis VFO was initially described in the May 1995 and March 1996 QST magazine. This upgrade adds features and useful capabilities to the original design. The upgraded unit can easily be user set for compatibility with many different radios and/or used on the workbench as a signal generator. |
| DigiVFO_DigiBrain_Upgrade.zip |
Design files for the DigiVFO/DigiBrain upgrade. Includes schematics, micro-controller firmware source code, firmware hex image file, photos and mechanical details. |
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| DigiVFO_DigiBrain_Firmware_20110630.zip |
The latest firmware update for the "upgraded" DigiVFO/DigiBrain. This firmware source code features compiler switches to set "up" or "down" rotation of the step sequencing and the use of either the original Varitronics MDL-16265K-LV or the newer Lumex LCM-S01602DSF/A display (Digi-Key P/N 67-1758-ND) which uses the Samsung S6A0069 controller and also has an LED backlight. Also included are some improvements related to updating of the display when doing "mode changes" from VFO to Signal Generator and visa-versa. |
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Dual Radio Sound Port Interface |
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A dual radio interface to a PC sound port. |
| RASPY.zip |
Design files for the RASPY - Radio and Sound Port Yoke. Includes schematics, photos and mechanical details. |
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CW Voltmeter |
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The CWVM is a low voltage, Morse code reporting, voltmeter. Instead of having to look at a display, the CWVM reports the reading in Morse code. The CW voltmeter operates from a +7VDC to +25VDC power source (9V battery or even the actual voltage source being monitored) and measures voltage levels from 0.00VDC to +25.50VDC. Pushing and holding the power button results in a Morse code voltage report similar to: "13.80V" followed by a two second delay. The report repeats, with a new A/D sample each time, as long as the button is pushed. Morse code sending speed is potentiometer adjustable from 5WPM to 45WPM. |
| CWVM.zip |
Design files for the CWVM - CW Voltmeter. Includes schematics, PCB layout, firmware source, hex image files, and photos. |
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Repeater Audio Graphic Equalizer |
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A Repeater Audio Graphic Equalizer small enough to fit inside almost any radio. This circuit provides individually adjustable audio levels in three different audio frequency bands to improve the readability of a radio's transmitted audio. |
| RAGE.zip |
Design files for the RAGE - Repeater Audio Graphic Equalizer. Includes schematics, PCB layout, and photos. |
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Test Equipment |
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The following links and files contain information for various test equipment. |
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Impedance Meter - USB |
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A surface mount implementation of Alfredo Accattatis' Visual Analyzer ZRLC Meter. This is one of the "coolest" pieces of test equipment that you could ever have. This relatively simple USB Sound Card Instrument is amazingly accurate and provides a wealth of information for those capacitors, inductors, resistors and other odds and ends in your parts bin or junk box. The Visual Analyzer software is free and is available from Alfredo Accattatis' excellent website: Visual Analyzer Software |
| VA_Zmeter_REV_A02.zip |
Design files for a surface mount implementation of the popular Visual Analyzer ZRLC Meter. Includes schematics, PCB layout, photos and details. |
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Oscilloscope - USB |
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A surface mount implementation of the Visual Analyzer Oscilloscope/Spectrum Analyzer/Signal Generator. This is an audio frequency range piece of test equipment. While it only covers the audio frequency range (up to 48KHz; 96KHz sample rate), this instrument provides a wealth of information about the quality of audio signals. Along with being a dual channel oscilloscope, it also provides a dual channel spectrum analyzer and dual signal generators that are capable of producing a wide range of signals from sine waves, square waves, triangular waves, pulses, even custom waveforms, etc. Here is another screen shot of the Visual Analyzer in action. The Visual Analyzer software is free and available from Alfredo Accattatis' excellent website: Visual Analyzer Software |
| VA_Oscope_Rev_A01.zip |
Design files for a surface mount implementation of the popular Visual Analyzer Oscilloscope/Spectrum Analyzer/Signal Generator. Includes schematics, PCB layout, photos and details. |
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Digital Storage Oscilloscope
1MHz Dual Channel |
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The DSOscope is a surface mount, and slightly modified/enhanced, implementation of Jonathan Weaver's famous PPMScope. The PPMScope is a 1.0 MHz sampling frequency, 5.0 MHz equivalent time, oscilloscope. Along with being a dual channel oscilloscope, the PPMscope also provides a spectrum analyzer function and multiple measurement capabilities for the displayed waveforms. The DSOscope version connects to the hosting PC via an internal USB interface. The internal USB interface uses the FT232RL serial to USB converter integrated circuit. The necessary driver code for the FT232RL is available from the FTDI website. The DSOscope is compatible with the PPMScope's PC software application code. Some of the feature enhancements of the DSOscope are:
A few screen captures of the DSOscope in action:
The PPMScope PC application software, that is compatible with, and used by the DSOscope implementation of the PPMscope, is available from Jonathan Weaver's PPMScope website. |
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Design files for the DSOscope (a surface mount, slightly modified version, of the PPMScope).
Includes firmware, schematics, PCB layouts, mechanical drawings, photos and details.
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!!! New Version !!! |
Design files for the latest A03 version of the DSOscope. This version of the A03 revision changes C14 and C15 from 10pF to "Do Not Install" on the Analog Board. Also, R6 and R19 values on the Analog Board are changed from 100K to 1.0K. Previous A02 versions of the DSOscope Analog Board should also apply the C14, C15, R6 and R19 changes to improve the DSOscope's bandwidth and to eliminate some overshoot issues on higher frequency signals. The A03 version updates the
the trigger source selection switch and the two input attenuator (÷1, ÷10) switches to
DPDT style. This allows the firmware to inform the PC application of these switches' states.
Also, the firmware now includes a "pre-trigger" acquisition capability. While this "pre-trigger"
capability is limited in its "pre-trigger" depth and works only for slower acquisition speeds, it
can be quite useful when needing to look back in time from a trigger event. (The "pre-trigger"
acquisition capability
does require a new version of the PC application code that is currently under development.
Some "early teaser" screen captures of this "pre-trigger" mode in action can be seen here:
PreTrigger1
PreTrigger2).
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Library symbol files used with the FreePCB and the TinyCAD design tools for the DSOscope. |
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Workbench - Techniques and Methods |
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SMT Desoldering Tips |
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The photo on the left shows two SMT Desoldering Tips that have been made from 1.375 inch long by 8-32 pan head brass bolts. The SMT Desoldering Tip, shown at the top of the photo on the left, is used to unsolder SOIC-8 pin devices. It was created by filing the pan head slightly narrower and then adding a small U-shape bent piece of copper sheet stock that has a 5/32" hole drilled in the center of it. The U-shaped copper is attached with an 8-32 brass hex nut. Using this same technique, desoldering tips can be built for various SOIC sized devices. By adding a second piece of copper sheet stock, rotated by 90 degrees, it is possible to build desoldering tips for TQFP style devices. The SMT Desoldering Tip, shown at the bottom of the photo on the left, is used to unsolder 0805 SMT devices. It was created by filing a notch into the pan head of the brass bolt along with filing the pan head a bit narrower. Again, using this same notch filing technique, desoldering tips can be built for various size SMT devices such as 1210, 0805, 0603, and even the smaller 0402 devices. The SMT Desoldering Tip is installed, in place of a standard replaceable 5/32" soldering iron tip, in a cheap 25 watt soldering iron that uses plain, solid metal, soldering iron tips. When used, it is handy to have a small pair of tweezers, or a toothpick handy, to quickly remove the unsoldered device from the SMT Desoldering Tip as the desoldered device will likely "stick" to the desoldering tip as it is removed from the printed circuit board. Also, very lightly pre-tinning the SMT Desoldering Tip helps transfer heat to the to be removed device's pins. |
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OCRG has been using circuit board fabrication products from "Pulsar" to produce many of our system unique circuit boards. These circuit boards range from simple one-sided attenuator boards for our A/D conversion telemetry to two layer fine pitch SMT boards with dual CPUs for processing our weather station data. Pulsar's website contains excellent information on fabricating PCBs using The "DirectEtch" Technique with their complete PCB "Fab-in-a-Box" products. | |
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Technology and techniques for making printed circuit boards using a laser printer toner transfer methodology. |
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