Ultra-RX1 Kit
You can DX the alien nations – insects, rodents, bats, and more – in the 35 to 45 kHz ultrasound band, listening to their feeding, communication, and navigational signals. Ultrasound, in general, refers to all sound waves above the range of human hearing, about 20 kHz.
Our ULTRA-RX1 receiver kit tunes an active part of the band, 35 to 45 kHz, with a 10 kHz wide audio bandwidth. Signals emitted across species vary from single sine waves to chatter with a rich mix of harmonics and pulses. Sound power levels (SPL) emitted range from roughly 70 to 110 dB, sufficient to be heard from 25 to 100 feet with a high gain receiver, such as our RX1. Signals heard generally are a pattern of “clicks.”
As pictured, the PCB (2.65 by 2.95 inches) and parts fit in our plastic clam-shell case (L 4.38 W 2.95 H 1.0 inches), along with a 9V battery (not included). A 40 kHz piezo transducer (PZT) is mounted on the front panel, and the power switch, frequency tuning pot, audio amp volume pot, and 3.5mm stereo jack, are accessible from the back panel. The stereo jack accepts 8-ohm, 24-ohm, or 2K headphones with a 3.5mm stereo plug. Our kit philosophy is to “build a little, test a little.” In each assembly section of the manual, step-by-step instructions are followed by test instructions, thereby confirming operation before proceeding. A 9V battery and VOM cover a majority and sufficient number of the measurements for success. To radio hobbyists, assembly, test, and use of this kit will feel like building a direct conversion radio receiver.
Build time for the experienced kitter is about 2 hours. Even though the construction is through-hole, a small iron, good lighting and good vision are necessary given that the parts are closely spaced. The manual is 18 pages and includes a comprehensive schematic, enlarged picture of the PCB, and brief explanation of each section of the receiver.
Ultra-Test Gen1 Kit
With this kit and an existing electronic function generator, you can create a simple ultrasound signal generator for the bench with a reasonably flat (~constant) pressure output for the 35 to 45 kHz band of frequencies. The kit includes a 400ST16-ROX transducer, or TX PZT. The frequency from the function generator is also the frequency of the pressure wave generated. For other frequency bands of interest, simply substituting another TX PZT should suffice, from about 20 through 80 kHz. The 400ST16-ROX puts out about 17 Pa, pressure at 1 foot, for a 10 V RMS input from the function generator. In addition to the PZT, this kit includes a case - same as used in the Ultra-RX1 noted above - and discrete parts including a 10 MHz GBP op-amp used to configure a synthetic inductor for broad-band tuning. You'll supply the vector board, which needs to be 2950 by 2650 mils to fit in the case.
For more detail, browse the following articles on the ultrsonic-articles page: "A PZT Signal Generator for the Bench," and "A PZT Receiver Jig for the Bench," which is offered as a kit below.
Ultra-RX Test Jig1 Kit
This bench receiver kit is designed to work in concert with the TEST GEN1 kit listed above for the 35 to 45 kHz ultrasonic band. It consists of a synthetic inductor for broad-band tuning of the RX PZT and a op-amp amplifier with gain, added to ease scope measurements. Again, since PZTs are inherently narrow-banded, you'll want to select another PZT if working outside this band of frequencies. The kit includes a 400SR16-ROX PZT, and two 10 MHZ GBP op-amps to provide frequency tuning and gain. The PZT is tuned by adjusting the value of the synthetic inductor, where the inductance is equal to ~ the product of the values to two resistors and one capacitor. In addition to the PZT and op-amps, this kit includes a case - same as used in the Ultra-RX1 noted above - and discrete parts. You'll supply the vector board, which needs to be 2950 by 2650 mils to fit in the case.
For more detail, browse the following articles on the ultrasonic-articles page: "A PZT Receiver Jig for the Bench," and "Transmitting Ultrasound with a 40 kHz PZT."
XSS-SA8: 8-Step Attenuator Kit
A step attenuator is a very useful tool for your radio bench. We were motivated to develop this kit for several reasons: It’s an integral part of equipment required when using the Trap Coil Q Measurement Method - see the articles-index page - and it’s useful in reducing function generator outputs or in isolating or buffering between circuits and reducing effects of circuit mismatches during tests. As pictured eight DPDT switches are included, each enabling the connection or bypassing of one pi-network resistive pad. Pads included are: 20, 20, 20, 10, 5, 3, 2, and 1 dB respectively, based on a 50-ohm system. PCB thickness, copper ground plane, and trace sizes enable a flat response to 10 MHz. As such any insertion loss (reduction in voltage) from 0 to 81 dB in 1 dB increments is available for measurements. BNC connectors provide input/output. All resistors are 1% metal film. The Kit is available with PCB, parts and manual or as PCB only.
