The TMB-1 is an RF amplifier unit / receiving accessory that can be used with a low-impedance broadband loop, a high-impedance terminated loop (such as a Pennant, Flag, or Kaz Delta), and whip (telescoping rod) antennas. This particular design is optimized for 0. 5 to 2. 0 MHz operation (medium wave broadcast and 160-m amateur). Sensitivity is sligh
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tly less, though still usable, in the 150-500 kHz and 2-6 MHz ranges for longwave, tropical band, and 80-m amateur operation. Circuit changes, mostly with regards to the RF transformers, would be necessary for better performance on other frequency ranges. The accompanying schematic drawing shows the TMB-1 circuit. The buffer amplifier is considered as a generic building-block assembly having an input, an output, DC power, and ground. The schematic of this amplifier card follows the main TMB-1 drawing. A table of suitable integrated circuit buffers is also presented. The antenna element (loop or whip) and TMB-1 box are often situated somewhere other than at the receiving position. Typical sites include the roof of a building or vehicle, the top of a mast, or out in a field. Sometimes two or more antennas are deployed a considerable distance (over 30 m) apart to form a phased array. DC power is transferred to, and RF output from, connector J9 of the TMB-1 through the 50-ohm coaxial cable. At the receiving position, DC is split off through an inductor and RF through a capacitor (the classic bias tee arrangement). This would normally be built into the phasing unit or preselector ahead of the receiver. A few receivers may themselves have a built-in DC-biased RF port. If the TMB-1 is used close to the receiving position, you can supply DC power (+12 V to +15 V typically) to J7 and take DC-blocked RF out to the receiver (or...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
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In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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