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  I almost built a 1954 Regency TR-1 superheterodyne transistor radio. It was the very first commercially available radio receiver in the United States and globally, built entirely on transistors. How much have inner and outer designs changed in 69 (excellent) years? The 1954 Regency TR-1 was not just portable but pocket-sized. And not just pocket-sized but autonomous and battery-efficient.   Pocket crystal radios, such as the popular back-in-the-day rocket-shaped ones, have been around for a long time. They required grounding, so listening to the radio while walking was impossible. The earbud cable performed the antenna function as somewhat recent cell phones with FM receiver functions. And the decorative antenna at the top of the rocket was a tuning plunger for moving the induction coil of the resonant tank core. There were pocket tube radios in the 1950s. But an expensive set of anode and incandescent batteries lasts for just 5 hours. And almost all such receivers could only be list

Introduction Why use HDMI over IP in some cases? The image quality is noticeably worse than a classic HDMI twisted-pair extender. Let's see a few examples and answer this together. When is the best case for HDMI over IP extenders? Previously, we have repeatedly compared two types of HDMI extenders with each other: HDMI over twisted pair cable HDMI over IP extender The second type also works over twisted pairs, but it has the additional ability to operate in populated local networks. Upon reading our posts, you may think using the first type of extender is always better. After all, it is indeed better in many respects: ideal video quality, no transmission delays, and many supplemental functions. The only thing is to stay within the twisted pair cable length limits, usually up to 330 feet. But it is only sometimes the case. Sometimes, having a separate twisted-pair cable from the video source to the TV makes it impossible to install a transmitter and receiver of the first type. But s

Let's see how the cables measure influence the range of the reflectometer. How do the noise filtering mode and methods for determining the unknown propagation coefficient affect the measurement accuracy? KEY FACTORS FOR CABLES The reflectometer's detection range depends on the cross-section of the cable cores, the overall quality of the cable, as well as on the way the reflectometer is connected to the cable being tested. The larger the cross-section of the cable cores, the less attenuation the electrical pulse supplied by the reflectometer to this cable undergoes and the longer the distance it covers. Old or defective cables may have reduced insulation resistance or increased attenuation. This significantly reduces the ability of the cable cores to conduct electrical signals and, as a result, reduces the maximum distance. The connection of the reflectometer to the cable must be done so that a pulse with the maximum possible amount of energy is emitted from the reflectometer to

Vacuum tube technology always means bulky, heavy cases, dangerously high voltages, and complex multi-channel power supplies. Or does it? This little amplifier is powered by a 12V wall-wart AC/AC transformer adapter. Its anode voltage is only 56 volts. It's high time to learn how this voltage is created from 12V and how a simple tube amp actually works. We will also see on the oscilloscope screen that that unique tube sound signature is loved by audiophiles and musicians, especially guitarists. And then, we'll talk about the difference between long and short vacuum tubes. The amplifier uses two 6BA6 pentodes. One can also use 6BD6, European EF93, and Chinese 6K4. In today's experiment, I specifically used 6K4s because they are inexpensive and easy to get. Instead of pentodes with long characteristics and long bodies, one can use short ones like 6AK5, EF95, 6J1, and 6J2. They will also sound great but in a different way. To understand the difference between a remote (long) cu