Practice some multiple choice questions on resistors

 


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Have you heard of zBITX?

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 Well, I had not heard till I read the program schedule of LARC-7 today. Most of you would be familiar with uBITX which has gone up to version 6. Some of you would be aware of sBITX, which is quite an advance over uBITX. Almost daily I am meeting a new uBITX user on the band, most of them using additional linear amplifiers. That made me join the BITX group on groups.io , where I am getting messages from uBITX and sBITX users from all sides of the globe. Still I was not aware of zBITX and that made me look around and came across two references. One was the video of a talk by VU2ESE at QRP ARCI . Another was an email in the BITX groups.io which was citing the former. zBITX is a new transceiver from VU2ESE based on Raspberry Pi Zero for 20W, having CW skimmer and FT8 modes in addition to the regular SSB mode and waterfall display which the sBITX also has. zBITX is quite small, just 3" x 3" x 1.5" in size. It is a Raspberry Pi Zero based 20 W software defined radio which h...
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The All New zBitx 5 watts QRP All Band, All Mode Radio is Here!

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 VU2ESE has announced the launch of zBitx on the BITX group. It is available for purchase at http://www.hfsignals.com/ and delivery will start in February 2025. According to VU2ESE, it is a low cost 5 Watt, 80m to 10m QRP radio with a 480x320 touch screen that allows you to run CW, FT8 and other digital modes without needing even a phone that the original zBitx needed. As previously posted, zBitx is based on a Raspberry Pi Zero 2 W, which gives it the prefix 'z'. The physical size of zBitx is just 6 inches by 3.5 inches, 1.5 inches thick, weighing just 250gm, and includes a battery case that can hold two 18650 lithium polymer batteries. One has to get batteries from elsewhere. External DC supply can also be used with a maximum of 9V. zBitx seems to be quite 'pocket friendly' both in the literal sense and cost wise! An HDMI monitor, keyboard and mouse can be plugged in, to use like a QRP base station. zBitx runs the same software as sBitx radios. zBitx will ship with...
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Basics of Radio Transmitter

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Every radio amateur should know about the basics of a radio transmitter, whether you are going to operate a commercial one or make one on your own, what we call by the pet name 'homebrew'. A radio transmitter is a device which generates a radiofrequency signal and sents it out as radio waves through the antenna. If only the radio frequency carrier wave is sent with breaks and makes corresponding to Morse Code formerly used in telegraphy, then it is known as a CW (Continuous Wave) transmitter, which is the simplest one. Like many other radio amateurs in the yester years, I had also homebrewed a basic CW transmitter using BD139 transistor as the final RF amplifier, running about 5W, known as QRP transmitter. Initial part of the transmitter is the radio frequency generator known as oscillator, which produces a high frequency oscillating current when you supply it with a direct current power supply. Oscillator section was called a VFO or Variable Frequency Oscillator as the freque...
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