Measuring filter response using a noise source

If you own a spectrum analyzer with tracking generator or, even better, a good vector network analyzer, measuring the frequency response of a filter is fairly easy. But there is one old approach using a noise source that can turn any oscilloscope with a FFT spectrum view into a useful tool for determining the frequency […]
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IC-706 MKII Extended Tx Modification

Expanding the transmit range of an amateur radio transceiver is probably the most common modification. Because of its use associated with the Military Auxiliary Radio Service (MARS) or Civil Air Patrol (CAP), this modification is often referred to as MARS or CAP mod. This article shows how to perform this extended transmit modification on the […]
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L-Network impedance matching

Impedance matching is an everyday problem for RF circuit designers. The L-Network is one of the easiest lossless ways of matching a low source impedance to a higher load impedance. This article shows how they work and how to design them. Matching a transistor amplifier’s low output impedance with the higher impedance of an antenna […]
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Review: Analog Devices ADF4360 PLL Synthesizer

The ADF4360 series from Analog Devices is a a family of integer-N-synthesizer chips with on-board VCOs. Since the chips cover all amateur radio bands between 4m – 13 cm and are rather inexpensive, they are predestined to be used in homebrew amateur radio equipment. Not too long ago I reviewed ADI’s wideband PLL synthesizer ADF4351 […]
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Review: Texas Instruments CC2531 USB Evaluation Module Kit

The CC2531 is the second generation ZigBee/IEEE 802.15.4 compliant System-onChip with an optimized 8051 MCU core and radio for the 2.4 GHz unlicensed ISM/SRD band from Texas Instruments. But what good is it, really? To make the evaluation of the CC2531 a bit easier, TI put together the CC2531EMK. The CC2531EMK is a an evaluation […]
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