K9AY LOOP SWITCH AND PREAMP
Description: Two board set consist of a loop antenna switch and switch impedance load board and a bandpass filter/preamp board. This is a complete kit less, cabinet, power transformer, and selector switch for $48.00. To see the boards click, to see the schematic click, to see the parts list click, tto see chip part locations click.
432-435 GaAsFET 70CM PREAMP, 15db, .55dbNF
ARRL HB CHP 32 FIG 1
Description: This preamp offers good noise performance and gain and is suitable for terrestrial, EME, and satellite applications at 432 to 435 MHz. Gain is approximately 15db, with a noise figure of .55db. The GaAsFET is a Mitsubishi MGF1402> The MGF1402 are no longer available through normal distribution and I refuss to pay $21.00 from China. Use the MAR-4 or MAR-4+ amplifier for the substutite.
Description: DC to Daylight, not quite!.The circuit uses a Mini-Circuits Lab MAR-6 that has a gain bandwidth from dc to approximately 2000Mhz with 20Db gain. The author's notes give examples of using the circuit at 432 and how to add a bandpass filter to the board. The board comes on G-10 but is available on Teflon for an increased price
Description: This is a two board set consisting of a power supply board and a pre amp board. The amp is designed for 136 kHz but works from 10 kHz to 30 Mhz. The amp consists of a CP666 JFET with variable gate bias. The amp board is 7" x .75" and the PS board is 4.25" x 2.6"
Description: The circuit is based on Mar-6 device and 78L07 regulator The parts are all surface mounted. The price includes the chip capacitors and the chip resistor, the preamp board and the 6 boards for the housing.
updated: Jan 24, 2009