Ramsey Electronics PR20 manual Circuit Description

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CIRCUIT DESCRIPTION

L1 and C2 form a tuned input filter for the preamp to reject out-of-band signals. The 3 db bandwidth of this filter is 6MHz. L1 is adjustable for peak performance. The 2SC2498 transistor is a bipolar silicon NPN low noise UHF/VHF amplifier in a TO-92 case suitable for service up to 5 GHz, with maximum device dissipation of 600 milliwatts. Q1 has a very low noise figure, determined by the bias established by R1 and R2. The actual circuit is about as simple as they come. Maximum gain and freedom from oscillation are accomplished by the quality of workmanship in parts installation and I/O connector wiring

PR20—3

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Contents LOW Noise Preamp KIT Introduction to the PR20 LOW Noise Preamplifier Circuit Description Parts Supplied with PR20 KIT Ramsey PR20 PRE-AMP Parts Layout Disregard C6PR20 PRE-AMP Assembly Procedure PR20-7 Input and Output Connections Testing and Adjustment Strong Signal OVER-LOADING PR20 ON-OFF Switching SuggestionMHz Active Antenna Switching Considerations for Transceiver Operation2SC2498 Characteristics Conclusion Troubleshooting GuideRamsey PR2 the Ultimate Broadband Preamplifier Ramsey Kit Warranty Call or write for our full line catalog