Ramsey Electronics PR40 Instruction Manual

440 mhz low noise preamp kit

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10 db Gain, 1 db Noise Figure
Runs on 9 to 15 VDC
Hi-Q tuned input to reduce
overload
Small size to fit in any rig
The most popular preamp kit in
the USA!
Easy 15 minute assembly
Perk up your reception on 440 Mhz with this easy-to-build and install kit.
Works well with any radio - especially effective in repeaters. Rugged design
using a microwave transistor outperforms units costing triple the price!
440 Mhz
LOW NOISE
PREAMP
KIT
PR40—1
Kit No. PR40

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Summary of Contents for Ramsey Electronics PR40

  • Page 1 • Perk up your reception on 440 Mhz with this easy-to-build and install kit. Works well with any radio - especially effective in repeaters. Rugged design using a microwave transistor outperforms units costing triple the price! Kit No. PR40 PR40—1...
  • Page 2 Preamps may be designed for either RF or audio use and may be either tuned or broadbanded. The Ramsey Low Noise PR10, 20, and 40 Preamplifiers for 144, 220, and 440 Mhz, respectively, differ from our popular SA7 and PR2 broadband preamplifiers in that these models include high-Q tuned input circuits to pre-select the desired frequency range, restricting the strength of other out-of-band signals.
  • Page 3: Circuit Description

    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. PR40—3...
  • Page 4: Other Components

    PARTS SUPPLIED WITH PR40 KIT CAPACITORS 2 2 or 2.2pF disc capacitor (C1,2) 2 4.7 or 5pF disc capacitor (C3,6) 1 100pF disc capacitor [marked 100 or 101] (C4) 1 .01uF disc capacitor [may be marked .01, 103, or 10nF] (C5)
  • Page 5 RAMSEY PR40 PRE-AMP PARTS LAYOUT DISREGARD HOLES FOR MOUNTING SCREW NOTE: Bend over L1 lead after installing to connect the two PC traces together PR40—5...
  • Page 6 PR40 PRE-AMP ASSEMBLY PROCEDURE Soldering 10 parts to a PC board is not a big job, but good performance of the PR40 requires attention to keeping all leads as short and neat as possible. The order of parts installation is not critical for this and other small kits, so the purpose of the following suggested order of assembly is just to make it as easy as possible for you to get the parts placed correctly on the first try.
  • Page 7 9. Install L1, the pre-wound 2-turn coil, into the two lower component holes. Bend over its non-ground lead on the bottom of the board to form a jumper to the adjoining PC trace, thus establishing a common connection between L1, C1, C2, and C3. PR40—7...
  • Page 8: Input And Output Connections

    PROGRESS SUMMARY: The wiring of your Ramsey PR series preamp PC board is now complete. It will take you less than a minute to completely recheck every single soldering connection as well as for the appropriate part installations. Correct parts placement checked.
  • Page 9: Testing And Adjustment

    Even though this sounds like unneeded advice and common-sense knowledge, we should remember that most of today’s receivers are in transceiver configuration, and that all it takes is one accidental push of a button out of habit, or an inadvertent bump of a keyer, to destroy a preamplifier. PR40—9...
  • Page 10 DPDT power switch with one pole controlling voltage and the other pole connecting the input and output of the PR40 when the DC supply voltage is in the “OFF” position. This setup is very practical when you want to switch the preamp in and out of a receiver antenna line.
  • Page 11 A 440 Mhz “ACTIVE ANTENNA” For situations where a simple indoor receiving antenna is needed, the PR40 preamp will add considerably improved performance to a whip antenna adjusted to 1/4 or 5/8 wave. And, for a very well engineered true active antenna for both HF and VHF at a break-through low...
  • Page 12 Standard replacements: ECG10 or SK9139. You may, of course, order replacement 2SC2498 transistors from the Ramsey factory in Victor, NY, but we are pleased also to give you this pipeline to your own local electronics parts dealer if 2SC2498 replacements are needed.
  • Page 13: Troubleshooting Guide

    TROUBLESHOOTING GUIDE The only possible causes for malfunction of the PR40 are faulty or incorrectly installed parts. Recheck your work. Transistor replacement information is provided. Poor performance such as oscillation can be caused by bad parts-mounting (excessive lead length of resistors or capacitors). Erratic operation will be traced to poor input, output, or voltage connections, or a faulty solder connection.
  • Page 14 THE RAMSEY PR2: THE ULTIMATE BROADBAND PREAMPLIFIER After you find out how practical a well-built PR40 can be for 440MHz operating, you will be quite impressed with the “all bands” higher gain (also with very low noise) plus the convenient AC power supply, BNC I/O connectors and LED ON-OFF indicator of the Ramsey PR2, available factory-wired.
  • Page 15 1. DEFECTIVE PARTS: It's always easy to blame a part for a problem in your kit, Before you conclude that a part may be bad, thoroughly check your work. All our kit parts carry the Ramsey Electronics Warranty that they are free from defects for a full ninety (90) days from the date of purchase. Defective parts will be replaced promptly at our expense.
  • Page 16 • MD3 Microwave Motion Detector • TFM3 Tri-Field Meter • STC1 Stereo Transmitter Companion Published by Ramsey Electronics, Inc. Call or write for our Copyright 1994 All rights reserved. Ramsey full line catalog! Electronics, Inc. 590 Fishers Station Drive Victor, NY 14564...

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