Ramsey Electronics PA1 User Manual

2 METER RF POWER
AMPLIFIER KIT

Ramsey Electronics Model No. PA1

Give your handheld a big boost with this economical power
amplifier kit. Thousands have built and enjoyed this kit; one
magazine review even said, “probably the best bargain in Ham
radio!”

• Works with any radio; mobile, fixed or handheld

• 8 to 10 times the power gain: 10 watts out for every 1 watts in, 20 watts

out for every 2 watts in, 30 watts out for every 3 watts in!

• Easy connection to a radio

• Operates on 12 - 14 volts DC, draws a maximum of 5 amps

• Just add a T-R relay, case, Pre-amp if desired and connectors

• Informative manual answers questions on theory, hookup and uses -

enhances resale value, too!

• Maximum output of 35 - 40 watts, max drive of 8 watts

• Mounts in any small aluminum case, which then will act as a heatsink

• Yes, this is the amplifier that’s been reviewed in all the Ham magazines!

• Clear, concise assembly instructions carefully guide you to a finished

kit that works FIRST time!

PA-1 • 1

PARTIAL LIST OF AVAILABLE KITS
RAMSEY TRANSMITTER KITS

• FM10, FM25B FM Stereo Transmitters

• FM100 Super Pro FM Transmitter

• MR6 Model Rocket Tracking Transmitter

• AM1, AM25 AM Transmitters

RAMSEY RECEIVER KITS

• FR1 FM Broadcast Receiver

• AR1 Aircraft Band Receiver

• SR2 Shortwave Receiver

• HFRC 10 MHz WWV Receiver

• SC1 Shortwave Converter

RAMSEY HOBBY KITS

• SG7 Personal Speed Radar

• SS70A Speech Scrambler

•TG1 DTMF Tone Grabber

• BS1 “Bullshooter” Digital Voice Storage Unit

• AVS10 Automatic Sequential Video Switcher

• WCT20 Cable Wizard Cable Tracer

• MD3 Microwave Motion Detector

• ML Music Lights Kit

• LC1 Inductance-Capacitance Meter

RAMSEY AMATEUR RADIO KITS

• HR Series HF All Mode Receivers

• QRP Series HF CW Transmitters

• CW7 CW Keyer

• QRP Power Amplifiers

RAMSEY MINI-KITS
Many other kits are available for hobby, school, scouts and just plain FUN. New
kits are always under development. Write or call for our free Ramsey catalog.

PA1 2 METER RF POWER AMPLIFIER KIT INSTRUCTION MANUAL

Ramsey Electronics publication No. PA1 Revision 1.1

First printing: December 1994

COPYRIGHT 1994 by Ramsey Electronics, Inc. 590 Fishers Station Drive, Victor, New York

14564. All rights reserved. No portion of this publication may be copied or duplicated without the
written permission of Ramsey Electronics, Inc. Printed in the United States of America.

PA-1 • 2

Ramsey Publication No. PA1

Price $5.00

KIT ASSEMBLY

AND INSTRUCTION MANUAL FOR

2 METER RF POWER
AMPLIFIER KIT

TABLE OF CONTENTS

Kit Building Tips ............................... 5

Parts list ........................................... 5

Assembly .......................................... 6

Parts Layout Diagram ...................... 6

Schematic Diagram .......................... 7

Testing ............................................. 11

Troubleshooting ............................... 11

Transmitting-Receiving .................... 12

Customizing ..................................... 13

Installation ........................................ 13

Operating Your PA1 ......................... 13

Warranty ........................................... 15

PA-1 • 3

RAMSEY ELECTRONICS, INC.

590 Fishers Station Drive

Victor, New York 14564

Phone [phone]

Fax [phone]

www.ramseykits.com

PA1 AMPLIFIER

All of us at Ramsey say THANKS for your interest in building the world's
most popular 2 Meter amplifier project. Successful construction and
installation of your PA1 amplifier can give your handheld 2 Meter transceiver
an RF power boost beyond the performance of many fixed and mobile units.

BEFORE you begin building your PA1, we ask you to read the warranty
information on page 14 and think about a few details in advance:

The PA1 is a true "Ham Radio" kit project which presumes the expertise that
goes along with your license. You need to know how to "tack solder", wind
simple VHF coils per our directions, and how to finish your PA1 with suitable
enclosure, connectors, T-R switching and I/O wiring.

The Ramsey RFS1 RF-sensing T-R switch kit is available as an easy
companion kit for the PA1.

The Ramsey PR10 Low Noise Pre-amplifier Kit can be worked into your final
T-R installation to boost those hard-to-copy signals.

We ask you to understand that the VHF Power Transistor that is the heart
and soul of this circuit cannot be guaranteed beyond careful tests by BOTH
the manufacturer and our technicians. Because this expensive transistor can
be damaged by either incorrect soldering OR incorrect physical mounting,
there can be NO warranty on this part unless your own additional test
BEFORE ANY soldering and mounting shows a clear defect.

Use of a VHF power output wattmeter is essential to correct adjustment of
the PA1.

If you decide, before beginning any assembly of your PA1 kit, that this
project is not quite what you're ready for, you may return the complete,
unassembled PA1 kit to the Ramsey factory.

OR, if you are ready to join the thousands of hams world-wide who enjoy the
PA1 as the most economical possible HT improvement for the highly-popular
2 Meter band, we will be happy to guide you through every construction step
in the spirit of the "Learn-As-You-Build" philosophy for all Ramsey Kit
manuals for the new millenium.

PA-1 • 4

KIT BUILDING TIPS

Use a good soldering technique - let your soldering iron tip gently heat the
traces to which you are soldering, heating both wires and pads simultaneously.
Apply the solder on the iron and the pad when the pad is hot enough to melt the
solder. The finished joint should look like a drop of water on paper, somewhat
soaked in.

Electrical part installation - when parts are installed, the part is placed flat to the
board, and the leads are bent on the backside of the board to prevent the part
from falling out before soldering. The part is then soldered securely to the
board, and the remaining lead length is then clipped off.

PA1 PARTS LIST:

❒ 1 PA1 Printed circuit board
❒ 1 BLW40 or SD1272 RF Power Transistor
❒ 1 Length of pre-tinned #18 wire (for L1,L2)
❒ 1 Length of #18 enameled wire (for L3)
❒ 1 Length of #24 wire (for winding 6 hole RF choke ferrite bead)
❒ 1 6 hole RF Choke ferrite bead (black cylinder) (to be hand-wound)
❒ 2 100 pf mica compression trimmers (rectangle shaped) (C1,C3)
❒ 2 60 pf variable trimmer capacitors (round shaped) (C2,C4)
❒ 2 47 or 56 pf ceramic disc capacitors (C5,C6)
❒ 1 .01uf ceramic disc capacitor (marked .01 or 103 or 10 nf) (C7)

PA-1 • 5