Ramsey Electronics Ramsey 220 MHZ FM RECEIVER KIT Owners Manual

							FR-220 • 1 
220 MHZ FM   
      RECEIVER KIT 
Ramsey Electronics Model No.               FR220 
Keep an ear  on the local repeater action from your easy chair 
with this simple and fun to build FM receiver. Tunes the entire 
220 MHz band. Ideal way to audition before buying a rig! 
•Tunes any 5 MHz portion of the 220 to 240 MHz band. 
•Excellent receiver for new Novice classes! 
•Excellent performance, less than 1 uV sensitivity. 
•Tuned input, low noise preamp stage. 
•True Dual-conversion superhet design with 2 pole 
Ceramic High IF and 6 pole Ceramic low IF filters! 
•Front Panel Volume, Squelch, and Tuning controls. 
•Excellent receiver for beginners and seasoned pros! 
•Informative manual answers questions on theory, hook-
ups, and uses - enhances resale value, too! 
•Add our case set for a finished ‘Pro’ look. Cases match 
all Ramsey products. 
•Clear, concise assembly instruction carefully guides 
you to a finished kit that works the FIRST time! 
  
						

							FR-220 • 2 
 
 
 
 
PARTIAL LIST OF AVAILABLE KITS
 
 
RAMSEY TRANSMITTER KITS
 
       • FM10A FM Stereo Transmitter 
       • FM25B Synthesized FM Stereo Transmitter 
       • AM25 Synthesized AM Transmitter 
       • AM1 AM Transmitter 
         
 
RAMSEY RECEIVER KITS
 
       • FR1 FM Broadcast Receiver 
       • AR1 Aircraft Band Receiver 
       • AA7 Acti ve Antenna 
       • SC1 Shortwave Converter 
 
RAMSEY HOBBY KITS
 
       • SG7 Personal Speed Radar 
       • SS70 Speech Scrambler 
       • TT1 Telephone Recorder 
       • SP1 Speakerphone 
       • MD3 Microwave Motion Detector 
       • TFM3 Tri-Field Meter 
       • LC1 Inductance-Capacitance Meter 
 
RAMSEY AMATEUR RADIO KITS
 
       • HR Series HF All Mode Receivers 
       • QRP Series HF CW Transmitters 
       • CW7 CW Keyer 
       • CPO3 Code Practice Oscillator 
       • 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.   
   
FR220 FM RECEIVER KIT INSTRUCTION MANUAL
 
Ramsey Electronics publication NO. MFR220 Rev. E1 
First printing: February 1992
  
COPYRIGHT  1992 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.
  
						

							FR-220 • 3 
FR220  FM RECEIVER 
KIT 
Ramsey Publication No. MFR220 
Price $5.00 
TABLE OF CONTENTS 
 
I
ntroduction to the FR220 ..............  4 
Circuit Description .........................  5 
Parts List ........................................  6 
Simplified Block Diagram ..............  8 
Parts Layout Diagram ....................  9 
FR220 Assembly Instructions ........  11 
Testing and Alignment ...................  21 
Enclosure Ideas .............................  24 
Troubleshooting Guide ..................  24 
Notes for Advanced Users ............  25 
Ramsey Kit W arranty .....................  27 
KIT ASSEMBLY 
 AND INSTRUCTION MANUAL FOR 
RAMSEY ELECTRONICS, INC. 
590 Fishers Station Drive 
Victor, New York 14564 
Phone (585) 924-4560 
Fax (585) 924-4555  
						

							FR-220 • 4 
INTRODUCTION 
Because all but the most expensive scanners skip over the 220 MHz 
band, and most Ham rigs are 144 or 440 MHz, 220 is the long 
forgotten child. This nifty little receiver will allow you to check out 220 
at a very affordable price! When you see how uncrowded the band is, 
and its excellent VHF propagation characteristics, were sure youll 
order our 220 MHz transceiver and join in. 
 
This receiver is a good project for amateurs wishing to become more 
familiar with 220 Mhz FM before choosing a transceiver, or for those 
active on 220 who want an inexpensive receiver to take on trips, keep 
in a briefcase or to watch for band openings. 
 
Most Ramsey Electronics can be classified as Skill Level 1 if we use 
the old Heathkit¦ guidelines for ease of assembly. That means that our 
kits are intended to be successful for first-time kit builders. This 
FR220 FM Receiver is best regarded as a Skill Level 2 project, and 
should not be taken lightly, even by experienced, licensed radio 
amateurs. 
 
Still, this step-by-step manual is written with the beginner in mind, 
because we are well aware of the fascination with 220 MHz and its 
maze of repeaters holds for newcomers, which means this could be 
your very first kit project. The same holds true for those who just want 
to peek in on LOW VHF public service communications without the 
cost of a scanner. To be honest, wed like to see first-time builders 
start out with an easier kit such as the Ramsey HR-40 Forty Meter 
receiver before assembling the FR220, but we are confident that you 
can construct the FR220 successfully if you follow this manual 
carefully and patiently. 
 
Before beginning the project or even studying the circuit description, it 
is  worthwhile to develop some prior respect for how much receiver is 
packed onto the circuit board. The nine semiconductor devices 
(diodes, transistors and IC chips) give the equivalent of about 30 or 
more transistors and diodes. And, in addition to four inductors, a 
crystal and two ceramic filters, there are nearly 60 capacitors and 
resistors. Surely, all that should result in a decent receiver! You could 
easily spend twice the money plus hours of time trying to gather the 
equivalent parts from catalogs and still need to make your own circuit 
board.     
						

							FR-220 • 5 
BUILDING YOUR FR220 KIT   
 
There are just over 200 solder connections on the FR220 printed circuit  
board. That means your work could be 99% excellent and you could 
STILL have 2 or 3 cold solder points or solder bridges. Since this circuit 
is more sophisticated than a direct-conversion HF receiver or a simple 
transmitter, a beginner or casual amateur could have a harder time 
tracing a problem due to a poor solder connection. Therefore, PLEASE 
take us seriously when we say that good soldering is essential to the 
proper operation of your receiver!  
 
ˆUse a 25-watt soldering pencil with a clean, sharp tip. 
ˆUse only rosin-core solder intended for electronics use.   
ˆUse bright lighting. A magnifying lamp or bench-style magnifier may 
be helpful.     
ˆDo your work in stages, taking breaks to check your work.   
ˆCarefully brush away wire cuttings so they dont lodge between 
solder connections. 
           
 
FR220 CIRCUIT DESCRIPTION   
 
VHF signals from the antenna are amplified through the tuned input 
circuit (L1,C3 and L2,C4) by Q1, a microwave bipolar transistor. Q1s 
output is fed to the input of the SA602 IC, an efficient single-package (8-
pin DIP) mixer-product detector-oscillator. The tunable oscillator section 
of the SA602 is aligned to operate at 10.7 MHz higher than the signal fed 
and amplified by Q1. For example, to receive 222-227 MHz signals, the 
oscillator must tune 232.7 to 237.7 MHz in order for the SA602s mixing 
capability to produce a steady 10.7 MHz output signal to the rest of the 
circuit. The oscillator frequency is determined by L3 and its associated 
capacitors, and varied by the varactor tuning network using D1 and 
varied by R1. 
 
The output from pin 4 of the SA602 passes through a ceramic 10.7 MHz 
filter, amplified by transistor Q2 and applied to input  pin 18 of U2. Q3 
provides AFC (automatic frequency control) by keeping the local 
oscillator of U1 from drifting away from an incoming signal. This is 
accomplished by tuning the varactor circuit in the direction opposite the 
drift. 
  
						

							FR-220 • 6 
The MC3359 IC has an internal oscillator controlled by the 10.245 MHz 
crystal. The 10.245 MHz signal is mixed with the 10.7 MHz input from U1 
to convert down to the low IF of 455 KHz. The 455 KHz IF is filtered by 
FL2 and then amplified by a limiting amplifier in U2. Audio demodulation 
takes place in the quadrature detector, with L4 adjusting the detector. 
 
The audio modulation is detected in U2, and the background noise is 
used to control the squelch. U3 amplifies the audio output from pin 10 of 
U2 to a practical level for speaker or headphone operation. Pin 16 of U2 
will ground the input of U3 when the squelch is closed. 
 
L4, a 455 KHz IF coil, permits adjustment of the 90-degree voltage-
current phasing (quadrature) of FL2s output to the FM detector 
demodulator (pin 8 of the MC3359). 
 
PARTS LIST   
 
Inductors  
❒2     small 4 turn coils (L1,L2) 
❒1     slug-tuned 3È turn coil (L3) 
❒1     shielded transformer coil marked LB 53303 HK (L4) 
 
Semiconductors and ICs
 
 
❒1     2SC2570A or 2SC2498 transistor (Q1) 
❒3     2N3904 transistor (Q2,Q3,Q4) 
❒1     SA602 8-pin IC (U1) 
❒1     MC3359 18-pin FM receiver IC (U2) 
❒1     LM386 8-pin audio amplifier IC (U3) 
❒1     Varactor diode, BB405 [small black body with white band] (D1) 
❒1     1N914/1N4148 signal diode (D2) 
 
Special Components
 
❒1     10.245 MHz Crystal (Y1) 
❒1     10.7 MHz ceramic filter [brown, molded, 3 leads] (FL1) 
❒1     455 KHz ceramic filter [black, square] (FL2) 
  
						

							FR-220 • 7 
Fixed Resistors  
❒1     2 ohm [red-black-gold] (R22) 
❒3     270 ohm [red-purple-brown] (R6,9,20) 
❒1     470 ohm [yellow-purple-brown] (R5) 
❒2     1K ohm [brown-black-red] (R11,12) 
❒3     10K ohm [brown-black-orange] (R7,17,19) 
❒1     18K ohm [brown-gray-orange] (R18) 
❒1     33K ohm [orange-orange-orange] (R14) 
❒4     47K ohm [yellow-purple-orange] (R4,8,13,21) 
❒1     100K ohm [brown-black-yellow] (R16) 
❒1     470K ohm [yellow-purple-yellow] (R15) 
❒1     1 megohm [brown-black-green] (R10) 
 
Capacitors 
 
❒1     2 or 2.2 pf (C2,12) 
❒4     4.7 or 5 pf (C1,5,9,10) 
❒2     10 pf (C3,4) 
❒1     22 pf (C19) 
❒1     27 pf (C11) 
❒2     100 pf [marked 100 or 101] (C6,22) 
❒1     220 pf [marked 220 or 221] (C18) 
❒6     .001 uf [marked .001 or 102 or 1nf] (C7,8,20,23,24,25) 
❒8     .01 uf [marked .01 or 103 or 10nf] (C13,16,17,21,26,28,29,31) 
❒1     .1 uf [marked .1 or 104] (C34) 
❒1     1.0 uf electrolytic (C27) 
❒3     4.7 or 10 uf electrolytic (C15,30,36) 
❒4     100 to 220 uf electrolytic (C14,32,33,35) 
 
Controls and Hardware  
 
❒1     Printed circuit board 
❒3     10K ohm potentiometer (R1,R2,R3) 
❒1     DPDT push switch (S1) 
❒1     PC mount RCA jack (J1) 
❒1     PC mount subminiature speaker jack (J2) 
❒1     9-volt battery bracket (B1) 
❒1     9-volt battery snap-on clip 
 
REQUIRED, NOT SUPPLIED 
 
❒1     9-volt alkaline battery 
❒1     VHF antenna with cable terminated in RCA-style plug or adapter 
❒1     Speaker or headphones     
  
						

							FR-220 • 8 
U2, 3359 
FR220 BLOCK DIAGRAM 
U1 
SA602 
MIXER  
						

							FR-220 • 9 
FR220 PARTS LAYOUT DIAGRAM  
						

							FR-220 • 10 
NOTE CONCERNING THE AUDIO OUTPUT JACK 
 
Your receiver kit is supplied with a standard subminiature 2.5 mm 
(3/32”) audio jack, which mates with commonly available earphone 
plugs and adapters available at Radio Shack, such as 274-290 (plug) or 
274-327 (adapter for 1/8” mono plug). If you prefer to use another size 
and style jack, we suggest that you still install the original jack and then 
wire your own jack in parallel with it rather than rough up the PC board 
to accommodate your jack. 
 
 
 
SEMICONDUCTOR REPLACEMENT DATA 
 
U1 SA602                                Contact Ramsey Factory 
U2 MC3359 (Motorola)            ECG860 or SK7731 
U3 LM386 (National)                available at Radio Shack, other suppliers 
Q1 2SC2498 or 2570               ECG10 or SK9139 
Q2,3 2N3904                            available at Radio Shack, other suppliers 
D1 BB405                                contact Ramsey Factory 
D2 1N4148                               available at Radio Shack, other suppliers