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...

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 
       •...

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...

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...

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...

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...

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]...

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....