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AM1 

 12

  

antenna) is extremely sensitive and a good indicator of what stations will be 
received in your area. 
 
Once your have determined what your operating frequency will be, refer to 
the following chart for the correct values of C9, C10 , and C16. 

ˆ

Install the correct values for C9, C10, and C16. 

 
CONGRATULATIONS 
 

You have just completed your AM1 wireless broadcast unit.  Take a well 
deserved break now. Give your eyes a rest. When you return, be sure to 
check over your work on the entire circuit board.  Energizing the circuit board 
with solder “bridges” or misplaced components can damage your kit. 

 
ANTENNA CONSIDERATIONS 
 

For many applications, a 5 - 6 foot wire antenna connected to the center pin 
of the “RF OUT” connector will produce satisfactory results. 
Another simple but effective hint is to connect the chassis “ground” to a good 
earth ground (like a cold water pipe, etc.). Be sure, however, that the total 
length of the antenna, feedline, and grounding wire is less than 10 feet as 
required by the FCC Part 15 rules.  

Transmitter 

Frequency (KHz) 

C9 (pF) 

C10 (pF) 

C16 (pF) 

 

520 - 660 

1000  

(marked .001 or 102) 

2000/2200 

(marked .002/.0022) 

2000/2200 

(marked .002/.0022) 

550 - 720 

2000/2200 

(marked .002/.0022) 

2000/2200 

(marked .002/.0022) 

Not used 

700 - 870  

1000 

(marked .001 or 102) 

2000/2200 

(marked .002/.0022) 

Not used 

800 - 1000 

470 

(marked 470) 

2000/2200 

(marked .002/.0022) 

Not used 

1000 -  1250 

470 

(marked 470) 

1000 

(marked .001 or 102) 

Not used 

1250 - 1600 

220 

(marked 220) 

1000 

(marked .001 or 102) 

Not used 

1500 - 1750 

220 

(marked 220) 

470 

(marked 470) 

not used 

Summary of Contents for AM1

Page 1: ...owerful enough for high school college or neighborhood radio station in use the world over Easily tunes to any clear channel on the AM broadcast band from 530 to 1750 KHz Operates on the same principl...

Page 2: ...MATEUR RADIO KITS FX 146 VHF Transceiver 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...

Page 3: ...am 6 Parts Layout Diagram 7 Parts List 8 Assembly Instructions 9 Antenna Considerations 13 Alignment Procedures 14 Experimental Broadcasting 14 Troubleshooting 15 FCC Information 16 Antenna Experiment...

Page 4: ...d for auditoriums churches or other events Short range experimentation We think that you will be very pleased with the transmitting range audio quality and frequency stability of this build it yoursel...

Page 5: ...d L3 Notice also that the audio information is applied at the power amplifier stage This is referred to as high level modulation and is commonly used for high power AM broadcast stations The distinct...

Page 6: ...AM1 6 PARTS LAYOUT DIAGRAM...

Page 7: ...9 10 16 4 002 or 0022 F disc capacitor marked 002 0022 or 2000 2200 C13 14 see text C9 10 16 7 01 F disc capacitor marked 01 or 103 or 10nF C3 5 6 7 8 11 12 3 10 F electrolytic capacitors C1 2 4 1 220...

Page 8: ...ou Build Kit building philosophy This entails describing the circuit that you are building instead of just blindly installing components We hope that this will not only make assembly of our kits easie...

Page 9: ...ix connections 2 Install RCA phono jacks J1 and J2 These connectors will snap into place before soldering Don t be afraid to completely solder all three ground connections as these will also limit the...

Page 10: ...solder connections Resolder any connections that are less than perfect We ll get back to building now starting at the audio input and working through the audio circuitry 15 Install trimmer potentiomet...

Page 11: ...eed to make some decisions on how we are going to use our AM transmitter Follow the following final assembly instructions carefully AM1 Final Assembly Instructions If you wish to use a microphone as t...

Page 12: ...re antenna connected to the center pin of the RF OUT connector will produce satisfactory results Another simple but effective hint is to connect the chassis ground to a good earth ground like a cold w...

Page 13: ...r testing if you ve configured the AM1 for line level is the line level outputs of a tape deck or CD player Most stereo systems have a variety of output jacks of which one or more are line level Conne...

Page 14: ...sembly steps going backwards from the last steps to the the first Bright lighting and a magnifying aid can be helpful in identifying soldering problems Use a methodical logical troubleshooting techniq...

Page 15: ...it is your responsibility to study the FCC regulations It is best if you personally read the rules and consult with a lawyer if you re in doubt and not bother understaffed and busy FCC employees with...

Page 16: ...on behalf of a school scout or community group ANTENNA EXPERIMENTING Since one wavelength at AM broadcast frequencies is over 950 feet and the distance of only ten feet is allowed between the transmi...

Page 17: ...ks best for you CONCLUSION We sincerely hope that you have enjoyed the construction and use of this Ramsey Kit As always we have tried to compose our manual in the easiest most user friendly format th...

Page 18: ...be assured that the 1K ohm resistors are actually the missing 10 K parts Hum m m I guess the red band really does look orange Ramsey Electronics project kits are packed with pride in the USA If you be...

Page 19: ...8 Holder for PC Board Parts RS64 2094 Desoldering Braid RS 2090 TOTAL SOLDER POINTS 99 ESTIMATED ASSEMBLY TIME Beginner 3 hrs Intermediate 1 5 hrs Advanced 1 hr RAMSEY ELECTRONICS INC 793 Canning Park...

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