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VEC-1002K Owner's Manual 

2 Meter FM Receiver Kit 

23 

The VEC-1002K requires an external antenna.  For local reception, a 19" length 
of wire may work reasonably well.  However, for longer-range reception, a low-
cost 2-meter ground-plane or VHF scanner antenna mounted outdoors and fed 
with coaxial cable provides much better performance.  You may purchase one 
from Tech America, Radio Shack, MFJ Enterprises Inc., and many other 
sources.  Alternatively, you may make your own "side-mount" vertical dipole 
using the following diagram: 

TV Mast

1-1/2" PVC Pipe

12"

Mast Clamp

38"

6-7 Turns RG-58

Brass Welding Rod 

 

Periodically Check Battery Condition: 

Operating your radio with a weak battery may lead to unstable tuning (signals 
drifting off channel rapidly), weak or distorted audio, and motor boating (a low-
frequency oscillation or "putt-putt-putt" noise in your speaker or headphones).  
Your radio needs a minimum of 7-8 volts in order to work properly. 

 

IN CASE OF DIFFICULTY 

The VEC-1002K design has been thoroughly field tested, and is known to be 
both reliable and "forgiving" of construction errors.  If you have difficulty with 
your unit, the cause may be something as simple as a broken cable or a dead 
battery.  In most cases, you will be able to find the cause with some organized 
troubleshooting.  Begin your search with this checklist of symptoms and cures: 

Summary of Contents for VEC-1002K

Page 1: ...ific part is no longer available or if Engineering has determined that an alternative component is more suitable Vectronics reserves the right to make substitutions at any time In most cases these cha...

Page 2: ...it well and include the minimum payment plus shipping and handling charges 25 00 total No work can be performed without pre payment Also provide a valid UPS return address and a day time phone number...

Page 3: ...ed while hitting the books Best of all once the license arrives you ll conquer mike fright easily because you ll know exactly what to say When it comes to pulling in weak signals the VEC 1002K rivals...

Page 4: ...e off air signals BEFORE YOU START BUILDING Experience shows there are four common mistakes builders make Avoid these and your kit will probably work on the first try Here s what they are 1 Installing...

Page 5: ...tip to promote rapid melting Desoldering Tips If you make a mistake and need to remove a part follow these instructions carefully First grasp the component with a pair or hemostats or needle nose pli...

Page 6: ...nce similar to resistors in both shape and band marking However a closer look will enable you to differentiate between the two chokes are generally larger in diameter and fatter at the ends than resis...

Page 7: ...ic transistors and voltage regulators use a case backed with a prominent metal tab to dissipate heat T 220 Here orientation is indicated by the positioning of the cooling tab Emitter Flat Side Metal T...

Page 8: ...R11 R14 2 4 7K yellow violet red R7 R17 2 10K brown black orange R5 R18 2 39K orange white orange R12 R15 1 47K yellow violet orange R8 4 100K brown black yellow R1 R9 R13 R19 2 10K potentiometer R6 R...

Page 9: ...For L1 L2 L3 1 074 uH slug tuned shielded red L4 1 660 uH adjustable shielded black L5 1 10 245 crystal Y1 1 10 7 MHz ceramic filter SFE10 7J FL1 1 455 KHz ceramic filter 55D or 55F FL2 Switches Jacks...

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Page 11: ...holes for integrated circuit U2 are toward the rear Find the 8 pin IC socket and if necessary straighten any bent pins 2 Position the 8 pin socket at U2 with its notch or key toward the left hand sid...

Page 12: ...Find four 4 100K resistors brown black yellow Install one at R1 and solder 14 Install a 100K resistor brown black yellow at R9 and solder 15 Install a 100K resistor brown black yellow at R13 and solde...

Page 13: ...C24 18 Install and solder a 1 uF at C26 19 Install and solder a 1 uF at C29 Phase 4 Multilayer Capacitors There are 9 multilayer capacitors provided with your kit Important Note A multilayer capacitor...

Page 14: ...ue Phase 5 Electrolytic Capacitors The last six 6 capacitors in the kit are electrolytic capacitors Electrolytic caps are polarized and must be installed the correct way in order to work Each capacito...

Page 15: ...ads of Q1 into the three mounting holes provided Make sure that the transistor body is properly keyed to the silk screened outline if you insert the transistor incorrectly it may be damaged when power...

Page 16: ...filter FL2 55D or 55F This is a small black cube with three pins and it will only fit one way on the PC board Install and solder 3 Find the 3 5 mm stereo mini headphone jack Install at J2 making sure...

Page 17: ...pes made from the 24 wire supplied with your kit In addition to the 24 wire you ll also need a 6 32 screw at least 1 2 long to use as a winding form longer is better 3 Carefully straighten the coil wi...

Page 18: ...ing wire wind a 10 turn coil for L3 Unlike L1 and L2 the turns of L3 should be compressed closely so the overall coil is about 3 in length about the distance between its mounting holes Install and sol...

Page 19: ...ind inadvertent assembly errors that might prevent the radio from working or cause damage to sensitive parts Follow this procedure Compare parts locations against the parts placement diagram Was each...

Page 20: ...ds are you ve overlooked something minor that s easy to correct Take a break come back fresh and carefully repeat the QC inspection If no undiscovered errors turn up during your second inspection proc...

Page 21: ...the red voltmeter lead to pin 17 Using a small screwdriver adjust L5 for a reading of 2 3 volts No further adjustment will be required Final Alignment Oscillator Coil L4 Your kit should be mounted in...

Page 22: ...CH counter clockwise open 2 Power the radio and set VOLUME for a comfortable level 3 Key the HT s transmit switch Slowly tune the slug in L4 until the HT signal is heard 4 Confirm the signal you hear...

Page 23: ...al is heard on the scanner at 135 3 MHz OPTION 6 Calibrating with an off air signal If no other option is available you may calibrate L3 using the signal generated by a local repeater To do this you m...

Page 24: ...tion indicates an improvement in signal strength As you find the best point for each coil stretch or compress it permanently into that position Don t attempt to adjust L1 and L2 while tuned to a stron...

Page 25: ...s RG 58 Brass Welding Rod Periodically Check Battery Condition Operating your radio with a weak battery may lead to unstable tuning signals drifting off channel rapidly weak or distorted audio and mot...

Page 26: ...ken sensitivity will be poor If these checks fail to uncover the problem repeat the QC check one more time Service records show that for most malfunctioning kits outright component failure is relative...

Page 27: ...of the radio If you have technical skills and can read a schematic diagram this will help you For example if you get an unreasonable reading on pin 23 of U1 the schematic shows that the radio s voltag...

Page 28: ...tablishes the radio s message channel bandwidth prior to 100 dB of signal amplification and limiting in the 2nd IF Signals are demodulated by quadrature detection and recovered audio signals are pream...

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Page 30: ...wo holes centered on each edge of the enclosure Refer to the diagram on the next page for location and orientation 3 Install the two 1 2 mounting screws next Insert the screws from the bottom through...

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