background image

VEC-1002K Owner's Manual 

2 Meter FM Receiver Kit 

22 

If coils L1 and L2 were formed and installed according to instructions, your 
radio should operate with near-maximum sensitivity and require no further 
adjustment.  However, if you wish, you may "tweak" these two coils to optimize 
performance on weak distant stations.  In order to make this adjustment, you'll 
need a weak signal source.  This could be a 1 uV 146.0 MHz signal produced by 
a signal generator, or a weak off-air signal with audible background noise 
present.  To adjust, use the blade of a non-metallic tuning wand or your 
fingernail to expand or compress the spacing between turns.  Note that adjusting 
L1 and L2 may change the radio's operating frequency slightly.  To compensate 
for this interaction, readjust 

TUNE 

as you make each change to ensure the signal 

remains tuned in. 

Reduced background hiss and lower distortion 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 strong local signal.  

Use only a weak signal with clearly-audible 

background hiss.  Note that L3 is non-critical, and requires no adjustment.  
When peaked, the VEC-1002K should render "solid copy" on FM signals of 1-
uV or less. 

 

OPERATING INSTRUCTIONS 

Power

Tune

Squelch

Volume

145

146

147

VEC-1002K

1

2

3

4

 

1. 

POWER:

  Push-on/push-off switch turns unit on and off.  The VEC-1002K 

runs on internal battery power and shouldn't be left 

ON

 for extended period 

when not in use. 

2. 

TUNE:

 Electrically tunes receiver oscillator, setting frequency where signals 

are received.  Tuning range may vary slightly from unit to unit, but should be 
approximately 145.1 to 147.6 MHz (the frequencies where most repeater and 
"simplex" FM activity take place). 

3. 

SQUELCH:

  Adjusts threshold-point for cutting off receiver background 

noise. 

4. 

VOLUME:

   Adjust audio amplifier gain to a comfortable listening level. 

Antennas: 

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...

Page 10: ......

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...

Page 29: ......

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...

Page 31: ......

Reviews: