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DZ HT-7 Assembly Manual Download Page 1

Page

DZKit

ASSEMBLY MANUAL

HT-7

40M AM HANDIE-TALKIE

Price: $10.00

DZ Com

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anY • L

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VELAND, COLORADO

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Summary of Contents for HT-7

Page 1: ...Page DZKit ASSEMBLY MANUAL HT 7 40M AM HANDIE TALKIE Price 10 00 DZ CompanY LOVELAND COLORADO...

Page 2: ...stance phone call on any problem you may encounter in the assembly or use of your DZKit product Just drop us a line email us give us a call or visit our website and click on Support That will give you...

Page 3: ...eserved 3 24 09 HT 7 TABLE OF CONTENTS Introduction 4 Available Accessories 5 General Assembly Safety Notes 6 Parts List 12 Step by step Assembly 14 Chassis Integration 19 Adjustments and Tests 22 Fin...

Page 4: ...enjoy the fun of those old style QSOs which were typically long winded since VOX was not used and switching over from transmit to receive took longer Now you can enjoy the fun of AM without spending...

Page 5: ...A 2 tuner HTA 1 Battery Pack Includes built in overcharge overdischarge overdrain short circuit and reversed polarity protection Weight 10 4 oz 370g Dimensions 2 6 66mm x 2 1 53mm x 1 7 43mm Must be r...

Page 6: ...g give us a call or email us and we will rush a replacement to you 4 Most electronic kits that are returned for service have poor soldering jobs Please take a moment to familiarize yourself with prope...

Page 7: ...containing pin 1 When you hold an IC with the notch pointing up or the beveled side to your left pin 1 is in the upper left corner The silkscreened outlines on the board all have notches and pin 1 als...

Page 8: ...ong will only delay that moment Before you start set up a ventilated static free work area with enough room to build the kit Prepare parts bins and get the tools you will need needle nose pliers wire...

Page 9: ...d cause damage to workbenches and carpets We recommend you use one with an auto matic shutoff in case you forget to turn it off when you are done 5 Do not work on electronic projects when you are tire...

Page 10: ...ouching the iron to both the component lead and the pad at the same time Solder bridge Solder that stretches from one trace or pad to another creates a short cir cuit Solution Hold the board upside do...

Page 11: ...ic items by touching a grounded object such as the corner of a wall In a dry environment simply standing up after sitting in a non grounded chair can also charge you with electricity If you stand up t...

Page 12: ...double throw momentary switch 1 11 T1 T36 1 1 12 T2 T3 FT37 43 2 13 J4 2 pin right angle MTA connector 1 14 U2 LM380 audio amplifier IC 1 15 Y1 Y7 7 287MHz HC49 U crystal 7 16 Screw 4 40 x 1 4 PH Phi...

Page 13: ...1 12 Screw 6 32 x 1 4 FH Phillips M S Black 4 13 Screw 6 32 x 3 8 PH Phillips M S 2 14 Nut 6 32 KEPS 5 15 Nut 6 32 hex 1 16 6 Solder lug 1 17 6 Nylon washer 2 18 Angle bracket 2 19 Knob 1 20 2 pin fe...

Page 14: ...both leads and clip excess lead length Load and solder RV2 the 10K trimpot Clip excess lead length Load and solder T1 the 6 pin DIP transformer The pin marked with a dot must go into the square pad L...

Page 15: ...Page 15 Pictorial 1 Component placement on HT 7 2 Board...

Page 16: ...sistor lies flat against the board Insert all 12 of the red magnet wire into an FT37 43 toroid core leaving 2 out side Wrap the wire nine times around the core pull ing tightly on each turn Re member...

Page 17: ...w heatsink 4 40 x 3 8 spacer Transistor ThermalsilTM insulator apply sticky side to heatsink and remove material covering the hole Pictorial 2 Q3 preparation Thermalsil is a trademark of Aavid Thermal...

Page 18: ...marked T3 1 and T3 2 and the green secondary leads go into holes marked T3 3 and T3 4 The center of the toroid should be placed directly over the center hole Prepare RF power transistor Q3 as shown i...

Page 19: ...the jack and save them Sandwich the speaker between the electret mic board and the preamp mixer board HT 7 1 using two 6 32 x 3 8 screws two 6 Nylon washers between the speaker and the HT 7 1 board o...

Page 20: ...wire that is attached to the crystal to the braid then cut the bare wire near the point where it attaches to the crystal Slide the tubing over the braid and ap ply heat until it shrinks over the conne...

Page 21: ...into the connector on top of the unit using a 5 5mm plug center pin positive One such connector with a lock ring is provided in the kit Set the voltage to 11 1VDC If you have a current limit control s...

Page 22: ...r is set for exactly 7 290MHz Board Transmit Receive Measurement point Voltage DCV HT 7 2 R T D3 cathode 11 1 HT 7 2 R T Q1 base 3 1 HT 7 2 R T Q1 emitter 2 4 HT 7 2 R T Q1 collector 6 8 HT 7 2 R T U3...

Page 23: ...the four connectors pointed up Insert the speaker as far as it will go into the opening in the HT 7 2 board with the termi nals facing to the right and the speaker cone facing you Insert the HT 7 2 b...

Page 24: ...pliers and make very slight turns until the nuts are tight Attach two 6 32 angle brack ets to the top using two 6 32 KEPS nuts Align the side with the non threaded opening with the mounting studs Ex...

Page 25: ...he lockwashers on the BNC con nector and the washer on the volume control pot are on the inside of the chassis Attach the knob to the volume control shaft aligning the white line on the knob with the...

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Page 27: ...inexpensive Lithium Ion charger or you can charge it inside the HT 7 by con necting a power supply set to 12V with a current limit of 4A to the power jack on the top of the HT 7 Internal protection ci...

Page 28: ...er U2 which mixes the audio with RF from the 7 290MHz local oscilla tor consisting of Q1 Y1 and re lated parts The balance is upset by pot RV1 which allows the car rier to pass through the mixer along...

Page 29: ...the 4 7 ohm emitter re sistance RFC1 and C33 assure that the top side of T2 is at AC ground T2 has a 9 3 turns ratio which causes an impedance step down to the next stage The 2SC2166 final amplifier h...

Page 30: ...ss A amplifier of 50 The output low pass filter is a 7 element Elliptical filter with a cutoff frequency of 8MHz This frequency was chosen to get as close to 7 29MHz as possible so as to eliminate har...

Page 31: ...known as input offset voltage a property of real op amps The inverting input is of ten called the summing junction as the sum of the currents in that node will be zero Since virtually no current flows...

Page 32: ...from a single supply Again any nonlinear voltages developed across the diodes are not rele vant The two rectified half waves are combined in the next two op amp stages The two out puts of the rectifi...

Page 33: ...ed gain state Its value is high so as not to affect the gain when the diodes are conducting Recall that an AM signal contains the carrier as well as the audio information Demodulation pro duces a sign...

Page 34: ...requency 7 290MHz Amplitude modulation Bandwidth 6kHz Output Power approx 2 Watts Transmitter Spurious Output 45dB Transmitter IMD 20dB Receive Sensitivity 1uV Power requirements 10 12VDC 50mA receive...

Page 35: ...Page 35 SCHEMATICS...

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Page 39: ...pin Reversed electro lytic capacitors can draw exces sive current and they can even smoke Verify all voltages using the chart on page 22 A review of the theory of opera tion may also help you determin...

Page 40: ...Page 40 COMPONENT LOCATOR...

Page 41: ...Page 41 NOTES Use this page to keep track of modifications purchase information service or anything you like...

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Page 44: ...Page 44 DZ COMPANY UNIQUE electronic equipment in kit form LOVELAND COLORADO...

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