Ramsey Electronics FT146 用户手册

FT146 

• 17 

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97.  Install D4, 1N4148 style signal diode (glass body with black band). 

Observe correct orientation of the banded end. 

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98.  Install TP3, the last test point. Select a 1K resistor, R29 (brown-black-

red). Trim back one lead wire to a length of inch. Bend this wire into a small 
loop as before. Insert the resistor into the PC board and hold it carefully 
while you solder it to the board. 

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99. Install R22, 1K ohm (brown-black-red). 

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100. Install C15, 39 pf disc capacitor (marked 39 or 39K). 

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101. Install L4, 2 turn coil wound previously. Be sure it sits flush against the 

PC board. 

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102. Install C14, 56 pf disc capacitor (marked 56 or 56K). 

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103. Install L3, another 2 turn coil. Be sure it sits flush against the PC board. 

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104. Install C13, 39 pf disc capacitor (marked 39 or 39K). 

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105. Install C7, .001 uf disc capacitor (marked .001 or 1000 or 102). 

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106. Install C12, trimmer capacitor (black body with orange top). 

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107. Install L2, 1 turn coil wound previously. Ensure it sits flush. 

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108. Install L1, 6 hole ferrite bead RF choke you wound. 

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109. Install C1, .01 uf disc capacitor (marked .01 or 103 or 10 nf). 

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110. Locate Q6, SD1127 RF power transistor. This transistor mounts 

somewhat differently from all the other parts. Turn over the PC board and 
set the transistor snugly into the large hole and bend the leads over and into 
the indicated holes. The leads should be as short as possible without 
shorting against the transistor case. Solder the three transistor leads. See 
drawing in the step below. 

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111. Now we call for something unusual - soldering the transistor case to the 

PC board. Run a neat "flow" of solder around the transistor case to the PC 
board ground plane. The SD1127 
power transistor is designed by 
the manufacturer to be soldered 
directly to a PC board ground 
plane for heat sinking and proper 
VHF performance. This part is different from other metal can transistors in 
that the case is connected internally to the emitter rather than the collector. 
This provides much higher gain at VHF frequencies.