2SC1972 WIDEBANT POWER AMPLIFIER

uydudoktoru

Tanınmış Üye
Yönetici
Yönetici
There is a very good and very cheap 88-108 Mhz 14w apmlifier. You can find all the components from farnell.co.uk.



Parts List 14 Watt RF Amplifier
C24, C27 – 470 pf mica capacitor
C25 – 100 pf mica capacitor
C26 – 39 pf mica capacitor
C28 – 15 pf mica capacitor
C23, C20, C31 – .001 uf disc or monolythic capacitor, marked eitther 102, .001 or 1n
C22, C21, C32 – .1 uf disc capacitor or monolythic capacitor, marked either 104, .1 or 100n
C29 – 10 uf electrolytic (observe correct polarity)
L1 – 1 turns #18 tinned copper, 1/4 ” diameter
L2 – 1 uh inductor, blue lumpy item
L3 – 2 turns #18, 1/4″ diameter
L4 – 7/10″ # 14, hairpin
L5, L6 – 5 turns # 20, 1/4 diameter
R17 – 56 ohm resistor with ferrite bead over lead at the base end of Q1
Q1 – 2SC1971 RF transistor
Misc – RG174 coax, hookup wire, SO239 sockets (2), 4-40 nuts and bolts (4 each) ferrite
bead, banana sockets & plugs (red/black 2 ea.) and solder lugs

Assemble by soldering the components to the pads indicated. Keep coil, resistor and capacitor leads as short as
possible. The coils should be 3/16″-1/4″ above the board and separate turns by one wire diamter, bend lead to
form a little mounting foot for soldering to the circuit boar. Tuning & power output are affected by the distance
between the coil turns, you can make fine adjustments by either spreading or compressing the coil slightly.
The area surrounding the pads is ground, C25, C28,C26 & C20-C32, L2 and R17 are soldered at one end to ground
as well as the shield braid on the coax cables. Bolt Q1 to a small heat sink or the chassis with heat sink thermal
compound or gray thermal pad underneath the tab. With an input level of 2.5w you should see an ouput
of 14 watts. Be sure to have a proper dummy load (50 ohms) or tuned antenna connected to the output, doing
otherwise will likely destroy the transistor.

Solder Q1 in with lettering up.
Use a 4-40 bolt and nut to attach
Q1 to either a small heat sink or
the chassis for proper heat disperal.
Use heat sink thermal compound
underneath the tab

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Huda

Yeni Üye
Kayıtlı Üye
Merhaba Bir projede kullanak üzere 2SC1972 transistörlerine ihtiyacım var. Hiçbir yerde orijinalini bulamadım. Eskiden kalma elinde olupta bedeli mukabil yardımcı olmak isteyen olursa çok sevinirim.
 
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