The heart of this stage is an RF transistor (the BLY90) which, together with the classical passive components in such systems, performs the function of amplifying the radio signal present at its base to deliver to its collector.

The power supply is 14V, with a current of 7 to 8A. It is almost impossible at this stage parasitic oscillations occur. Second harmonic suppression is better than 45dB.

L1 3 Turns on air 7mm
L2 Shock of RF 0.22μH
L3 15 turns 0.5mm wire on a 47K resistor ½ W
L4 3 Turns on air 5mm
L5 Arch 25mm high by 15mm wide. 0.5mm to 5mm wire
L6 Shock RF
L7 3 Turns on air 7mm
L8 4 Turns on 8mm air

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The 100 watt linear amplifier operating from a 28 volt supply, 8 dB of power gain is achieved along with excellent practical performance featuring: maximum input SWR of 2:1, harmonic suppression more than-63 dB below 100 watts output, efficiency greater than 40%, circuit stability with a 3:1 collector mismatch at all phase angles.

100 watt linear amplifier Parts list :
Ti & T2 - Balun. Unbalanced to Balanced RG 58, I = 2.5"
R1 : 1 k, 1/2 W
R2 : 10 ohm 1/2 W
R3 : 10 ohm 1/2W
R4 : 5.6 ohm 1 W
R5 : 5.6 ohm 1 W
R6 :  2.7 ohm 1/4 W
Z1 & Z3 : Microstrip - W = 200 mils, I = 1 8"
Z2 & 24 : Microstrip - W = 200 mils, I = 300 mils
Z5 & 26 : Microstrip - W = 150 mlls, I = 300 mils
Z6 & Z8 : Microstrip - W = 150 mils, I = 1.4"
RFC 1,4 : Ferroxcube Bead 56 590-65-38
RFC 2,3 : 0,16 uH Cambion Molded Coil
RFC5, 6 - 1 Turn #20 Enameled Wire Wound on 5/16" Bolt
RFC7, 8 : VK200 20/48
C1,3,4,5,7,8,11,15 : Underwood 40 pF
C12,16 : Underwood 25 pF
C13, 14, 22, 23 : Underwood 18 pF
C9, 10, 18,20 : I uF Tantalum
C21, 24 : Underwood 10 pF
C2, 6 : Arco 403
C17.. 19 : Underwood J102. 1000 PF Feed Thru
C25, 26 : 0,1 uF, Erus  Red Cap
L1 : 24 nH, #14 Wire, I = 1.2"
L2 : 12 nH, #14 Wire, I= 0.6"
L3 : 24 nH, #14 Wire, I = 1 2"
Board : G10, cR : 5. t=0.062" , I = 8.0", W = 4.0"
Q1 : 2N5192
Q2 : 2N5194
Q3 : MRF309
Q4 :  MRF309
D1 : 1N4001

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The transition from reception to transmission by VOX-switch, made by transistors VT2/VT3 (KT315). Kodensator Cl – 0,5-2,2 pF, establishes a reliable operation of the relay Kl.

Inductors L6 – L8 made wire of 0.4 mm, L6/L7 -6 turns, L8 – 100 turns. High-frequency coil wound around a silver-plated wire of 0.8 mm: Ll – 2 turns, the frame – 8 mm, the winding length of 11 mm; L2/L3 – 4 turns, the frame – 6.8 mm, the winding length of 10 mm; L4/L5 – 5 turns, the frame – 5.2 mm, the winding length of 12 mm.
Output impedance 75 ohms cascade. Capacitor C4 provides from 33 to 180 pF.

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