VHF Linear Amplifier
BLY 89C


There is not a personal design on this page, just I've transfered useful notes from
PHILIPS RF Bipolar Transistors - Data HandBook (1993 Edition),
about BLY89C VHF Power transistor, which is very popular among Amateur Radio "homebrewers".
This components is a NPN silicon planar epitaxial transistor intended for use in Class A, B & C operated mobile, industrial and military transmitters with a nomimal supply of 13.8 Volts.
The transistor is resistance stabilized and is quaranteed to withstand severe load mismatch conditions with a supply over-voltage to 16,5 V. It has a 3/8" capstan envelope with a ceramic cap. All leads are isolated from the stub.

RF performance up to 25C in an unneutralized commom emmiter class-B circuit.

Mode VCC F(MHZ) PL (w) Gp (DB) h (%) zi Ohm YL (mS) CW 13,5 V 175 25 >6 >70% 1,6+j1,4 210+j5,5

APPLICATION

The above Figure is a typical application for a VHF Linear Amplifier on Class-B for FM or CW operation, designed for the 175 MHZ, but working also perfect on the 2m. amateur band giving an output power of 25 Watts/13,8 V with a driving power of 6-7 Watts. (> 6 Db Gain)

	The circuit and the components are situated on one side of the epoxy fibre-glass board, the other side being fully metallized to serve as earth. Earth connections are made by means of hollow rivets, whilst under the emmiter leads Cu straps are used for a direct contact between upper - lower sheets.
	Upper side of PCB (Double-side Epoxy, lower side all grounded ) 150 x 72 mm The picture is fully processed with Adobe Photoshop for best contrast and its ready for use, after a printout. Don't forget to "set" the output dimensions: 150 x 72 mm ("black area").

Part List

C1	2-20 pF film dielectric trimmer (cat. no. 2222 809 07004)
C2, C8	4-40 pF trimmer, film dielectric (cat. no. 2222 809 07008)
C3a, C3b	47 pF/ 500V ceramic
C4	120pF ceramic
C5	100 nF polyester capacitor
C6a, C6b	8,2 pF / 500V ceramic
C7	5-60 pF, film dielectric trimmer (cat. no. 2222 809 07011)
L1	1 turn enamelled Cu wire 1,6mm; int. diam= 9mm; leads 2x5mm
L2	100 nH; 7 trns close winding; 0,5 mm wire; D=3mm; leads 2x 5mm
L3, L8	VK 200 chock coil
L4, L5	strip (12 x 6 mm)
L6	2 turns enam. wire 1,6mm; D=5 mm; L= 6mm; leads= 2 x 5mm
L7	simillar L6, except D = 4,5mm
L4 & L5	"strips" on PCB, 1/16" thickness
R1	10 Ohms (10%) 0,5 W - Carbon resistor
R2	4,7 Ohms (5%) 0,5 W - Carbon resistor

Makis SV1BSX
Literature: PHILIPS RF Bipolar Transistors - Data HandBook SC08a

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