2003 Sep 19
17
Philips Semiconductors
Product Specification
VHF push-pull power MOS transistor
BLF278
Notes
1. American Technical Ceramics capacitor, type 100B or other capacitor of the same quality.
2. L1, L3 to L13, L18 to L22 and L24 are microstriplines on a double copper-clad printed-circuit board, with fibre-glass
reinforced PTFE dielectric (
ε
r
= 2.2), thickness
1
⁄
16
inch; thickness of copper sheet 2
×
35
µ
m.
3. L2 and L23 are soldered on to striplines L1 and L24 respectively.
L14, L17
2
×
grade 3B Ferroxcube
wideband HF chokes in parallel
4312 020 36642
L15, L16
1
3
⁄
4
turns enamelled 2 mm copper
wire
40 nH
int. dia. 10 mm
leads 2
×
7 mm
space 1 mm
L18, L19
stripline; note 2
43
Ω
length 13 mm
width 6 mm
L20, L21
stripline; note 2
43
Ω
length 29.5 mm
width 6 mm
R1
metal film resistor
10
Ω
, 0.4 W
R2, R7
10 turns potentiometer
50 k
Ω
R3, R6
metal film resistor
1 k
Ω
, 0.4 W
R4, R5
metal film resistor
2
×
5.62
Ω,
in
parallel, 0.4 W
R8, R9
metal film resistor
10
Ω ±
5%, 1 W
R10
metal film resistor
4
×
42.2
Ω
in
parallel, 1 W
R11
metal film resistor
5.11 k
Ω,
1 W
IC1
voltage regulator 78L05
COMPONENT
DESCRIPTION
VALUE
DIMENSIONS
CATALOGUE NO.