|
Up
| |
AN762 140 WATT HF AMPLIFIER
The AN762 amplifier is designed for mobile operations. The
amplifier operates over the 1.6 to 30 MHZ frequency band with a 13.6 Vdc power
supply. Two MRF454 transistors are used to generate a 140 watt output. The use
of chip capacitors results in good repeatability, making the overall design
suitable for reproduction. The AN762 HF amplifier was also featured in the ARRL
HANDBOOK. The AN762 is also designed for an output of 100 watts using two MRF453
transistors or 180 watts using two MRF421 transistors.
SPECIFICATIONS :
| Frequency Range |
1.6 to 30 MHZ |
| RF Input Power |
1-5 watts |
| RF Output Power |
140 watts |
| DC Input Voltage |
13.6 Vdc |
| DC Input Current |
20 to 30 amps (typical) |
| R1, R2 - 2 x 3.6 Ohm, 1/2 W in
parallel |
R12 - 20 Ohm, 5 W |
C12 - 1000 pF Ceramic Disc |
| R3, R4 - 2 x 5.6 Ohm, 1/2 W in
parallel |
C1 - 51 pF Ceramic Chip |
L1, L2 - Ferroxcube VK200 19/4B
choke |
| R5 - 0.5 Onm, 1/2 W |
C2, C3 - 5600 pF Ceramic Chip |
L3, L4 - Two Ferrite Beads on #
16 AWG wire each |
| R6 - 1k Ohm, 1/2 W |
C4 - 390 pF Ceramic Chip |
L5 - 1 Separate Turn Thru Toroid
of T2 |
| R7 - 18k Ohm, 1/2 W |
C5 - 680 pF Ceramic Chip |
T1 - 9:1 Impedance Ratio RF
Transformer |
| R8 - 8.2k Ohm, 1/2 W |
C6 - 1760 pF (2 x 470 pF Ceramic
Chip + 820 pF Dipped Mica in parrallel) |
T2 - 6 Turns #18 AWG enameled,
Bifilar Wire |
| R9 - 1k Ohm Trimpot |
C8, C9 - 0.68 uF Ceramic Chip |
T3 - 16:1 Impedance Ratio RF
Transformer |
| R10 - 150 Ohm, 1/2 W |
C10 - 100 uF, 20 V Electrolytic |
Q1, Q2 - MRF454 |
| R11 - 1k Ohm, 1/2 W |
C11 - 500 uF, 3 V Electrolytic |
Q3 - 2N5989 or equivalent |
| |
|
D1 - 2N5190 or equivalent |
Printed Circuit Boards and Components Available
The above is a summary description of an HF
amplifier described in the MOTOROLA Engineering Bulletins and Application Notes.
These Engineering Bulletins and Application Notes may be obtained from your
local MOTOROLA office or can be found in the MOTOROLA RF DEVICE DATA MANUAL.
These amplifiers have been designed and tested by engineers at Motorola.
COMPONENT SETS FOR AN762
| Chip Capacitor Set |
$ 5.10 |
| 1 ea. |
56pf Ceramic Chip Cap. |
| 1 ea. |
390pf Ceramic Chip Cap. |
| 2 ea. |
470pf Ceramic Chip Cap. |
| 1 ea. |
680pf Ceramic Chip Cap. |
| 2 ea. |
5600pf Ceramic Chip Cap. |
| 2 ea. |
.68uf Ceramic Chip Cap. |
| Discrete Capacitor
Set |
$ 2.05 |
| 1 ea. |
820pf Silver Mica Cap |
| 1 ea. |
.001uf 1Kv Ceramic Disc Cap. |
| 1 ea. |
100 uf 25 Vdc Electrolytic Cap. |
| 1 ea. |
470 uf 6.3 Vdc Electrolytic Cap. |
| Resistor Set |
$ 4.55 |
| 1 ea. |
0.5 ohm 1/2W Resistor |
| 4 ea. |
3.6 ohm 1/2W Resistor |
| 4 ea. |
5.6 ohm 1/2W Resistor |
| 1 ea. |
150 ohm 1/2W Resistor |
| 2 ea. |
1K ohm 1/2W Resistor |
| 1 ea. |
8.2K ohm 1/2W Resistor |
| 1 ea. |
18K ohm 1/2W Resistor |
| 1 ea. |
20 ohm 5W W.W. Resistor |
| 1 ea. |
1K ohm Trim Variable Resistor |
| Semiconductor Set |
$ 6.50 |
| 1 ea. |
2N5192 Transistor |
| 1 ea. |
2N6488 Transistor |
| 1 ea. |
MC1723CG Voltage Regulator |
| Ferrite Set |
$ 2.75 |
| 4 ea. |
56-590-65-3B Ferrite Beads |
| 2 ea. |
VK200 20/4B Ferrite Chokes |
| Transformer
Set:..(wound) |
$ 12.10 |
| Printed Circuit Board (3"W x 5
1/4"L) |
$ 14.00 |
| MRF454MP Matched Transistor Pair |
$ 51.00 |
180 Watt component sets also available.
| MRF421MP Matched Transistor Pair |
$ 95.00 |
|
This Page was last
updated April 17, 2007
