BBVA-A VMOS Input Broadband Amplifier
revision date: 5 NOV 1999
Mark Connelly, WA1ION – Billerica, MA, USA
web: http://home.comcast.net/~markwa1ion/exaol1/weblink.htm
The BBVA-A broadband amplifier is a good choice for low-noise amplification in the 150 to 6500 kHz frequency range. A VMOS type FET, the Vishay-Siliconix VN10KM, is used as the gain device. The input impedance of the amplifier is about 300 to 600 ohms and its output works well into 50 or 75 ohm loads. For maximum power transfer to the amplifier's input from a 50 or 75 ohm source, a 1:4 step-up transformer, Mini-Circuits T4-6T-X65, is recommended. Gain is approximately 20 dB. Outputs of at least 1.5 Vrms (4.2 vpp or +16.5 dBm) into 50 ohms should be achievable before distortion becomes excessive. The supply should be regulated at +10 VDC if possible. Operation at higher voltages will not improve gain or intercept point greatly; further it will require the transistor to be heat-sinked to prevent thermal failure.
GIF drawing files may be downloaded and subsequently viewed and printed at correct scaling by using a program such as Microsoft Photo Editor or Adobe Photoshop.
Figure 1: Schematic (fits one page)
Figure 1: Schematic (high resolution)
Figure 2: Assembly (fits one page)
Figure 2: Assembly (high resolution)
|
BBVA-A VMOS Input Broadband Amplifier Card parts list |
|||||||
|
|
Item |
Designator |
Description/Value |
Vendor |
Vendor Stock # |
QTY |
|
|
|
|||||||
|
|
1 |
- |
perfboard:1.0"X1.4" |
RS |
276-1396 (cut) |
1 |
|
|
|
2 |
C 1,2,3 |
capacitor, 0.1 uF |
MOU |
539-CK05104K |
3 |
|
|
|
3 |
D 1 |
diode, 1N4003 |
MOU |
592-1N4003A |
1 |
|
|
|
4 |
H 1 |
screw, 4-40 X .25" |
MOU |
572-01880 |
1 |
|
|
|
5 |
H 1 |
spacer, 4-40 X .5" |
MOU |
534-1450C |
1 |
|
|
|
6 |
H 1 |
solder lug, #4 |
MOU |
534-7311 |
1 |
|
|
|
7 |
P 1-5 |
flea-clip,.042"hole |
MOU |
574-T42-1/100 |
5 |
|
|
|
8 |
Q 1 |
FET, VN10KM |
RSC |
900-5530 |
1 |
|
|
|
9 |
R 1 |
resistor, 47 ohm |
CS |
RA47 |
1 |
|
|
|
10 |
R 2 |
resistor,2.2 megohm |
CS |
RA2.2M |
1 |
|
|
|
11 |
R 3 |
resistor,4.7 megohm |
CS |
RA4.7M |
1 |
|
|
|
12 |
R 4 |
resistor, 680 ohm |
CS |
RA680 |
1 |
|
|
|
13 |
R 5 |
resistor, 4.7 ohm |
CS |
RA4.7 |
1 |
|
|
|
14 |
R 6 |
resistor, 10 ohm |
CS |
RA10 |
1 |
|
|
|
15 |
RFC 1 |
inductor, 1.8 mH |
MOU |
434-05-182J |
1 |
|
|
|
Misc. items: hook-up wire, buss wire, solder "AS REQUIRED" |
||||||
|
Vendor Codes |
|||||||
|
CS |
Circuit Specialists = http://www.cir.com |
||||||
|
MOU |
Mouser Electronics = http://www.mouser.com |
||||||
|
RS |
Radio Shack (retail) = http://www.radioshack.com |
||||||
|
RSC |
RadioShack.com (on-line, ex-Tech America) = http://www.radioshack.com |
||||||
