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BBVA-A
Broadband Amplifier
By Mark
Connelly, WA1ION
revision date November 5, 1999
Comercial
amplifiers:
Advanced
Receivers
-- "1-30 MHz amplifier, 2.5 dB noise figure,
20 dB gain; modified model for operation down to 0.5 MHz,
at $32.95."
Kiwa
Electronics
|
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.
BBVA-A Broadband Amplifier Card
Click
here for larger image
BBVA-A Broadband Amplifier Card
Click
here for larger image
BBVA-A VMOS Input
Broadband Amplifier Card parts list
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Item
|
Designator
|
Description
and Value
|
Ven-
dor
|
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
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434-05-182J
|
1
|
|
|
|
|
|
|
|
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Misc.
items: hook-up wire, buss wire, solder "AS REQUIRED"
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|
|
|
|
|
|
|
|
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Vendor
Codes
|
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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/
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- More on
Mark Connelly's web site:
RF
Circuit Building Blocks
WA1ION
DX Labs Web links
|
antennX