Article
AM Receiver
From DC to 1.8 MHz
Not all AM receivers are created equal. The receiver described here is definitely not a run-of-the-mill type. The tuning range is not limited to the medium or long wave bands but extends down to extremely low frequencies. This opens up new possibilities.The receiving range of the receiver described here is continuously variable from DC to 1.8 MHz. That makes this receiver special, since most AM-receivers are only suitable for the long wave band (150-433 kHz) and the medium wave band (approximately 520-1612 kHz). What does this widened range have to offer?Those who live near the coast will especially appreciate the extra section from 1600 to about 1800 kHz. Several coast guard stations operate in this range and these often provide very interesting information, usually weather conditions.
Materials
Gerber file
CAM/CAD data for the PCB referred to in this article is available as a Gerber file. Elektor GREEN and GOLD members can exclusively download these files for free as part of their membership. Gerber files allow a PCB to be produced on an appropriate device available locally, or through an online PCB manufacturing service.
Elektor recommends the Elektor PCB Service service from its business partner Eurocircuits or AISLER as the best services for its own prototypes and volume production.
The use of our Gerber files is provided under a modified Creative Commons license. Creative Commons offers authors, scientists, educators and other creatives the freedom to handle their copyright in a more free way without losing their ownership.
PCB
Component list
Resistors:
R1 = 1M
R2,R3 = 100k
R4 = 1k
R5 = 820 ohm
R6 = 1k 8
R7 = 150k
R8 = 3k 9
R9 = 1k 2
R10 = 2k 7
R11 = 330k
R12 = 100 ohm
R13 = 22 ohm
R14 = 1 ohm
R16 = 10k
R17 = 820k
R18,R20 = 2k 2
R19 = 220k
P1 = 50 k 10-turn cermet
P2 = 50 k logarithmic potentiometer
P3 = 2k 5 preset
Capacitors:
C1,C23,C35 = 10pF
C2,C3,C5,C11,C17,C18,C21,C24,C26,C27,C33,C36,C44 = 100nF
C4,C9,C10,C28,C29 = 220nF
C6,C8 = 56pF
C7 = 180pF
C12 = 22pF
C13 = 33pF
C14,C16,C43 = 100pF
C15 = 40pF trimmer
C19,C20,C41 = 10nF
C22 = 120pF
C25 = 47µF 16V radial
C30 = 2µF2 16V radial
C31,C34 = 22µF 16V radial
C32 = 3nF3
C37,C38 = 220µF 16V radial
C39,C40 = 10µF 63V radial
C42 = 39pF
Inductors:
L1 = 3µH9
L2,L3 = 100µH
L4 = 1µH5
L5 = 680µH
L6 = 82µH
L7 = 12µH
Semiconductors:
D1 = MV1401 (Motorola)*
D2 = 1N4001
D3 = LED high-efficiency
T1 = BF961
T2 = BF494
T3 = BC550C
T4 = J310*
IC1 = SA612AN (Philips Semiconductors)*
IC2 = TDA1572
IC3 = LM386N
IC4 = 78L09
IC5 = 78L06
Miscellaneous:
LS1 = miniature loudspeaker 8 ohm 1 watt
X1 = 10M7A* ceramic filter
X2 = SFR455H* ceramic filter
X3 = 10.245 MHz quartz crystal
Enclosure: e.g., Bopla type E440
PCB, order code 000176-1
*) suggested supplier: Barend Hendriksen, website at http://www.xs4all.nl/~barendh/ , Email: barendh@xs4all.nl
R1 = 1M
R2,R3 = 100k
R4 = 1k
R5 = 820 ohm
R6 = 1k 8
R7 = 150k
R8 = 3k 9
R9 = 1k 2
R10 = 2k 7
R11 = 330k
R12 = 100 ohm
R13 = 22 ohm
R14 = 1 ohm
R16 = 10k
R17 = 820k
R18,R20 = 2k 2
R19 = 220k
P1 = 50 k 10-turn cermet
P2 = 50 k logarithmic potentiometer
P3 = 2k 5 preset
Capacitors:
C1,C23,C35 = 10pF
C2,C3,C5,C11,C17,C18,C21,C24,C26,C27,C33,C36,C44 = 100nF
C4,C9,C10,C28,C29 = 220nF
C6,C8 = 56pF
C7 = 180pF
C12 = 22pF
C13 = 33pF
C14,C16,C43 = 100pF
C15 = 40pF trimmer
C19,C20,C41 = 10nF
C22 = 120pF
C25 = 47µF 16V radial
C30 = 2µF2 16V radial
C31,C34 = 22µF 16V radial
C32 = 3nF3
C37,C38 = 220µF 16V radial
C39,C40 = 10µF 63V radial
C42 = 39pF
Inductors:
L1 = 3µH9
L2,L3 = 100µH
L4 = 1µH5
L5 = 680µH
L6 = 82µH
L7 = 12µH
Semiconductors:
D1 = MV1401 (Motorola)*
D2 = 1N4001
D3 = LED high-efficiency
T1 = BF961
T2 = BF494
T3 = BC550C
T4 = J310*
IC1 = SA612AN (Philips Semiconductors)*
IC2 = TDA1572
IC3 = LM386N
IC4 = 78L09
IC5 = 78L06
Miscellaneous:
LS1 = miniature loudspeaker 8 ohm 1 watt
X1 = 10M7A* ceramic filter
X2 = SFR455H* ceramic filter
X3 = 10.245 MHz quartz crystal
Enclosure: e.g., Bopla type E440
PCB, order code 000176-1
*) suggested supplier: Barend Hendriksen, website at http://www.xs4all.nl/~barendh/ , Email: barendh@xs4all.nl
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