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DJ4KI > VLF 12.11.96 04:48l 101 Lines 7276 Bytes #-10837 (0) @ ALL
BID : CB6DB0ABH006
Read: DL3MHM DL5MAV GUEST
Subj: VLF RX zu GRAM22
Path: DB0KCP<DB0IGL<DB0FSG<DB0SL<DB0RGB<DB0ABH
Sent: 961112/0242z @:DB0ABH.#BAY.DEU.EU [BayComBox Nuernberg] BCM1.38
From: DJ4KI @ DB0ABH.#BAY.DEU.EU (Rue)
To : VLF @ ALL
Reply-To: DJ4KI @ DB0BOX.#BAY.DEU.EU
X-Info: No login password
Es gibt mehrere Moeglichkeiten um sich die Sprache unserer Erde
anzuhoeren.
Leider sind beim Empfang die " MAN MADE NOISE " ein grosses Problem.
In dichtbesiedelten Gebieten braucht man mit dem Experimentieren gar
erst anfangen.
Aus dem Internet habe ich WAV Dateien, die ich gerne zur Verfuegung
stelle.
Wenn man weit ab von Netzleitungen ( Hochspannungsleitungen ) wohnt,
hier das passende Schaltbild welches nicht auf meinem Mist gewachsen
ist, und nur zur Anregung dienen soll:
01) __________ o +9 Volts
02) \ | / |
03) \ | / ___________________|_____________\ To Audio
04) \ | / C9 + | |0.1uF | / amp. 9 v
05) \ |/ 100uF __|__ __|__ C10 | rail.
06) \/ _____ _____ |
07) | | | \
08) 1 to | |__________| / 4.7K
09) 3 mtr.| __|__ \ R4
10) whip | R1 C1 / / / 2N5484 /
11) ant. | 1 Meg. 0.1uF Q1 D |_______||____\ To filter &
12) | G |_____| || / A.F. AMP.
13) |---/\/\/\---||---|-----|-------| 0.1 uF
14) | | |-----| C3
15) C2 _|_ \ S |
16) 47pF ___ / R2 /
17) | \ 10 Meg. \
18) | / / 1K
19) | | \ R3
20) |-----| /
21) __|__ __|__
22) / / / / / /
23)
24)-------------------------------------------------------------------------
25) AUDIO FILTER
26) * (^^^ = coil windings)
27) From FET drain coupling L1 (xfmr pri.) or 180-200 mH choke
28) cap. ==============
29) \_____ _________|^^^^^^|^^^^^^ To input of
30) / | |_______________| |____\ bi-polar
31) | | | | / audio amp.
32) | .0047 uF | 0.1 uF
33) __|__ C4 .0047 uF | C6
34) _____ C5 __|__
35) | _____
36) | |
37) | |
38) __|__ __|__
39) / / / / / /
40)
41)
42) * L1 is a 1 KCT pri. to 8 ohm sec. audio xfmr. using one end of primary
43) winding and the center-tap as a series inductor equalling approx 160 mH.
44)
45)-------------------------------------------------------------------------
46) MIC. LEVEL NPN AUDIO AMPLIFIER
47) (+9 volt rail)
48) \__________________________________
49) / | |
50) | 10 K /
51) 33 K \ R7 \
52) R5 / / MIC. LEVEL
53) \ C ____|______| |_______\ OUTPUT
54) From audio / / | | / To tape rec. or
55) filter | B | / 0.1 uF speaker amp.
56) \________________|_________|/ C8
57) / | |\__
58) | Q2 | \/ E
59) | 2N3904 \______
60) | NPN | |
61) | Bipolar + | |
62) | Transistor __|__ \
63) \ 1uF _____ / R8
64) 4.7K / C7 | \ 1.5K
65) R6 \ | /
66) / |_____|
67) | |
68) __|__ __|__
69) / / / / / /
70)
71)
72)-------------------------------------------------------------------------
The "BBB-4" is a broadband 0.2 to 11 kHz V.L.F. receiver with a
passband peak at approximately 2 kHz, and is designed to receive
naturally-occurring V.L.F. phenomena (such as "whistlers") that occur as
electromagnetic (radio) waves at audio-frequencies. This receiver was
designed to be hand-held, and its output patched to a microphone-level input
such as a tape-recorder or speaker-amplifier (such as the one available at
Radio Shack ("Mini Audio Amplifier/Speaker" cat. # 277-1008).
73 de Rue ( DJ4KI @ DB0BOX )
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