19.12. - 20.12. 2020
Through-the-Earth RadioLocation Device - ver.2
EN | CZ
Published 31.10.2020
Cave radiolocation device based on B. Pease immortal design (radiolocation.tripod.com). The scheme remained the same, new PC boards for SMD components were designed.
The article describes the construction inc. production documentation. How to use the device is decribed here or here. Aletrnatively in Speleonics #26, page 2-3
Beacon
Transformer T1
is wound on MPP (Molypermalloy Powder) toroid core (27x14x11mm 125u). Primary winding is wound in two layers and has 90 turns 0,8mm Cu wire. Inductance is about 1242 uH.
The secondary winding has about 15-25 turns 1mm Cu wire. The number of turns depends on transmit loop antena parameters.
Transmitter loop
Usually I use antenna from 40 turns and 55cm in diameter. This allows measurements even at a transmitter depth exceeding 100 meters
Capacitors C1,C2,C3,C4,C13 - are connected in parallel and their final value (like the secondary winding T1) depends on the transmitting antenna. The total value is typically from 1uF to 2,5uF
Info about tunning are described here (page 4 - Beacon notes)
Notes
LED D3 lights up only if a signal is actually being transmitted.
PCB has dimensions 100x74mm for placement in a Hammond box 1455K1201 (120x78x43mm)
Receiver
RF amp
Construction
PCB for RF amp. has size 25.4x40.6mm for placement into shielding minibox - e.g. AH100 (45x30x22mm)
The input from the antenna is connected with a small coax cable. BNC conenctor is insulated - is not connected with the box.
Switch S3 and potentiometer R22 are connected with a shielded 3-wires cable.
DQ Receiver
PCB has size 71.1x65.7mm for placement into shielding box AH102 (92x67x22mm).
Complete receiver (ie RF amp and DQ receiver) is built into a Hammond box 1455N1601 (dimensions 160x103x53mm). Example of placing controls on the top panel:
Receiver settings - see DQ RECEIVER NOTES, page 2,3
Receiver loop
Receiver antenna is wound from 0.3mm cu wire, 55 cm in dia. The number of turns from 1kg package is about 550. The inductance is about 430mH. Loop is tune to resonance by connecting a 6.8nF capacitor. The capacitor(s) should be at least 600V.
Part list
Beacon
| Qty | Parts | Value | Package |
|---|---|---|---|
| 1 | C1 | 2u2/250V | XC27B13 |
| 1 | C11 | 27p/50V | 0805 |
| 1 | C12 | 33p/50V | 0805 |
| 1 | C13 | 10n/50V | XC15B5 |
| 1 | C2 | 1u/250V | XC27B11 |
| 1 | C3 | 560n/250V | XC15B10 |
| 1 | C4 | 470n/250V | XC22B10 |
| 1 | C5 | 2200u/25V | E5-13 |
| 2 | C6, CX6 | 680n/250V | XC27B11 |
| 1 | C7 | 4.7n/250V | C102-043X133 |
| 4 | C8, C9, C10, C50 | 100n | C0805 |
| 1 | D1 | 5A 30V Schottky | SMC |
| 2 | D2, D4 | 1N4148 | SOD80C |
| 1 | D3 | 3mm LED | 6410-02 |
| 1 | FUSE | RDL60V160 | POLYFUSE_RDL60V160 |
| 1 | Q1 | IRLIZ44Z | TO220BH |
| 1 | R1 | 1M | 0805 |
| 1 | R2 | 100k | 0805 |
| 1 | T1 | viz. text | TOROID |
| 1 | U1 | 74HC4060 | SO16 |
| 1 | U2 | 78L05 | SOT89 |
| 1 | X1 | 3MHz | HC49U-V |
RF Amp
| Qty | Parts | Value | Package |
|---|---|---|---|
| 1 | C13 | 1n/50V | 0805 |
| 3 | C14, C17, C202 | 100n/50V | 0805 |
| 2 | C15, C16 | 10u/16V | 1210 |
| 3 | C18, C201, C203 | 150p/50V | 0805 |
| 2 | D3, D4 | 1n4148 | SOD80C |
| 2 | R17, R18 | 10k | 0805 |
| 2 | R20, R20-2 | 1M | 0805 |
| 1 | R204 | 1k | 0805 |
| 1 | R21 | 20k | 0805 |
| 1 | R22 | 100k pot. RF Gain | Potentiometer |
| 3 | R23, R26, R202 | 2k2 | 0805 |
| 2 | R24, R201 | 100k | 0805 |
| 1 | R55 | 200 | 0805 |
| 1 | S3 | RF Gain x1 x100 | Toggle Switch |
| 1 | U0 | LF356 (TL071) | SO08 |
| 1 | U1 | LF412 (AD712) | SO08 |
DQ Receiver
| Qty | Parts | Value | Package |
|---|---|---|---|
| 1 | BZ | Buzzer 3-18V | |
| 2 | C1, C2 | 33n/50V | 0805 |
| 1 | C19 | 10-60p | Trimm capacitor |
| 1 | C20 | 56p/50V | 0805 |
| 1 | C21 | 2u/16V | 0805 |
| 1 | C23 | 2.2u tant./16V | SMC_A |
| 1 | C24 | 47n/50V | 0805 |
| 7 | C25, C30, C31, C32, C37, C38, C42 | 100n/50V | 0805 |
| 1 | C27 | 3.3u tant./16V | SMC_A |
| 1 | C29 | 100u elect./16V | E2,5-6 |
| 4 | C3, C4, C22, C40 | 1u/25V | 0805 |
| 1 | C41 | 4u7/100V | 0805 |
| 2 | C5, C26 | 1u tant./16V | SMC_A |
| 4 | C6, C7, C8, C39 | 10n/50V | 0805 |
| 2 | C9, C28 | 10u tant./16V | SMC_A |
| 1 | D1 | Power ON | 3mm green LED |
| 1 | D2 | 1N4001 | DO214AC |
| 1 | D5 | 1n4148 | SOD80C |
| 1 | D6 | RF_Overload | 3mm red LED |
| 1 | D7 | Phase Lock | 3mm green LED |
| 1 | IC1 | 78M12 | DPACK_3 |
| 1 | IC2 | 78M09 | DPACK_3 |
| 1 | J1 | DVM | 200mV DVM (WPB5035-DV) |
| 1 | P1 | Headphones | 3.5 mono jack |
| 2 | R1, R2 | 221k | 0805 |
| 11 | R10, R11, R14, R28, R43, R44, R47, R48, R49, R50, R54 | 100k | 0805 |
| 2 | R15, R45 | 2.4k | 0805 |
| 2 | R150, R450 | 180 | 0805 |
| 2 | R16, R46 | 750k | 0805 |
| 1 | R19 | 5k6 | 0805 |
| 2 | R29, R40 | 220k | 0805 |
| 4 | R3, R4, R25, R27 | 1M | 0805 |
| 2 | R30, R37 | 1k | 0805 |
| 1 | R32 | 9.1M | 0805 |
| 1 | R33 | 2k | 0805 |
| 1 | R34 | Volume 10k | Potentiometer + on/off switch |
| 1 | R36 | 10 | 0805 |
| 1 | R39 | 27k | 0805 |
| 1 | R41 | 2k2 | 0805 |
| 1 | R42 | 1k | RTRIMT93YA multiturn |
| 1 | R5 | 5k | RTRIMT93XA multiturn |
| 1 | R51 | 4.7M | 0805 |
| 1 | R52 | 2M | 0805 |
| 2 | R6, R7 | 47.5k | 0805 |
| 6 | R8, R12, R13, R31, R35, R53 | 10k | 0805 |
| 1 | R9 | Front panel audio null | Multiturn Potentiometer |
| 1 | S1 | Bandwidth | Toggle Switch |
| 1 | S4 | Alarm On | Toggle Switch |
| 1 | S5 | Slow meter | Toggle Switch (not used) |
| 1 | S6 | PLL/RCV | Toggle Switch |
| 1 | U2 | LF412 (AD712) | SO08 |
| 4 | U3, U4, U8, U11 | LF442 (LF412/AD712/TL072) | SO08 |
| 1 | U5 | 4016 | SO14 |
| 1 | U6 | 4060 | SO16 |
| 1 | U7 | 4070 | SO14 |
| 1 | U9 | LM386 | SO08 |
| 1 | V1 | MV2109 | SOT54H |
| 1 | X1 | 3Mhz | HC49U-V |