Our engineering group Gap GeoPak has developed a range of high power, high current and high voltage transmitters optimised for different survey applications:
- HPTX-70/80 – High Powered Transmitters
- EMTX-200 – High Current Transmitters
- IPTX-2500 – High Voltage Transmitters
- LPTX-25 – Low Voltage Transmitters
No single transmitter is ideal for all survey requirements:
- The HPTX and EMTX Series transmitters are generally more suitable for inductive loop applications like surface and downhole EM.
- The HPTX and IPTX Series transmitters are generally more suitable for galvanic applications such as IP, and MMR.
- The LPTX Series transmitters are generally more suitable for smaller geotechnical applications like Moving Loop EM.
HPTX Series High Powered Transmitters
The GeoPak HPTX Series comprise the HPTX-70 and HPTX-80 High Powered transmitters. These transmitters are typically used for large loop or deep search applications.
The HPTX series transmitters are fully self-contained. They are capable of:
- Output Power of up to 70 or 80 kW respectively
- Output currents up to 350A
- Output Voltages of up to 1200V (suitable for DHEM)
- Typical current for 800m x 800m loop: 165A (with high ampacity cable)
- Ideal for FLEM / DHEM / MMR
EMTX-200 Portable EM Transmitter
For applications which require small or underground loops, GeoPak has developed the more portable EMTX-200 transmitter. The EMTX-200 is a modular transmitter which can be powered by a range of DC sources including the DC10LV-2 or a PS10LV power supply. The PS10LV is powered by a standard 3-phase generator. It is commonly used for underground surveys where it can be connected to the mine’s 3-phase power supply.
The EMTX-200 is a high current transmitter capable of:
- DC10LV2 (10KW), DC14MV (14kW), PS10LV (10KW), or PS30MV (30kW) power supplies; capable of over 100 kW
- Output currents up to 200A (power supply dependent)
- Output Voltages of up to 120V (Extra Low Voltage)
- Designed for Lightweight / Portability (Ideal for MLEM)
The EMTX-200 is commonly used for 200 x 200 to 400m x 400m loop sizes. Typical output current for a 200m x 200m loop with a DC10LV2 power supply would be 120A.
IPTX-2500 Portable IP Transmitter
For galvanic surveys like MMR, IP or SAM, GeoPak has developed the more portable IPTX-2500 transmitter The IPTX-2500 is a modular transmitter which can be powered by a range of DC sources including the DC8MV, DC10HV and DV14HV generators or a PS30HV 3-phase power supply.
The IPTX-2500 is a high voltage transmitter capable of:
- Output power depends on power supply: DC14HV (14kW) or PS30HV (30kW); capable of over 100kW
- Output currents up to 50A (power supply dependent)
- Output Voltages of up to 2500V (power supply dependent)
- Designed for Portability / Remote Access – (can be slung)
- Typical currents: Grounded dipole: 15-30A; Loop 20-50A
The IPX-2500 is commonly used for galvanic surveys with dipoles up to 10km. It can also be used for EM surveys where smaller gauge wire is required (often due to difficult access). Output currents are very dependent on electrode resistance but generally range from 20-30A.
LPTX-25 Portable EM Transmitter
Applications which require very small loops, GeoPak has developed the portable LPTX-25 transmitter. The LPTX-25 is a modular transmitter which can be powered by 12V 20 Ah Lithium batteries.
The LPTX-25 is capable of:
- Output Power of up to 0.2kW (power supply dependent)
- Output currents up to 13A (Battery storage dependent)
- Output Voltages of up to 10V (Extra Low Voltage)
The LPTX-25 is commonly used for 25m x 25m to 50m x 50m loop sizes. Typical output current for a 25m x 25m loop with a D12V 20 Ah Lithium would be 12A.
GeoPak Transmitter Summary
A summary of the Gap GeoPak transmitter options is shown in the table below. The survey application column details the modes of operation available for each transmitter with the primary application highlighted in bold.