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TM258 Transducer

Transom-mount 1kW fishfinder transducer.

The TM258 can be used to enhance the performance of 600W sounders.


Type Standard non-CHIRP fishfinder transducer
Frequency50 kHz / 200 kHz
Beam Width15x21° at 50kHz / 3x5° at 200kHz
Power Rating1000 watts
Mounting Transom Mount
Housing Urethane
Cable Length 10 meters
Mix and Match
Temperature Sensor
Speed Sensor Χ
Retractable Insert Χ
Tilted Χ
Status In production
Reference Page View the TM258 page on the Airmar website


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Base Models

These Mix and Match base models must be combined with a Mix and Match cable for installation. The suffix '-MM' in the Gemeco part number designates a Mix and Match base model.

TransducerGemeco Part #Airmar Part #Description
TM258-MM41-519-1-01TM258 Base Transducer

Mix and Match Cables

This transducer uses the Mix and Match system. Installation requires two parts - a base model plus one of the Mix and Match 1000W cables (MM1) listed below.

Each base model has a 2 meter pigtail cable permanently attached. This cable ends in an Airmar 9-pin female connector. The Mix and Match cables are 8 meters long and have a male Airmar 9-pin connector at one end (to connect to the transducer pigtail) and a brand-specific connector at the other end (to connect to the sounder or fishfinder). If an owner changes their fishfinder or sounder, a different MM1 cable can be installed without disturbing the transducer itself.

Gemeco sells kits containing a base model and a Mix and Match cable. For example, the TM258-8G kit contains a base transducer and an MM1-DST-8G cable.

Cable ConnectorGemeco Part #Airmar Part #LengthEquipment
MM1-DO-6G33-599-018 metersGarmin 6-pin depth-only
MM1-DST-10F33-594-018 metersFuruno 10-pin
MM1-DST-14HB33-1245-018 metersHumminbird 14-pin
MM1-DST-6G33-591-018 metersGarmin 6-pin
MM1-DST-6N33-601-018 metersNavman/Northstar/Simrad 6-pin
MM1-DST-733-593-018 metersSimrad 32, 33, 34 series 7-pin
MM1-DST-8F33-635-018 metersOlder Furuno/SiTex/Raytheon 8-pin
MM1-DST-8G33-1179-018 metersGarmin blue 8-pin
MM1-DST-8S33-629-018 metersSiTex CVS, SVS 8-pin
MM1-DST-BB33-592-018 metersStandard Horizon 8-pin
MM1-DST-BL33-642-018 metersLowrance/Simrad blue 7-pin
MM1-DST-RAY33-602-018 metersRaymarine DSM300 and equivalent
MM1-DST-RAYA33-666-018 metersRaymarine current series 6/9-pin
MM1-DT-HB33-631-018 metersHumminbird #9
MM1-EXT33-604-016 metersExtension cable for 1kW Mix and Match

Replacement Parts

PartAirmar Part #Description
33-749-01Transom Bracket Kit