MGL Avionics User Forum

Sorry for the dumb question - received my TC-6 12 channel EGT and CHT Blaze gauge with thermocouples - the bug I received in the MGL box has no 'face' - just a shell of the plug and the connections on the back are not pins or sockets. Does this mean the temocouples get soldered directly onto the pins on the back of the gauge?
cheers

TOBY1 wrote: ↑Sun May 16, 2021 11:44 pm Sorry for the dumb question - received my TC-6 12 channel EGT and CHT Blaze gauge with thermocouples - the bug I received in the MGL box has no 'face' - just a shell of the plug and the connections on the back are not pins or sockets. Does this mean the temocouples get soldered directly onto the pins on the back of the gauge?
cheers

You would have received a standard solder bucket connector. It sounds like the connector has simply been fitted to your gauge - just pull it off.

Thermocouple wires cannot be soldered. The most common method is to use electrical crimp terminals. You can solder ordinary copper wire (short) onto the connector and crimp to the thermocouples as needed.
If you need long wires (usually likely) then please use K-type extention wire to bring the location where the K-type wire joins onto your copper wire very close to the instrument - it measures the temperature at the back of the instrument for cold junction compensation so that bridge must be close to the instrument.

Alternatively you can source a crimp type connector with individual pins you can crimp straight onto the K-type cable.

I didn't see anything in the instructions about not soldering thermocouple connections.

The reason I ask is that I just ran up my engine, and it started with a positive temperature, and then as the engine warmed up it went to a negative value!

The OAT was about 60 degrees F, but it actually started at 44, and went down from there.

Could this have been caused by using solder instead of crimp connectors?

If the temps go negative it means the thermocouple has been connected with inverted polarity.