What is the proper sequence to remotely power-off a Flex 6400?

W4AFK Bruno

I ask I am am seeing two different responses. Assuming that you turned ON the REM ON function in SmartSDR: One method follows the manual which says that if REMOTE ON is shorted, the radio is powered. If REMOTE ON is open, the radio powers of. Hence my dilemma, which is right?

Method 1 power-up:

• Power up - Using MHCOZY (Relay 1), turn ON DC (I run it through a 40A relay)
• Power up - Using MHCOZY (Relay 2), short the "REM ON" line to the radio

Method 1 (power down):

• Power Down - Turn OFF MHCOZY (Relay 2). The REMOTE ON line is now open
• Power Down - Wait ~60 seconds then turn off MHCOZY Relay 1, which removes DC to the radio

—

Method 2 power-up:

• Power up - Using MHCOZY (Relay 1), turn ON DC (I run it through a 40A relay)
• Power up - Configure MHCOZY to keep Relay 2 on for 1 second when activated
  • In other words, it sends a 1-second pulse on the REMOTE ON line and the radio boots up

Method 2 (power down):

• Power Down - Configure MHCOZY to keep Relay 2 on for 1 second when activated
  • In other words, it sends a 1-second pulse on the REMOTE ON line to tell the radio to shut down
• Power Down - Wait ~60 seconds the turn off MHCOZY Relay 1

KD0RC

Hi Bruno, the REM ON jack expects a relay closure for the duration of the on period, not a pulse.

Your Method 1 is correct.

W4AFK Bruno

THANK YOU!!! That's how I have been running it.

Ken Wells

BTW: It is not recommended to use the "Shorted RCA Plug" method that some have recommended in the past — putting a shorted RCA Plug into the RCA REM jack and simply switching the 13.8 V power ON and OFF. — This does not allow enough delay between application of 13.8 Volts and the Closure of the RCA REM port.

This is especially true when using M-Model Radios that need about two minutes delay after application of 13.8 Volts before turning the radio ON.

To turn the Radio ON:

• Turn ON the 13.8 Volts.
• WAIT two minutes for the radio's processors to initialize.
• THEN close the RCA REM Relay to turn ON the radio.
  

• To Turn OFF the Radio:

• Open the RCA REM Relay to turn OFF the radio.
• WAIT about two minutes for the radio to power down and make final writes to the internal memory.
• THEN turn off the 13.8 Volts. (If you plan to turn off the power supply or 13.8 V feed)

NOTE: Simply switching off the 13.8 Volts while the radio is still running is the radio equivalent of turning off your computer by yanking the power cord.

Rick N0VT

So are we not supposed to use the Remote On feature? If not, why have it?

KD0RC

Hi Rick, that is not what Ken is saying. He is making the clarification about the "shorted plug" technique that some hams were using along with just shutting off the power supply with a permanently shorted REM ON jack.

A switch or relay connected to REM ON is used just like the front panel power button.

Look at Ken's post again.

Rick N0VT

Ok..I've never heard of a "shorted plug" that was mentioned so that threw me off. I have the Remote On jack connected to a wifi operated relay so it sounds like I'm good. Thanks.

Ken Wells

I edited my post to make it less ambiguous. Sorry for any confusion.