6300 Quiescent Current Draw?

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  • Updated 4 years ago

My 6300 runs from my 12V (13.5V) battery backup system, and I'm wondering whether the 6300 draws a small amount of current when it's "off." If so, how much?

If current is drawn, I'm also wondering whether part of this is the TXCO drawing current to keep the crystal at a stable temperature? Or does the TXCO start off "cold" upon turn-on.

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Jim, KJ3P

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Posted 4 years ago

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Tom K3TF

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I believe the 6300 and the 6500 use a TXCO (Temperature compensated crystal oscillator) which does not have a heater so no current when turned off.

The 6700 has an OCXO (oven controlled crystal oscillator) which has a small oven that keeps the crystal at a specific temperature when the rig is shut off, as long as you keep 13.8V applied. 

Tom, K3TF.......
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Al / NN4ZZ

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Hi Tom,
There was some confusion/misinformation about the OXCO being powered when the radio is off.  But according to Steve H.  it is not.  See the discussion at this thread.  

https://community.flexradio.com/flexradio/topics/thunderstorms_persistence_and_remote_operation_3_qu...

Regards, Al / NN4ZZ  
al (at) nn4zz (dot) com
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Steve N4LQ

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Maybe I'm wrong but I thought a tcxo had to have a heater and needed to run 24/7 to regulate temperature. Also these rigs all use a "soft switch" turn on for the push button off/on and remote off/on so it does need a small current for that. Of course we could find out  in 2 minutes with a VOM.
Steve
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Jim, KJ3P

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VOM:  Ok, I'm lazy!...didn't want to go to the trouble only to find out that my VOM isn't sensitive enough.
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Tom K3TF

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HI Al,

Thanks for the info. Just got my Flex 6500 last week and still learning. 

Tom K3TF.........
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Jim, KJ3P

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In Summary:  I've learned the difference between OXCO and TXCO, and that none of the 6x00 radios keeps the oscillator running when "Off". Except maybe the 6700's GPS option. I had found that the 6300 is on frequency so quickly after turn-on, that I thought it might be kept warm. As usual, my assumption was wrong. I also understand that the current for the tiny housekeeping circuit for the ON button will not be a worry for my situation.

As always, thanks for the education!
73, --Jim