KX3 internal batt. questions?

[Mike Maloney]

Dont have a KX3 (yet) but curious about the points below if someone can enlighten me?
 
Is access to terminals and exchange of  int. battery for KX3 as inconvenient as it is for the K2? 
Is there a series diode on the ext. power connector that will cause forward bias voltage drop if powered by external battery?
 
thanks,
Mike/ac5p
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[KE6BB]

I don't have a K2, but maybe I can shed some light on it:

<<Is access to terminals and exchange of  int. battery for KX3 as inconvenient as it is for the K2?>>
Access to the terminals is not really required to change the internal battery.  You simply loosen the 4 screws that hold the case halves together, pull and rotate the case halves apart, remove the 8 cells from the holder, and replace them with new ones.

Take a look at the Owner's Manual, Page 23:

http://www.elecraft.com/manual/E740163%20KX3%20Owner%27s%20man%20Rev%20B4.pdf

I went with NiMH rechargeable cells since I don't trust alkaline cells to remained sealed.  NiMH can leak as well, but it is far less common and doesn't seem to be as destructive.  I have been using them for years, and the only leakage I have experienced has been with them sitting in a box completely discharged for several years.  The latest generation (Sanyo Eneloop among others) may be even better since they have a much lower self-discharge rate.  That is what I use in my KX3.  Since I also use the KXBC3 charger, I seldom open the case.


<<Is there a series diode on the ext. power connector that will cause forward bias voltage drop if powered by external battery?>>
Yes, but it is on the Control Panel Board Assembly.  It is a CMS04 Schottky Barrier Diode, so the drop is only about 0.2 volts during receive, and 0.3 volts during transmit.

Hope this helps.

Mark
KE6BB
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[Don Wilhelm-4]

Mike,

The KX3 uses 8 AA size batteries.  Access to the batteries is easy -
loosen the 4 thumbscrews on the corners and separate the 2 halves.

You do not have access directly to the battery terminals.  The KXBC3
option will keep NiMH batteries charged.  Without that option, the
batteries must be removed for charging.

It is not like the K2 which uses an SLA (Sealed Lead Acid - aka Gell
Cell) battery.  Alkaline AA cells can be used as well as NiMH, and
although they are not rechargeable, they are commonly available in case
of an emergency.

Yes, there is a series diode for reverse polarity protection.  The
internal voltage will be about 0.3 volts less than the external supply.

73,
Don W3FPR

On 6/24/2013 11:29 AM, [hidden email] wrote:
> Dont have a KX3 (yet) but curious about the points below if someone can enlighten me?
>  
> Is access to terminals and exchange of  int. battery for KX3 as inconvenient as it is for the K2?
> Is there a series diode on the ext. power connector that will cause forward bias voltage drop if powered by external battery?
>  
>

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