[Elecraft] Battery requirements for NPOTA activation with KX3/KXPA100

[Nr4c]

I think you'll draw a lot more than 8A at 100 watts. 

Also note that to get 100 watts from this setup will require a bit more than 14 volts I think. I ran my PS at 14.5 or better to make it. YMMV!  

You're gonna get a lot responses on this query, so be prepared. 

Your best friend here is going to be AMPHOURS. The more you have the longer you'll be able to keep the voltage drop down. When the voltage drops too low the KX3 will drop the power. You might consider starting st 75 watts and drop a bit when the pileup gets going. 

Where at you going. And have your spotters note the park or Unit ID. 

Sent from my iPhone
...nr4c. bill


> On Mar 29, 2016, at 4:41 PM, Esquer Dave <dave.esquer at gmail.com> wrote:
> 
> Hi folks,
> I know this has been asked and discussed before but I can’t seem to get a handle on a clear-cut answer …
> 
> I am going to do a SSB NPOTA (National Parks on the Air) activation with my KX3/KXPA100/PX3 on battery power. It has been in the works for a while with a special use permit required by the NPS.
> 
> How much battery capacity do I need if I want to run full 100 watts? For planning purposes, I am assuming a 6 hour activation with a (highly optimistic I know) 60 QSOs per hour.
> 
> The PX3 will be powered by a separate LiFePo 4.8 aH battery, it will do just fine. My concern is the amount of draw I will need to last the 6 hours. With an inline (Hobby King) HK-010 Power Analyzer, I see a max current (KX3/KXPA100 combo) of about 8 amps and about 80 watts during a QSO. The QSOs varies between 50-80 watts on transmit.
> 
> I also know that once I am spotted, I can drop the power down to maybe 75-50 watts to save some battery juice.
> 
> I have 2 12v-18aH SLA batteries at the ready, am I woefully underpowered? If you have any real-world experience or tips, it is most valuable and appreciated. You can contact me offline at dave dot esquer AT gmail as well.
> 
> Thanks,
> Dave, K6WDE
> 
> 
> 
> 
> 
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