[Elecraft] KX2, KX3 supply voltage

[Nr4c]

A 1.5 A regulator isn’t going to handle the 12 to 20 A drain of an HF Radio. 

Sent from my iPhone
...nr4c. bill


> On Jul 18, 2018, at 11:22 PM, Bob McGraw K4TAX <rmcgraw at blomand.net> wrote:
> 
> Why not use a 7812 three terminal regulator?   It will accept up to 30 V on the input, deliver 12 V on the output at 1.5 amps. These cost about $1.50 or less.    If one needs more current then add a 2N3055H as a pass transistor for up to 5 amps of current.
> 
> Another choice is a regular AC 120V power supply, remove the transformer and bridge rectifier, feed the 24 volts to the unregulated input, where the bridge rectifier was connected and you have 12V DC regulated.   These should be available for $10 to $20 new.  just don't buy a switching supply.
> 
> 73
> 
> Bob, K4TAX
> 
> 
>> On 7/18/2018 9:50 PM, Dennis Haarsager wrote:
>> I just bought a 24V 3.5A battery to power my CPAP machine when AC isn’t available. Would be nice if I could use it to power my KX2 or KX3. 24v-12V down converters are cheap, but the only 24V-13.8V one I’ve found so far is an order of magnitude more. Does anyone think the extra cost is worth it in terms of extra tx performance?
>> 
>> 73,
>> Dennis, N7DH/1, MM/N7DH
>> 
>> Sent from my iPhone
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Elecraft at mailman.qth.net
>> 
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to rmcgraw at blomand.net
> 
> 
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to nr4c at widomaker.com