[Elecraft] ... and solar power

[George Dubovsky]

I posed the question to one of the Engineers at Morningstar. His response,
in part:





*That said, for low power MPPT really isn't a huge requirement.  The peak
power of those panels listed is only 15.4V.  When they are hot it will drop
further too.  SO charging a battery to 14.xV there is almost nothing to be
gained by mppt (and its more expensive AND lower running efficiency.)
Money is better spent on buying X more watts of panel w/ a cheaper
control.  You'll get more power out of it. The ProStar and SunSaver
controls even have a on/off mode jumper that changes the switching from
~300Hz to <=1Hz.  EMI isn't the problem there its the PSRR.  At 300Hz
current pulses from the panel, the battery voltage will jump up/down due to
its internal resistance (which goes up as it gets full.)  As you know, no
one in the mobile RF world uses regulators on the P12 supply instead just
running the amp transistors right off it.  So you can get a 300Hz 'buzz'
modulated into your audio pretty easily.  The <1Hz doesn't charge quite as
well but simply 'clicks' vs buzzes which people find much less
objectionable in their audio.  MPPTs switch so fast they have filtered DC
coming out so you don't hear that.  But they have conducted and radiated
EMI.  *
FWIW...

73,

geo - n4ua


On Mon, Dec 2, 2013 at 3:33 PM, Igor Sokolov <ua9cdc at gmail.com> wrote:

> Dave,
> Can you point to a "good" regulator and/or chjarger suitable for HF radio
> use?
>
> 73, Igor UA9CDC
>
>
>> Yes, very good.
>>
>> Alternative URL:-
>> http://preview.tinyurl.com/mznv6e2
>> Goes to the same place as quoted above..
>>
>> You can often find them on eBay too (for a price!)   I have a 45W
>> version. Take
>> care though, in bright sunlight, they can produce well over 28V to an
>> open cct or
>> low power load.  A good regulator is needed.  Otherwise, very good, and
>> very
>> portable.
>>
>> Sadly, many of the "good" regulators (with MPPT functionality) are not
>> exactly
>> "RF quiet" for HF radio users.
>>
>> 73.
>>
>> Dave G0WBX.
>>
>> ______________________________________________________________
>> 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
>>
>
> ______________________________________________________________
> 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
>