[Elecraft] KPA1500 fan speeds and fan noise

[Ed Gray W0SD]

I have a KPA-1500  #171 and when I set the fans at 1 the air is being 
pulled from the back by only the middle fan on  the back. The air is 
exiting out the top cover, front, right.  This exit area is just a 
little over 5" x 8".  I feel a good deal of air coming out the top 
evenly distributed over the 5" x 8" area.

Set at position 2, 3, 4 and 5 all three fans run and the fan speed is 
increased with each setting.  2 is IMHO is not very noisy, 3 is more 
noise than I like if ran continuously. Sporadically would be OK assuming 
it would not be needed a lot. 4 and especially 5 are noisy.  However I 
would think you would only need 4 or 5 with lots of TX in RTTY or WSJT 
modes so one would not need to be concerned about mic pick up however I 
will say 4 and 5 are not pleasant to listen to.  More to be learned by 
me but I suspect letting the fan be regulated by the temperature rather 
than a fixed setting may be the way to go for lots of TX in RTTY or WSJT.

Anyway the air comes in the back and goes out the top cover on the KPA-1500.

Ed W0SD



On 5/21/2018 9:13 AM, ANDY DURBIN wrote:
> >From the KPA500 kit build manual:
>
> "If airflow arrows are visible on the fan housing, they will show that air will be blown out of the back of the KPA500."
>
>
> It was a bit surprising to me that the KPA500 fan airflow is the opposite of natural convective flow but I accepted that was the intended design.  My KPA500 fan does pull air in the top and exhaust it out of the back.
>
>
> "They are running on a 19-volt supply at a slow but effective cooling speed and are very quiet (drawing air upward)."
>
>
> Do the KPA1500 fans push air into the box? If so, why doesn't the KPA500 fan do that. If the KPA1500 fans pull out of the box why would it be appropriate to use an additional fan that opposes this airflow?
>
>
> 73,
>
> Andy k3wyc
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