Re: SSPA cooling at mast-head
Bob Lockley VK6KW
toggle quoted messageShow quoted text
You will only get condensation on any cool surfaces within the box if warm moist air is drawn in to it.
In your case the temp inside during operation is likely to be higher than ambient so condensation is unlikely unless on the inside wall of the outer shell. Drawing fresh air through a ball of stainless steel wool will reduce the intake humidity as well as other undesirables, installing an internal ‘chimney’ so that exhaust air is drawn from nearest the top of the cabinet will ensure the removal of the warmest (most humid) air and further reduce the problem.
From: ukmicrowaves@... [mailto:ukmicrowaves@...]
Sent: Sunday, June 19, 2016 11:06 PM
Subject: Re: [ukmicrowaves] SSPA coooling at mast-head
Yes, the method proposed should work. Keep the hot and cold air as far apart as possible at the entry and exit points to avoid too much recirculation. I have two small axial fans outside the box on my 10GHz system, they worked fine for several years but you will need to clean the spiders out from time to time. They are well protected from rain with a plastic hood covering them. If the heatsink is outside the box and the PA inside you need to consider how the interface between them will be waterproofed. My 10GHz system has been at masthead for 16 years now without any failures so I wouldn't get too hung up about potential moisture issues, so long as you make sure condensate can't build up inside a sealed box.
I'm looking forward to hearing a big signal from IO81 soon!
On 19/06/2016 14:10, g4asr@... [ukmicrowaves] wrote: