Heat Sinks 2

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Heat Sinks 2

Postby Phil G4ZOW » Fri Feb 21, 2003 9:31 am

Hi Guys,

I'd be interested to know the smallest size heatsinks that are being used on both the PA and modulator in the 350w TX's.

What's the total heat dissipation of both the PA and modulator?

I'd like to keep construction fairly low profile and don't blowing the sinks in a slim 19" rack.


Phil G4ZOW
Phil G4ZOW
Posts: 16
Joined: Fri Feb 21, 2003 9:16 am
Location: London, United Kingdom


Postby frank carcia » Fri Feb 21, 2003 4:07 pm

My heatsink is 17 inches wide and fits in a rack. My FETS sometimes hit
100 degrees "F" on a hot summer day. I monitor the case temperature
of one of them all the time.The heat sink is quite large with 3 inch fins.
The fins point up while mounted in the rack. The best way to mount a heat sink is with the fins vertical so my configuration isn't the best but there
is so much area it works fine. I think 1 of 1 1/2 inch fins would be fine.
The heat sink is 10 by 17 inches with 3 inch fins. Very over kill.
My modulator has a 8 by 8 inch heat sink with 1 inch fins, again pointing up. It runs cool at 350 watts carrier 1500 watts peak. My efficiency is
just over 90 % in the final and around 91 % modulator (PDM)
Pictures in Blaine's area. wa1gfz
frank carcia
Senior Contributer
Posts: 765
Joined: Fri Jan 31, 2003 10:48 am
Location: Enfield Ct. / Niantic Ct.

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