KNS80 Question

[Bob - S50]

I didn't see anything about this in the archives so I'll ask.  I apologize if it is a repeat.

 

For those of you that have a KNS80, do you have a cooling fan for it?

 

Our DME died and I've now read a couple places that the DME section gets pretty hot and needs a cooling fan.  I'm just wondering if it really does or if King and the repair shops are saying that to cover their back ends.  If it really needs the fan, I'd hate for us to pay for repair and have it burn out again.

 

Thanks,

 

Bob

[N601RX]

Mine has been repaired a few times due to power supply components failing. I added a gps last year that required a cooling fan and removed the ram air cooling system. I connected the kns 80 to the fan also. If it's stuck in the stack between older equipment it will get pretty hot. The install manual for it says it must have a cooling fan and that ram air is no longer good enough. That leads me to believe that at some point it must have been considered acceptable to use ram air cooling.

[RJBrown]

I had a KNS80 in N231NH. It had ram air cooling for the radios when I bought it in 1992. I noticed moisture was getting in the radio displays. I had a cooling fan installed at that point and never had any failure over the 10 years I owned it.

[N601RX]

Here is what moisture did to a friends 340 audio panel.  It was only a few years old and was unrepairable. It and a 430 were left unprotected in the drawer of a toolbox for about a year while work was being done on the plane. 

[Bob - S50]

Thanks to all of you.

 

Ours is at the bottom of the stack below the audio panel and the GPS.  I'm not sure how cooling air from a fan could be forced over the top to help cool it.  That's why I was wondering.

 

Bob

[N601RX]

It has a hole in the back that a tube from the fan connects to blows cool air into.

[Bob - S50]

Thanks again to all for the input.

 

Bob

[N201MKTurbo]

Here is what moisture did to a friends 340 audio panel.  It was only a few years old and was unrepairable. It and a 430 were left unprotected in the drawer of a toolbox for about a year while work was being done on the plane.

I had good luck fixing corroded PCBs by glass bead blasting them. It will remove the solder mask and silk screen from the board and components but it will work again.