HEAT goes up!!!

[Lindsey97]

first off i am new to the forum and am learning alot. i have been into CB as a hobby for approx 20 years, and i have a few dump trucks now.

my question is: galaxy, connex and magnum are building radios with heat sinks located on the bottom. some have cooling fans, some don't. the last time i checked, radiated heat travels up in direction. so why are the radio makers putting the heat sinks on the bottom with the mosfets, and letting the heat have an easy, natural path to soak into the board of the radio. why dont't they install the heat sink on top with a hole for the fan? it appears to me that a radio would cool better, and last longer if the heat sink was on top. please correct me if i am misinformed on this idea.

also i am interested in in a galaxy 98vhp, connex 4600, or magnum S9-175. i am curious as to how to tell a magnum S9-175 from a S9-80 in person. can you run a serial number with magnum? does either radio have cooling fans? some pics of a s980 from the back and bottom would be awesome. i am not completely sold on just a magnum, i am currently looking at one for sale in an auction.

thanks, lindsey

[petriach]

I can only answer part of your post.

The reason for heatsink being on the bottom or back is because of 1.)aesthetics,no one likes looking at a heat sink,and 2.)most people install them where putting the heatsink on the bottom gives the most clearance for it.

And yes,having the heatsink on top with the fins facing up would probably work better,but for most of the devices we use,this is not necessary.

[Tucker442]

Hey Lindsey from what I have seen about the Magnums the s980 has the RFX unit on the back of the radio sticking out a little more than the stock S9, that keeps the heat out of the radio and works very well as for the s9-175 the entire bottom of the radio is a heat sink and has the name Magnum made into the heat sink visable from the front. From what I have read the Magnum radios use a little thicker material for the circuit board which makes them a little tougher than most radios, the heat sink on the 175 model is really the bottom cover for the radio so with all that heat sink size it takes care of the heat dissapation pretty well. The RFX-75 until will actually lower the power when it gets hot to keep the mosfets from frying themselves, kind of a great idea from my take of it. Depending on what your looking to do the S980 should be enough to be heard or drive the snot of any amp you want to use. If your going to use an amp that doesn't require power to drive it both radios have an out control to turn down the power also.

[Corn_Bread]

not an answer to your question and yeah heat does rise. and electrons dont like heat. but this is just a thought that ran thur my mind, just turn the radio up side down. or mount it where the radios heat sink is in clear air to dissapate heat.

[Night Crawler]

this is just a thought that ran thur my mind, just turn the radio up side down.

There you go problem solved

[warlock35po]

Yeah but then wouldn't that in the words of the old song turn a 6 into a 9 ? Regards warlock35po

[murdoc]

I couldn't agree more about the heat rising thing!!! I have seen Radio Active does a cool mod on the RCI-2970, they flip it and put the heatsink on top but the face panel/buttons and dials are all as they should be, able to be read!!! Don't know if they or anyone else does anything like this with other radios, such as the 4600 Turbo, 4300-300 etc... Never seen it done... I would sure like it done on my 4600 Turbo and 4300-300 connex radios, but I'm one of those that has a mobile setup that would allow the heatsink on top... Like others said, its not always practical for some installs...

[dirtyjob]

I know this post is old as dirt, just wondering if anyone has flipped their 2970n4 display so the heatsink is on top, if so whats involved , is it easily done ?

[MDYoungblood]

Hey, welcome back, long time no see. I don’t remember Mike doing a upside down RCI 2970, if he did it wasn’t highly publicized or it didn’t turn out well. I do believe the faceplate components are just jumped and the chassis section unscrews so flipping it is just the jumper length issue, nothing is physically attached to the main PCB. Only way to tell is to pop the lids on the radio and see.

3’s

Greg

[dirtyjob]

I figured there was a wiring issue to address, i will have to look into this

[MDYoungblood]

I figured there was a wiring issue to address, i will have to look into this

The issue in wiring would only be a length problem. There isn’t much slack.

3’s

Greg

[warlock35po]

Hey dirtyjob, I did the simple thing.Put a big **Censored** exhaust fan on the back wit a thermostatic control on/off switch for temp control.It is on an old Galaxy Saturn-Turbo.You know how prone they were to over heating if you got into a rag chew.If you think one big won't do it put two smaller ones evenly spaced.Regarfs,warlock35po

[443 Arizona]

i like Warlocks idea, and you could build a nitrogen tube chiller too if so inclined, like what the supergeek computer nerds have , , or just be a redneck like me and leave the covers off.