Trust not thine holy high powered boxes of pill to mere heateth of sink. Add a fan.
Heat sinks can do the job on small equipment. The factory heat sink on the back of a medium power radio (35-50 watt p.e.p.) usually do the job fine with no extra help.
But move up to any sort of pill box or a radio doing 100 watts or more and ya get into forced air territory. You can get by without it if you tend to talk very little and/or your transmissions are typically brief.....but that's no fun. Everybody in my neck of the woods are broadcast grade bucketmouths and were born to talk.
Pill boxes, even with seeming large heat sinks will get hot !!
Heat is the enemy of electronics particularly transistors so why take a chance when you can add a small fan on the cheap?
Another example is the RCI 2970 mobile version with the full across the bottom heat sink. I'm running one now for a base unit. It looks big (heat sink) and it is big but I'm a ratchetjaw and with the dead key set to 25 watts and easy swings to 60-80 watts with normal voice the radio will get hot in just a couple of minutes. So I have raised the radio up off the table 3 inches and have a typical 1" deep by 4" square 12 volt box fan, such as you see in computers, sitting underneath it. I added 1" standoffs to the fan to raise it up off the tabletop so it can draw air and this one little fan blows plenty enough air to keep the 2970 cool and I can operate all I want continuously.
Have another 4" fan with standoffs mounted on top of a 2 pill Texas Star 350 next to it and provides all the cooling needed for it.
These 12 volts fans, depending on make, type and condition, may be noisy and moving more than the necessary amount of air to keep this sort of gear cool. On a base station you make think first of simply wiring a fan to the power supply that the radio and amp is running on. You may further be running the power supply voltage at 14-15 volts. This 14-15 volts will really be pushing these little fans and they may simply be overly noisy especially right at a radio and near your mic.
You can easily reduce the speed, and therefore the noise, of a 12 volt fan by adding a 100 ohm potentiometer in the power line of the fan. Typical pot always has 3 terminals. Attach incoming voltage from the power supply to the middle terminal and the wire to go to the fan to either side terminal. Just pick one and leave the other side blank. Now you have an adjustable speed fan! You will find that these fans move plenty of air when turned down to 9 or 10 volts and it's not necessary to know or measure the voltage....just adjust the speed with the pot until the fan noise suits you and it seems like it's moving plenty of air to do the cooling job.
Moral of Chapter 37: Don't be a fool, keep your high power gear cool
Heat sinks can do the job on small equipment. The factory heat sink on the back of a medium power radio (35-50 watt p.e.p.) usually do the job fine with no extra help.
But move up to any sort of pill box or a radio doing 100 watts or more and ya get into forced air territory. You can get by without it if you tend to talk very little and/or your transmissions are typically brief.....but that's no fun. Everybody in my neck of the woods are broadcast grade bucketmouths and were born to talk.
Pill boxes, even with seeming large heat sinks will get hot !!
Heat is the enemy of electronics particularly transistors so why take a chance when you can add a small fan on the cheap?Another example is the RCI 2970 mobile version with the full across the bottom heat sink. I'm running one now for a base unit. It looks big (heat sink) and it is big but I'm a ratchetjaw and with the dead key set to 25 watts and easy swings to 60-80 watts with normal voice the radio will get hot
in just a couple of minutes. So I have raised the radio up off the table 3 inches and have a typical 1" deep by 4" square 12 volt box fan, such as you see in computers, sitting underneath it. I added 1" standoffs to the fan to raise it up off the tabletop so it can draw air and this one little fan blows plenty enough air to keep the 2970 cool and I can operate all I want continuously. Have another 4" fan with standoffs mounted on top of a 2 pill Texas Star 350 next to it and provides all the cooling needed for it.
These 12 volts fans, depending on make, type and condition, may be noisy and moving more than the necessary amount of air to keep this sort of gear cool. On a base station you make think first of simply wiring a fan to the power supply that the radio and amp is running on. You may further be running the power supply voltage at 14-15 volts. This 14-15 volts will really be pushing these little fans and they may simply be overly noisy especially right at a radio and near your mic.
You can easily reduce the speed, and therefore the noise, of a 12 volt fan by adding a 100 ohm potentiometer in the power line of the fan. Typical pot always has 3 terminals. Attach incoming voltage from the power supply to the middle terminal and the wire to go to the fan to either side terminal. Just pick one and leave the other side blank. Now you have an adjustable speed fan! You will find that these fans move plenty of air when turned down to 9 or 10 volts and it's not necessary to know or measure the voltage....just adjust the speed with the pot until the fan noise suits you and it seems like it's moving plenty of air to do the cooling job.
Moral of Chapter 37: Don't be a fool, keep your high power gear cool
