Small 12v fan for linear ?

[gmham]

Guys have an old Microwave Modules 100 watt 2mtr linear here and planning to fit a small 12v top mounted fan to the top heat sink . Plenty on eBay but not sure if the cheap ones are any good and pass enough air to be effective . Anyone done similar ?

[ch25]

I usually take fan out from broke PC power supply.
Any 12V fan will do.

[gmham]

Okay cheers will try avoid buying one off the light up led types ..don't want to add to the overall noise level on the radio itself !

[Auldgeek]

Okay cheers will try avoid buying one off the light up led types ..don't want to add to the overall noise level on the radio itself !

The Artic silent range are exceptionally quiet and provide very good airflow. They are quiet enough to run continuously if you don't fancy putting together a sensing circuit for either ptt or temperature.

I recently tamed a jet turbine fan that was fitted to a power supply by using one and I have them in my PCs. Definitely recommended.

80mm or 120mm but pick the silent series.

[gmham]

Perfect , cheers drew appreciatte that.

[gmham]

Further to the Artic silent series off small fans just wonder if they are easily enough adapted as supplied to run off say your shack 13.8v psu or do they come with a cable / plug for attatching within the pc etc

[Auldgeek]

Further to the Artic silent series off small fans just wonder if they are easily enough adapted as supplied to run off say your shack 13.8v psu or do they come with a cable / plug for attatching within the pc etc

As standard, they are fitted with a small 3 pin plug for connecting directly on to PC motherboards. Normally, these fans are controlled by PWM (pulse width modulation) which allows the fans speed to be directly controlled by temperature sensors on the motherboard.

However, you can bypass these by disconnecting the 3rd wire and run it directly from the + 12v rail. Alternatively, use a converter to an ATX type plug and then use the two wires from that.
Consider using a resistor to drop the voltage to the fan, as they do normally like + 12v, rather than 14v. They will run from 14v but their life span could be shortened.
You may also wish to supply the feed from the switched output of your amp, so that it only runs when your amp is on.

[gmham]

Great stuff thanks again drew.