Uploaded June 2018 | Updated September 2026, 2 weeks ago
The Heathkit SB-104 and HW-104 are some of the best Amateur radio Heathkits produced of course that is my opinion . I First saw a prototype SB-104 back ( guessing here ) in 1964 at a Ham club meeting in South Bend Indiana the plug in circuit boards and all solid state really caught my interest at that meeting . Recently the heat sink on my HW-104 was quite hot after a long QSO . Those Final transistors can stand a lot more heat than me but they are also very hard to find these days. So would it be possible to devise a simple way to mount a fan on the heat sink ? I saw a simple method to do that on the Icom 706MkiiG on the internet using plastic wall anchors . So a short time later I found that cheap 1/4 inch plastic wall anchors would work between the cooling fins of my HW-104 . The fan I have is a thin one so the 1 1/4 inch #8 screws work fine however with a thicker bigger fan you may have to obtain some longer sheet metal screws. Ordinary machine screws might work as well you just need a nice snug fit of the anchors between the slots on the cooling fins notice that the resistors are in clear heat shink tubing so they won't short out . The fan I used here was out of a junk computer power supply it is absolutely silent running with the 100 ohm resistor in series the fan is thin about 1/2 inch thick is all . Note the little rattling sound you may hear on this video is not from the cooling fan it is from something else in my work shop I am not sure what ? I have noticed that rattling sound on other videos I have made . NOTE a Small 12 volt power pack that plugs in the wall could be used to power the fan with NO connections to the rig also this setup could be used on a lot of other rigs and it can be removed in seconds with no physical damage to the rig 73 Bob
The Heathkit SB-104 and HW-104 are some of the best Amateur radio Heathkits produced of course that is my opinion . I First saw a prototype SB-104 back ( guessing here ) in 1964 at a Ham club meeting in South Bend Indiana the plug in circuit boards and all solid state really caught my interest at that meeting . Recently the heat sink on my HW-104 was quite hot after a long QSO . Those Final transistors can stand a lot more heat than me but they are also very hard to find these days. So would it be possible to devise a simple way to mount a fan on the heat sink ? I saw a simple method to do that on the Icom 706MkiiG on the internet using plastic wall anchors . So a short time later I found that cheap 1/4 inch plastic wall anchors would work between the cooling fins of my HW-104 . The fan I have is a thin one so the 1 1/4 inch #8 screws work fine however with a thicker bigger fan you may have to obtain some longer sheet metal screws. Ordinary machine screws might work as well you just need a nice snug fit of the anchors between the slots on the cooling fins notice that the resistors are in clear heat shink tubing so they won't short out . The fan I used here was out of a junk computer power supply it is absolutely silent running with the 100 ohm resistor in series the fan is thin about 1/2 inch thick is all . Note the little rattling sound you may hear on this video is not from the cooling fan it is from something else in my work shop I am not sure what ? I have noticed that rattling sound on other videos I have made . NOTE a Small 12 volt power pack that plugs in the wall could be used to power the fan with NO connections to the rig also this setup could be used on a lot of other rigs and it can be removed in seconds with no physical damage to the rig 73 Bob
