Affordable heat sink for dummy load

[LTig]

Does anybody know a source in the EU for an big affordable heat sink? I've got 16 resistors 1 Ohm/50W (ARCOL HS50 series) but the cheapest passive heat sink I could find (austerlitz electronic KS 300.6-100E, 0.3 K/W, 300mm x 100mm x 83 mm) was 40€ for 8 resistors (which means I need 2) , and it's probably not big enough for long term tests (haven't done proper calculations yet). My attempts to find suitable pieces of aluminium at a local smithery and recycling place were naught.

 

[NTK]

AliExpress?
https://www.aliexpress.com/item/327...68#1000022185#1000066059#0_668#3468#15614#599
What's your heat dissipation requirement and for how long? Have you considered adapting CPU coolers for your purpose?

[Edit] Looked closer at the heat sink you found, it isn't any more expensive compared to those on AliExpress. At 235 g/cm, the one you are looking at (100mm length) weighs 2.35 kg and is a pretty substantial heat sink.

 

[pma]

Guys, it is piece of good expensive material, not a mass produced plastic junk like most things discussed. So it costs money. Quality is expensive, junk BS is cheap.

 

[gene_stl]

Ham Radio operators use a "Cantenna" dummy load to test their kilowatt transmitters. They are metal paint cans villed with oil. Sized from one to five gallons depending on how big your transmitter is.

 

[raindance]

Don't laugh, but I used to simply dunk my dummy load in cold water. Did lots of testing on PA amps under repair that way.

 

[LTig]

Don't laugh, but I used to simply dunk my dummy load in cold water. Did lots of testing on PA amps under repair that way.

I actually thought about this, but I'm not sure about the connectors having contact to the water.

 

[NTK]

I actually thought about this, but I'm not sure about the connectors having contact to the water.

You can dunk it instead into cooking oil.

 

[gattaca]

You can use simple water heater coils, in multiple configurations, with the coil submerged into a 5 gallon bucket of water... I saw someone build one of those somewhere a while back.

 

[RayDunzl]

I actually thought about this, but I'm not sure about the connectors having contact to the water.

Pure (distilled or deionized) water is not very conductive.

 

[gattaca]

Since the water heater coils are designed to be in contact with water, (NOT THE CONNECTOR ENDS), maybe I did not understand the question. The photo I recall seeing somewhere had an engineer made a grid of "water heater elements" submerged into the bucket of water so he could change the loading by re-arranging the jumpers. I cannot put my hands on the thread right now..

These --> https://www.amazon.com/Dernord-Immersion-Submersible-Heating-Element/dp/B01M34BZBO/ref=sr_1_8?dchild=1&keywords=2000W+water+heater+element&qid=1608658749&sr=8-8&th=1

Found it scroll down a few pictures, the thread is relevant to your ? too -> https://www.avsforum.com/threads/measuring-amplifiers.855865/

 

[pma]

Water is one of the possible solutions. Or a heatsink with heat-pipe inside.

https://www.radianheatsinks.com/heatpipe/

 

[Helicopter]

You can use simple water heater coils, in multiple configurations, with the coil submerged into a 5 gallon bucket of water... I saw someone build one of those somewhere a while back.

Pretty hard to beat this. 9.6 ohm 1500W liquid cooled resistor for about $6 each.

 

[JohnYang1997]

I use a board consists 50 or so 5W metal film resistors in series. It doesn't need cooling.