Re: Water cooling question

Conrad, PA5Y

I have a 120l barrel but actually it would be a nuisance. The room is adjacent to the shack so I don’t worry about blowers and the such like but at no point did I say that I had plenty of space. Its 3 x 4 x 2.4m and of course you forgot to allow for the ‘junk factor’. It’s a space so I already filled it!


It sounds much grander than it is although it does have airco 😉




Conrad PA5Y


From: <> On Behalf Of Ian White via
Sent: 13 May 2020 16:53
Subject: Re: [UKMicrowaves] Water cooling question


As others have said, it's difficult to remove heat from a coolant that is barely above room temperature itself. On the other hand, it's very easy to increase the total mass of water and continue to use passive cooling.

Changing to a full-size 110 litre dustbin would reduce the temperature rise by a factor of 2 and increase the surface area for passive cooling by a factor closer to 4. Next step in that direction would be a 240 litre wheelie bin. It sounds like you have space enough for that.


Another data-point from the 2C39 days is that K2UYH used to operate a water cooled ring of 8 for a whole EME weekend using a large bin with no other cooling.


73 from Ian GM3SEK



On 13/05/2020 10:03, Conrad, PA5Y wrote:

Last night I ran my new water-cooled PA for 4.5hrs during the NAC/UKAC. I use 50l of distilled water in a barrel and a 30l/min pond pump. It all worked fine but the water was lukewarm so I was thinking that a small car heater radiator might be appropriate? I will bring the thermocouple from work and make some measurements but I estimate that the water was less than 30 deg C. I was wondering if these cheaper and small car heater radiators would help? Ironically I don't care about fan noise as I have a machine room next to the shack. It's an ex broadcast PA and just happened to be water-cooled and cheap. 


I have no idea how much heat such a radiator with a fan would take out of the water.




Conrad PA5Y

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