Re: Water cooling question

Robin Szemeti - G1YFG

I think extra credits should be given in contests to people using water cooled valves :) ... it is such a big effort to make for the power.  I actually found my watercooled  PA stage in a box this week, where it was put for storage 25 years ago ... I don't think I will rebuild it, there is no PSU .. these days it is easier to build a big LDMOS PA .. but there is some good fun to be had building a water cooled PA, even if only for the excitement of trying not to die from the electricity!

On Wed, 13 May 2020 at 18:37, Conrad, PA5Y <g0ruz@...> wrote:

Ben don’t be daft! It’s a journey, it takes years to get there and that is the fun of it. Besides it could be argued that low power operation is equally satisfying, it’s just different. I am trying to work people over 400-600kms away when I do the UKACs. Or EME. In both cases the ERP is necessary, on EME to overcome the path loss and during the UKAC to overcome splatter from UK based stations. It does not always work but I like to try,


In every contest I work guys running 10W @ 500kms distance, not easily but I don’t give up.


If I had loads of money I would not be using a surplus TV transmitter amplifier that needs water-cooling.  That is seen as a barrier by most and so the price was low. It took me a while to get it going and I am still learning. Last night was good because nobody was answering me and 4.5hrs of almost constant CQs proved that it is quite reliable at least.




Conrad PA5Y




From: <> On Behalf Of militaryoperator via
Sent: 13 May 2020 18:10
Subject: Re: [UKMicrowaves] Water cooling question


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.

-- ----------------

OMG........ water cooled pa's.............. strikes me that with my dismally pathetic 25watt no matter how well 'I' hear this BIG signal 
the same will not happen in reverse. 
Guess its time to throw it all in the skip and stop wasting time, mine and the station who can't hear me...... 

Pity the pubs are shut. Hey ho. 


Best regards,

Robin Szemeti

Redpoint Consulting Limited

E: robin@...
T: +44 (0) 1299 405028
M: +44 (0) 7971 883371

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