{Collins} 30S-1

["Steve Darveniza" <stevedz@xxxxxxxxxxxxxxx>]

Hi All,,there is a europeon website (still aroundI hope) where the original 2 pole blower motor has been changed out for 4 pole higher flow type.The author described a light dimmer type electronic speed controller that varied the motor speed/ air flow and hence reducing background noise at will.My 30S-1 has it fitted and it is the best of both worlds.As Floyd rightly reminds us ,if you look down through the top anode assembly of a 4CX1000A and a 1500B you will see that there is 40% more cooling fin surface area on the 1500B.The 1500B has to have a higher static pressure delivery from the blower to effect the same cooling mass flow provided to the 1000A.
Also the 1500B delivers  cleaner RF and the grid is more robust.The 1000A has a "glass grid" it will  tolerate hardly any dissapation at all ,where as the 1500B will sustain 15 watts all day. As the archives will remind us, for an extra S point on some one's receiver the 1500B will deliver quite a bit more RF if the screen voltage is also increased along with the higher airflow needed.An interesting side to this is that the OEM 30S-1 blower is exactly the same as the 1950  KW-1 blower.
73 from VK4VN