[BC] SS versus thermionic finals

[Ronald J. Dot'o Sr.]

I wrote an article on EMP suppression for Radio Guide which was intended for 
A.C. power and lightning protection.  I think it appeared in the March and 
April issues of 2005.  It's a good idea as power spikes gradually weaken ss 
devices causing eventual failure and doesn't do the caps much good either. 
The ATU can be protected with gas gap suppressors to bypass lightning.  The 
A.C. power should have big MOV's going to a good ground to bypass the A.C. 
power spikes both in the studio and in the TX plant.  It's also a good idea 
to suppress the power service at home to protect your computer, stereo, TV 
etc.  Every time a motor starts (fridge, air conditioning, furnace, power 
tools etc.) it puts a spike on the line.  If you and your neighbor are on 
the same pole transformer you get their spikes too.  It doesn't cost that 
much when you factor in the cost of the equipment being protected.

Ron D


----- Original Message ----- 
From: "Robert Meuser" <Robertm at broadcast.net>

>
> Remember with both lightning and EMP what does not come down the antenna 
> can come in through the AC supply which is solid state regardless of the 
> RF amplifier technology.
>
> R
>
>
> John Lyles wrote:
>>
>>I wonder if people worry about this anymore: Lightning susceptability and 
>>EMP
>>
>>SS transmitters require active or passive lightning protection on the 
>>output, whereas tube finals don't, due the nature of the design having 
>>high voltage DC already.
>>EMP. Solid State transmitters don't have a chance with this. Of course, 
>>the days that we worry about USSR dropping the bomb here are gone. But the 
>>chances of an airborne explosion of a nuclear device, can generator 
>>horrendous impulse. Tube finals survive it, SS don't. Its a given. 
>>Hardening can be applied, as the military has done, but significant cost 
>>added.
>>Just another thought to factor in besides cost alone.
>