Re: 50W PA Damaged


George Korper
 

Using Allison's suggestion, a 4 amp fuse sometimes will blow before the finals in the
event of no antenna connected. Also using Allsion's tapping technique is easy and makes
replacing the two IRF510's a breeze. 
Having this occur doesn't mean you're an idiot. 
Sometimes I have left the house without a mask, and then I feel like an idiot. 
Now I leave one in the car!
It happens to all of us one time or another. I have made use of three sets of spares (hi hi)
Just make sure you order 10 at a time (five sets) as they are not expensive and use a Vishay or equivalent high quality
part from a supplier like Digikey or Mouser. 

On Sat, May 30, 2020 at 7:46 AM Bill Cromwell <wrcromwell@...> wrote:
Hi,

It isn't possible to pass laws nor make any equipment of any kind "idiot
proof". As soon as we design or legislate to protect from idiots then
better idiots will be made :)

73,

Bill  KU8H

On 5/30/20 7:12 AM, geoff M0ORE via groups.io wrote:
> I don't think any ATU will prevent damage to a transmitter due to human
> error. The commercial and military  equipment employ extensive circuitry
> in the transmitter to take care of such mishaps and shut down to a safe
> level. A soldier under fire can be forgiven for not checking the aerial
> matching. Likewise, an aerial on a vehicle may be damaged without the
> operator being aware of the damage.
>
> An ATU is basically a means of transforming one impedance to another. If
> no load is connected i.e. a very high impedance, then that is reflected
> back through the ATU to your transmitter as a very high impedance. Hence
> the blown finals.
>
> You could design an interlock system such that if the aerial is not
> connected the transmitter does not power up.

--
bark less - wag more



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