[Flexradio] [SPAM] Re: thank you SDr

[Tom Thompson]

In the homebrew , 600 watt amplifier that I built, I placed the SWR 
bridge before the filters so the amplifier will fault if the antenna is 
wrong or the bandswitch is wrong.  The fault mode just does not allow 
the amplifier to be in line.  If it is a high SWR that causes the fault, 
then the exciter cuts back the power after the amplifier faults and 
takes itself out of the line.  My amplifier also faults with over drive 
and over temperature.  It really should be the amplifier that handles 
these conditions, so that the amplifier can be used with a variety of 
exciters.

Tom Thompson   W0IVJ

Robert McGwier wrote:

>FireBrick wrote:
>  
>
>>Maybe I don't understand but...
>>In the Quadra, ALC is also used to cut back ft1000mp power in case of 
>>wrong antenna selection.
>>The high swr, would cause the Quadra ALC to shut down exciter power to 
>>protect the Quadra finals.
>>Especially in dxing or contesting, it's so easy to select the wrong 
>>antenna.
>>And, as you move around in a band the swr varies slightly.
>>In my case, the 80 dipole it can vary greatly.
>>
>>Maybe I need to understand how the ALC in the Flex works to prevent a 
>>higher swr from overloading the Quadra.
>>I know that a high swr/high drive situation will trip out the Quadra.
>>    
>>
>
>Now that is something I had not considered.  There is not a feedback 
>mechanism that would allow us to know the Quadra saw a crappy load.  In 
>this case, it would see the 50 Ohm input of the Quadra input circuit and 
>be happy to rock right along at full power.  That is a valid input.  Who 
>has not contested and hooked up the wrong antenna?
>
>  
>
>>when I had my MP/Quadra combo, if I errored and my 80 tuner was set for 
>>cw and I was in ssb, the ALC from Quadra backed down the MP before it 
>>could trip out.
>>
>>    
>>
>
>Bob
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