[Amps] Question: Ameritron AL-80A tuning

[NW7US, Tomas]

Hi,

I am using an AL-80A and have need as an Army MARS and National Guard Net  
member to utilize frequencies far out of normal Amateur Radio  
allocations.  I am finding it hard to get the Amp to tune on certain  
frequencies "out of band" - I can get about 100 watts on those problem  
frequencies.

I suspect that the filter netwoks in this Amp prevent it from being used  
too far out of frequency.  Is that true?

For instance, let's say that I need to be on a frequency close to 5 MHz.   
I cannot get more than about 100 watts out of the amp.  However, if I am  
just above 4 MHz, I can get full power out.  So - it must be a filtering  
issue.  In this case, I am keeping the BAND switch on 80, and the PLATE  
ends up around the 40 section, and LOAD is between 5 and 6.  I have tried  
other positions, and nothing works nearly as well as this - but this  
position only gets about 100 out.

Now - is there a mod for the amp that would allow a wider range to tune??   
Or, do I give up on this amp for MARS usage?

Thanks in advance.

-- 

73 de Tomas, NW7US (AAR0JA/AAA0WA)

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