[1000mp] Re: amps

[lhlousek]

Very interesting and informative amp info again.  Thanks!

I�ve pretty much ruled out the AL-1200 and AL-82 on the basis that they can take over 100W of drive to reach 1500W
depending on band.

That leaves the AL-800H and AL-1500.  Also in the running is the Alpha 99.  All get by with between 50 and 60W of drive.

It appears that among the 4 Ameritron 1.5KW amps, only the AL-1200 uses a tube with thoriated tungsten filaments.  The
800H is the only one that employs a fast grid current detection to protect the tube (also has dynamic bias control). The
AL-1500 is rated for full output only on the traditional bands (80% on WARC bands).  I assume 10 meters can be enabled
on the 1500 by a licensed ham although the Ameritron info doesn�t say so.

It was said the Alpha 99 wouldn�t go above 1.6 SWR.  I assume this is because the high SWR protection kicked in.  The
Alpha sense SWR and 6 other parameters to protect the tubes.  Among the Ameritron amps it appears only the 800H has any
protection circuitry and it is only for grid current and transformer temp.  With QSK it is $1100 less than the Alpha.

To me, it seems the only real downside to the 800H compared to the other amps is that it is rated for only 1kW constant
carrier instead of the 1.5kW.  I operate 99.9% CW and have no experience with RTTY .  RTTY may be constant carrier but
what is the typical TX/RX duty cycle?

Lou W7dzn