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Old April 23rd 09, 07:03 PM posted to rec.radio.amateur.equipment
JB[_3_] JB[_3_] is offline
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First recorded activity by RadioBanter: Apr 2008
Posts: 543
Default Tuning 40M on new Ameritron AL-80B Amp

"Bob D." wrote in message
...
I think I found the problem. The ALC SET control was set too low. It was
"capping" the output power. I couldn't see the LOAD peak because the ALC

was
holding the power down.

--
Bob D.


ALC on those takes a little getting used to.



"JB" wrote in message
...
"Bob D." wrote in message
news
The LOAD control on my Ameritron AL-80B has almost no peak on 40

meters.
Does this indicate something is bad?

The PLATE control peaks nicely on 40M.
The LOAD control peaks sharply on the other bands.
I'm getting full output power and good reports on 40M SSB.

I'm tuning the PLATE and LOAD controls for max output with 100W CW

input,
using a Cantenna dummy load.

--
Bob ND9B

See page 13 in the manual. They can be downloaded from the

Ameritron/MFJ
website.

Start with a dip in Plate current with PLATE adj.

What are you looking at for a "peak"? It should be tuned for maximum RF
output from the AMP. The peak should be shallow when properly loaded.

Because of the Q of the tank circuit, the adjustment is less sharp on

the
lower frequencies.

Perhaps the LOAD adj. is too far clockwise. Be careful not to exceed

grid
current. All this should be doable with less than 80w CW.