Posted by
Jerry Flanders on
Dec 01, 2008; 7:39pm
URL: http://elecraft.85.s1.nabble.com/VGA-cable-beware-tp1595397p1600271.html
Your research is not complete, if you actually meant ALC. Yaesu's
Quadra uses ALC as an emergency shutdown method to protect the amp in
emergency situations. It is REQUIRED.
I once had a flakey antenna coax open up when running full 1500 watts
on RTTY with an AL-1200 and blew up the output circuit. I was not
using ALC then. I use the Quadra now, and insist on using ALC per
Yaesu's recommendation.
You probably could not manually shut down drive fast enough in an
emergency to save the SS output devices if you were not using the
ALC. Tubes maybe. Either way, why risk it?
I agree that we shouldn't be trying to regulate power levels this way
- but as an emergency protective measure, it can save your butt.
Jerry W4UK
At 01:43 PM 12/1/2008, Jim Brown wrote:
>Modern power amps (built after about 1975) do NOT need AGC -- in
>fact, they often create lots of distortion (splatter, clicks,
>sideband noise) when you use AGC. The RIGHT way to control power
>(drive) is to use the power control on the rig that you're using to
>drive it. Simply bring up the power on the transceiver until you
>reach the desired power from the amplifier.
>
>While many power amps include an AGC line, their manuals often tell
>you not to use it. The manuals for my Ten Tec amps (Titan 425,
>Hercules I, Hercules II) specifically tell you NOT to use AGC.
>
>73,
>
>Jim K9YC
>
>--Original Message Text---
>From: Monty Shultes
>Date: Sun, 30 Nov 2008 10:02:50 -0500
>
>To get the ALC signal from the 15 pin DIN plug I was hoping to use a
>VGA cable, cut one end off, and wire it up accordingly.
>
>
>______________________________
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