Date: Thu, 5 Apr 2012 08:21:10 +0930
From: "Leigh Turner" <invertech@frontierisp.net.au>
Subject: Re: [Amps] amp cooling / triodes vs tetrodes
Good point Peter. That higher ZSAC is completely subsumed and absorbed into
the total plate current when the amp is producing RF output.
An EBS controlled amp provides its best efficacy in standard PTT SSB mode
operation. EBS yields lower heat dissipation improvement in VOX operation.
73
Leigh
VK5KLT
## he’s dead on too. EBS and PTT is good. EBS and VOX SSB is a waste of
effort.
Its not fast enough to bias off between syllables and words. It only works
between the
last word spoken..and when the vox drops out. With a typ 300-500 msec vox
delay,
ur wasting your time with ebs.
## I have seen a lot of them that wont work, even on PTT, since the back grnd
noise is too high. And cranking up the threshold is not the answer either.
ON4UN
tried that in one of his older low band dx books. he would set the threshold
just above the
noise back ground. IOW, he was trying to use the EBS as a noise gate as well.
That’s a
disaster on the air. If you use a real audio type noise gate or downward
expander, at least
your EBS will have half a chance at success.
## On CW, ebs is fubar engineering. Just crank up the bias V... so the idle
current is reduced to
a miniscule amount. Problem solved. Since EBS isnt required at all for
CW-FM.... and buys
you almost next to nothing in heat redux on VOX ssb.... I dumped the ebs.
EBS doesn’t work at
all on ESSB mode, not with low freq audio portion of it.
later... Jim VE7RF
a,It
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