Hi Jim,
I think the easiest way is to tune and load for maximum output, then reduce
drive to find the power output at the compression point by reducing the
drive level and retuning to maximum output again.
Lets say at 2KW output gain is 19db.
Reduce drive until gain increases to 20db at the 1db compression point.
With very low drive gain sometimes appear much higher, especially with your
oversized power supply capacitor.
For more look at this German webpage:
http://de.wikipedia.org/wiki/Kompressionspunkt
73
Peter
-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
Behalf Of Jim Thomson
Sent: Mittwoch, 30. Juni 2010 14:40
To: amps@contesting.com
Subject: [Amps] 1 db compression point procedure ?
Ok
What's the exact procedure for finding the ..'1db compression point' on a
HF amp ??
I have conflicting info on the procedure. With hardly any drive, the typ
HF amp has a
lot of gain. As drive levels increase, the gain goes down. Question
is.... where is the
starting point of all this?? With 1 watt of drive... or 5w or what ?
It makes a big diff
to the results.
I'm assuming the amp is 1st tuned to say normal power output... like
1200-1500w out..
IE: tune and load tweaked for max power out at normal power, then maybe
increase the
loading a tiny bit [ slightly more Un meshed].
Then leave the tune and load caps alone... and reduce drive to a very small
amount... and then measure
both the drive to the amp... and also the power output of the amp [ say 1-5
w of drive.. and 20-100w out]
Then start increasing drive level a bit and measure the gain once more
[ it should be dropping off a bit]
Does this procedure have to be done with a cxr.. or can we do it pulse tuned
?? Have I even got the
procedure any where near correct??
I take it, we don't want to operate the amp beyond the point where the gain
drops by 1 db ? But
where is the starting point ?
I can also tweak the bias on the GG amp quite a bit.
tnx.... Jim VE7RF
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|