5
5
5
DOCNUMBER 8410
Document Issue 1.1
August 2015
Page 5–5
RKR Designs LLC
Alpha 8410 Linear Amplifier User Manual
Operating the Amplifier
4. Turn the
OPR/STBY
switch to
OPR
.
5.
Proceed with the tuning procedure
.
Tuning by the
Recommended Dip-
and-Load Method
This is our recommended way to tune the amplifier.
Procedure 5-2
Tune by the recommended dip-and-load method
Step 1
Start up the amplifier as described in
“Start Up the Amplifier,” page 5–2
.
Step 2
Set the BAND, TUNE, and LOAD controls to the values given in your
amplifier’s specific tuneup table. Note that final TUNE and LOAD
settings will vary with operating frequency, antenna characteristics, and
power level.
Step 3
Please limit the transceiver drive to ~65 W for tuning and operating the
amplifier.
Step 4
Move the multimeter selector switch to
Ip
(plate current).
Step 5
Set the TUNE and LOAD controls to the values given in your amplifier’s
specific tuneup table.
Step 6
Key the amplifier with 20 W drive and adjust the TUNE control for a peak
in RF out that should be at the same point as a dip in Ip.
Step 7
Increase the drive to get 1000 W output, going back and forth between
TUNE and LOAD to peak the RF output. If more output is desired,
increase drive from the amplifier slightly, increase LOAD for a peak in
RF out, then peak RF out with TUNE control.
When the amplifier is tuned correctly on 160 through 40 m, the following
should be the case:
•
The Ip should range between 0.9A and 1.1 A (read on the 0–1.5-A
scale) for 1500 W output.
•
The input-drive power should not be more than ~60 W.
•
On 20 m, the Ip is usually ~1.0 A for 1500-W output.
Plate current (Ip) is the most useful parameter to monitor on the
multimeter bargraph during normal operation.
Step 8
Proceed to
“Operate the Amplifier,” page 5–7
.
Tuning by the Alternate
Nominal-Gain Method
This is an alternative way to tune the amplifier.
Procedure 5-3
Tune by the alternate nominal-gain method
Step 1
Start up the amplifier as described in
“Start Up the Amplifier,” page 5–2
.
