Specifications

**But tranceiver ALC control characteristics are not standardized; each model has
its own unique gain and dynamic characteristics. (Internal ALC in
tranceivers works well because the ALC source and controlled stages are
designed together as a system.)
ALC feedback from Alpha 87A to tranceiver normally isn't necessary because
the power output of most modern tranceivers can be quite accurately
controlled ....and because the Alpha 87A's grid current limiting system
easily absorbs occasional drive peaks. Extensive tests with TS-859, TS-940,
TS-950, IC-761, IC-781, FT-1000 and TR-7 tranceivers have revealed no need
for Alpha 87A to tranceiver ALC feedback to achieve excellent results.
However, the 87A does incorporate an excellent and versatile ALC generator
so that the rare cases where tranceiver output cannot be controlled
adequately usually can be handled by using the ALC feedback if the
tranceiver has an input for negative-going-from-zero ALC. (This type of ALC
is standard with most modern tranceivers)
In this case connect the tranceiver ALC input to the Alpha 87A's phono-type
ALC jack with a shielded cable and turn the ALC adjust pot fully clockwise
to start (except set to mid rotation when using Icom tranceivers).
The adjustment goal is to use the smallest amount of ALC feedback (the least
clockwise rotation of the ALC pot) that will eliminate overdrive faults and
distortion. No hard and fast universal procedure exists but the
following....."
A post from the TenTec archive from contesting.com also said: "I have had my 87A for 10 years, I have used it with a very
wide range of
tranceivers and have never found it necessary to utilise the 87A ALC output."
Here's the web link for Alpha: http://www.alpha-amps.com/manuals.asp
73, Chris
ALC Adjustment Procedure
by WA2JJH on February 12, 2005 Mail this to a friend!
How about this. All new rigs and amps will have to have a BLUE TOOTH CARD.
You set up your rig any way you like. The BLUE TOOTH
INTERFACE in Your New amp will read your rigs ALC constants, flat top drive level, -33db down level, then
come up with an ALC curve approximation.
All the correction will be done in the amp!. The amp will switch in attenuators or adjust ALC generator to add or subtract
ALC SLOPE, time delay, and attact.
The goal would be max PEP(1497w), minimum distortion, and meet FCC IMD and spur specs. -33db down 2 tone, 40 db
down.
If the Amp Cpu decides it is a matter of too much mic. gain or speech proc. the amp goes into LID mode.
The amp is bypassed. The RF out of your rig gets routed to a DUMMY LOAD. THE BUILT in speech synth will tell you
what to crank down on your rig.
MIKE GAIN DOWN, DOWN MORE, CUT OFF SPEECH PROC. PLEASE READ MANUAL ON MAXIMUM
COMPRESSION. YOU HAVE JUST CUT 200 HOURS OFF THE AMPS LIFE
LID ALERT!
IT HAS BEEN DETERMAINED YOUR THE TYPE THAT SHOULD NOT HAVE AN AMP...........
TUBE FILIMINTS WILL BE DESTROYED IN 5 SECONDS.