Asymod IIIs, Installation Manual, Page: 3 / 57

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General Description
The Asymod IIIs compact design makes it ideal for mobile and base station operation and allows for
internal mounting and simple installation in the transceiver with the included hardware and only
requires a 12 Volt supply.
Improvements in the Asymod IIIs Include selectable passive and active low pass filters, Remote Control
on board Solid State switch for ease of installation on multimode transceivers, enhanced RF suppression
and single-supply design providing quieter very low noise operation. New onboard preamplifier with
independent input and output to be used in any installation where audio levels need to be matched as it
applies to the SSB Balanced Modulator input levels or as a microphone preamp in series-loop
configuration into the Line-In input. See the
Asymod IIIs Description Manual for more details.
The Asymod IIIs allows for amplitudes in excess of positive 300% modulation while not exceeding the
negative peaks at negative 100%. The Asymod IIIs is compatible with most transceivers and it is fully
adjustable via the onboard controls and accepts microphone and line level inputs. It offers the flexibility
to use a stock hand microphone to a high end audio processing chain using a broadcast microphone.
This unit will work with all High Level Modulation transceivers by direct coupling to the driver and final’s
collectors via the existing transceiver's onboard RF chokes without the need for a heavy, costly and large
modulation transformer. Low Level Modulation transceivers will require some modification. Instructions
for specific multiband HF transceivers is available upon request.
The Asymod IIIs produces modulation levels well above the norm and broadcast levels without
distortion, allowing for your station to sound loud and clean. With the Asymod IIIs connected to your
audio processing chain and a transceiver of your choice, your mobile or base station will sound just as or
better than commercial broadcast stations.
The Asymod IIIs can be readily interfaced with most high level modulation transceivers and its compact
design allows for internal mounting inside the transceiver. This manual is partially based on an
installation for a Stryker SR-955 HPC transceiver. These instructions can be applied to most makes and
models by following the general guidelines implied herein. Installation instructions and insertion points
for other makes and models can be found starting on page 18 of this manual. To achieve optimum
results, an adequate AM audio process chain catered to emphasize on your natural voice is highly
recommended. For advice on Hi-Fi audio processing, Please visit
http://www.nu9n.com/am.html . If in
doubt, you may request specific transceiver installation instructions including low level modulation
transceivers, such as, multiband / multimode HF rigs.
NOTE:
IMPORTANT
The transceiver/radio is only the exciter and should not be expected to generate high levels of RF power,
it should be expected, however, to generate a clean, perfectly modulated wide-band Hi-Fi audio and RF
signal well within the limits of the headroom available without pinching or clipping which can be later
amplified with a class AB or C, RF power amplifier and is best heard or monitored on a good quality
receiver equipped with a 6 kHz AM wideband receive filter and monitored on an oscilloscope. Audio
processing and a high quality microphone is strongly recommended for optimum performance. Audio
processing for mobile operation is possible with the use of the iRig PRE or iRig PRO interface using the
companion IK Multimedia's VocalLive Vocal Processor and Recording Studio app on your iOS device.