Asymod Mini 

NEW - Asymod Mini Asymmetrical AM / Hi-Fi eSSB Modulator & Controller

Asymod Mini Manual link: https://dock-services.com/images/asymod-pics/Asymod%20Mini%20Manual.pdf

Introducing the new Asymod Mini Asymmetrical Hi-Fi AM Modulator for use with mobile or base CB & HAM radio transmitters and transceivers.

Designed to fit inside most compact radios with very little or no space. Now its easy to go mobile without external standalone units. 

The Asymod Mini is the complete Hi-Fi solution to make your presence on the air. In addition to its predecessor’s functions, the Asymod Mini includes all the necessary options to control your transceiver function signals and modes. It’s rugged SMD design provides auto divert for the RF final’s VCC (Voltage Common Collector) and modulation feed path for easy installation in HF multi-band, multi-mode transceivers. The built-in amp keyer with TX indicator allows keying RF amplifiers directly. The SSB mute, automatically stops audio from flowing into the Balanced Modulator when on AM. New on-board remote power switch eliminates the need for an externally mounted transistor requiring heat sinking. An audio stage gain coarse control stage has been implemented for additional audio gain for low level playback devises. To allow for full potentiometer range for given transceivers preselect controls for carrier inject and level have been implemented. JST connectors provide easy external connections and the new auxiliary input provides simple connectivity for record / playback devices.

The Asymod Mini is a complete Hi-Fi solution to make your presence shine on the air! No doubt is the right choice to sound pro & proud. It expands your radio’s TX audio bandwidth and allows you to increase your audio loudness without distortion using the asymmetrical gain.

Be sure to see the  Asymod Mini Hi Fi Asymmetrical AM & eSSB Ranger RCI X9  video.

Download the manual:  Asymod Mini Manual

Got questions? Visit the new Asymod related FAQs and get answers to the most frequently asked questions and lots of valuable information related to Hi-Fi communications.

The Asymod Mini has a 15 kHz TX bandwidth which can be adjusted in the audio process by rolling off the high frequencies to the desired bandwidth.

The Asymod Mini compact design makes it ideal for mobile or base 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 Mini include increased RF suppression, active audio filters, carrier stabilization, zero crossover distortion, supply conditioning, auto mode switching, VCC/MOD divert and on-board JST connectors for easy connection to external controls and connections.

The Asymod Mini is compatible with most transceivers and it is fully adjustable externally via the JST connections or the onboard controls. It accepts line level input that can be configured to microphone level to use a microphone directly if necessary. The auxiliary input accepts low level audio and its ideal for recorder/playback devices or external audio source.

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 Mini not only provides the Hi-Fi wide audio bandwidth but also allows for amplitudes in excess of positive 300% modulation while not exceeding the negative peaks at negative 100%. The Asymod Mini produces positive modulation levels well above the norm and broadcast levels without distortion, allowing for your station to sound loud and clean. With the Asymod Mini connected to your audio process gear and a transceiver of your choice, your mobile or base station will sound just as or better than commercial broadcast stations.

To achieve optimum results and to make the most of the Asymod Mini, adequate audio processing catered to emphasize on your natural voice is necessary.

NOTE: IMPORTANT

Read through all related documents, including the Asymod FAQs and manuals to see the requirements for an effective Hi-Fi setup before committing to purchase. All sales are final and there are no returns. If the unit breaks, please send it back for repair. All repairs are free within the first two months after the sale.

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 RF signal well within the limits of the headroom available without pinching or clipping at the crest or troughs of the modulation envelope which can be later amplified with a class AB, RF power amplifier and is best heard or monitored on a good quality receiver equipped with a 6 kHz AM wideband filter and monitored on an oscilloscope.

The Asymod is not an audio processor, but it does allow for full bandwidth control with the use of Pro Tools, a combination of rack gear, or a broadcast multi band compressor / limiter.

Audio processing and a high quality microphone is necessary for optimum performance.

Audio processing for mobile or base operation is possible with the use of the iRig PRE or iRig PRO interface using the companion IK Multimedia's VocalLive Vocal Processor app (not the free version) on your iOS device.

Audio processing for base operation is possible with the use of rack audio processing gear or computer based processing such as Pro Tools for PC or Mac along with its companion interface such as the Mbox 2 Mini or newer.

Pro Tools is the best choice and is highly recommended. Pro Tools sessions are free and available for download.

The Asymod Mini is NOT designed to give transceivers more RF power, more swing, or loud distorted modulation. It is however, to be used with the appropriate audio processing to produce a broadcast quality transmission.

Features

The Asymod Mini compact design allows for easy mounting inside your transceiver and offers all the combined features comparable to high end, very expensive broadcast gear and other available Hi-Fi mods upwards of $1000, and makes for the most important part of a Hi-Fi AM station. Hi-Fi Audio is very thought after by many radio operators nowadays and the Asymod Mini delivers all the necessary functionality and stands as the backbone of the station.

Now you can make your mobile or base station sound like you always wanted it to at an affordable price. If you are tired of spending on expensive gear or trying different combinations and still don't have the Hi-Fi audio you want for your CB or Ham AM radio station setup this is the way to go.  With this setup you will save in time to come as there will never be the need to upgrade again.

· Mobile or base operation, ease of use and simple installation; only a 12 Volt, 5 Amp power supply is required.

· Rugged SMD design built on a tough PCB to provide years of continuous use. 

· RF final Vcc / modulator auto divert.

· Built in RF amplifier keyer.

· Carrier inject and level trim adjustment.

· JST connectors for easy connectivity.

· Auxilary audio input.

· Audio gain control allowing for proper drive from the microphone and line level input.

· Modulation Level control allows for final audio control and is set in combination with the Carrier and Asymmetry controls to achieve   the level on modulation desired.

· Carrier controls sets the reference carrier level (dead key) to set the modulation and asymmetry levels.

· The Asymmetry control maintains the negative peaks at -100% modulation while allowing for positive peaks of excess of 300% without pinching or clipping.

· Preamplifier gain control to allow matching of audio levels.

· eSSB auto audio mute & mode switching. (NEW)

· On-board jumpers to set audio routing configuration. (NEW)

· Remote ON/OFF control.

· Power status LEDs for the 12V and onboard 24V supply.

· Input voltage polarity protected.

· Modulation peak indicator.

· Convenient mount holes.

· Heavy duty screw terminal block connectors for the line in, power in, modulator output, pre-in and pre-out connections.

· TO-220 and TO-247 onboard compatibility for mounting single or dual modulating stage transistors.

The Asymod unit will arrive pre adjusted, however, in some cases it might require some fine tuning to perfectly match your particular setup. This unit requires basic electronic skills to install and adjust. It is recommended to use an oscilloscope to do all the initial adjustments. Refer to the Asymod Mini Manual for details. 

Requirements:

· +12 volt supply @ 5A

· +20 volt, 5A DC/DC Up Converter (included).

· Heat Sink for final stage modulator transistor/s.

· Enclosure if not mounted inside a transceiver.

Absolute maximum ratings:

· Audio input: +4 dBu, 1.74 VPK  or  1.23 VRMS

· +15 volt supply @ 5A

Remote control sensitivity:

· +8V ~ +12 V

Audio Input Range:

· Audio input: -30 dBu to +4 dBu

Frequency response:

· Input: 20 Hz – 11 kHz.       Expandable to 20 kHz.

· Output: 20 Hz – 11 kHz.    Expandable to 20 kHz.

Total System Distortion (@ 300% modulation):

· <0.01% THD 20 Hz – 1 kHz

· <0.02% THD 1 kHz – 5 kHz

· <0.03% THD 5 kHz – 14 kHz

· <0.05% THD 14 kHz – 24 kHz

Input & Output Passive Low Pass Filter:

Selectable: 5 kHz, 8 kHz, 11 kHz or 20 kHz

Preamplifier Active Low Pass Filter:

Selectable: 8 kHz, 16 kHz

Modulator Output:

*The following values were recorded using configuration A, modulating an AM transceiver manufacturer rated at 4W carrier and 16W peak with a 1 KHz tone.

Refer to the captured oscilloscope pictures in the Asymod IIIs Operation & Troubleshooting Guide. 

· @100 % modulation: 3W carrier, 12W peak. (4X carrier = 100% modulation).

· @200 % modulation: 2W carrier, 16W peak. (8X carrier = 200% modulation).

· @300 % modulation: 1.0W carrier, 15W peak. (15X+ carrier = 300% + modulation).  

*The following values were recorded using configuration B, modulating a CRE-8900 transceiver with one IRF-520 driver and two IRF-520 finals with a 1 KHz tone, manufacturer rated at 12W carrier, 48W modulated.  

· @100 % modulation: 15W carrier, 60W peak. (4X carrier = 100% modulation).

· @200 % modulation: 7.5W carrier, 60W peak. (8X carrier = 200% modulation).

· @300 % modulation: 4W carrier, 60W peak. (15X carrier = 300% modulation).

*For higher RF output power levels use a class AB amplifier. It is best to generate your original modulated signals at lower levels and use the amplifier to amplify your output to the desired level.

Shielded cable should be used in all audio connections and RF bypass capacitors where ever possible.

The Asymod comes with:

· +20 volt, 5A DC/DC Up Converter (included).

· Downloadable Asymod Mini Manual

· Downloadable PC Oscilloscope Manual (For those who don't have oscilloscopes)

      Asymod FAQs

· Mounting hardware

· TO-220 / TO-247 Thermal Silicone Rubber & Fiberglass Composite Insulator

· Single MJE3055T transistor (T2), configuration A. Configuration B or C available upon request

· Downloadable Pro Tools sessions      

For advice on Hi-Fi audio processing you may visit the NU9N page.

**This design is based on the oldest technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. In amplitude modulation, the amplitude (signal strength) of the carrier wave is varied in proportion to the waveform being transmitted. That waveform may, for instance, correspond to the sounds to be reproduced by a loudspeaker, or the light intensity of television pixels. This technique contrasts with frequency modulation, in which the frequency of the carrier signal is varied, and phase modulation, in which its phase is varied.