How to Improve Shortwave Reception on the Malahit DSP SDR V3

Published by IWISTAO

The Malahit DSP SDR V3 is one of the most powerful portable SDR receivers available today. With wide frequency coverage, DSP filtering, and spectrum display, it can receive signals from across the world.

However many users experience weak reception or excessive noise when listening to shortwave bands.

The radio itself is rarely the problem. The key factors are antenna placement, noise environment, and correct gain settings.

In this guide we explain how to dramatically improve reception performance.

1. Understanding Shortwave Reception

Shortwave signals propagate through the ionosphere and can travel thousands of kilometers. Reception quality depends on several factors:

Factor	Impact
Antenna efficiency	Determines how much signal is captured
Local noise floor	Limits the ability to detect weak signals
Receiver gain structure	Controls amplification and overload
Propagation conditions	Solar activity affects signal strength

Among these factors, antenna placement has the largest effect.

2. Antenna Placement

The built-in telescopic antenna on the Malahit SDR is not optimal for shortwave reception. Using an external antenna can dramatically improve sensitivity. Recommended Antenna Types as below.

1. Long Wire Antenna

Or,

A simple 10-20 meter wire can work extremely well for shortwave listening for SW band of the radio.

Example setup:

Radio → 9:1 Unun → 15m wire antenna

Height recommendation:

3 – 10 meters above ground

2. Magnetic Loop Antennas

Magnetic loops are excellent for urban environments where electrical noise is high.

Popular models include:

• MLA-30 Active Loop
• YouLoop Passive Loop
• Airspy HF Loop

Advantages:

• Low noise pickup
• Compact size
• Works well indoors

3. Active Loop Antennas

Active loops include a built-in amplifier and can receive weak signals effectively.

However placement is critical to avoid amplifying noise. 

3. Reduce Electrical Noise

Modern homes contain many devices that generate RF interference:

• LED lighting
• Switching power supplies
• Wi-Fi routers
• Computers
• Phone chargers
• Solar power inverters

These devices raise the noise floor and mask weak signals.

Practical Noise Reduction Tips

• Move the antenna away from buildings
• Operate the radio using battery power
• Install ferrite chokes on cables
• Turn off nearby switching power supplies

4. Gain Settings on Malahit SDR

Correct gain configuration is essential. Many beginners set gain too high, which causes overload and distortion. The Malahit SDR offers extensive gain and DSP control, allowing the user to optimize reception.

Key parameters include:

• RF Gain

• Preamp

• Attenuator

• AGC

• Noise Reduction

• Bandwidth filters

The receiver allows RF gain adjustment from 0 to 59 levels

Many beginners make this mistake, Maximum gain = best reception.This is incorrect.

Too much gain causes:

• Overload

• Intermodulation distortion

• Increased noise floor

Recommended Baseline Settings

Parameter	Recommended Value
RF Gain	20 – 30
Preamp	OFF
AGC	Slow
Noise Reduction	Low
Filter Bandwidth	3-5 kHz

Increase gain slowly while watching the waterfall display, adjust gradually depending on signal strength.

When to enable Preamp

Enable the preamp only when:

• Using small antennas

• Listening to weak signals

• Operating indoors

But avoid preamp if strong broadcast stations are nearby.

When to use Attenuation

If the waterfall shows:

• Strong wide signals

• Distorted audio

• Multiple ghost signals

Then activate 10-20 dB attenuatio

5. DSP Filtering

The Malahit SDR includes powerful digital signal processing tools.The Malahit SDR includes powerful DSP features:

• Adaptive Noise Reduction

• Noise Blankers

• Variable Bandwidth Filters

• Auto Notch Filtering

These tools dramatically improve weak signal readability.

Recommended bandwidth settings:

Mode	Bandwidth
AM Broadcast	5-8 kHz
Shortwave AM	3-5 kHz
SSB	2.2-2.8 kHz
CW	300-500 Hz

Noise reduction can greatly improve weak signals. Adaptive noise reduction helps suppress background noise and improves intelligibility

6. Example Setup

Receiver Malahit DSP SDR V3

Antenna 15m long wire

Frequency 9.585 MHz

Mode AM

Recommended settings:

RF Gain: 25
Preamp: OFF
AGC: Slow
Noise Reduction: Level 10
Bandwidth: 4kHz

Expected improvement:

• Lower noise floor

• Clearer audio

• Stable signal

7. Advanced Tips for Serious DX Listening

Use a balun or unun

Improves impedance matching.

Example: 9:1 unun for long wire

Use coax feedline

Reduces noise pickup. 

Example: RG-58 or RG-174 cable

Install antenna outdoors

Outdoor antennas outperform indoor antennas by a large margin.

Monitor propagation

Websites such as:

• Solar flux reports

• DX cluster networks

• Shortwave schedules

help predict good listening times.

Conclusion

The Malahit DSP SDR V3 is capable of excellent performance when properly configured.

The three most important improvements are:

• Better antenna placement
• Lower electrical noise
• Correct gain settings

With these techniques the radio can receive shortwave signals from across the globe.

References

 

• Malahit DSP User Manual
  https://fms.komkon.org/Malahit/Malahit-Manual.pdf

• RTL-SDR Blog – Improving Malachite DSP Sensitivity
  https://www.rtl-sdr.com/improving-sensitivity-on-the-malachite-dsp-via-usb-grounding/

• N9EWO Malahit DSP Review
  https://www.qsl.net/n9ewo/malahit.html

• Malahit SDR Receiver Feature Overview
  https://manuals.plus