Custom Products from Masters Communications

Overview of RL-20

• PTT, HB, and COS LEDs onboard.
  
• Silkscreen descriptions for COS and PTT (or not (inverse).
• Radio or Radio Less Operation.
  
• An EEPROM is not supplied, or is even an option.
  
• Access to all GPIO from circuit board 'lands' marked G1 through G8.
  
• Kits come with the surface-mount IC preinstalled.
  
• A custom case is available - it's just like the one for the RA and DRA, but shorter to fit the RL boards length.

If you purchased our kit, refer to the parts list and make sure you have all of the components you need to build it.
Click here for Parts List.

Construction/Assembly:
Click here for assembly instructions and construction notes - with large photo.

Installation:
This device is intended to be installed inside a radio, computer, or plastic box for protection. Refer to the schematic for the pinout of the DB9F where all of the logic signals, power connections, and audio signals are listed.
Click here for DB9, jumpers and other board connection assignments.

RL-20 Radio-Less Explanation. Defines the signals and how they are 'backwards' when a radio interface is used in a radio-less application.

Recommended powering requirements:
The board is supplied with 5 VDC from the USB connection.

Recommended receive audio input level:
The RL-20 accepts the widest range of audio compared to any other similar radio adapter. The input signal is attenuated by a potentiometer, giving the broadest range of acceptable levels. As little as 20 mV P-P can be used with a setting of rxboost=1, and as much as 20 volts P-P with a setting of rxboost=0. If your receive audio level is adjustable or programmable, we recommend around 2.0 volts P-P and a rxboost=0 setting. This allows very good signal-to-noise ratio and low cabling cross talk. This level results in a 50% rotational setting of the potentiometer.

Which C-Media chipset is used?
All RL series radio adapter boards are supplied with a Genuine C-Media CM119A.

The PC board was designed to be versatile. A CM108 and CM119 is also acceptable. There are slight differences between these components, and the board can be 'programmed' to accept any of the three.

Information on the CM119A.
Click here to download a manual for the C-Media CM119A.

Secure PayPal ordering is available from the main RL-20 page.

Custom radio cables are available from URI Cables. They can build a custom cable for the RL-20 for many radios.

Email Kevin Custer for ordering information, ordering by check, and/or support of this exciting product.
 
 

Product of Masters Communications, all rights reserved.
Specifications may change without notice.
Images property of Kevin Custer - W3KKC
Board layout by Kevin Custer - W3KKC.
HTML June 3, 2020, W3KKC All Rights Reserved!