Custom Products from Masters Communications
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Custom Products from Masters Communications |
|
Support Documentation
for
Model RA-25
Looking for radio adapters for digital applications? See our new DRA-Series.
Top side of RA-25 board - shown slightly enlarged.
(Click photo to show a larger image)
Bottom side of RA-25 board - shown slightly enlarged.
(Click photo to show a larger image)
Schematic Image - Click to download a high quality PDF.
Overview of RA-25
1, EEPROM is not supplied or is even an option.
2, Access to all GPIO from circuit board 'lands' marked G1 through G8.
3, Kits come with the surface-mount IC preinstalled.
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.
Optional Plastic Case:
A Plastic Case is available optionally for the RA-25.
Choose this option from our PayPal ordering drop-down. See below.
A case can be 3D-printed
from these free files - designed by Richard Bateman KD7BBC
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.
Recommended powering requirements:
The board is supplied with 5 VDC from the USB connection.
Recommended receive audio input level:
The RA-25 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 receiver audio level is adjustable or programmable
(like in a Kenwood TKR-750),
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 RA 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.
Information on the CM119.
Click here
to download a manual for the C-Media CM119.
Secure PayPal ordering available from the main RA-25 page.
Custom radio cables are available from URI Cables. They will build a custom cable for the RA-25 for many radios.
Third Party Compatible Projects:
MABEL is an interface and software that allows analog control of the Yaesu DR-1X repeater and access
to the AllStar VOIP network with the Raspberry Pi3 and AllStar Asterisk. (Offsite Link)
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 May 20, 2019, W3KKC All Rights Reserved!