Custom Products from Masters Communications
|
Custom Products from Masters Communications |
|
Support Documentation
for
Model RA-25M
Looking for radio adapters for digital applications? See our new DRA-Series.
Top side of RA-25M board - shown slightly enlarged.
(Click photo to show a very large image)
Bottom side of RA-25M board - shown slightly enlarged.
(Click photo to show a very large image)
Schematic Image - Click to download a high quality PDF.
Overview of the REV2:
1, CM119A is supplied pre-installed on all kits.
2, Access to all GPIO from circuit board 'lands' marked G1 through G8.
3, PSEL option (preconfigured for a ground - see below).
4, VSEL option (preconfigured for an open - see below).
5, Kits come with the surface-mount IC preinstalled.
The PSEL and VSEL options are only required for proper operation of the CM119 (without the A suffix) or the CM108. All REV2 and beyond boards are shipped with CM119A chips, and PSEL and VSEL are preconfigured for normal operation and won't require any jumpers or other attention.
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.
DB9 Pinout:
Refer to the schematic and the document below for the pinout of the DB9F where all of the
logic signals, power connections, and audio signals are listed.
Click here
for DB9 connection assignments.
Jumper Settings:
Click here
for Jumper Settings and switching between transistor and relay PTT keying.
Recommended powering requirements:
The board is supplied with 5 VDC from the USB connection.
Recommended receive audio input level:
The RA-25M 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 boards are supplied with a Genuine C-Media CM119A.
The REV2 board is designed to be versatile; the board can be 'programmed' to accept any of the C-Media CM119(X) chipsets.
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-25M page.
Custom radio cables are available from URI Cables. They can build a custom cable for the RA-25M 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 November 11, 2024, W3KKC All Rights Reserved!