Custom Products for the Digital Radio Amateur Enthusiast
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Construction of the DRA-39M USB Digital Radio Adapter Board

Top photo of the DRA-39M circuit board (click for a larger view).

Assembly:
If you purchased our kit, refer to the parts list and make sure you have all of the components you need to build the kit. All of the components are supplied with the kit, and while we make every effort to be sure we didn't omit any components, it can happen. If you are missing anything, or ruin something, just contact us.

Click here for Parts List.

Assembly can be done by personal choice, but you may find it easier to install the shortest components first, building toward the tallest, and finish with the connectors on the ends.
The Parts List has several construction notes as well.

Install all fixed resistors. Some resistors color bands may be hard to make out. If in doubt, use an ohm meter to verify the value before soldering it in place.

Now install all diodes. The square pads are the banded end of the diodes.

Install the crystal - it doesn't matter which way.

Install the shortest capacitors, observing polarity on the polarized ones! The square pads are the + of the electrolytic and Tantalum capacitors. Small capacitors are identified as follows: "47" or "470" = 47pF, "103" = 0.01uF, "104" = 0.1uF, "105" = 1uF. In other words the first two digits are the leading value and the third digit (if present) is the number of zeros (multiplier) you add to determine the final value.

Install the IC sockets aligning the notch with the silkscreen, and then the potentiometers.

Install the relay. It doesn't really matter which way it's oriented, but it looks better if the printing is outward so you can read it.

Next, install the transistors (flat to flat on silkscreen).

Install JU1, JU2, JU4 and the two PTT 2-pin headers - the last two are red, and it doesn't matter which direction they are installed.

Install JU3 3-pin header.

Next, install the larger capacitors. If required, bend the leads of these straight so they sit down against the board.

Then, install the RJ45, Speaker Jack, and USB "B" Socket connectors, 555 IC, configuration socket wires and anything else I forgot to tell you about. The notch on the 555 lines up with the notch on the socket.

Lastly, install the 3 LEDs (long lead into the round hole). Use the front panel as a guide.

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

Email Kevin Custer for support.
 

 

Product of Masters Communications, all rights reserved.
Specifications may change without notice.
Images property of Kevin Custer - Masters Communications.
Board layout by Kevin Custer - W3KKC
HTML May 30, 2022, W3KKC All Rights Reserved!