Custom Products from Masters Communications

Model RL-20M
For Two-Way Radio Applications

Pricing:

Unassembled Kit with Metal Case - $50.00 each.

Assembled and Tested with Metal Case - $80.00 each.

A (NO Case) option is not available - please click back and choose a RL-20.

Shipping and handling is calculated at checkout for US and International orders.
First-Class shipping available to most locations worldwide, calculated at checkout.
PayPal accepted - order below.

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RL-20M top photo - shown larger than actual size.
Click for larger image.

What is it, and what does it do?

• The RL-20M is a very small metal AllStar Link audio interface used to make a radio connected node.
  
• It can be used with the UA-10 adapter to replace a DMK URI.
• If you're a builder, it can be done for a fraction of the cost of comparable products - Bonus!

The RL-20M is used as a radio adapter interface in the simplest and most inexpensive form. It doesn't have the 555 (Heart Beat) timer protection circuit that is standard on our RA and DRA products to prevent a stuck PTT. It doesn't allow for installation of our optional FL-10 filters. It doesn't have a relay for the PTT switching. It does, however, have large quality coupling capacitors that aren't found in cheap Chinese sound FOBs. It has a genuine crystal stabilized CM119A for the best audio quality.

COS Activity Indication:
By asserting a change on one of the GPIOs on the CM119A, the Yellow LED3 position can indicate receiver activity (COS) following the software status of the COS logic input. Some code is necessary to make this work and is different for HamVoIP and AllStarLink. Examples for both are included below.

The status of the COS can be generated by either GPIO4 or GPIO8. The Gsel header allows you to easily select which one of these is uesd to drive the yellow LED. This is a mechanical switch and no soldering is required.

In HamVoIP this code is necessary to make the LED3 option work.

In AllStarLink this code is necessary to make the LED3 option work.

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Choose selection carefully ! - case currently only available in black.

RL-20M Unassembled Kit with Metal Case

RL-20M Assembled & Tested with Metal Case

Shipping amount is calculated at checkout for shipping to most locations Worldwide.

Support Documentation - Schematic, parts list, installation and set-up instructions and all support documantation for the RL-20M is linked inside this page.

RL-20M Construction Article.

Custom cables available from URI Cables. They can build a custom cable for the RL-20M 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 are property of Kevin Custer - W3KKC
Board layout by Kevin Custer - W3KKC
HTML March 6, 2025, W3KKC All Rights Reserved!