Jumpers for Rec Mute and PA Disable Jacks

By John May, K6MAY

The rear RCA connectors J5 and J6 (PA Disable) are internally shorted together. The short needs to be removed if you are using a VHF Converter with the KWM-2. Another reason to remove the short is to disable the screen voltage to the PA section during the neutralization process.

Jacks J20 and J21 (Rec Mute) are also shorted. The jumper should be removed if you plan to use an external switch or relay to mute the KWM-2.

The last time I had to neutralize my finals, I found it was convenient to go ahead a remove the internal jumper between J5 and J6 permanently. While I was at it, I also removed the J20 and J21 internal jumper. Both internal jumpers were replaced with a pair of external jumpers.

To remove the jumpers simply cut off or un-solder the shorting wires (usually black). Make up a pair of jumpers (see figure below) and use them instead.

This makes the process of removing the voltage supplies to the PA simple - just unplug the 5R4GYA rectifier tube (V1) in the 516F-2 and the external jumper between J5 and J6 on the KWM-2. It also gives you maximum flexibility if you want to quickly connect an external muting switch to your KWM-2.

Collins Tip 1

Version 1.0 - Copyright © 2004. John May, K6MAY. All Rights Reserved

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