This page is all about modifying radio equipment for a better way to pass signals for long-distance links and other uses,
Starting with the COR/Audio board. Several versions were designed, however, not produced. Your main starting point will be version 5.3.

COR/Audio board Ver. 5.3 Updated 7/6/03, 3/29/04, 8/27/05, 6-25-06, 4-10-09

COR/Audio board Ver. 5.4 For Downlinks

COR/Audio board Ver. 5.5 For Uplinks only

COR/Audio board Ver. 6.0 Designed for a conventional repeater (single site).(alpha-not produced)

COR/Audio board Ver. 6.1 Designed only for mitrek (to mount upside down, in place of PL deck.(beta-in prototype stage)

COR/Audio board Ver. 7.0 Designed only for mitrek and micor link radios.(alpha-not produced)

COR/Audio board Ver. 7.1 Designed only for mitrek (to mount upside down, possibly in place of PL deck.(alpha-not produced)

COR/Audio board Ver. 7.2 Designed only for mitrek (to mount upside down, in place of PL deck.(alpha-not produced)

COR/Audio board Ver. 7.3 Designed only for mitrek (to mount upside down, in place of PL deck.(alpha-not produced)

Version Chart Quick comparison charge for different versions over the years.

Audio Standards Flat or conventional audio and level standards

Microphone discussion

Micor Transmitter Notes used for SRG remote area transmitters

Micor Receiver Notes used for SRG out lying remote Receivers

Mitrek conversion to Repeater or link used in SRG 20 repeater (extensive details and sub-pages)

Direct F.M. a Midland 13-509, or most any transmitter

Midland 13-509 Full story on F.M. and repeater conversions for 1 1/4 meters

Wilson 1 1/4 meter radio For the model T2202SM HT.

MX-350 Portable Radio for links Used in some SRG 20 repeater links

Fan assemby to cool a transmitter Used in some SRG 20 repeater equipment

Note: Many of these projects are in the R-n-D stage, therefore, are subject to change and improvement without notice. They are intended to get the experienced builder in the right direction and not necessarily for the beginner.