VE7AVV -- Linear Amplifier Selection Switching |
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I wanted to have either the Kenwood TL-922 or the Heathkit SB-220 linear amplifier available for service -- never at the same time, but in line and able to be selected. If the amplifiers were permanently cabled 'ready for service', this would eliminate the need to reach behind the units and swap one set of connecting cables between the two units. In order to do so I needed 2 good quality coax switches and several coax jumpers. All coax jumpers needed to be color coded to ensure the correct pair were always selected when switching between the amplifier. The switching arrangement needed to be visible from the operating position. |
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| Layout | |
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| Pictures | |
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Click on any image to enlarge |
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 The general layout |
 Note the colored dot on each amp. It corresponds to the color coding on the coax jumpers |
 In order to ensure fool-proof switch position selection, the centre position on each switch was not used. The input / output or common position of each switch is the far right -- the red coax jumper connection |
 The input from the MK V enters from the left (red shrink color code) and goes to the Amplifier INPUT switch. |
 The OUTPUT goes through the sending head for the Autek WM1 meter and then into the Low Pass Filter |
 PTT keying line from the NT-box using a color coded 'Y' cord |
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