Differences
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563upgrade [2011/10/07 11:53] n1eu |
563upgrade [2015/11/24 12:54] n1eu |
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| *The later 564's have certain changes to top and bottom foil grounding on certain boards to improve 10M birdies which are a major problem with this rig. | *The later 564's have certain changes to top and bottom foil grounding on certain boards to improve 10M birdies which are a major problem with this rig. | ||
| *The BPF filter on later 564's has a broadcast band mod to improve intermod in the presence of strong local AM BCB or SW signals. Night and Day difference on my rig. | *The BPF filter on later 564's has a broadcast band mod to improve intermod in the presence of strong local AM BCB or SW signals. Night and Day difference on my rig. | ||
| - | *An aftermarket mod from INRAD is available to improve the SSB audio response involving a swap of two component values. This became a semi-approved factory mod. Stock audio is degraded by passing through the DSP chip when DSP is not engaged | + | *An aftermarket mod from INRAD is available to improve the SSB audio response involving a swap of two component values. This became a semi-approved factory mod. Stock audio is degraded by passing through the DSP chip when DSP is not engaged ///(N1EU note: "high pass filtered" is a more accurate description than "degraded" - see [[http://omni6.wikidot.com/rxaudio|Omni6 rx audio discussion]])/// |
| *Later 564's use significant amounts of SMT construction | *Later 564's use significant amounts of SMT construction | ||
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| N1LQ does a great job of tracing the 564 evolution, but I'd like to offer up some comments: | N1LQ does a great job of tracing the 564 evolution, but I'd like to offer up some comments: | ||
| - | 1. I've spent many hours of A/B comparisons of various vintages of Omni 6/6+ from 1992 to 2001. My conclusion is that any improvements in rx noise/birdies was subtle, if at all audible, and that the earliest units performed as well as the latest units. | + | 1. I've spent many hours of A/B comparisons of various vintages of Omni 6/6+ from 1992 to 2001. My conclusion is that any improvements in rx noise/birdies was subtle, if at all audible, and that the earliest units performed just about as well as the latest units. |
| - | 2. The Inrad mod audio improvements are slight compared to the real problem, which is the audio dsp. This is [[563ssbaud|discussed elsewhere]]. | + | |
| - | 3. In terms of the use of SMT in later units, the logic board, PBT board, 9Mhz Xtal Filter board, Control board and IF/AF board all became SMT. | + | 2. The Inrad mod audio improvements are slight compared to the real problem, which is the audio dsp. This is [[http://omni6.wikidot.com/rxaudio|discussed elsewhere]]. |
| - | 4. One additional evolutionary change was that covers were added over the 9Mhz/6.3Mhz filter slot panel openings in later 564's. | + | |
| + | 3. In terms of the use of SMT in later units, the logic board, PBT board, Control board and IF/AF board all became SMT. The 9Mhz Xtal Filter board was SMT from the start of production. | ||
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| + | 4. Changes were made in components in the product detector circuit on the IF/AF board of the Omni 6+ to improve intermod distortion over the Omni 6. | ||
