Differences
This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision Next revision | Previous revision Last revision Both sides next revision | ||
|
563upgrade [2011/10/07 11:43] n1eu |
563upgrade [2015/11/24 12:54] n1eu |
||
|---|---|---|---|
| Line 29: | Line 29: | ||
| *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 | ||
| Line 49: | Line 49: | ||
| **July 2011** //(comment from N1EU)// | **July 2011** //(comment from N1EU)// | ||
| - | In light of the improvements described above by N1LQ, I spent several hours comparing a 1992 vintage Omni 6 with a 2001 vintage Omni 6+ from the very last production batch (serial number 08XXXXX1 purchased in early 2002). My conclusion was that any improvements in rx noise/birdies was subtle, if at all audible. | + | 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 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 [[http://omni6.wikidot.com/rxaudio|discussed elsewhere]]. | ||
| + | |||
| + | 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. | ||
| + | |||
| + | 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. | ||
