Timeline for SSB Transceiver Architecture - USB with Crystal Filter
Current License: CC BY-SA 4.0
10 events
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| Dec 10, 2020 at 22:28 | history | edited | Phil Frost - W8II | CC BY-SA 4.0 |
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| Dec 10, 2020 at 22:25 | comment | added | Phil Frost - W8II | @F.Sessink Yes, good point. I tried to broach this a little in the last paragraph: the filter response is just one of many concerns that weigh in the overall design. You are right that in most designs, there will be concerns other than the asymmetrical response of the filter that can contribute more significantly to performance. | |
| Dec 10, 2020 at 21:44 | comment | added | user16925 | The sideband suppression of the filter does not need to better than the phase noise at that (unwanted sideband) frequency. Reciprocal mixing with phase noise is probably determining/limiting the power in the sideband (at TX) and the selectivity of the receiver at RX. | |
| Dec 10, 2020 at 20:49 | comment | added | Phil Frost - W8II | @F.Sessink sorry I'm not following your comment. What 1 kHz offset? | |
| Dec 10, 2020 at 20:27 | comment | added | user16925 | Huh? What is your phase noise at 1 kHz offset? | |
| Dec 10, 2020 at 16:18 | comment | added | Buck8pe | Super, that's reassuring. | |
| Dec 10, 2020 at 16:06 | comment | added | Phil Frost - W8II | @Buck8pe yes, because it provides for greater attenuation of the image frequency, which is red in the illustrations above. | |
| Dec 10, 2020 at 14:41 | comment | added | Buck8pe | Thanks for that Phil, intuitively explained as always! But, regarding my plan to chose USB but select a higher frequency LO (than RF). I've noted how that seems to place the lower end of the USB at the higher end of the filter passband. I assume then that this is desirable, since it places the carrier end at the side with steeper attenuation slope? | |
| Dec 10, 2020 at 14:22 | history | edited | Phil Frost - W8II | CC BY-SA 4.0 |
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| Dec 10, 2020 at 14:13 | history | answered | Phil Frost - W8II | CC BY-SA 4.0 |