| Yaesu FTDX101D |
| Znalezione na https://www.eham.net : K3OX Jul 19, 2019 17:19 FT8 issue The radio is great, but here's a significant issue if you operate FT8. I am trying to use Data-U mode for WSJT-x (FT8) but there is a problem. The maximum Bandwidth in Data-U mode is 3 khz. But if you look at the Filter Display, the bandwidth is centered on the phantom carrier (I assume this is the yellow line with "C" at the top) so that the effective Upper SB bandwidth is 1.5 Khz which means anyone above the 1500khz FT8 channel are not demodulated (and if there are any signals on what would be Data-L they can interfere since they are in the passband). And these undemodulatable (?) signals can be seen to be outside the Red filter lines on the Filter Display. This is with the Roofing Filter wide open. The phantom carrier line (yellow line) should be on the edge of the red passband indictor (LEFT for DATA-U, RIGHT for DATA-L) rather than the middle so that the DATA-U is actually USB only. Using the SSB mode for computer data modes would mean having to reset in the SSB menu from MIC to Rear USB port when changing from SSB to FT8 and back, not an acceptable solution, IMO. I sent a message to Yaesu on this DESIGN ERROR (I mean, there's another reason that their DATA implementation makes no sense, why have distinct DATA-U and DATA-L if both sidebands always come through the filter???). Here was their reply: "Kevin: What you are experiencing is correct for the Data -U bandpass. You will find this on all of our radios. This is why, traditionally FT-8, and all other AFSK modes were set to SSB not Data U-" Which makes Data-U essentially useless. Whatever Yaesu's tradition regarding what DATA mode is, it really needs to change. So I would say that Yaesu needs to be flooded with Tech Support questions asking why DATA-U was implemented in a way that makes it useless for computer data modes. Just to get their attention. If you don't operate FT8 now, you may in the future. Best, Kevin |