First Impressions: Immediately noticed after turning the radio on, was the 'thumpedy' sound of the stepping motors as the u-Tuning unit automatically followed the VFO up and down the band. This was music to my ears, it meant that my 'flying blind' installation was successful; the FTDX-9000 had recognized the MTU. Scope wise, there is a 3-4db drop in band noise with little or no noticeable drop in received SSB audio. I am also able to realize an approximate 50% decrease using the NR control to reach the equivalent result before the MTU was installed. Whereas before the installation I might have to turn NR up to "10", I now get equivalent noise reduction results at "5". This means a less processed, less suppressed incoming signal. Probably the most rewarding result, is to lose the crackly bacon type atmospheric noise that is common at my QTH on 80/75M. This is especially effective when the RF u-Tuning unit is on and used in conjunction with the attenuation control, adding just enough ATT until this noise on the DMU scope disappears. At that point, if I toggle off the u-Tuning unit, there is an immediate return to the bacon frying in the pan (I can almost smell it cook'n.) The following DMU screen photos best illustrate the before and after effects of the MTU. DMU screen photo 1# below shows the stock FTDX-9000 with the VRF unit turned off. We see a fairly high level of noise mixed with signals across the band (3,5KHz-4KHz shown here). The higher peaks are where the strongest signals happened to be at the time the photos were taken and not due to any filtering. DMU owners should note that the text "VRF" on VFO A (circled on upper left of screen) is in white or red, depending on the color scheme used, when the VRF and RF u-Tuning units are off. |
DMU screen photo #2 (below), shows the same band conditions with the stock VRF filter toggled "on" ("VRF/u" button on front of radio). As expected the band noise gently slopes off outside the manually tuned VRF peaked frequency (dotted verticle yellow line). DMU owners note that the text "VRF" on VFO A (circled on upper left of screen) is now orange indicating that the VRF is activated. |
DMU screen photo #3 shows the striking results across the band when the RF u-tuning unit is turned on! Noise is heavily suppressed across the band with the exception of the tuned frequency range (dotted verticle yellow line area), which the MTU automatically follows (you can override and manually tune the u-Tuning unit if desired.) DMU users note that the text in the upper left now reads "u-T" in orange, indication the RF u-Tuning unit is now activated. |