Very interesting video! Great to hear the difference in ringing between 300Hz DSP filter and the 300Hz roofing filter. In this case, I would use the shift knob so that the signal I want to hear is just starting to get attenuated, while greatly reducing the interfering signal. I have tried to find out whether the 500Hz built-in filter is sharper (attenuation per decade) than the 300Hz one, but I haven't found any details.
@JayN4GO Жыл бұрын
Perfect test man! Thank you for taking the time to make this and saving people 200$
@HamRadioQRP Жыл бұрын
Glad to help!
@johnc34035 ай бұрын
The real advantage of the 300Hz filter is that it an interfering signal won't have as much effect on the AGC. The DSP is after the AGC when co-signal blocking has already happened. Admittedly, this is less obvious in these hybrid rigs but even so, AGC blocking is the real issue. Also, astute use of the shift control can serve to put the interfering signal deeper into the skirt. I use a combination of R.Fil, DSP, Shift and APF to eek the best out of a signal on a crowded band. ..not a big fan of DSP NR though, even at level 1.
@thirtycrows Жыл бұрын
The 300 is a corner case filter. It makes a difference if the interfering signal overdrives the dsp but you can't decrease the rf gain because the wanted signal is already very weak.
@Bob5mith7 ай бұрын
Can the 300 Hz filter be used in SSB? DATA-U specifically? I want to use it for FT8. I haven't been able to find a clear answer if it will turn on in all modes or if it's blocked in some. I regularly use the 500 Hz and digital shift/width/notch/contour controls to isolate weak signals from strong ones, but sometimes they are too many packed too close to really get the one I'm after.
@HamRadioQRP7 ай бұрын
I'm looking for suggestions. What you like to hear?
@taekehf Жыл бұрын
Doesn't the AGC, set to Auto, also influence the reception? The volume is "pumping". Does it make a difference when the AGC is set to Fast?
@HamRadioQRP Жыл бұрын
AGC is controlling how much it will increase gain in the absence of a signal. In the case of this test I was demonstrating how much the additional filtering reduced a strong adjacent signal. Since I was connected to a dummy load, the noise floor was not part of the equation. It certainly pumped the volume as it attempted to reduce the strong adjacent signal's impact on the audio, but with it off the adjacent signal would have distorted the audio. I know some people turn it OFF to copy a weak signal but I don't think that's the norm and it's certainly unpleasant to operate without the AGC in operation. I do plan to do a video at some point comparing the FT-DX10's AGC to my Ten-Tec and Elecraft radios. Spoiler alert: It has far better AGC than either of those radios, and the AUTO mode works very well for most conditions. I have to ride the AF / RF on other rigs in the presence of QSB. The DX10's AGC is very responsive and smooth in comparison, requiring very little interaction with the controls across fading or when listening to two stations with markedly different signal strengths.
@iz6byc Жыл бұрын
In a situation likes this, in real life, i would had put AGC to off and manually tweaked It...