For VHF 108 - 138 and military 200 - 380 MHz listening, what's the right bandwidth setting? I always seem to get a tinny, scratchy sound quality instead of the usual just-right type sound from a scanner.
SDR# What's The Right BandWidth For AM Aircraft Monitoring?
- Thread starter CanesFan95
- Start date
- Status
- Joined
- Dec 19, 2002
- Messages
- 2,685
- Reaction score
- 1,554
Since aircraft are AM instead of FM (I assume you know this and correctly programmed your scanner), it is not going to sound the same as FM. With AM, you do not have the capture effect of an FM signal. Also, I have noted aircraft are often not exactly on frequency so if you tune to the specified frequency with the bandwidth expected, you will not hear some aircraft well. Anyway, aircraft are generally most aircraft transmit in a bandwidth of 6 to 8kHz wide but as noted, if you set for such, aircraft a little off frequency may be a problem (my experience). In addition, some receivers/transcievers notoriously have poor or weak AM audio as they were in design designed primarily as FM receivers.
That is channel spacing and I do not believe that is what the op is asking for. I believe he is playing with the Sdr# settings to obtain better audio.
" The audio quality in the airband is limited by the RF bandwidth used. In the newer channel spacing scheme, the largest bandwidth of an airband channel is limited to 8.33 kHz, so the highest possible audio frequency is 4.166 kHz.[16] In the 25 kHz channel spacing scheme, an upper audio frequency of 12.5 kHz would be theoretically possible.[16] However, most airband voice transmissions never actually reach these limits. Usually, the whole transmission is contained within a 6 kHz to 8 kHz bandwidth, corresponding to an upper audio frequency of 3 kHz to 4 kHz.[16] This frequency, while low compared to the top of the human hearing range, is sufficient to convey speech. Different aircraft, control towers and other users transmit with different bandwidths and audio characteristics. "
Airband - Wikipedia
en.wikipedia.org
@Homeboys-Scanna I have found (for me anyway) that setting it between 6000 and 10,000 gives me the better audio. Anything under 6 is very tinny and over 10000 adds more hiss. I have somewhere more in-depth settings from other areas that cleaned the signal up.
Yes, that's what I'm hoping for. To improve the audio quality and get rid of that high hissing type sound. But I notice lowering the bandwidth (especially under 6 kHz) makes it sound more bassy and muffled, rather than tinny.
You can clean it up some with the IF Noise Reduction * plug in
- Joined
- Dec 19, 2002
- Messages
- 2,685
- Reaction score
- 1,554
Like I mentioned, I have found that I do that, some aircraft are so far off frequency that I do not hear them. Going below 6 kHz will do as you described--it has to because narrower than that cuts out frequencies above 3 kHz and will no as you describe. Remember, communication quality is not the same as audio quality. Best range and understandability will result from cutting some of the base but you cannot do that by adsting the bandwidth this way. So if the filters in the software allow, cut the audio also below 400 Hz. Usually something like 400-3000 or 2800 Hz will give the best communications audio (but not good for music etc.).
I've also noticed the audio quality from the Airspy R2 just isn't very good .Compared to both my Icom IC-R20 and MBITR,it has much more noise with with some other artifacts to the sound and just sounds tinnier all together.
There are filters in Sdr# to play with. I had mine sound real good at one point.
- Joined
- Dec 19, 2002
- Messages
- 2,685
- Reaction score
- 1,554
As mentioned before, some people want more bass than others but bass actually does not add to readability. Generally, voice intelligence is carried in the 400-3000 kHz audio frequencies. But the audio quality you mention is not that of the Airspy as it does not produce the audio. The audio is produced by your PC and the software. Try tuning an AM signal set your audio filters to limit it to 400-3000 (sometimes one has to use SSB to do this). That is what you want to hear for intelligibility (but definitely not for music).
I meant to imply that using the Airspy and SDR# results in the audio quality I'm hearing. I should have been more clear on that.It's not the computer because the audio quality sounds acceptable with everything else piped through it.
I've adjusted all the settings including using the audio processor plug-in to get the best compromise and the audio is still not that great.
I've adjusted all the settings including using the audio processor plug-in to get the best compromise and the audio is still not that great.
- Joined
- Dec 19, 2002
- Messages
- 2,685
- Reaction score
- 1,554
I thought you probably meant that. I do not see that you mentioned what bandwidth you set?
It's currently set at 10,000 for AM.
- Joined
- Dec 19, 2002
- Messages
- 2,685
- Reaction score
- 1,554
I would roll it off below 400 Hz.
- Status
Similar threads
