Author Topic: Pacific HF Feed low audio?  (Read 4943 times)

Offline wb2uzr

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Pacific HF Feed low audio?
« on: January 10, 2010, 07:28:32 PM »
Is the audio on the Pacific HF feed very low? Other feeds that I tried sound fine.

Scott





Offline dave

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Re: Pacific HF Feed low audio?
« Reply #1 on: January 10, 2010, 07:49:58 PM »
It is a little bit on the lower side.  I find the controllers and aircraft fairly audible, though, when they're coming in.  If that is not the case for you we can see about getting the volume increased.

Offline wb2uzr

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Re: Pacific HF Feed low audio?
« Reply #2 on: January 11, 2010, 12:39:41 PM »
Thanks Dave:

Whatever works for everybody. I find I have to crank up the volume control all the way up on Winamp to even begin to hear the audio here. I can always bring the speaker volume way up, I just have to remember to bring it back down later! :-D


Scott/WB2UZR



Offline dave

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Re: Pacific HF Feed low audio?
« Reply #3 on: January 11, 2010, 01:11:44 PM »
Should be better now.

Offline wb2uzr

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Re: Pacific HF Feed low audio?
« Reply #4 on: January 11, 2010, 02:46:27 PM »
Indeed it is! Thanks!


Scott/WB2UZR


Offline Rob K

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Re: Pacific HF Feed low audio?
« Reply #5 on: January 12, 2010, 07:46:27 PM »
Dave is it possible to offset the frequencies slightly so that the selcal decoders will work?  Some radios seem to suffer from this where the frequency displayed isn't actually bang on.  From looking at where the spikes are landing on the decoder spectrum I'd take a guess that the freqs need increasing by around .04 khz, ie. 8915.04.  This won't make any noticeable difference to the voice audio, but the decoders will be able to do their job.

Just for your info if interested, your NAT HF radio feeds are very slightly below the actual freqs as the spikes on the spectrum are landing just to the left of the actual selcal letters.  Fortunately the decoder seems fairly happy decoding them as it stands, but to be spot on freq you need to drop maybe .005 to .01 off, eg. 5615.99 or 5615.995.  Sounds like a pathetic amount, I know, but I know that those people who are using Airnav decoder or the Skysweep will be getting constant bad decodes from your feeds as neither decoder has any leniency for 'under' freqs and will decode the next higher letter, eg. if the actual selcal is BCDE then they will show ABCD.  No such problems using my multiPSK decoder though  :-).

By the way, the audio on that feed is still VERY quiet.  Volume on max here and only getting faint mumblings.
« Last Edit: January 12, 2010, 07:56:09 PM by Rob K »

Offline dave

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Re: Pacific HF Feed low audio?
« Reply #6 on: January 13, 2010, 12:44:28 PM »
Dave is it possible to offset the frequencies slightly so that the selcal decoders will work?  Some radios seem to suffer from this where the frequency displayed isn't actually bang on.  From looking at where the spikes are landing on the decoder spectrum I'd take a guess that the freqs need increasing by around .04 khz, ie. 8915.04.  This won't make any noticeable difference to the voice audio, but the decoders will be able to do their job.

Just for your info if interested, your NAT HF radio feeds are very slightly below the actual freqs as the spikes on the spectrum are landing just to the left of the actual selcal letters.  Fortunately the decoder seems fairly happy decoding them as it stands, but to be spot on freq you need to drop maybe .005 to .01 off, eg. 5615.99 or 5615.995.  Sounds like a pathetic amount, I know, but I know that those people who are using Airnav decoder or the Skysweep will be getting constant bad decodes from your feeds as neither decoder has any leniency for 'under' freqs and will decode the next higher letter, eg. if the actual selcal is BCDE then they will show ABCD.  No such problems using my multiPSK decoder though  :-).

By the way, the audio on that feed is still VERY quiet.  Volume on max here and only getting faint mumblings.

I will check the receiver calibration and whether RIT is accidentally on.  I have a good frequency source that I can check with.  Failing that I will look at a slight offset as you described. 

This is unrelated to this thread so let's take this off onto email.