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HT1000 distortion during scan

Posted: Sun Mar 20, 2011 5:10 pm
by ke6vqy
I am experiencing a noticeable audio distortion on my HT1000 when scan is active. Typically at the end of the transmission when the squelch burst occurs as the carrier is dropped, it sounds like the speaker is being overdriven and the audio is very distorted. At first I thought I had a bad speaker, because it sounds very badly distorted like the speaker is damaged. But when I switch to normal operation it goes away and the transmissions and audio are very clear and quite normal. Is it possibly there's some bad setting in one of the fields set during programming that could cause this? Not sure why it would only happen during scan. Any suggestions?

Re: HT1000 distortion during scan

Posted: Sun Mar 20, 2011 6:13 pm
by maxkelley_kc2spy
I've noticed this as well, often with DPL'ed channels, as the radio is constantly checking the priority channel for traffic. Often, the DPL turnoff code, which tells the radio to mute the audio, is garbled by the priority channel being checked (and therefore not detected by the radio). So, after checking the priority channel, the radio will return to the non-priority channel with an open squelch because it assumes the signal is still present (more on this assumption later), when in reality, it isn't. It'll take a second for the radio to realize this, and re-mute it, so you'll end up with a long, choppy, distorted squelch tail/crash. (sounds sorta like chakakacrsh, if you will)

This assumption is made because waiting for the DPL/PL decoder to get a good decode when returning to the non-priority channel would take too long, and therefore chop even more of the audio.

Did that make any sense? I tried to explain it the best I could...

Re: HT1000 distortion during scan

Posted: Mon Mar 21, 2011 9:01 am
by ke6vqy
Thx. I understand. However, the radio 'Scan Type' is programmed for 'Non-Priority Scan'. Also, there are no DPL codes being used. The issue happens to all channels it receives; those with PL codes or CSQ. The radio does have "PL Scan' set to 'Enabled'. I wonder if disabling that might make a difference?

Re: HT1000 distortion during scan

Posted: Mon Mar 21, 2011 12:47 pm
by maxkelley_kc2spy
Only one way to find out!

Re: HT1000 distortion during scan

Posted: Wed Mar 30, 2011 8:44 am
by olderookie
I have noticed the same thing on a CSQ channel when in scan but sometimes it just keeps going. I have meant to change the PL detect on that channel to see if that changes it, time is just not on my side right now BTW this is VHF