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HT1000 audio issues
Posted: Sat Jul 12, 2008 10:12 am
by dw200
Questions for any of you. I was adding/changing the programming in the last of my HT1000 radios to accept 2 new narrowband frequencies. I assumed that the channel spacing should be 12.5 mhz and set it acccordingly. I decided to check the interoperability frequencies that are in the radio to make sure but they were set to 25/30 mhz. They were programmed by another individual a while back. I made the assumption that was incorrect are set them to 12.5. When testing with other radios later on that i know are set correctly, they sounded like crap.
1....Is the spacing right or wrong?
2....Don't know if the "companding" is on or off but will check Monday. Which should it be?
Re: HT1000 audio issues
Posted: Sat Jul 12, 2008 10:58 am
by MTS2000des
What model HT1000's? DN models are required to support narrowband. none of the HT1000's support companding. The DN models don't support 6.25KHz steps either.
Re: HT1000 audio issues
Posted: Sat Jul 12, 2008 2:46 pm
by dw200
I have 4 CN models and my personal radio is a DN. I have gotten conflicting info on this subject. I have been told that the C radios will accept the narrowband frequencies but not all. I have also been told to check the "companding" by others but i can find no reference to this in the programming which follows with what you stated. Sadly, these are the last of the Motorola's in my fleet , aside from 30 MT1000's but I am not here to discuss them. They are in reserve status and I am trying to keep them as current as possible.
Re: HT1000 audio issues
Posted: Sat Jul 12, 2008 6:56 pm
by MTS2000des
hmm...the CN radios date to 1996, before the narrowband kick which didn't get going until a couple of years later. I know the CN's were the first with the OptionMate controllers, but AFAIK the DN's were the only ones capable of narrowband. No HT1000's have companders, the circuitry simply is not there on the controller boards. The Pro series (HT750/1250/1550) were the first models other than the P1225 to have Xpand.
Re: HT1000 audio issues
Posted: Mon Jul 14, 2008 6:57 am
by jpu535
Speaking from personal experience, the fire department I work for has 44 HT1000 "D" series portables and about 40 Astro Spectra's on UHF. When the system was purchased new in 1998 we were originally programmed narrow band (trying to be politically correct). Within weeks of going on the air complaints started about receive audio quality on the HT1000's. The complaints were that audio was muffled at full volume and near full volume. All radios were using public safety speaker mics. If the volume was turned down to half way then audio quality did improve but that's difficult to do on a noisy fire ground. Removing the speaker mics did not improve anything. Motorola sent an engineer down and tweaked the firmware in the HT's but there was no difference. To make a really long story short they reprogrammed the entire system to wide band and all the audio issues went away and to this day not one complaint about muffled audio at full volume. Looking back from today I would say that the narrowband technology that exists in those radios is first generation and they do not have the software tweaking features to adjust audio quality like the radios being produced today. So I don't think there is anything you can do make an HT1000 sound the same on narrow band as say a Pro series or an XTS radio. Just my 3 1/2 cents worth.