Users may not create topics, posts, or private messages containing or relating to the following material (especially pertaining to Motorola copyrighted software, unless you want Motorola to come along and shut this site down):

  • Listing for sale or trade of, or links to sites offering for sale or trade of, or giving away, Radio
    Service Software (RSS) or Customer Programming Software (CPS)
  • Profanity, pornography, defamation, or slanderous remarks directed towards any individual or entity
  • Commercial advertising (except in the Batboard Vendors forum, as approved by the Admin/Mod Staff)
  • Any other items which may be deemed as offensive

If any topics, posts, or private messages containing or relating to the aforementioned material are brought to the attention of the Admin/Mod Staff, they will be deleted.

Additional FAQ items appear here in Forum Rules. Please review them for posting guidelines and further clarification.

Narrow channel works better in wide than it does in narrow?

This forum is dedicated to discussions pertaining specifically to the Motorola ASTRO line of radios (those that use VSELP/IMBE/AMBE), including using digital modulation, digital programming, FlashPort upgrades, etc. If you have general questions please use the General or Programming forums.

Moderator: Queue Moderator

User avatar
nmfire10
Batboard $upporter
Posts: 4109
Joined: Sat Jun 29, 2002 4:41 pm

Narrow channel works better in wide than it does in narrow?

Postby nmfire10 » Sun Mar 01, 2009 8:24 am

Conventional UHF astro channel. It is narrowband (460.2875). I live in a pretty bad spot so the signal that reaches me is weak. If I accidentally program my portable for wideband, it receives GREAT. The audio doesn't get choppy or anything. If I program it correctly for narrowband, the audio gets choppy and cuts out due to the weak signal.

I would think it would be the other way around? Am tripping on something here? This is demonstrated with two different radios (XTS1500 and XTS3000).
"I'll eat you like a plate of bacon and eggs in the morning. "
- Some loser on rr.com

eBay at it's finest:
Me: "What exactly is a 900Mhz UHF CB?"
Them: "A very nice CB at 900Mhz speed!"

:-?

User avatar
Tom in D.C.
Posts: 3859
Joined: Tue Sep 04, 2001 4:00 pm
What radios do you own?: Progreso soup can with CRT

Re: Narrow channel works better in wide than it does in narrow?

Postby Tom in D.C. » Sun Mar 01, 2009 3:13 pm

Sure sounds to me as if the signal is being sent wideband, regardless of the frequency being on a 12.5 kHz split.
Tom in D.C.
In 1920, the U.S. Post Office Department ruled
that children may not be sent by parcel post.

User avatar
nmfire10
Batboard $upporter
Posts: 4109
Joined: Sat Jun 29, 2002 4:41 pm

Re: Narrow channel works better in wide than it does in narrow?

Postby nmfire10 » Sun Mar 01, 2009 4:51 pm

Heh. Ya know, given the history of this system, which I believe you're probably familiar with due to all the problems I keep posting here about, I seriously would not be surprised if they screwed that up too. Unfortunately I don't have a cable for a Quantar to read it so I can only assume they did it right.... which would be a first for this thing.

Next time I get my hands on a service monitor, I'll park under the tower and see what is expelling fourth from its transmitter.
"I'll eat you like a plate of bacon and eggs in the morning. "
- Some loser on rr.com

eBay at it's finest:
Me: "What exactly is a 900Mhz UHF CB?"
Them: "A very nice CB at 900Mhz speed!"

:-?

User avatar
d119
Posts: 3501
Joined: Tue Mar 19, 2002 4:00 pm

Re: Narrow channel works better in wide than it does in narrow?

Postby d119 » Sun Mar 01, 2009 6:52 pm

Just because it's on a splinter channel does not mean that it is narrowband, Marc.

User avatar
nmfire10
Batboard $upporter
Posts: 4109
Joined: Sat Jun 29, 2002 4:41 pm

Re: Narrow channel works better in wide than it does in narrow?

Postby nmfire10 » Sun Mar 01, 2009 6:56 pm

Oh I know the background of this system and it is supposed to be narrow. It is also licensed as narrow. In fact, the police chief claims "astro works better on narrowband" (direct quote). I don't know why it would make a difference and based on this experience, I think he might be mistaken :)
"I'll eat you like a plate of bacon and eggs in the morning. "
- Some loser on rr.com

eBay at it's finest:
Me: "What exactly is a 900Mhz UHF CB?"
Them: "A very nice CB at 900Mhz speed!"

:-?

User avatar
Josh
Posts: 1926
Joined: Mon Sep 03, 2001 4:00 pm
What radios do you own?: ASpectra+, XTS2.5K, Kenwood NX

Re: Narrow channel works better in wide than it does in narrow?

Postby Josh » Mon Mar 02, 2009 10:42 am

I would say something is programmed wrong.

There is an Astro ham repeater here in narrow-band mode. I had my astro spectra programmed wide-band and couldn't RX worth a darn at a distance, it would get easily desensed by other nearby signals and repeaters. I made it narrow band as it should have been and RX cleared up and was way more selective. RX range significantly improved too.

Narrow band can work better than mis-programmed radios set up conversely!

User avatar
wavetar
Administrator
Posts: 7335
Joined: Sun Sep 09, 2001 4:00 pm

Re: Narrow channel works better in wide than it does in narrow?

Postby wavetar » Mon Mar 02, 2009 11:02 am

In a given radio, selectivity, intermodulation & spurious rejection are all spec'd worse in narrowband than wideband, usually by at least 5 db, sometimes 10. Also, although I cannot find it listed separately in an Astro manual, sensitivity in a given radio was generally worse by 0.05 uV. So, it doesn't surprise me that a radio may work better with a weak signal in wide band mode as opposed to narrow.
No trees were harmed in the posting of this message...however an extraordinarily large number of electrons were horribly inconvenienced.

Welcome to the /\/\achine.


Return to “Legacy Batboard Motorola ASTRO (VSELP/IMBE/AMBE) Equipment Forum”

Who is online

Users browsing this forum: No registered users and 2 guests