quantar narrowband

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ccip4911
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quantar narrowband

Post by ccip4911 »

I'm new to quantars and just purchased a uhf r2 to replace my msf5000. I was playing around with the RSS to try and get famialr with it before I program the quantar. When I changed the modulation from 25 to 12.5 the RSS said I needed to install the uhso fru or have an external one connected. Is true? Can I have the quantar work on narrowband without the uhso or an external reference?

Brian
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Bill_G
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Re: quantar narrowband

Post by Bill_G »

News to me. Every Quantar I've ever worked on could be narrow or wide without needing extra parts. I'll have to check a couple to see what's installed. Only the 900's had UHSO's installed, but they are native 12.5kc band. Maybe I haven't been paying attention to the UHF and VHF stations very closely.
wa6ylb
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Re: quantar narrowband

Post by wa6ylb »

The RSS says you need this even if you have the UHSO installed and or have the external 5 MHz osc connected. I suspect it’s a pop up banner to remind us that that the frequency accuracy is more critical than it was when the radio was setup for wide band. In the narrow band world, being off frequency is more critical than it was with wide band. We have our Quantars at radio sites on external GPS frequency references (Trak GPS) and when we look at them over the air, on the service monitor, I see they are within +- 1 Hz. Sweet.
Another thing to consider - even though we may have radios in hand that can be programmed from wide band to narrow band, we need to look at them with a service monitor to make sure they are on frequency. Most synthesized radios have reference oscillators that actually drift over time, due to the reference crystal aging. When we converted a local city PD recently, we had to net all of their radios after the conversion. Just to change mode from wide to narrow can give you poor results, if you find the radios are actually between 1 and 2 KHz off frequency.
B.
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Bill_G
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Re: quantar narrowband

Post by Bill_G »

But does a Quantar require a UHSO to operate at 12.5khz? I don't know. I'll have to look it up.
MassFD
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Re: quantar narrowband

Post by MassFD »

I have 3 UHF quantars that have been narrowband since 2005 and do not have any external reference, never got any pop ups on the inital programing or on any later reprogram.

I do not think I have any internal High Stability oprions either, would have to look.
Cause Motorola said so that's why
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The Pager Geek
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Re: quantar narrowband

Post by The Pager Geek »

MassFD wrote:I have 3 UHF quantars that have been narrowband since 2005 and do not have any external reference, never got any pop ups on the inital programing or on any later reprogram.

I do not think I have any internal High Stability oprions either, would have to look.
Same for me... close to 20ish VHF Quantars, FW 20.14.038, narrowbanded in 2010. No issues.

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MassFD
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Re: quantar narrowband

Post by MassFD »

Just looked at 1 of my working codeplugs, on the Hardware Config screen in the RSS there is the selection box for Freq Ref. Mine is set for INTERNAL-STANDARD.

All the other options are External, take a look and see what yours is set for.

I have no idea why changing BW on the Channel Info screen would change what the station is looking for on Feq Ref, on my channel info screen when I change from Narrow 12.5 to Wide 25-30 then back again I get the same pop up that the OP got. I do not remember seeing that back in 2005 when I originaly NB the stations but it was with an older RSS back then.
Cause Motorola said so that's why
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xmo
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Re: quantar narrowband

Post by xmo »

The Motorola Quantar Planner has this to say:

"The following frequency stability is required in order to meet TSB102.CAAB (Project 25) and is HIGHLY RECOMMENDED for optimized Narrowband(12.5 kHz) operation..

QUANTAR UHF
Analog 25 kHz 1 PPM
Analog 12.5 kHz 0.5 PPM* , **

* To meet this stability the Quantar/Quantro Stations offers an Internal Ultra High Stability Oscillator or an external site reference can be used.

**Note: Under certain conditions a Frequency Stability of 1 PPM may be adequate."
MassFD
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Re: quantar narrowband

Post by MassFD »

Just remembered that I used the DOS version of the CPS on all my stations and still use it.

The codeplug I played with yesterday at home was with the XP version. I have never used the XP version on a live station as my XP laptop does not have a real serial port and I am afraid to try the USB to serial convertor on a high $ Quantar.

I do not think the DOS version ever gave me a pop up but will try it later in the week and report back
Cause Motorola said so that's why
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d119
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Re: quantar narrowband

Post by d119 »

I maintain several Quantar stations operating in analog narrow-band mode, none of them have an external frequency reference.

I've seen the pop-up screen that's being referred to here, I just ignore it. Proper alignment with a calibrated service monitor is critical to narrow-band operation, but once the station is aligned correctly, it should play fine in narrow-band mode.

UHSO / site reference is nice to have and an ideal configuration, but with the stability of the Quantar, I would say it's not a necessity unless the station is being used in a simulcast environment. If that were the case, there would already be a site reference present.
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Bill_G
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Re: quantar narrowband

Post by Bill_G »

Well, there we go. It's a warning, not an error.
ccip4911
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Re: quantar narrowband

Post by ccip4911 »

Thanks for the info guys

Brian
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