Noise (Interference???) on digital Quantar VHF

[Equinox]

Few months back we installed a Quantar VHF repeater programmed for mixed mode (Analog/Astro CAI) operation for the local SO. Plans are for digital mobiles to be installed soon, but none are in so far. Anywho, soon after installing the repeater they started to hear noise that sounds similar to data. It isn't clear, but rather pretty obnoxious sounding. It won't get into the repeater until one of the units has keyed it up and then drops off. Usually it will only make this noise for a second or two after the field unit drops off, but on a couple of ocassions it has done it almost nonstop for quite a while. My problem is, as with many interference problems, by the time I get out to the site it has usually quit, or at least it is so sporadic that it does it for a second or two but quits before I can react to it. I'm 99% sure it's interference, but assuming it's not is there anything that could be causing it within the unit, perhaps the way it's programmed, etc? Previously I had tightened the squelch up some but the noise returned yesterday pretty badly. One thing I did today in the programming is set the repeat hold in and repeat enable to PL/DPL only, hoping that whatever this interference might be does not have the proper PL. No report of the noise so far. I know this is a vague description but maybe someone has run across some goofy quirk or whatever.

[batdude]

my ham quantar does the same thing on occasion.


the data sound you hear is the astro end of message burst.

RARARARARARARARARARRAAAAAAAAAA

very obnoxious.

best i can figure is that the repeater receiver is somehow "falsing" on what it things is valid inbound astro data -

i have my machine set up for mixed mode operation w/ PL hold in on analog.... so the receiver definately thinks it's hearing a valid digital signal to key up...like there is a crack hoe running things inside the quantar or something.


my take: screw it - the quantar is rated for continuous duty....


like sgt. klink sez "I HEAR NOOTHING!"




d

[Dan562]

Hello Equinox,

The way you've had your VHF Quantar programmed sounds like it was in the Carrier Squelch Mode for both Analog and Astro (Digital) signaling. If you've Enabled PL / DPL Detect only then the only time the receiver should open is with the proper PL code. There's a parameter for PL and Carrier Squelch which is the "AND SQUELCH" function which is normally set up for 20 dB Quieting plus the proper PL Code.

There is one other parameter you should determine and set up for the Digital Astro Mode. This is the Network Access Code otherwise known as the NAC which is the equivalent of PL / DPL in the Astro Mode. I believe your using this VHF Quantar in a commercial application being Public Safety and you don't want other users to access your system without the proper written permission. Take your RSS and locate the NAC parameter field, enter a three digit number and remember this code when you program the Astro subscriber units so they can access the repeater in Digital Astro Mode. This may help rid yourself of hearing the complaints from your users.

Dan

[batdude]

dan, just FYI - been there tried that. didn't fix the problem for mine.


best i could figure with my site / situation was that for whatever reason every so often my receiver falsely detects inbound astro data (hence the crack hoe comment)

i am 100% certain it's my site - b/c my UHF machine at another site hasn't ever done what my VHF does...of course, you could argue firmware/codeplug/yada yada yada all day long....


doug

[Equinox]

dan, just FYI - been there tried that. didn't fix the problem for mine.


best i could figure with my site / situation was that for whatever reason every so often my receiver falsely detects inbound astro data (hence the crack hoe comment)

i am 100% certain it's my site - b/c my UHF machine at another site hasn't ever done what my VHF does...of course, you could argue firmware/codeplug/yada yada yada all day long....


doug

Your description sounds like what they have been hearing. One of my first guesses was that this might be coming from another digital setup somewhere else and since nobody (yet) is monitoring in digital, we're just hearing the noise. I'd hope there is a solution of some sort.

Since it has mainly happened in the morning I'm planning on calling the SO dispatcher first thing every morning to see if it is doing it, so I can haul @$$ out to the site before it stops. One more thing to add to my obsession list.

[Equinox]

Hello Equinox,

The way you've had your VHF Quantar programmed sounds like it was in the Carrier Squelch Mode for both Analog and Astro (Digital) signaling. If you've Enabled PL / DPL Detect only then the only time the receiver should open is with the proper PL code. There's a parameter for PL and Carrier Squelch which is the "AND SQUELCH" function which is normally set up for 20 dB Quieting plus the proper PL Code.

There is one other parameter you should determine and set up for the Digital Astro Mode. This is the Network Access Code otherwise known as the NAC which is the equivalent of PL / DPL in the Astro Mode. I believe your using this VHF Quantar in a commercial application being Public Safety and you don't want other users to access your system without the proper written permission. Take your RSS and locate the NAC parameter field, enter a three digit number and remember this code when you program the Astro subscriber units so they can access the repeater in Digital Astro Mode. This may help rid yourself of hearing the complaints from your users.

Dan

I originally had all 3 parameters set for "Carrier and PL/DPL" but just yesterday set the Repeater activation and Repeater hold-in to "PL/DPL" only. Like I said previously, whatever this is won't open the repeater on its own. It only does it after a subscriber has talked on the repeater. BTW, once it starts doing it, a unit can still transmit over it with no problem.

Concerning the NAC, so far I haven't touched that. I believe it is set from the factory at code 283. Who knows, maybe (if it is interference) some other system somewhere didn't change theirs from the default when it was setup, and that is the problem. I might change that (and make a note of it of course) just for grins next time I'm out there. Like I said in the previous reply, hopefully I'll catch it one morning where I can get out there and troubleshoot it a bit.

[Dan562]

Hello Equinox & Batdude,

Both of you guys have valid points but as Equinox has pointed out, "Since it has mainly happened in the morning" then makes me think about early morning VHF tropo signal conditions that can be between 100-150 miles away, caused by another digital system on the same frequency. I can imagine your antenna is probably a couple hundred feet in the air making it almost impossible to pin point the interferring signal. On the other hand have you looked at your potential receiver's coverage area based on path losses. You might consider a Doppler Direction Finding equipment to place in you mobile to track down the interferring source during the early morning hours ... as if you don't have anything better to do with your time.

The older /\/\ system range calculator would privide coverage for 90%, 70% & 50% Analog in air miles radius coverage from the Base Station Repeater. Whatever was determined to be the 50% mileage, as an example 30 miles X 98% = 29.4 miles is now the normal Digital Astro coverage. I realize there are better software programs to provide coverage maps but it all equals the same thing. Your interference could be 0 to 50 miles away being produced by an intermod mix, spurious or co-channel mobile transmitter.

I've often heard the younger /\/\ engineers say there's no interference problems in the digital mode but that's not true. Interference can happen in FDMA, TDMA, CDMA. Frequency Hopping and plain old Analog. There's only one minor detail while using the digital mode, and that's identifying the interferring signal source. The same rules hold true for RF practices when colocating Analog and Digital transmitters with circulators, filters, feedlines and antennas. The digital mode is only as good as it's weakest link.

Dan

[ASTROMODAT]

APCO P25 Data 18 packets (Acknowledged data) will sound like this, if you don't have your radio set to mute the speaker for data.

larry

[Equinox]

APCO P25 Data 18 packets (Acknowledged data) will sound like this, if you don't have your radio set to mute the speaker for data.

larry

Where is this setting to change it?

[ASTROMODAT]

There is a setting for "Mute on Data" in the CPS.

[CTAMontrose]

ive heard this "sawmill" sound alot of several quants, ironically all on VHF.. probably just a co-incidence...

its a very unique sound to say the least.. sometimes on the local machine, you can hear it under users in analog mode.

also, atleast in the case of batdudes quant, i dont think any of us are playing with astro data, and while this sound is going on, its being encoded with the PL, so the analog subscriber radios unmute to let this gawd awful sound in

[allplowedout]

chECK out my post and the link to the noise I've recorded, if it's this noise, I can assure you it's NOT the digital end noise you mentioned. I've yet to determine what is causing this.

[Equinox]

chECK out my post and the link to the noise I've recorded, if it's this noise, I can assure you it's NOT the digital end noise you mentioned. I've yet to determine what is causing this.

I did, and it wasn't quite the same thing you posted (although it may be related). My problem with this particular unit was eliminated when I changed the RX activation parameters to PL/DPL only.

Early this week I installed another Quantar VHF for an SO in far West Texas. We were on top of a mountain (helicopter acess only) and I did not have my service monitor with me. I attempted to adjust the squelch settings on the Quantar and when I did, it started making the same noise yours is making. It wouldn't do it until the unit was keyed up (by a portable) but once it did it would not stop until I power cycled the unit. I finally wrote the original program archive back into the Quantar w/ the original squelch settings, and the noise hasn't happened since. Weird deal.

[ASTROMODAT]

Neither one of our Quantars has ever done such a thing.

I assume from your post that these Quantars for the Sheriff's Office are factory new, as opposed to the typical eBay Quantar garbage (where ANYTHING can, and does, happen!). So, why are you swetting it? Contact your sales guy and tell him to get the FTR guy out their under warranty like PRONTO and get it fixed. Alternatively, open up a GCI and go from there.

It should be Motorola's nickel, and not the SO (unless you somehow caused this with an inadequate install, and/or you saved a buck and didn't get the tripple isolator/circulator option, in which case it will be YOUR DOLLARS).

In any event, since it's new from the factory, please don't take offense (because none is intended), but why in the heck are you asking strangers on the Internet for technical repair advice when your Quantar is new and under warranty? That's a HUGE part of the reason that a new Quantar set back the Sheriff's Office (a tax supported public entity that we all pay for) $18,000 to $30,000 (list price) new from Motorola, because they WILL stand behind it. The problem you describe is definitely abnormal, and something is clearly wrong.

For heaven's sake, Man, make Motorola fix it. Only if youy have an eBay piece of junk Quantar for Ham use should you be chewing up your valuable time getting hints from strangers on the Net. Make them fix it!

Good luck.

[allplowedout]

Hi just wondering what the following two things were specifically:

FTR guy

and

open up a GCI and go from there

[ASTROMODAT]

Motorola Field Technical Rep

Global Customer Inquiry (which should be unnecessary, since I suspect your FTR will solve the problem)

I have used GCI's for bizarre problems, such as some of the complexities of ASTRO digital mode ASTRO dialing in the manual mode on a conventional UHF system, with the DIU3000 connected to the MRTI2000, with encryption.

They will set up such elaborate tests as the above in their Base and Secure Group in Schaumberg to simulate your EXACT conditions. They even have you email your codeplugs for your ASTRO P&M radios, your Quantar, and the DIU3000 and MRTI2000 to their lab. This way, they can EXACTLY duplicate in their lab what you've got in the field. Of course, you have to supply all of your serial numbers, etc. as they do it on their nickel.

I've had great help with GCI's, albeit I think I also helped Motorola as they found a lot of issues with their firmware and CPS via this process, so we both won. For a non-emergency issue, it usually takes about 3 to 4 weeks, from start to solution. This is one of the great benefits of buying new from Motorola. You get this sort of support, and it has been worth every penny, in my opinion.

Folks here often try to surmise as to why an ASTRO radio costs $5,000. One of the reasons is that this sort of support is awesome, albeit costly for Motorola. There's no such thing as a free lunch.

[RFdude]

ASTROMODAT wrote: "I've had great help with GCI's, albeit I think I also helped Motorola as they found a lot of issues with their firmware and CPS via this process, so we both won."



And then they keep the bug to themselves and don't tell others about it. So every Motorola customer that has that same issue spents resources troubleshooting it to the point that they are finally convinced it isn't self induced and can prove Motorola is responsibe. The typical response from Motorola is: "Thanks... but we already know about it."

Geez, thanks /\/\ for sharing your knowledge!

Sometimes Motorola will fix, other times they won't. Depends if enough customers get wind of the issue and the liability it presents. But I don't have the impression Motorola welcomes various customers talking to each other for this reason. For instance, is there such a thing as a SmartZone user group that provides input to /\/\, or prioritizes new features or bug fixes for them?

So I guess the attitude prevents customers from trolling for firmware upgrades when their operation might not be affected by the bug in question. If a customer finds it and brings it forward, it must be a legit irritant.

RFDude.

[Equinox]

I HATE calling Motorola. It's like accepting defeat.

I have had many issues solved by the fine folks who frequent these boards, and always learn something new in the process. I sincerely appreciate it.

[ASTROMODAT]

Actually, if you were aware of Motorola's ISO 9000 Quality Process, you'd understand that part of their quality process is that once a GCI is solved, the results are run through their Continual Improvement Processes to avoid a repeat problem(s).

BTW, once you open up a GCI, you are assigned a specific case number, and Motorola will NOT close out that particular GCI until it is solved to the customer's satisfaction (the one who opened it).

There is a good reason why Motorola won The Malcom Baldridge Award.

[MTS2000des]

Actually, if you were aware of Motorola's ISO 9000 Quality Process, you'd understand that part of their quality process is that once a GCI is solved, the results are run through their Continual Improvement Processes to avoid a repeat problem(s).

BTW, once you open up a GCI, you are assigned a specific case number, and Motorola will NOT close out that particular GCI until it is solved to the customer's satisfaction (the one who opened it).

There is a good reason why Motorola won The Malcom Baldridge Award.

Yeah, okay, so this is why it took almost 8 years to work all the major bugs out of the Jedi series (loose antenna connectors, bad flex, wierd noises on TX caused by RF shielding issues)...maybe because it took 8 years for Ma M to get their heads out of their butts and listen to their users.

Larry your cheerleading is cute and all, but this person has a legitimate problem. Maybe he is here because Ma M keeps blowing smoke up his ass.
If he is like most of us he wants his system to work like he paid for.

Right now as I write this, your friends with Ma M (our FTR is here in case your wondering) are working hard to relocate our county's prime site for their Smartnet II 800 system...a whole 1000 feet from one building to another, and moving to a new antenna system they sold us, along with 21 new Quantars. Guess what Larry, it's 1:37 AM...this was supposed to be over with YESTERDAY. In the meantime, our county has more reliable communications from two cups and a string. Failsoft for coming up on 48 hours. What's the problem? Not sure, they won't tell us. All I know is I am glad we have a cache of good old VHF KENWOOD radios and our old repeater so we can "get right through".

Maybe our FTR will come on here and post so you can tell him yourself how great their ISO9000 processs is.

Motorola isn't exactly the easiest company to deal with Larry. Face facts. If they were so good as you say, then there wouldn't be a Batlabs now would there be?

[ASTROMODAT]

I here these anecdotal stories from strangers on the Internet, and I suspect that 99%+ of them are Hams with eBay Motorola equipment. I have always had great service from Motorola, and I don't think it's just good luck.

[MTS2000des]

yeah well, our county system isn't bought from Ebay. We are on day 3 of failsoft...the FTR has called in some help. I am sure this means nothing another 20 million dollars can't fix...

meanwhile our conventional VHF is humming right along...

[kb0nly]

I here these anecdotal stories from strangers on the Internet, and I suspect that 99%+ of them are Hams with eBay Motorola equipment. I have always had great service from Motorola, and I don't think it's just good luck.

Cough...

Ok, now that i about choked on my supper...

Motorola service sucks the big one no matter what! From PS to Ham's, they always fall behind compared to other companies. Its sad, since a lot of their products are great, but the customer service really degrades their usability.

The local PD got screwed last year, the FTR here pushed and pushed and sold them a bunch of HT750's that have been nothing but a liability to officers who use them, and the Astro Spectra's are nice but when dispatch is still using analog what was the point of the extra cash there!

And don't even get me started on the redo of the county radio system, and we are not talking 800Mhz, just plain old VHF. They screwed that up so bad that cell phones were being used for a while to bypass all the radio problems. Took nearly a year to straighten all that crap out!

Like i said, Motorola has a problem, they have a problem with dealing with customers who use the radios in the real world and try to provide feedback on problems. I remember when a problem with the HT750's was reported, the FTR basically told everyone its not the radios fault, its the end user, and their product is fine. Funny, when the officers went back to their old standby's, MT1000's, all was well again!

[ASTROMODAT]

Last time I checked, we live in a Capitalist country where the free hand and "invisible forces" of "The Free Marketplace" rule supreme. If Motorola is so terrible, how come they have 95%+ of the two way Public Safety market? The crumbs go to M/A-COMM, and a few others.

I rest my case...

[kb0nly]

Last time I checked, we live in a Capitalist country where the free hand and "invisible forces" of "The Free Marketplace" rule supreme. If Motorola is so terrible, how come they have 95%+ of the two way Public Safety market? The crumbs go to M/A-COMM, and a few others.

I rest my case...

Market supremacy has nothing to do with "Customer Satisfaction" these days. Also, Motorola is a technology Nazi, they don't share patents obviously, so they eliminate competition by having something nobody else does. Like Microsoft, just another monopoly, only it happens to be the communications industry rather than the IT software industry.

It's like comparing Microsoft to Apple/Mac, customer satisfaction has always been a problem with Microsoft products, but they have a large portion of the market share, possibly larger numbers than Motorola even. A recent survey of Apple/Mac users found customer satisfaction to be nearly 100%!!! But, when they did the same survey on Microsoft users they found it to be much lower than anyone thought, after all, Microsoft owns such a large amount of the public when it comes to software users how could they be so low on customer satisfaction? The answer is simple, to use a lot of today's software one needs to be running a Microsoft OS, regardless of customer satisfaction, there is nothing that can be done to change that until all the software, games, and other utilities that people use on a daily basis with a Microsoft OS are available on other platforms. And most likely will never happen because Microsoft isn't about to share any info, just like Motorola.

Same with the communications industry, if the County is using Motorola, than all the local city governments will as well to match the equipment in use. Around here you will find that if the County dispatch is Motorola you won't find a single other brand of radio in use, this is to guarantee inter operation of all. At least that's how the cities see it, regardless of how wrong it might be. The local FD recently had a choice of radios, many wanted to go with Kenwood HT's that they used while in training or employed elsewhere before coming here, but the city put a stop to that telling them they needed to purchase Motorola because the rest of the system already is. Do you think the fire department has a high customer satisfaction if they wanted a different manufacturers product in the first place but were forced to use Motorola "because everyone else is doing it".

I know plenty of departments with officers, and plenty of fire departments with firefighters, that prefer other brands but are stuck with Moto gear because they "have always been" Motorola. Most cities won't make a change once they have a contract with one company. Regardless of any problems!

My point is, if you think that Motorola customer service is so great, and that there is never a problem, then go become a poster boy for them, but us that have experienced the bad side of Motorola aren't likely to change our opinion! Does this mean that despite my low satisfaction that i don't use or own Motorola radios? Nope, i own quite a few, and buy and sell and repair and program more than i can count sometimes. But that doesn't mean as a company i still don't hate them! I just like their radios! So when you see a companies market share, don't immediately think they also have the same market share of customer satisfaction!

Enough said on the topic...

[ASTROMODAT]

Once you can run OS-X on Dell, like sometime late next year, that will be the beginning of Apple's demise. Their hardware is extremely pretty, but "he who has the lowest cost wins." And that spells 'Ba-Bye Apple!'

No one can compete with Microsoft because no one else has a competitive product. Name me a competitve operating system (and PaLeeze, don't say Linux!!!). Likewise, if you think you can buy a better high end 2-Way radio than Motorola, have at it with the off-shore garbage. Keep in mind that 99%+ of the big city cop departments rely on Motorola, and it ain't no accident!

[kb0nly]

Exactly! But don't translate that into "Customer Satisfaction". Though technically one could call Motorola Off-Shore these days. Even the big M outsources a lot of its stuff.

That's all that i was getting at!

[RFdude]

And how many large customers in North America wanted to see TETRA come ashore? Some of these large customers even went to Europe to Radio Comm shows to look into it. As soon as exhibitors found out they were from America, the stonewalling started. As if a gun was placed to the exhibitors head. Don't talk to the Americans. It was /\/\ who successfully blocked TETRA from North America like a cleverly played game of chess. Now that there are a few more years worth of old radio networks replaced with SmartZone or P25, in the interest of interoperability, Tetra would face an uphill battle. Too bad.

It IS about shareholder return on investment. That is the reality. If you think it is about saving lives, performance, or good customer service, it is co-incidental.

RF Dude

[mr.syntrx]

And how many large customers in North America wanted to see TETRA come ashore? Some of these large customers even went to Europe to Radio Comm shows to look into it. As soon as exhibitors found out they were from America, the stonewalling started. As if a gun was placed to the exhibitors head. Don't talk to the Americans. It was /\/\ who successfully blocked TETRA from North America like a cleverly played game of chess. Now that there are a few more years worth of old radio networks replaced with SmartZone or P25, in the interest of interoperability, Tetra would face an uphill battle. Too bad.

/\/\ did the same thing with MPT-1327 trunking, 5-tone signalling, and a bunch of other open standards.

[batdude]

back to the subj topic


i forgot to add that one of the navy bases here just had quants installed on VHF... and they "burp" every once in a while too......


with what i call the "astro disconnect tone" -- BRRRRRRRRRRRRRRRRRRRR

about 2 secs worth

[CTAMontrose]

Once you can run OS-X on Dell, like sometime late next year, that will be the beginning of Apple's demise.

just because an OS runs on X86, that doesnt mean that it will run on ANYTHING X86.

ex: an XBOX is an X86 platform, yet XP doesnt run on it, NOR does its dashboard OS run on anyother machine.

apple hasnt announced that OS-X will run on a current windows machine, rather they have merely said that their architechture has changed. I would be very surprised if OS-X86 would run on anything other than an apple motherboard with apple firmware on it.

[ASTROMODAT]

I disagree. I think we'll see Apple throw the towell in on their expensive PCs and let the Dell's of the world have the cut throat box business, while Apple concentrates on their OS. The iPod will last a bit longer, but once Motorola and others get a ton of flash in their phones, and secure licensing agreements with Apple for the iTunes Store, it's BaBye iPod, and other expensive Apple white hardware, and Hello to the new Apple that will sell only software. Probably makes good sense from a stockholder's perspective, albeit the Apple bunnies will be crying their hearts out. Just the nature of the cold realities of the marketplace. Pay $300 for an iPod, or a mere $5 to add iTunes AAC capabilities to your new Motorola phone. One less box to buy and lug around to the beach. BaBye Apple---it was nice while it lasted, but I told you The Red Head Guy would get 'ya! When it's Apple with OS only (and no more pretty white boxes) versus The Red Head's Long Horn, BaBye Apple! Apple's market share will go from today's 5%, to 4, 3, 2, 1--- Blast Off! Oops, or I meant to say, implossion. Sigh...

[mr.syntrx]

Won't happen. Apple is a hardware company - giving their OS up to generic PCs means committing hari kiri. All of their software is subsidised by their hardware sales, which is the reason they can sell very high quality applications like iLife and iWork so damn cheap.

As for the iPod, Creative Labs and the various Asian companies have been selling MP3 players far cheaper than iPods, with greater storage capacities etc for YEARS now. Why is the iPod still on top? Because the iPod is the best.

As for Longhorn - that's currently nothing more than vapourware, and anyhow, the truly new features that were going to be incorporated, such as WinFS, are being dropped by the minute to allow MICROS~1 to actually release it some time before my grandkids get their pensions. Windows doen't hold a candle to any operating system - the main reason it's still entrenched on the desktop is because of compatibility reasons with existing Windows apps.

Anyway, this is going waaaaay off topic.

[ASTROMODAT]

Apple is going the way of Colt Commercial, which sadly has happened. The venerable 1911 can now only be copied by immitators.