The Good Old Days

[lmrtek]

There's any number of possible causes. Lower output power, link configuration issues (if the repeaters were connected to DMR-MARCS or whatever), interference (if the repeaters were not on the same frequencies as analog), and any number of other things if the DMR repeater was compared to a different analog-only unit.

I've done comparison testing with dual-mode radios, where the same transmitter, receiver, frequency, power level, antennas, coax, and locations were used to compare analog FM and DMR, and there was little, if any, difference in maximum usable range when an actual apples-to-apples comparison was made. So I know from experience that when DMR is done right, it will at least match the usable range of analog FM.

Those of us that have earned their living installing and maintaining repeaters for 30 plus years know that there are no digital radios made today that even come CLOSE to the performance of repeaters and radios made decades ago.

New repeaters and new radios have lousy front ends compared to those made decades ago.

Today you are lucky to find a radio with 70db of selectivity.

Motorola and GE radios used to have over 90.

And repeaters all had well over 100db

So yes, it's a fact that those old school analog repeaters worked MUCH better than any made today.

And when analog gets a little interference due to power supply hum, or interference, it may only be an annoying but you will hear every word.

But with the same interference, digital is gone

Like it or not those are the FACTS.

 

[NC1]

There's any number of possible causes. Lower output power, link configuration issues (if the repeaters were connected to DMR-MARCS or whatever), interference (if the repeaters were not on the same frequencies as analog), and any number of other things if the DMR repeater was compared to a different analog-only unit.

These were on the same frequency and in the same location. Initially they were at the same previous power level as the analog, and put at maximum to try and overcome the deficiencies. Nothing else changed but it simply under performed.. People who have installed professionally were also at a loss as to why it did not have the same coverage. The consensus was that the DMR does not do well in this terrain. Back on analog again and everything is fine.

If it were just one installation, I would think it was not installed correctly. However there were three, and not all in the same area. I would think human error is not even on the radar at that point.

Maybe your area is more conducive to using DMR more so than other areas. Earth's magnetic field? General makeup of the soil? Metallic properties of the ground? At least it works for you, but it is not happening here. We'll just use what works here where the signal can get through.

The main goal is to enjoy the hobby, whether it be analog or digital is of no real consequence - as long as you are happy with the end result.

 

[NC1]

Those of us that have earned their living installing and maintaining repeaters for 30 plus years know that there are no digital radios made today that even come CLOSE to the performance of repeaters and radios made decades ago.

New repeaters and new radios have lousy front ends compared to those made decades ago.

Today you are lucky to find a radio with 70db of selectivity.

Motorola and GE radios used to have over 90.

And repeaters all had well over 100db

So yes, it's a fact that those old school analog repeaters worked MUCH better than any made today.

And when analog gets a little interference due to power supply hum, or interference, it may only be an annoying but you will hear every word.

But with the same interference, digital is gone

Like it or not those are the FACTS.

Thank you MOTEX for that excellent post.

I do believe that is the answer.
It appears to apply exactly in this situation and is the most rational explanation.

So I guess that does mean that the DMR will not be equal to analog because good DMR repeaters are not made. That sheds a new light on things.

 

[jonwienke]

Maybe your area is more conducive to using DMR more so than other areas. Earth's magnetic field? General makeup of the soil? Metallic properties of the ground?

None of that makes any sense. DMR is just a different modulation type. Something was overlooked or misconfigured in the installations, or there was an issue with the DMR repeaters. When installed correctly, DMR has at least as much range as analog FM when compared apples to apples.

 

[jonwienke]

New repeaters and new radios have lousy front ends compared to those made decades ago.

Today you are lucky to find a radio with 70db of selectivity.

Motorola and GE radios used to have over 90.

And repeaters all had well over 100db

So yes, it's a fact that those old school analog repeaters worked MUCH better than any made today.

Which also means that if/when the old analog repeater fails, any unit replacing it will perform no better than the DMR unit. Which means that the problem has nothing to do with DMR or digital technology, but crappy quality/design of all newer repeaters, analog or digital.

Let's just say I'm skeptical that NOBODY makes a repeater capable of duplicating the specs of 20-30-year-old equipment.

 

[kayn1n32008]

DMR is nothing more than an alternative modulation technique, and it will propagate exactly the same as an analog FM signal of the same power on the same frequency.

DMR actually has a huge advantage that analogue does not.

Forward Error Correction.

While it does propagate the same, DMR has an edge when signals get down towards the noise floor. Where an analogue signal, on the extreme edge of coverage, will be unintelligible, DMR will likely still recover full audio due to the error correction.



Sent from my iPhone using Tapatalk

 

[zz0468]

Let's just say I'm skeptical that NOBODY makes a repeater capable of duplicating the specs of 20-30-year-old equipment.

Don't be. I'm pushing about 45 years in the business, came in towards the tail end tube gear, and am now working on P25 systems. From analog microwave gear with 2C39 "lighthouse" tubes to digital IP based microwave radios, I've pretty much seen it all.

I absolutely agree that the newer equipment doesn't light a candle to the older gear, in terms of construction quality and RF performance. The lower end business radios and repeaters, DMR and NXDN repeaters, especially the boxes built into a unified chassis of a couple of rack units, absolutely don't compare to things like the Micor, the MSF5000, and the MastrPro. Even the old RCA 500s and 700s had solid copper chassis's.

The base station radios from the 70s and 80s had nearly uncrunchable front ends, and the crystal based local oscillators were exceptionally clean with very low phase noise and spurs. That makes a HUGE difference in receiver and transmitter performance, more than most people realize.

Never mind DMR voice quality. Yeah, I well understand the push to digital, but don't try to convince me that digital audio quality is better. I'm not buying it. The mere fact that digital radios won't even pass alert tones, let alone DTMF, should tell you something. Want to send tones over the radio now? Well, there's a digital word sent for that, and the tone is generated by the receiver. That's how much the reproduced audio sucks.

Things change, and we're trading voice quality for feature sets, build quality for affordability, interference rejection for forward error correction, and phase noise performance for bit error ratio.

Some people think it's an improvement, and some of us know better. Until P25 and DMR came along, no one ever had to tell their customers "you'll eventually get used to it" about the voice quality of their radios.

 

[K7MFC]

I am going to Linux after this

lol - if you don't like stuff that won't work right out of the box without a lot of fussing around, you're going to HATE Linux.. A modern digital scanner will seem like operating a calculator when you're elbows deep in confg files and searching for stable drivers trying to get everything working properly.

 

[NC1]

lol - if you don't like stuff that won't work right out of the box without a lot of fussing around, you're going to HATE Linux.. A modern digital scanner will seem like operating a calculator when you're elbows deep in confg files and searching for stable drivers trying to get everything working properly.

I am quite comfortable with Linux. I was one of the first to use Linux Red Hat, Fedora, and Mandrake. I have also used Ubuntu and Backtrack, and currently have Debian and Mint on older laptops.

Windows 3.1 was a lot of fussing around, especially if you had to format your hard drive and install DOS before you even got started. Then you had to load in all your hardware drivers one by one. It was time consuming, but it was a logical process.

I don't mind things that do not work right out of the box and like the challenge, but I do take issue with things that do not work as people claim they do. What really annoys me is someone trying to sell me on something that just ain't so.

 

[jonwienke]

I don't mind things that do not work right out of the box and like the challenge, but I do take issue with things that do not work as people claim they do. What really annoys me is someone trying to sell me on something that just ain't so.

But that's the thing. Uniden scanners do pretty much work as advertised, when they are set up and configured properly. I've been using them for years, and have no trouble getting them to monitor what I want, and ignore traffic I don't find interesting. Your problem isn't so much the scanner, as your unwillingness to invest the time and effort necessary to learn how to use it effectively. You want a digital trunking scanner to be as simple to operate as an old crystal-controlled scanner, and that's simply not realistic.

If you're sufficiently technologically astute to set up, configure, and use Linux, then you have the ability to master the finer points of programming and operating a x36 scanner, like adjusting Range, working with GPS, toggling Service Types, setting up Favorite Lists and Quick Keys, etc.

 

[K7MFC]

You want a digital trunking scanner to be as simple to operate as an old crystal-controlled scanner, and that's simply not realistic

This thread neatly summed up.

 

[NC1]

But that's the thing. Uniden scanners do pretty much work as advertised, when they are set up and configured properly. I've been using them for years, and have no trouble getting them to monitor what I want, and ignore traffic I don't find interesting. Your problem isn't so much the scanner, as your unwillingness to invest the time and effort necessary to learn how to use it effectively. You want a digital trunking scanner to be as simple to operate as an old crystal-controlled scanner, and that's simply not realistic.

If you're sufficiently technologically astute to set up, configure, and use Linux, then you have the ability to master the finer points of programming and operating a x36 scanner, like adjusting Range, working with GPS, toggling Service Types, setting up Favorite Lists and Quick Keys, etc.

I don't have a Uniden, but anyway the programming issue still applies. Plus you said they "pretty much" work as advertised, which to me means it does not reach the full extent of the claims. If a statement is made that something goes from 0 to 100, but stops at 89, then the statement is false.

As far as being willing to invest the time and effort learning, I don't have a problem with that. I think the problem is with the manual. There is no where near enough detail to get you where you can assemble the pertinent information. I glanced through the "easier to understand" manual for the pro-668 and while I found it helpful for some issues I was having, it still did not address others. So, when I have time I will post those questions on the appropriate forum. I think there are still some gaps in the manuals that were inadvertently overlooked that could be closed up.

I only had one crystal controlled scanner, but the programmable units were a great advancement. I agree some changes are good, and others not so much. Take for instance the Corvair and Pinto, they were changes and supposed advancements, but those cars blew up when hit from behind. Only time and real world implementation revealed the problems. Not every car was burnt to cinders with the occupant inside, but enough of them were to expose the inherent design flaws.

 

[jonwienke]

I don't have a Uniden, but anyway the programming issue still applies. Plus you said they "pretty much" work as advertised, which to me means it does not reach the full extent of the claims. If a statement is made that something goes from 0 to 100, but stops at 89, then the statement is false.

I don't recall Uniden making any specific promises about simulcast reception, which is the only real issue I have. And even that is more of a minor annoyance than a major problem IMO.

As to the manual, it covers most of the issues being discussed here, at least the one for the x86 series units.

 

[slicerwizard]

I agree some changes are good, and others not so much. Take for instance the Corvair and Pinto, they were changes and supposed advancements, but those cars blew up when hit from behind. Only time and real world implementation revealed the problems. Not every car was burnt to cinders with the occupant inside, but enough of them were to expose the inherent design flaws.

The Pinto was a rushed design that Ford produced and sold despite knowing that it had multiple serious flaws. Are you suggesting that Uniden scanners are Pinto-quality rushed designs?

 

[a29zuk]

Never mind DMR voice quality. Yeah, I well understand the push to digital, but don't try to convince me that digital audio quality is better. I'm not buying it. The mere fact that digital radios won't even pass alert tones, let alone DTMF, should tell you something. Want to send tones over the radio now? Well, there's a digital word sent for that, and the tone is generated by the receiver. That's how much the reproduced audio sucks.

Things change, and we're trading voice quality for feature sets, build quality for affordability, interference rejection for forward error correction, and phase noise performance for bit error ratio.

Some people think it's an improvement, and some of us know better. Until P25 and DMR came along, no one ever had to tell their customers "you'll eventually get used to it" about the voice quality of their radios.

And not to mention using digital in an industrial landscape, i.e. stamping plant, foundry, etc. With all of the background noise the digital radios cannot compete with their analog predecessors. The audio sucks and the users are constantly having to repeat themselves to understand what is being said.

Just hoping some day this won't happen to someone with a health emergency that can't be understood because his digital radio cannot be copied.

Jim

 

[NC1]

The Pinto was a rushed design that Ford produced and sold despite knowing that it had multiple serious flaws. Are you suggesting that Uniden scanners are Pinto-quality rushed designs?

Maybe I am not writing in the English language. Or, there is the off chance that people who read what I write cannot comprehend it, or they skim through and think it means what they want it to mean.

I'll say it again because there seems to be a pattern emerging. I do own the Uniden that was referred to in this post, nor was I discussing a Uniden scanner.

I believe the discussion I was involved in was DMR vs Analog.

 

[jonwienke]

I'll say it again because there seems to be a pattern emerging. I do own the Uniden that was referred to in this post, nor was I discussing a Uniden scanner.

I believe the discussion I was involved in was DMR vs Analog.

This thread isn't all about you. The original post in this thread was about the difficulty of operating Uniden x36 scanners vs older models. You jumped in a few posts later talking about DMR.

 

[KK4JUG]

The Pinto was a rushed design that Ford produced and sold despite knowing that it had multiple serious flaws. Are you suggesting that Uniden scanners are Pinto-quality rushed designs?

What kind of comparison is that? I don't think the gas tank on my Uniden scanners will explode if I drop them.

 

[frazpo]

Now this is the way This site Should be

Helpful & learning from others

Take note & you know who you are.

The world would be a better place

PLU

Plus one on that. All I see Wienkey doing is arguing his opinion through every post. Condescending to say the least.

 

[K7MFC]

I don't think the gas tank on my Uniden scanners will explode if I drop them.

Just added to my Christmas list for next year - a gas powered Uniden!