Chinese APCO P25 Transceiver

[TEKurtz]

Can your brain decode a sine wave within a frequency that's not audible by the human ear?
If you even had a notion of a clue you'd know that analog is the same as digital in the respect that it's all decoded by something other than your own brain (so that you can hear the transmission).
Tell me how it is that you speak analog? You just speak

 

[TEKurtz]

I think we all have to remember here that us, humans, speak analog........So, there is really no such thing as "sounding better than analog".

I mean what kind of whacked rationalization is that? A digital mode will come closer to matching natural voice than any analog transmission. That's just bat-**** crazy

 

[w4rez]

I will say, in digital's defense, that if you have multiple links or segments that the audio has to traverse, then by the time it gets to the end, digital is going to sound better. Assuming that there's no transcoding happening along the path, it only has to be turned into the 1s and 0s once, and then the signal stays exactly the same until it's converted back to analog audio at the end. With analog, there's always going to be some loss of quality each time the signal has to go through any sort of amplification or intermediate stage.

A full quieting analog signal, to my ears, still sounds better, and more natural than digital. There's definitely more dynamic range. Sorry but you can't fit the same audio fidelity of a 20 Khz analog FM signal into a 9600 baud bit stream. There's always going to be a tradeoff and in this case, it's audio quality.

 

[TEKurtz]

I can understand getting used to something and sticking with it. But I feel the same way about DMR and P25 as I do HDradio. Who knows which codecs and modes will stick around, all I know is I prefer the audio quality of HDR channels to that of their analog mode. Call me crazy [emoji6]

 

[mm]

It was a safe assumption because there were two possibilities. One, you are like my Ham friends who are petrified of the latest ham tech (digital, internet repeaters) mainly because it's way over their head. Two, you haven't actually heard a typical digital transmission on an average properly working network.

12dbinad, that makes no sense. Analog radio modes are still modulated and demodulated. Can your brain hear and demodulate 220 mhz FM?

what the hell is 220 millihertz and why pick on 220 anyway but maybe u meant to type MHz so I'll let it slide?

I guess p25 is so good and works much better than analog and that's why many public safety agencies in the Pacific Northwest are sticking with or going back to analog FM.

Talk to any Washington State patrol officer and tell them how much better P25 is compared to analog FM and I guarantee you'll get punched in the mouth.

Same goes for every other digital format such as DMR OR NXDN, another public safety agency ready to shoot their consultants is Woodburn Oregon Police for going with a crappy NXDN SYSTEM and now even with new Kenwood, NXDN/P25 equipment the frustration level of the officers has not improved one bit.

It's not just poor audio with P25 it's also coverage issues especially with simulcast systems.

The IWIN system in the Pacific Northwest for example worked so poorly For the Customs Air units that techs had to EITHER #1. change simulcast antenna patterns which resulted in numerous dead spots between coverage areas or #2, place simulcast towers within 10 miles of each other to reduce TDI which is not feasible or #3 reprogram radios to use towers that were at lower elevations which is impossible in the PNW since most infrastructure is on tall mountains.

Guess which option Customs used, neither of the above, they went back to manual selection of towers in a simulcast network, now this was done due to TDI issues in phase 1 and phase 2 TDI issues are even worse than those of phase 1.

 

[12dbsinad]

Can your brain decode a sine wave within a frequency that's not audible by the human ear?
If you even had a notion of a clue you'd know that analog is the same as digital in the respect that it's all decoded by something other than your own brain (so that you can hear the transmission).
Tell me how it is that you speak analog? You just speak

Please read this, under Analog Voice Characteristics:

Defining Analog Voice - Cisco

This is just one of the first things on a quick google search. Google is your friend. Speech is analog. What else do we use to decode? A QAM tuner?

 

[TEKurtz]

It's all about implementation, you can't put gold on top of **** and expect it to not still be ****.
Agencies usually have little money to spend but they still want digital and enc capabilities. So dealers gladly blow smoke and take their money for all new radios, without any other proper implementation.
It's lack of education within the departments/agencies/counties. Digital modes can't be blamed for greedy sales departments and ignorant decision makers.

 

[TEKurtz]

My point is that a human voice is converted out of the auditory spectrum of the human ear when broadcast over analog freq, no matter what it's being modulated and then demodulated....so what does it matter if it's being modulated into an inefficient analog signal or an efficient digital signal? Its not an organic voice either way.
The point is moot.

 

[jbailey618]

P25 Vs Analog.

I'm in the Pacific Northwest as well and I own both P25 Motorola gear and analog commercial and amateur Kenwood radios. I'll say hands down the audio quality is far superior on my Motorola XTS3000's on FM Analog than it is on P25 Astro. The local Sheriffs Department recently replaced all of their equipment with P25 capable Motorola gear, and had issues with coverage, so they mainly use FM Analog still, and very rarely is there any digital traffic on their system. Our local city PD is using P25 Motorola gear, and the audio quality isn't bad when you're within the city, but it completely lacks the audio fidelity of FM analog. That's my experience with P25 in the VHF band.

With that said, the features are valuable and we're currently trying to source a VHF Quantar to add P25 in the amateur band locally considering used P25 equipment is coming down in price.

What is great is that my simple Kenwood TKR-850 GMRS repeater at 40 watts (wideband) sounds better than 90% of the commercial repeaters in the area on UHF and VHF due to the narrow banding in part 90 radio.

The OP that brought up trashing perfectly good second hand digital equipment is an example of why amateur radio is behind. We should be putting Mixed Mode Quantars all over for 440 and 2m, but greed is obviously what's slowing that down and keeping old P25 repeaters on eBay in the 2-3K range. Thanks A holes!

Today's curious amateurs are tomorrows commercial technicians. This used equipment should be put in service as amateur systems further expanding emergency communications and getting a younger more digital curious generation of radio operators licensed and ready to help in the event of emergencies.

 

[Elfnetdesigns]

Ok so hams need public safety and government level communications equipment for learning purposes?
Umm no, buy a manual and read up on it,
Public safety, military and government equipment should never be allowed to the general public and decommissioned, and retired equipment be destroyed working or not.
This is why we have criminals and terrorists and wack jobs out there that stay ahead of the police and military because they get equipment online or from a ham sale and set it up to monitor digital secure communications which mind you under FCC rules is illegal to intercept any encrypted transmission on purpose if you do not have permission or to use knowledge for criminal activity or personal gain.
I HOPE the Government mandates ALL this gear be destroyed by law and none of it ever sees the light of public hands.
I know all digital equipment public safety and government grade devices that they retire or we deem un-repairable we drill in a drill press before shipping it to a recycling center. We have to do this as part of contract agreement with the local and state and homeland security. Sure we could keep some gear but if it ever got out we could be in serious legal trouble. Thus fore I cannot "donate" any trunking, DES, P25, DMR, OpenSky public safety or government equipment to anyone not even a volunteer fire dept. and this is how it should be for every radio shop. All the gear I own personally was bought at my cost but every serial number is registered and all of the radios are legal to use. No hacked up ham modified gear here, if I was to program a non-commercial frequency into one of my digital radios and they found out I could lose my government clearance.

 

[techman210]

This should be fun. Getting out the jiffy pop right now.

 

[TEKurtz]

Ok so hams need public safety and government level communications equipment for learning purposes?
Umm no, buy a manual and read up on it,
Public safety, military and government equipment should never be allowed to the general public and decommissioned, and retired equipment be destroyed working or not.
This is why we have criminals and terrorists and wack jobs out there that stay ahead of the police and military because they get equipment online or from a ham sale and set it up to monitor digital secure communications which mind you under FCC rules is illegal to intercept any encrypted transmission on purpose if you do not have permission or to use knowledge for criminal activity or personal gain.
I HOPE the Government mandates ALL this gear be destroyed by law and none of it ever sees the light of public hands.
I know all digital equipment public safety and government grade devices that they retire or we deem un-repairable we drill in a drill press before shipping it to a recycling center. We have to do this as part of contract agreement with the local and state and homeland security. Sure we could keep some gear but if it ever got out we could be in serious legal trouble. Thus fore I cannot "donate" any trunking, DES, P25, DMR, OpenSky public safety or government equipment to anyone not even a volunteer fire dept. and this is how it should be for every radio shop. All the gear I own personally was bought at my cost but every serial number is registered and all of the radios are legal to use. No hacked up ham modified gear here, if I was to program a non-commercial frequency into one of my digital radios and they found out I could lose my government clearance.

Ignorance must be bliss Elf.
Enjoy your jiffy pop techman

No one is as you said "staying ahead of the military and police"
The NSA controls the sale and distribution of all NSA certified crypto boards for top secret and classified data and voice. I assure you no one gets this technology second hand.
Anything less than what's considered classified crypto technology is free to be exchanged, such as the old *** equipment referenced earlier.
Www.nsa.gov
Read up...cause you don't have a clue


Sent from my iPhone using Tapatalk

 

[TEKurtz]

Technology progresses so quickly, including crypto methods, that by handing down surplus equipment that's considered obsolete to the government's encryption standards it will in now way put the public or gov at risk.
In fact it will only do good by flooding the private market with high quality equipment where it still has some use..

Two more points to prove you need to rethink your point of view:

All this digital technology is open source and free to use with SDR and GNU radio.

IF someone were to get their hands on one of these crypto boards guarded by the NSA, OR by using a home brew GNU radio to attempt to bruit force crack even the lowest level of 'classified level' 128 bit aes encryption, the time it would take is 1.02 x 10 to the 18th power...
So I assure you, no one is "getting ahead" of the military

Paranoid, low information population at its finest

Sent from my iPhone using Tapatalk

 

[scannermanner1]

Y are you so against the public or hams having old or retired commercial radios

 

[TEKurtz]

Who knows.. Out of fear of technology they don't understand. Like an elderly person with an iPhone.


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[VE3RADIO]

Ok so hams need public safety and government level communications equipment for learning purposes?
Umm no, buy a manual and read up on it,
Public safety, military and government equipment should never be allowed to the general public and decommissioned, and retired equipment be destroyed working or not.
This is why we have criminals and terrorists and wack jobs out there that stay ahead of the police and military because they get equipment online or from a ham sale and set it up to monitor digital secure communications which mind you under FCC rules is illegal to intercept any encrypted transmission on purpose if you do not have permission or to use knowledge for criminal activity or personal gain.
I HOPE the Government mandates ALL this gear be destroyed by law and none of it ever sees the light of public hands.
I know all digital equipment public safety and government grade devices that they retire or we deem un-repairable we drill in a drill press before shipping it to a recycling center. We have to do this as part of contract agreement with the local and state and homeland security. Sure we could keep some gear but if it ever got out we could be in serious legal trouble. Thus fore I cannot "donate" any trunking, DES, P25, DMR, OpenSky public safety or government equipment to anyone not even a volunteer fire dept. and this is how it should be for every radio shop. All the gear I own personally was bought at my cost but every serial number is registered and all of the radios are legal to use. No hacked up ham modified gear here, if I was to program a non-commercial frequency into one of my digital radios and they found out I could lose my government clearance.

Thinking within your borders I guess.. you realize even if everything you suggested happened there are still hundreds of other countries out there with no rules.. anyone who wants something can get it, legally or illegally.. what does it matter to someone with bad intent.

 

[sefrischling]

Public safety, military and government equipment should never be allowed to the general public and decommissioned, and retired equipment be destroyed working or not.
This is why we have criminals and terrorists and wack jobs out there that stay ahead of the police and military because they get equipment online or from a ham sale and set it up to monitor digital secure communications which mind you under FCC rules is illegal to intercept any encrypted transmission on purpose if you do not have permission or to use knowledge for criminal activity or personal gain.
I HOPE the Government mandates ALL this gear be destroyed by law and none of it ever sees the light of public hands.

Soooooo let me get this straight ... my conventional UHF Motorola MT1000, that I picked up after the LIRR Police (now the MTA Police) eliminated these radios from their inventory back in 1996, that has no encryption, somehow lets me do something illegal or dangerous to the public welfare of others?

How is my Moto Saber III a threat? The only way my Moto Astro Saber II/III radios are a threat to national security is if I I walk up to a Federal Agent and smack them in the head with them.

If you want to monitor P25 communications, go on ebay and buy a Uniden 396T/396xt/436hp. They are far easier to program and use.

None of these radios decode encryption and government surplus radios are stripped of their encryption before they are sold.

... and I cover Aviation & Transportation Security as a journalist professionally, having covered this niche specifically since Sept 15 2001, after leaving Ground Zero where I had been since Sept 11. I listen to the Feds all day, almost every day, in one way or another.