• To anyone looking to acquire commercial radio programming software:

    Please do not make requests for copies of radio programming software which is sold (or was sold) by the manufacturer for any monetary value. All requests will be deleted and a forum infraction issued. Making a request such as this is attempting to engage in software piracy and this forum cannot be involved or associated with this activity. The same goes for any private transaction via Private Message. Even if you attempt to engage in this activity in PM's we will still enforce the forum rules. Your PM's are not private and the administration has the right to read them if there's a hint to criminal activity.

    If you are having trouble legally obtaining software please state so. We do not want any hurt feelings when your vague post is mistaken for a free request. It is YOUR responsibility to properly word your request.

    To obtain Motorola software see the Sticky in the Motorola forum.

    The various other vendors often permit their dealers to sell the software online (i.e., Kenwood). Please use Google or some other search engine to find a dealer that sells the software. Typically each series or individual radio requires its own software package. Often the Kenwood software is less than $100 so don't be a cheapskate; just purchase it.

    For M/A Com/Harris/GE, etc: there are two software packages that program all current and past radios. One package is for conventional programming and the other for trunked programming. The trunked package is in upwards of $2,500. The conventional package is more reasonable though is still several hundred dollars. The benefit is you do not need multiple versions for each radio (unlike Motorola).

    This is a large and very visible forum. We cannot jeopardize the ability to provide the RadioReference services by allowing this activity to occur. Please respect this.

ASTRO Digital modulation

Status
Not open for further replies.

station32

Member
Joined
Jan 10, 2006
Messages
226
Location
Augusta Me
I have looked this up and read a little but i still dont really get the difference. C4FM is p-25 digital if i am not mistaken. What is CQPSK and WIDE i saw them in the cps unter conventional and astro can any one help me out?
Thanks in advance
 

n3obl

Ø
Database Admin
Joined
Dec 19, 2002
Messages
1,817
Location
PA
CQPSK is for use on simulcast trunked systems. Not sure was WIDE is for.
 

N4DES

Retired 0598 Czar ÆS Ø
Joined
Dec 19, 2002
Messages
2,386
Location
South FL
Wide should be used in simulcast. CQPSK is for other special applications that use 6.25 kHz of bandwidth.
 

MattSR

Member
Joined
Jul 26, 2002
Messages
407
Location
Sydney, Australia
Kind of - Theres two flavours of simulcast, the old WIDE which isn't P25 compliant and uses a 25kHz channel, and the newer LSM (CQPSK based) Linear Simulcast Modulation which uses a 12.5kHz channel and is defined in the P25 standards.

WIDE is old, spectrally inefficient and not P25 compliant.

LSM is the new P25 compliant CQPSK based Simulcast thats popping up everywhere.

Max, KA1RBI has done an analysis and written a GNUradio decoder for this. Lots of juicy LSM info here - LSM Gallery
 

rbrtklamp2

Member
Premium Subscriber
Joined
Dec 8, 2005
Messages
847
Location
Dupage County, Illinois
Ive wondered about this for a while too I would love to see the definition of how the different modes are used and what purposes they serve? The CPS isn't exactly forthcoming when it comes to defining these three modes.

Thanks for any answers,
Bob
 

Rescue1

Member
Joined
Oct 4, 2003
Messages
49
Location
South Jersey
I agree. What would be really cool is if someone were too take the time(a lot of time) and explain all the crazy menus upon menus in CPS. Sort of like the guides on how to disassemble the ASTRO radios, and the one about the workings of the radios, and encryption. Those are simply awesome, and those authors are amazing for doing the work...:)
 

Scanner-geek

Member
Joined
Dec 20, 2005
Messages
207
Is it possible that an APCO25 transmission can sound "encrypted" when in actuality it is not encrypted, because of a prgramming error? I have been trying to monitor a conventional APCO25 channel with an XTS5000, but SOME of the transmissions are garbled, suggesting encryption, while others are in the clear.
A local commercial radio enthusiast assures me that this particular channel is NOT encrypted, and that he is able to regularly receive ALL transmissions on this frequency in the clear using a Motorola radio. His assertion is that it is a programming error on my part.

I have the CPS and have been playing with the settings but can't seem to receive it entirely in the clear. Has anyone else come across this phenomenon? Is there a parameter in the CPS relating to Astro that I am missing? Or am I to assume that this knowledegable individual is incorrect and the channel is in fact encrypted on selected transmissions. A third party inferrred that my problem was with P25 "encoding" and NOT "encryption" and that this frequency was monitorable in the clear with the right equipment. He did not elaborate. I assume an XTS5000 and CPS are the right equipment for Astro P25 conventional transmissions.

Is there anyway I can differentiate an "encoding" issue from encryption? Also, why would only certain transmissions be encdoded or encrypted? How can I confirm that this channel is, in fact, encrypted?

I would greatly appreciate any insight into this
 
Status
Not open for further replies.
Top