DONE

Personal preference is a Raspberry Pi and a CM108 audio interface. These can be built up with the image for connecting to the system and then just not connected to the Internet if you are not looking to link. Another option right now since R-Pi's are a bit hard to come by is a WYSE thin client with Linux loaded on it and the CM108 interface that is basically acting as the Pi. Those are cheap to acquire and will fill the need but you have to be a bit of a computer geek to get that running. If you a comfortable with Linux and hardware hacking, this is the way to go in my opinion.

Didn't realize thread had changed and was old. Never mind

If you end up with the software and a cable let me know.... If you can read teh codeplug and email it to me I can set it up for teh first go around

Yeah,,, color codes too. I have built a couple code plugs for Motorola XPR radios. And the one constant is it's time consuming.

And yet NO ONE actually answered this mans question. With most radios (non-motorola) you program them in one big spreadsheet looking thing where you name the channel, put in the frequencies and tones and then blow it into the radio. CDM software and Astro25 software are different and you need to understand how to use the software. With CDM software, you build all the channels independently and then once the channels are built, you go into the zone list, create the desired zones and set the channel configurations in the zones. This is done two different places in the software. Scan lists are also build elsewhere in the software and assigned to the channels. Of course, you can't add a channel to a scan list that doesn't exist so there is some back and forth that goes on. Astro25 software (XTS /XTL) software This is a bit more complicated as the radio has multiple transmit modes that are set in a 'conventional personality' that is assigned to the channels. It DOES however program more like the spreadsheet radios, but there is some prep work that has to be done. the XTS XTL stuff is P25 and analog. So the settings for the modulation are set in the personality, but not the frequency as in the CDM. You DON'T have to create a personality for each channel either. THe personalities can be shared across many channels. Be aware that the scan list is set in the personality and a scan list can only have 16 channels in it. So if you get crazy and program up zones by state, county or whatever, you will need to create a scan list and personality for each zone. Not hard once you understand it but really time consuming. Once you have the conventional personalities built, you then add zones and program the channel frequencies and tones in a spreadsheet format in the zone configuration area. Ask if you have questions. I have a bit of experience with Astro25 as I have been using it for about 15 years now.

There are significant differences and the specific version of the software needs to be correct as well. Could you go through and figure out the required changes and make them on the correct release version of the software if you KNEW Asterisk fairly well, yes, to a point. Will you spend more time going through all that to modify the config files, DNS entries and all the rest needed to get an Allstar version modded to operate on the GMRS network. And there is NO support for modded versions from the system admin. They support the available release. And they know quickly if it's a modded version or the supported image. You have to image a drive to get this to work, no way around that. So why go through all the effort of getting a non-supported version, then needing to modify the heck out of it so it will work and be on your own if there are problems. Just DL the correct version and configure it per the provided directions. If you are worried about the audio level settings since you already have them configured for a current repeater then go in and document that info and write it down. It will not change with the new version.

Interesting. With the latest batch of regulations, you CAN have a private repeater, but you don't get exclusive use of the frequency. I ran into a guy here sort of locally that had a BUNCH or repeaters listed on here that were stale. And in fact never really existed. And he was running a business trying to sell air time on GMRS. That was when I decided that full free open access was the ONLY way to put up a GMRS repeater and I put up three. He was NOT happy, and I really don't care. But if I were in the position that you are currently in, because I am the way I am, I would park a DB-420 at 240 feet and locate the repeater about 10 feet from it and have it force ID every 10 minutes. Different PL of course, but that's just me. Now this chewing out and threats??? Karen's are EVERYWHERE, even in GMRS radio. But the threats are interesting. Are we talking threats of contacting the FCC or threats of violence / arrest or similar? At that point if the guy IS a part of law enforcement, then there is a whole other level of illegal crap going on. And at that point a letter to the state with recordings (if legal in your state) to the State's Attorney General are certainly in order. But I would need to know what was said. If the guy was threatening arrest based on you communicating on some 'public safety' radio system then you include the FCC in the letters going out. As mentioned before, I have seen radio tech's pull frequencies out of their butts for applications where they should NOT have been used. I mentioned 151.625 before. That is a standard low power (2 watt) simplex only frequency. Some clown radio guy was using it for public safety dispatch on a 100 watt repeater. And the department got told about it. If this department has gotten similar treatment from some radio tech, they need to be made aware of it. And the FCC needs notified. But if this guy KNOWS what he's doing, and thinks he can threaten people,,, that's a real problem.

Two pages to discuss roger beep settings???? It's simple, turn that crap off. End of story.

LEERN is 154.935. I am confused. Now I have seen where stupid radio tech's had put 151.625, an itinerant frequency, it a 100 watt repeater and was using it as a link. But That got taken care of real quick when I called the department and told them what someone had done to them. They pushed back a bit, but when I told them whatever and I would be calling the FCC they saw the light. So my next question would be, Ohio and some other states have a licensed VHF frequency that is statewide and referred to as LEERN. Is this a statewide LEO channel actually used by actual cops or is this some SAR / EMCOMM group with no official public safety affiliation playing cops and robbers with FRS/GMRS radios?

While it's specifically not my call, I don't believe that personal nodes are allowed on the system. Has to be a repeater with reasonable coverage. That being said, how this is being accomplished is not some super secret thing that you can't have info on. It's really nothing more than a IP PBX (Asterisk) running some additional software to allow it to communicate to radios. That being said, Hams refer to it as ALL-Star link and there are tons of pages that will lay out how to do it with very cheap parts. And you really DON'T need to be on a system. You just need one end of it to have a public IP on the Internet so the other node can always find it. Two nodes that are aware of each other that are programmed to connect to each other will do so without any additional servers. Now that's out of the way, remember that this DOES use the Internet to provide connection between the nodes. This system is no different. Having expectation that it's going to work in the event of a disaster is setting yourself up for a serious disappointment. So that that under advisement.

Yes, there is. You are going to connect it up as if you are tuning it and look at the notch that shows up on the VNA. With one that's correctly tuned for a single frequency, the notch should be fairly tight, but you will be able to see the notch go down, and then come back up. The deepest part of the notch is the primary tuned frequency. You can also put markers on the close repeater frequencies and see what the difference in the notch value is. Obviously it will NOT be as deep as the primary tuned frequency but you can see what the numbers are. If the numbers are 3 dB or less between the center tuned frequency and the frequency of operation then you are gonna be safe to use it on that frequency. Now if you don't understand dB measurement then 3 dB doesn't sound like a lot. But it's 50% of the specific signal level. Lets say you are running full legal power of 50 watts. That is 47dBm. If you loose 3 dB of power it's now 44dBm. Thing is 44dBm is 25 watts. So a 3 dB change is NOT insignificant.

Yeah, I am glad we figured that out. And I hope the guy finds a location and gets a repeater on the air. I actually went back and read the first post and of course, NONE of what I was talking about was in there. So I went down and found the post I was referring to. I sort of figured it was something like that, since what you were saying didn't at all fit with what I was talking about. I am really glad I did that so we could get clarification and on the same page. I hate seeing stuff like that. And unfortunately it's more common than folks might think. Since we were discussing MOU's. I am actually getting ready to work on one with the county I live in for two repeaters I am housing on the tower. Both are ham repeaters that will be general amateur use unless there is a specific need for EMCOMM. I have a unique situation with the tower location and coverage foot print that allows access from both my county of residence and the county to my West that has the state capital and the State EMA office that is almost LOS to my tower. The repeaters will be running from a battery plant and rectifier (150 AH will be the initial storage capacity) that will hopefully be solar and wind fed along with grid to the rectifier. I plan on growing the battery plant as funds become available and getting it to at least 300Ah at 48 volt.

OK, maybe I read it wrong. From what I understand of this situation. The water company (which may or may NOT be a government entity at this point) has granted not only access but total control for antenna access to a water tower that is owned by the water company. Now again, if this is a private entity and NON-government, they are free to do what ever they want. Except even a private water company has to have back ground checks done on ANYONE accessing a water tower, or potable water facility if that water is a source for public consumption. But we aren't even going to go there. But like you said, these places are HIGHLY regulated, even the private water systems. He further said that the ham group in charge of granting access for antenna/ equipment installation on the site requires a membership with their ham group (which no doubt has a fee THEY are collecting for that membership and no doubt a current ham license) in order to even be considered for access to the site to install antenna's and other equipment. So this would be strike two on the crap you can't allow as a government entity. A private entity CHARGING money to access a government asset. And what do you suppose the chances are they are sending those access payments to the owner of the site? Can't go to the local court house and put up a barrier and require payment for access to a government building as a private citizen. And that is sort of what they MAY be doing.... but with a water tower and not a court house. At least that's what I understood from the original post. OK<<<< NOT ORIGINAL POST This was the post that was created by WRAM370 and NOT the original poster. That might help a LOT. Read what he had to say and then we might be on the same page. Sorry brother,,, I kept sayin OP, and that was NOT the OP's post.

do you have your gmrs call sign is your profile?

Lets NOT take it to a level of corruption. That's using stronger wording than is necessary, or in truth even warranted. The average elected official, or employee of a government entity is not even gonna understand that they CAN'T do what the OP has presented here. Again, some group of ham operators (and voters) comes with the semi- hard sell of ARES and disaster communications. The average city or town mayor is gonna know his police force uses radios for their communication. Beyond that they know nothing. You have a bunch of well meaning individuals in front of you describing how they can communicate with other states, agencies and even provide satellite communications with no 'direct cost' to the governmental entity. They have no basis to form an opinion that if a tornado hits, that they are NOT gonna need to be able to communicate with the UK, or even 3 states away. They may have previous experience with a communications outage that happened in the 60's and fear that again. So they agree to allow things to happen that shouldn't, and in truth they may not even, from a legal standpoint, be allowed to have happen. It's not corruption in the sense of taking a payoff or anything like that. They just don't see a problem, think it may provide SOME solution to a non-existent problem so they agree. And I have raised these sort of issues to city leaders and county commissioners when an EMA director was going to use county taxpayer funds for antenna replacement on a ham repeater that wasn't in any disaster plan for the county in question. It immediately got squashed. That director retired, and the new guy did the very thing the last guy got called on the carpet for and was reprimanded for doing so. I know what you mean about having an agreement and MOU in place. But that isn't very common place around here. It's the exception rather than the rule in fact. Point is that with the OP and that situation, there is some shady stuff going on, if he's got the whole story and has conveyed it to us here. It seems that the HAMS are the ones issuing the MOU's and managing the asset and have requirements that are restrictive beyond what is reasonable. At least in my opinion.

Oh, I almost forgot. The above mentioned site was a water storage facility for the city that owned the site.

This is the tower I have access to that was bought and paid for by a ham. I am gonna say that jealousy doesn't really play into it. But I could be wrong. As far as the misappropriation of taxpayer assets. Gonna have to say that, yes, that tends to irritate me. Now i am not gonna say that every ham group is full of idiots that would pull crap like the OP was talking about. But those guys and groups are out there. And I have seen where hams had gotten into agreements that were out of bounds. If a ham repeater is in place for EMCOMM for a county or other served agency that is being hosted totally free of charge, no insurance, power bill or anything else, then that equipment, at least in the eyes of the state of Ohio is to be tested on a regular interval and NOT used for general communications. There were two ham repeaters that were installed for an ARES group locally that were actually pulled from service because they were specifically paid for with a federal grant and then were used for general communications. The tower access agreements were also written specifying emergency use only and were granted free tower access due to them being for that specific use. And like I said, we can't approach a street department and borrow their tractor, dump truck, put crap in their buildings for storage or any of that. It ain't allowed. Because they are government (taxpayer) assets. A tower really should be no different. Tower rental rates. Have multiple customers on ATC sites. Paying between 1000 and 1600 per site for two antenna's and a microwave dish. Antenna's are at 130 and 150 and the dish is up at 200. These prices are common in this area. They are also on private sites and are paying less than that. But if you are renting from any of the major players, then you are paying these sort of rates for relatively low mounting positions on the towers. The pricing structure in your area may not be the same. I can only speak to what I have first hand knowledge of. This also applies to the way hams and ham clubs conduct themselves. If what he's saying is 100% correct and you are REQUIRED to be a member of their club to access a tower that doesn't belong to them, they are not doing it right. I have been to sites that hams were allowed full access to and they are typically a total mess. Cable held to tower legs with electrical tape if at all, improper cables used in the radio hut to protect from interfering with other tenants at the site. Skipping on proper grounding (of course I am R56 certified so I am a grounding and install NAZI and immediately notice such things). And I directly deal with it as a ham and a tower site manager. I get requests, some that almost sound like a mandate, that some ARES group NEEDS access to a tower for EMCOMM for free. I know better, the problem is that elected officials typically don't. They hear it's for public safety and disaster preparedness and immediately agree without any actual research, or it was done years ago by some verbal agreement by a friend that was also an elected official that never really had the right to do it and now it's just in place. I am all for providing hams access within reason for both EMCOMM and hobby use. And I don't believe they need to be made to pay the standard going rates that a cell phone company is required to pay. But they need to install to the same standards, use good equipment and not mobiles screwed to a sheet of plywood and hung on a wall with wires going every which way. But then again I have seen commercial radio companies that had install quality that made most ham install look good. But that's another story. And as far as the government being aware. The guy that owns that tower shown above is an IT admin and a ham. Of course he also climbs towers, since he has that one, but is not a licensed bonded climber. I went at the request of a county EMA to oversee and test antenna's and lines once the climbing and work had been completed by the tower climber that the hams were bringing in. The county had been told the guy was a TOWER PROFESSIONAL by the local ham group the work was being done for on a county owned tower at a city owned site. The guy that showed up as the TOWER PROFESSIONAL was the guy that owned this tower. They had told him little about what he was going to be doing, and I questioned what was gonna happen so I brought MY rigging equipment and tower winch in case it was needed. We pulled 300 pounds of stuff off that day and replaced 4 antenna's and two feed lines. He was totally unprepared for the job, because HE wasn't told what it was. I had a feeling that something like that would happen and was prepared for it with equipment. And the whole situation stuck me between my buddy and my customer that I HAD to tell them he wasn't a tower pro. And I even had hams coming up to me trying to tell me how to rig the tower, tie proper knots, and all sorts of crap. I ahve spent to last four years working all over that tower, rigging it, installing and removing antenna's and I was the one with the gear that was even gonna make the job possible. And I am getting told I am using the wrong knots. BTW, I was using bow-lines and figure 8 knots. So yeah, my personal experience with hams has been questionable at times for the last 20 years I have been a ham.

Have to ask. Is the water company in question a private business or a government agency? Private businesses can basically do as they please. Including allowing a bunch of hams to takeover their antenna tower. A government agency doesn't have that ability and can be brought to task over it. If they are showing preferential treatment to the hams, which it seems would be the case, then I would with documentation (certified letter) to both the government entity and the ham group managing access for the necessary request forms to gain access. Ten days later, I would send a second certified letter to BOTH entities, making a SECOND request if they haven't provided you with the correct documentation. After an additional ten days, I would write another certified letter to BOTH about the cost of tower rental in the current market being up to 20 dollars PER foot of height, which IS a factual statement, and that as a governmental entity showing preference to ANY group and not the community as a whole is illegal (search your local laws and provide reference to the code stating this). Now THAT will NOT get you on the tower. But it will get the hams a FAT bill or told to get their gear off the tower. If neither happens, the next move is to get an attorney to write a letter to both informing them of legal action if you are not allowed to at least fill out a request for access. The water company has NO IDEA the hams are doing this. Requiring a ham license and membership to their ham club to access the tower that may well be taxpayer owned. That is where the problem starts. If the same water company had a backhoe and you ask to borrow it, let alone free use, they would laugh and tell you no and explain that it's NOT possible due to the regulations pertaining to publicly owned equipment. A tower owned by a government entity is no different than a backhoe, automobile, building or structure, or any other tangible asset. You can no more personally use any of those other things for your own private enjoyment than they can. And if they argue that the hams are allowed access for ARES (emergency communications) then you can simply indicate that the repeater you would be installing is ALSO for EMCOMM on a different radio service and should fall under that same agreement. To tell the truth, some hams really irritate me with their 'we're important cuz we can communicate" crap. And as an extension to that feel that they are entitled to free crap, tower access and anything else they desire based on ARES and EMCOMM. Of course, as mentioned, if it's a PRIVATE water company and has no connection to a local government entity, then you are basically out of luck. You could write a letter to them requesting access directly and try to bypass the ham group, but I don't know how that would go.

So I may have missed it, but are the old Nextel phones OOB direct connect and the DTR radios compatible and able to talk to each other? Running around in public with a 'working' NEXTEL phone would be interesting as that system has been gone for years now. Beyond that, if compatibility exists, it provides a source of radios that work with the DTR stuff that are cheap and available.

Ahhh, no. I am all for people that know what they are doing putting up good equipment after they have PROPERLY identified an open repeater pair in their area that will not interfere with the operations of others. I am willing to assist folks that want to do it right, work with other repeater / system owners to minimize interference and create additional coverage in area's that are lacking any current coverage. But I don't really think it's a good idea for EVERYONE to put up a repeater. First problem is the definition of a repeater. And depending on who you talk to that ranges from a quality 100% duty cycle commercial repeater and duplexer on an antenna of reasonable height to two mobiles or even handhelds taped together with an vehicle antenna on a wall mount screwed to the peak of a roof on a one story garage. And what that sort of this does is screw with a big repeater because the person that was told they needed to put up a repeater did so without even bothering to check the frequency first to see if there was another one that covered their area. You need to monitor a frequency for a MONTH before thinking you can use it. You need to setup a PC with a VOX audio recorder like ScannerRecorder that will record any traffic on that repeater output. And you need to do this with an antenna that's outside and up at least 30 feet. If you can't do that, IMO, you don't need to even consider putting up a repeater. We are limited to 8 repeater pairs for all of GMRS, everywhere. And repeater owners need to cooperate with each other to manage this resource. Failure to do so will just create problems.

I too think that we have little chance of getting the FCC to grant digital modulation schemes to GMRS. The one possibility where it COULD happen is if the FCC decides to make GMRS 12.5 Khz channel widths mandatory on all GMRS frequencies. From my experience with this in the commercial realm, we will sell a 25 to 50% decrease in coverage area for a given repeater. At that point the MAY allow DMR as an equivalency to the 12.5Khz analog move, but even then I don't hold out a lot of hope. I think it's gonna depend on if we continue to see the level of growth in license holders or not. And it may not happen until the first go around of renewals in 10 years. GMRS is currently growing in leaps and bounds. But we saw that in the 90's with ham radio as well and now most ham repeaters are quiet. Will we see that with GMRS as well, who knows. I would like to say no. But I would be lying if I said I see it hanging on with this growth rate for that length of time.

Yeah, lots of discussion trying to sort this out. FCC requires each station to ID. A repeater is a station, if the owner / license holder and those directly authorized by that specific license (family members) are the only ones using the repeater, then no ID is required. If another license holder uses that station, then the station (repeater), owned by another license holder, is activated the station (repeater) must ID with the owners call sign. I know this is one of those topics that gets beaten around on here every so often. And maybe it's in the manner that you want to interpret the FCC regulations. Honestly, it's just easier to have the dumb thing ID and error on the side of caution. Using HT's with an amplifier as a repeater. There 's a TON of wrong there. But part of this is learning. And folks that do this will learn why it's a bad idea. So I ain't gonna go there.

First WHY would you NOT use both slots of DMR if you had that option. Stay with analog and be done with it. P25 and NXDN should be pushed aside because neither make a real contribution to the basic operation of the service and provide a second talk path to a single repeater pair. As I said before, I would PREFER P25 as it at least would increase range somewhat, and the audio is better in my opinion than DMR. But yes, I run it on HAM and am fine with that. Why should a repeater owner that has had a repeater on the air for twenty years...... simple. When the FCC removed the direct assignment of repeater pairs from an individuals license and allowed ANYONE with a license to use any pair they desired, they created the initial problem. And we DO, as mentioned, face that issue currently. It's nothing new. Being reasonable and showing good faith, the new repeater owner should choose an different pair than the guy down the street with the analog repeater. Pure and simple. We self regulate, and as such actually need to do just that. I didn't say that linking should be part of any standard, but if we as the license holders are going to petition for a change, that is something that needs changed. It needs to be either ZERO linking or linking. No more of this stuff of it saying don't' link with the PSTN specifically, which we are or are not depending on what day it is and who's defining PSTN. Not trying to turn GMRS into ham radio. Trying to put forward some path forward to newer technology within the service to make it better. If you look at the definition of GMRS, then you know we aren't technically within that definition to begin with. Some of us ARE using it as hobby radio. And operate within the confines of the regulations other than that. Right now we are experiencing a boom in licenses and activity. We make it better and there will be more interest. I have said this to ham operators with big heads to bring them down a notch or two, but it's still the truth. Ham radio is now defined by people that studied for 3 hours to take a test they had all the answers to the questions from a book written by Gorden West. I will add this to that statement. We didn't even need to take the test to get our license. Of course we SHARE our bandwidth with another unlicensed service that the hams don't have to contend with. And don't forget, this is ALL a discussion of peoples OPINION. Not a discussion board for creating a petition to the FCC for a change. I forgot that EVERYTHING is now political and NO ONE can have a differing OPINION than the ones held by a select few who want to MANDATE their opinion is the only one that matters. AKA, discuss NOTHING, fall into line and do NOT ever have a differing view. Sorry for the mix up.

Honestly I think the reasonable move is take some number of the repeater pairs but not all at this time and allow them to be DMR. Because you're right, the FCC can certainly make a mess of things. DMR is going to increase the 'available' channels due to the TDMA portion of it. This CAN'T be applied to the FRS portion because no radios that are DMR can legally be FRS due to power and antenna restrictions. It would need to be a repeater only sort of thing. Now is that every other repeater pair, the lower or upper half, or what,,, I have no idea. I think every other pair starting with 550 and going up, but that's just my opinion. And no specific requirement to switch should exist. If an area or group of users has an analog repeater in place and don't see a need to change, then they shouldn't. But they would need to understand that someone else CAN bring up a digital repeater on their frequency and they would have no grounds to complain about the interference from that repeater. What I don't see is any significant benefit for applying digital to simplex channels. This should be a repeater only effort, and done in a way to minimize the number of people that are going to be negatively effected. I will also say that if this happens, the regulations for NOT linking need to go completely away. There is a sot of gray area that we operate in right now as the regulation specifically states that the switched telephone network can't be used for linking. We operate the links based on the fact they are IP and not switched telephone circuits. But much of the telephone system is now IP based and NOT the old two technology that existed when the regulation was written. One of the other things with DMR is the ease of standardization of the subscriber configuration. Meaning that we as repeater owners can mandate that if a user is going to operate on our repeater, they will use specific settings in their radios for microphone gain and such. This is something the Ham's never really enforced and the reason one guy will boom in and you can barely hear the next guy. No standardization. And controlling access to 'private' repeaters is simpler with DMR as well. Motorola, after suing Hytera started pushing RAC (repeater access control) very hard. Where before you needed to turn in on in a new repeater, now you have the turn it off. But this lends it self to controlling access in a repeater system as only folks with permission and the code can access the repeater. The only negative to that is the users will need to have a Motorola radio to access the Motorola repeater if RAC is enabled. But for private groups, that is a small price to pay and second gen (XRP4500 and 6000 series ) radios are getting less expensive on the used market.

Lscott and gortex2 are both correct. But there is a bit of explanation that needs to be done to have a better understanding of it. First is receiver technology. Back in the day, and in the present, a standard analog FM receiver has a number of stages that the RF goes through as its stripped of it's intelligence (the voice communication) and presented to the user via the speaker. First is an RF stage, this is connected to the antenna and amplifies the signal (and ALL other signals it can hear) to be shipped up the line. These are typically fairly wide band amplifiers that will amplify much more than just the frequency range of the radio. Here's the first part of receiver degradation. That first RF stage has a design gain of X number of dB gain for the stage. So, lets say that's 10dB. If you connect said radio to a signal generator and feed it a signal level of -110dBm the output of that state SHOULD be -100dBm. An increase of the 10dB of the stage. BUT, if you feed that antenna with 2 signals from a generator that are different frequencies and also are -110dBm and look at the output of that stage, the signal level of each frequency will be -105dBm which is half as much as the single signal gain because the state can only generate 10dB of TOTAL gain. We are talking GMRS, so 462Mhz. But that RF stage exhibits gain at 140 Mhz too. To deal with out of band frequencies a GOOD receiver will have a band pass filter that will only let in 460 to 470 blocking the out of band stuff. Cheap receivers don't have expensive filters. And receiver sensitivity is measured with a SINGLE frequency in a controlled environment at the BEST measured level. Meaning they will sweep around and find where the radio performs it's very best and that's the spec. Second is shielding. Keeping the signals that are floating around in the radio out of other circuits in the radio requires shielding and isolation. Go find an old Motorola Spectra and take it apart, look at the designed isolation. Then take a part a kenwood TK860 or other radio from another manufacture of the same era. Spectra's were a BEAST for performance. Other's not so much. But you could buy 4 TK-860's for the cost of ONE Motorola Spectra. So stage two is the IF stage, a second signal is created in the radio and mixed with the RF. This mixing creates two frequencies. The sum of the two frequencies and the difference between the two frequencies, which is the one that's important here. Of course, what ever else has leaked through beyond the primary frequency of concern (what the radios actually tuned to) is also present and ends up converted as well. This is where the 10.7 IF frequency is created and passed to the IF amplifier. Stuff is cleaner now and more filtering happens. Then it's stripped of the intelligence from the IF and sent to the amplifier for presentation by the speaker. Digital processed radios. These are analog radios that operate in the digital realm. An SDR receiver if you want to think of it that way. Some of these directly take the RF into the digital processing chip and some operate at the IF frequency mentioned before. Because the RF is directly converted to a data stream it's now easily processed and can be filtered much better than even the best designed analog receiver could hope for. If it's not specific to the frequency of concern, it's simply ignored. And 'amplification' is as simple as changing the bit stream. All amplifiers can mix frequencies. so RF. IF whatever, mixing can occur. If there isn't any amplifier in the sense of a stage with an analog transistor that exhibits gain in the stage, then no mixing happens. Remember that the RF is now a digital stream of date, even in an analog radio. The SDR chip take the RF in and outputs the intelligence directly to the audio amplifier. All the A to D and D to A (analog to digital and digital to analog) happens in that chip along with all other signal processing. This allows for greater First RF stage gain, better filtering and error correction (something that CAN"T happen in an analog receiver at all) and a whole host of filtering that's done in the digital domain. And that's how we are seeing a huge increase in receiver sensitivity in these newer radios that are Digital and analog like the XPR Motorola offerings. They are barely analog at all. Doing all RF and IF processing in the digital domain while being 'analog' radios.