WROZ250

Did a quick search on QRZ.com for Bob's area. No clubs came up, but there are 43 licensed hams in his town. More in the surrounding towns. As @wayoverthere notes, there are some clubs a bit out of town, but not too far (certainly within a 5-10 mile radius). I suggest contacting them and would think they would be more than willing to point you in the right direction if they can't directly assist you.

One last thing, sort of related to the subject/topic... During my career at Motorola, over 65% of the engineers in the company were licensed amateur radio operators (Hams). These are the same people who designed those radios so many love and want. Indeed, in many of the communications fields, the engineers and maintenance people (not all) are also hams. In the day, Milwaukee County Wisconsin's radio department had a policy of only hiring technicians who had both a commercial license and, at least a General class amateur radio license. As I recall, they were not the only agency to follow that practice. The logic was they wanted to hire people who not only knew how to fix radios, but had an active interest in the job. I don't know if that still exists today, probably not because the FCC changed the rules regarding who may legally repair radios (It was better back then IMHO). So while I am not suggesting non hams should suddenly like 'Hams', that level of respect from public safety, despite the stereotypes says, IMHO, a lot about that 'hobby'. Not to mention, but I'd venture a guess that a lot of GMRS users, indeed, many here, are also Amateur Radio Operators ("Hams'). ?

That's not entirely untrue. In my own experience, I'd heard that as well from site managers and yet, there were some commercial sites that allowed hams (or they knew somebody who looked the other way) and, some of those 'ham' repeaters were pretty disgusting in how poorly assembled the 'system' was. Many times, when discovered they were thrown out and their equipment held for 'Back Rent", many times if they were stupid enough to mention who let them in, that person was terminated. Not so much of the 'free rides' since 911. Even the professionals have to go through some serious screening for access, just to just maintain equipment. Site access in general changed quite a bit, almost overnight, after 911. Started in the big cities first and has been slowly migrating out to the rest of the country. All that said, there are a lot of ham repeaters that are part 90, didn't have to be modified for that service, were properly maintained, and nobody takes issue with them on site. "Ham' by definition isn't a bad thing, but there is a perception in commercial radio circles is that Hams are a problem because they 'kluge together junk'. Both statements are accurate, but not necessarily so (if you get my meaning). When I was much younger and still in field service, my manager had a saying 'Hams can fix anything, just not the right way". He said things like that because that was his experience. Additionally, commercial radio is about service and revenue and so he had no reason to care if his experience was accurate or not. The (SAD) fact is, there are 'Hams' who do just cobble shit together to serve a purpose ('repeater'), and many times that 'system' ends up being an RF nightmare or, as we use to joke, a DIY wide-band noise generator. So the concern about allowing a ham repeater into a commercial site is somewhat justified, just not in every case. However, in my own experience there are far more Hams, when talking about repeater systems, who take a very serious and professional approach to system design and site conformity. Indeed, most of the latter are, or are overseen by, professional RF engineers who also happen to be Hams. Those are the 'Hams' who, even in this post 911 world, are still are able to obtain access to commercial sites for their systems. It's their (site managers) game. Play by their rules and you're cool. Otherwise, go elsewhere. For all the bad mouthing about 'hams' in the forums here, the reality is that Ham Radio operators, like any large group, represent a cross section of society. So don't condemn and entire hobby/group because of a generalized stereotype. The same can be said of GMRS users. The "Sad Hams" OffRoaderX refers to a lot, are real but (fortunately) do not represent the majority of Hams. That said, there are far too many Hams for which the statement is accurate. I also think many of them haunt the forums and YouTube (or maybe just Randy LOL!), just waiting to point out things they really don't know anything about (but "think they read somewhere"). This (GMRS) is really just another aspect of the radio hobby. We have noobs and we have genuine experts, neither of which should take themselves too seriously! ?

I usually stay out of this Motorola verses other brand Frey, and similarly, I don't always agree with gman1971. In this case I could not agree with him more! The reason site operators insist on type accepted equipment is to ensure said equipment will not cause harm/interference/etc.. to existing and/or future users. And for the record it doesn't start or stop with the type acceptance. So, to suggest that a GMRS operator needs to be 95e (legal grey area notwithstanding), and that using a part 90 repeater (Motorola Quantar for example) would be rejected and/or a basis for contractual violation is, IMHO, ludicrous. The likelihood of a properly adjusted Quantar causing, 'legally actionable' or contractual issues at a commercial tower site is again, ludicrous. As pointed out, generally speaking, Part 90 equipment is superior to 95e. Indeed, some (not all) of the part95e equipment is more likely to cause site issues than the more common Part 90 stations, which in the vast majority of commercial tower sites, is the dominant type of two-way equipment. One would be hard pressed to argue that the (properly adjusted) part 90 Quantar GMRS repeater is inferior and/or a problem for the part 90 commercial repeater a few Khz away. All that said, my own aversion to Motorola equipment is, when it comes to GMRS, price. For me personally, it is also the legal concerns over possession of the programming software. The FCC is not the concern by any stretch. Motorola legal on the other hand can, and has, destroyed the lives of people who violate the license terms and, Joe Private Citizen typically cannot even get a license agreement. Only qualified service shops and large volume, self maintained, users. If not for the software issue, I would always go with the Motorola if I could afford it! But back to price... The average GMRS user just can't pay for that level of quality. This is not a shot at Chinese (or Japanese) equipment. Neither is it 'snobbery' as I read somewhere else. Desiring/owning Motorola equipment is not 'snobbery' (except perhaps for a few individuals), it is simply superior hardware that any serious operator would aspire or strive to own and operate. To each their own in any case So if you want to play strictly 'by the book', then only purchase and operate Part 95e equipment. However, please don't try and tell someone else they cannot or should not use part 90 equipment. If it isn't obvious by other posts throughout the forums, you are in the minority and generally talking to yourself. Besides, what someone else does isn't your proverbial ass on the line, it's theirs.

I need to clarify something... First, this specific subject (at this level) is a bit out of the scope of the site (IMHO). Moving on... The difference between phase modulation and 'True FM' is, fundamentally, how the information is imposed on the RF carrier. That said, all FM signals, be it Voice, Data, or Combined Voice&Data is still just 'FM', but more typical these days, it is generated in the radio using a phase modulator. Technically speaking, even Analog Voice (generated by a 'true FM modulator') is phase modulation, which is why an FM discriminator will recover information from either 'True FM" or Phase Modulation. Correct, the human ear is not sensitive to phase (as far as I know). It is sensitive to pressure which, after the radio has done it's job (regardless of the modulation/demodulation), is what the speaker reproduces after any internal processing. At that point, other than perhaps fidelity, what goes on inside the radio really has nothing to do with what one hears coming from the speaker (assuming a properly working radio). That however, is not necessarily the same as the information (prior to processing) within the radio and, internal to a repeater, that gets transferred between the transmitter and receiver portions. As gman1971 alluded to, even if one manages to pass voice information by connecting two radios 'back to back' there is other 'digital' information that would never be transferred through 'base-band' (audio), and so many 'digital features' of the particular technology in question would not function. Basically, you have de-rated (degraded) a digital system to analog, that the voice is still digitized is irrelevant. IMHO, all of the above said, this discussion has gone way too far beyond the original question. ?

The issue isn't so much the vocoder(s) involved, as it is how the desired base-band (audio) is received, processed, and where and how it is fed into the transmitter chain. That said, there are some FM modulators that will, or can, have issues trying to generate a multi-phase digital modulation. I seem to recall some of the early radios (I could be wrong, but Syntor comes to mind) having a compensation adjustment for digital modulation, because the digital modulation would screw with the PLL. This isn't worth overthinking (IMHO) just look how others have done it and what their success level was. ?

True, but FM itself is simply variations of phase. You kinda have to see digital modulation on an analyzer. Virtually all digital transmitters are just phase modulation. Quadrature modulation is basically created by the phase and, you can't really look at any FM modulation in just one dimension. It's always just a given phase angle at a given time in space. All of that of course is why you really need a spectrum analyzer to see and adjust the modulation of a digital transmitter (Yeah, I can see Randy stroking out from that last comment, but I just can't think of a simpler way of describing it).

Depends on the digital technology. DMR for example, would likely not work by simply cross connecting the speaker and microphone between two radios. Indeed, pretty sure that is also the case for P25, Fusion, and D-Star. Could it work? Possibly. I suspect the audio quality would be less than optimum. That sort of goes to your question about vocoders. Nevertheless, virtually all digital systems convert the analog to digital before feeding it to the vocoder. The comment about 'elements of human speech' is true for P25 but that is not necessarily true for other digital formats. A better way would be to use one of the MMDVM modem cards (the ones without the onboard radios...i.e. not a hotspot modem). This solution, however, typically means connecting directly to the modulator and discriminator of the radios. That said, many radios such as the Motorola mobiles with the expanded accessory connector or, a stand alone repeater, provide these connections, so hookup can be simple. The downside is that virtually all of these MMDVM modems require that the modulation be manually adjusted (A spectrum analyzer is a definite plus here for best results (but not strictly needed). Good Luck!

Well, looking at the schematic, my interpretation is that it is 0 (zero) volts when on and some sort of high impedance when off. Pin 14 is literally an open collector, meaning there is nothing connected to the collector of the transistor and, when activated, there is a low impedance path to ground. Remember that these manuals were translated from Japanese to English and so sometimes things don't sound correct, even with major brands like Icom. A simple (safe) test would be to take a LED and feed it 15V from Pin 13 (via a dropping resistor, Figure ~ 1K to 1.2K ohm for a typical/common LED) to the Anode and then connect the Cathode (banded end or side with the flat spot) to pin 14. (I'd test this for you but my repeater is buried in a rack.) If the circuit functions as I believe it does, then the LED will be off until the transmitter is active. Worse case, it would be the reverse of that, with the LED on and then turning off when transmit is active, but I don't expect that to be the case based on the schematic. Hope that helps...

Funny how that is exactly what it did.

It wasn't so much price as it was features. Specifically, the ability to add additional GMRS frequencies/channels into memory, which cannot be done. I never suggested it was a 'bad radio', just that for the money, there are other radios available that provided more of what one might expect in an over $200 (Chinese) radio (and I exclude the KG-1000). Indeed, there are many sub $200 radios that offer a lot more capability. All that said, it seems the radio meets your needs and I am happy for you. The 50x1 simply did not meet my needs or expectations for a radio in the $200+ price range. IMHO, the 50x1, while a perhaps a good performing radio (RF wise), is anything but a good value at $220 given it's lack of flexibility when it comes to memories/programming. If there was any benefit to me from purchasing it, it was the learning experience and a lesson in doing your research before buying. As noted, I returned the radio the next day. However, as always, to each their own.

MTR2000 Repeater Specific Link/page http://www.repeater-builder.com/motorola/mtr2k/mtr-index.html

OK, seemed like you have been referring only to duplexers. MTR2000, being a commercial grade repeater, has limited internal options. To do some of the more 'hobbyist' features requires an external controller. Repeater Builder has many articles on this repeater and possible options. http://www.repeater-builder.com/rbtip/mojoindex.html

For just a duplexer, all you need is the transmit and receive frequencies. They don't program it, they tune it.

One more thing, the emitter of the (open collector) transistor is referenced to ground internally (I assume it is the same as pin 25) so you should not require that connection. Indeed, everything on that port that has an associated ground is to the same reference, at least on the schematic.

OK, I was just looking at the schematic in the service manual (I have the same repeater), and the (open collector) output transistor, 'XP4311' (actually it's an IC with 2 transistors in it) on pin 14 is rated at 50V @ 100mA max. That should be enough to drive a smaller relay coil. However, I'd still go with an opto-isolator as there is virtually zero chance of over currenting the circuit in the repeater. Just my opinion.

Well, yes. The open collector output on Pin 14 is going to require a reference. Basically, and since I don't know the current/voltage rating of the transistor, I'd suggest driving a 5, 10, or 12V relay (with the appropriate current limiting resistor) from Pin 13, through said resistor, through the relay coil, and then to/into pin 14. It may be the open collector output is at the same potential as pin 25. Does that all make sense? I suggest reading through the manual, preferably the service manual, to discover the ratings for the open collector on pin 14. I think the relay or even an opto-isolator is the safe way to go. Indeed, feed the +15V on pin 13 (again through a dropping/current limiting resistor) to the LED anode in the opti-isolator, and then the LED cathode to Pin 14 would let you drive/control almost anything safely, without fear of shorting out or over-current anything in the repeater (Think 4N28 type or similar). ?

A quality duplexer is, or can be expensive, but it's what you want. Stay away from the 'flat pack' mobile devices. They do work, but these days you can never be sure of where and how they are built. You are looking for low insertion loss and at least 80dB (or more) isolation. The aforementioned (used) Cellwave duplexer mentioned by a previous poster looks like a good deal. Most new duplexers of that grade cost twice if not three times the price.

It looks like pin 14 might be a possibility. Would be simple enough to test, it's basically a switch (open collector). The 25Pin connector is generally used for connecting to a controller.

Dunno, personally I prefer the analog meter movement over digital. I suppose it could be argued that digital is easier to read, etc... However, and especially when aligning at transmitter (yeah, I realize that isn't common in this hobby), it's a lot easier to see a peak with an analog meter than with digital (unless one is talking about lab quality, but even then...). At the end of the day, all you really need care about is accuracy. Even that term (accuracy) is a debatable statement, as 'accuracy' depends on the manufacturer's reference. The common reference, at least for analog based meters, is n% accuracy at a full scale reading. Unfortunately, that does not equate to mid scale (or quarter or three quarter scale) accuracy of the same percent, so you need to verify/calibrate your meter. BTW, I include Bird meters in that statement, although I seem to recall the back of meter (the 43 anyway) having some kind of calibration chart/scale (it's been a while since I had the luxury of using one). Who knows what it is for a digital meter, so you have to hope for and read the specifications (if they exist) and, as with an analog meter, calibrate it. I think a lot of people would love to have any of the Bird meters (they have an excellent reputation), but realistically, they are out of the financial budget of the average hobbyist. Don't even get me started on collecting the plug in elements. Indeed, the basic Bird43 costs more than most high end GMRS radios! A quality dummy load probably is a good idea as well, as all dummy loads are not created equal. Even a Bird coupled/calibrated against a bad load reference will be inaccurate. Bottom line, buy the meter you can afford with the best reputation (in it's price range) and, if you're a 'watt counter' do some testing to discover any discrepancies in the meter or variances in readings across a given range. Just one opinion (based on years of experience)...

https://birdrf.com/en/Products/Test and Measurement/RF-Power-Meters/Wattmeters-Line-Sections/RF-Wattmeters.aspx

Yeah, a healthy disposable budget!

Short Answer is, sadly, Yes.

Like a lot of equipment, especially 'bench equipment', I've always considered the purchase choice as an investment. My own preference is still linear but I do own some (name brand/well respected) switching power supplies, all rated to at least 25A @ 13.8Vdc (nominal). Switchers have the advantage of being extremely lightweight and far smaller than most linear power supplies. That said, you probably should go with one specifically for the radio market as some lesser manufacturers switchers make a lot of RF noise. Samlex, Astron, and a few other brands are a good choice. The Samlex SEC-1235 has some pretty good reviews and almost anything from Astron (switching or Linear) are good choices. While I do own an MFJ switching supply, and it has to date been reliable, I would avoid MFJ as, having repaired a few of them, I find their design (or at least construction) to be less than desired (my personal opinion). Again, look at the price of a good supply as an investment. Also, I don't know if I necessarily would trust my radios to a 30 Year old power supply. 300W rated or not, a GT5R should not cause a 1.5V drop. Power supply technology has improved a lot in 30 Years. Just one opinion.

The manuals for that radio should still be available. The manual would have all the wiring information. https://www.manualslib.com/products/Motorola-Syntor-X9000-3997312.html As for programming, only the original Syntor used an eeprom. The X-9000 (and you're taking me back many years) as I recall, had a programming adapter that fit between the control cable and the radio for programming by computer. However, that radio is so old it may be a DOS based software. FWIW, a quick search for "X-9000 programming" came up with several 2-way shops that still offer programming for that radio.