Radioguy7268

More than 20 years ago, I got involved in an FCC Auction & made an honest effort to get some VHF channels in my economic area. The economic area I was interested in went for over $2.5 million for what amounted to about 8 possible channel pairs. Part 22 channels from back in the IMTS days were gold. Most of them around my area are being used for linked DMR wide area systems. There's even still some wide area Paging on the old VHF Part 22 channels. Not sure how much availability there would be if the FCC protected incumbent operations.

Yeah, but the desense issue is huge with a compact duplexer. Even when properly tuned, if you over-power the transmit side, you are still introducing a weak but competing signal on the receive side that WILL reduce the talk-back range of your portables. Worst of all, your own equipment is what's producing the interference, and you probably paid more money to get all that interference!

Or, spend $800 to $1000 and get a purpose built repeater with a decent receiver front end that won't desense, and cooling fans to boot. Public Service announcement: your "50 watts" won't perform any better than a properly configured 10 watt repeater when you are talking back in with 5 watt portables. Especially if you're talking through a cheap compact duplexer that's probably rated at 65 or 70 dB isolation (and that's when it's properly tuned).

I've still got my Navajo codebook from Windtalkers.

In a SHTF / Post apocalyptic scenario the bad guys you are trying to protect your family from are going to be keenly interested to know who is trying to move valuable items. Value can be subjective, but a couple of yahoos getting on their GMRS radios and talking in code is more likely to draw attention than to deflect it. I don't think I ever said that trying to protect your family was a bad intention, but the people with truly bad intentions are not going to care how good your GMRS code ettiquete is. You have fun though - and by all means, keep us informed of your progress and the best code words to use. Things have been dead over here on mygrms forums lately.

If you think using codes will "protect" you - then have at it. If you're really looking at things from a SHTF perspective, analog radios are problematic to begin with, especially if you're in a single frequency/channelized domain. If I have bad intentions, I really don't need to know specifically what you're talking about, I can pretty much determine how many different people I hear talking, and I can easily triangulate your signal to figure out where you are.

Is it possible that you are misreading the cable, and it's really "RG8/U 95 foam" ??

Sounds like it's some type of oddball 95 ohm coax. What's the application? I sure wouldn't use it for any GMRS applications (which almost always requires 50 ohm cable). Could you even source proper connectors for it? Old coax is more likely to be the cause of problems than the solution, at least in my experience.

Those compact "flat pack" duplexers are not really designed for 50 watt applications. I also didn't quite catch who was tuning those duplexers. I've seen some sold on Ebay that are horribly tuned, and others that have been tuned quite well. I would not blindly trust that a CCD (CheapChineseDuplexer?) is actually tuned to the frequencies requested when it was ordered. I would also tell you that the amount of isolation between transmit and receive doesn't really allow you to run 50 watts through one of those flat packs (even when it's properly tuned) without some level of desense. In short - a portion of your transmit signal is going to leak over to the receive side and cause you interference - AKA desense, reducing the performance of your own repeater. And finally - the point I always get back to. Every rookie out there wants to get a full 50 watts, because more power is always more better - right? Well, think about what you're doing. You may get a full 50 watts heading into your duplexer, and if you're lucky, 30 or 35 watts heading out of the duplexer & up to your high gain antenna. But, what are you talking to? Hand held portables at 4 or 5 watts? How far can they talk back in? You just reduced their talk-back performance by leaking some transmit power over to the receive side, probably killing 2 or 3 dB of receiver sensitivity. Now that 4 watt portable is effectively talking in with the same effectiveness as a 2 watt portable, because you're reducing the receive side performance all so you can crank 50 watts into the duplexer. Back the power down to 20 watts, still have ERP to spare, and suddenly your 4 watt portable gets back into the system a bunch better, repeater coverage is balanced between transmit and receive, and as an added bonus, parts live longer due to reduced power. Turn down the power. Improve your system performance.

QFT! Talk with a frequency Coordinator, tell them that you want to put up your own Private Carrier system for "Part 90 eligibles" and license your DMR system as FB6 repeaters. Yes, it will cost you more than $35 up front, but now you have the keys to your DMR kingdom, and you can DMR to your heart's content, because every user on your FB6/M06 system now runs under your fancy Private Carrier license. You can (but don't have to) even collect user fees for the use of your system.

Lscott is correct. The handhelds will only transmit half the time - saving battery life on a portable. However, on the repeater side, both time slots are keyed up - even if only one time slot is actually active.

What are you using to measure the power output? Do you know it's an accurate measurement? Do you have a way to measure frequency stability and frequency center if you start changing power levels? What do you wish to accomplish by raising the power, other than to reach the "maximum allowed"? Raising the power on a smaller repeater generally increases the heat being generated, and reduces the duty cycle of the repeater. Many smaller repeaters were advertised as being 50% or even 100% duty cycle at high power, but in reality they don't last when you run them at full power for more than a few minutes at a time. I won't get started on the overkill concept of using a 50 watt repeater to talk to 5 watt portables. Sometimes less is more. I'd rather have 5 watts ERP at 100 ft. above average terrain than 50 watts at 10 ft. Not exactly the answer you were asking for, but hopefully something to think about.

The "best" is one that works well & fits your budget. Are you looking to work simplex to local portables? Mobiles? Or, do you just want to communicate through distant (or local) repeater(s)? If it's through a repeater, do you want to work multiple repeaters in different compass directions? Or, just one specific repeater? How far away are the repeaters you want to work? Any issues of terrain? 75 miles in Kansas is a probably a different solution than 25 miles in the foothills of Colorado. The answers to those questions would likely change the suggestions you are going to get, and you might want to put up a budget range or limit to define the dollars you'd intend to spend. I've seen people work a repeater with a paperclip for an antenna. I've also seen guys working earth-moon-earth contests. Those are probably the 2 extremes you could fall between.

I'm close enough to know where (and what!) the Qmart is, and trust me, they are not the only local users on 151.625. I've got a license for that frequency & use it in my VHF rental fleet. My biggest problem on that channel is a bunch of paving contractors who use it as an unlicensed "chat channel" while they're driving between jobs. Judging by what I've heard & how far apart they've been, they're using at least 25 to 40 watt mobile radios on what's supposed to be a low power channel. Not quite sure why you would willingly admit to operating unlicensed on a freq, but if you're looking for a blessing I doubt you're going to find it. However, in reality you are not the first and probably won't be the last to violate the rules in VHF.

To be clear, Motorola XPR radios do not have a "promiscuous" mode to listen in to DMR timeslot activity without regard to color code or timeslot. You can listen in analog mode, and then when you press monitor, you hear all activity on the frequency - but listening to encoded DMR digital in analog carrier mode is akin to listening to a buzzsaw. It is not pleasant, and it's not going to give you decoded voice on an XPR.

Motorola P/N is: HVN9025 Professional Radio CPS which runs under Windows 95, 98, XP, 7 - not so sure on Win10. Originally 32 bit, but the later versions would do 64 bit. R06.12.05 (released @ December 2011) is the one to look for as it is the last one that allows wide or narrow selection on a per-channel basis (it also fixed a number of problems including the 64 bit Windows USB problems, and it can be found "out there". Revision R06.12.09 was the very last one, however it is narrowband only unless you have the wideband entitlement key. There's also a ton of firmware flashes available (and probably needed for really old first generation units). There's also lots to know if you picked up an eBay refugee that was flashed/converted from an early LS trunking model. The go to bookmark for anything Waris (Pro Series mobile CDM & HT750/1250) is: W9CR.net

I've said it before, I'll say it again. If you want to have your own repeater channel, don't bother trying to petition the FCC to change GMRS rules - just go set yourself up with a Private Carrier FB6 on a properly coordinated UHF business channel. You won't need to convince anyone of your need, you just pay your money & go. You can do Analog, DMR, NXDN, Encryption - whatever. Create your own special 10 codes, use speech inversion, whatever floats your boat. You can even crank out more than 50 watts on your repeater (although there are actual ERP limits to deal with).)

I'm not a Kenwood expert. I use the programs once or twice a month, but I only load the programs once in a blue moon, and all the newer Kenwood stuff follows a different licensing format & procedure. The biggest thing you will need when trying to load up the KPG software for Kenwood is the K44xxxxxxxxxxx serial number that matches the software. If you got the software from a legit source, the Serial Number should have been provided to you. The username is just one of your choice - Call yourself Bob, XYZ Corp, Hammy or whatever you choose. If you don't know the Serial Number for your software, then I can't help you. My suggestion would be to contact a local Kenwood dealer & spend a few $. Others may have some different suggestions.

You're welcome. As far as your other questions, I'll just tell you that Digital DMR is not a legal mode for GMRS, so I'll leave those questions unanswered.

The EVX repeater wants to connect as an IP device - even through your USB cable. You may have some type of conflict with internal addresses vs. the IP address of the repeater itself. Since you cannot change the repeater IP until you actually can read/write the repeater, you are left guessing what address might be conflicting. The standard IP CPS connection address for an EVX repeater would be: 192.168.10.1 You also need to have open Ports in the 50000 range, with no funking forwarding or firewall blocks on your PC. There's a guy named Wayne Holmes over in the EU who works for Motorola and has his own personal blog hat dives into Motorola and IP addresses/networking/port issues. He's worth bookmarking, and he has more information, patience and details than you would ever get out of me: https://cwh050.blogspot.com/2012/10/mototrbo-and-ip.html https://cwh050.blogspot.com/2013/08/ip-repeater-programming-repeaters.html

If you have a strong signal outside those metal walls - a passive repeater (just 2 antennas hooked together as described above by kidphc) is a workable solution. I usually tell people that a passive antenna system will fix a small problem in a small area. You use an outdoor Yagi directional antenna pointed towards the repeater site, along with LOW loss (Heliax hardline is your friend for this type of setup) cable with the fewest possible connectors. Any loss is more loss than you want. Then install and connect an interior antenna in the center of the room/area where you need signal the most. The antenna system acts as a conduit/pipeline for the signal - both incoming and outgoing... thus the passive repeater nickname. Plus, that sounds more exotic than "I'm gonna screw 2 antennas together back to back". I've done setups like this for job trailers or basement offices, and while I tell the customer they can expect portable coverage within 8-10 feet of the interior antenna, they usually do better than double that. You should have an outdoor signal level above -85 dBm for this type of setup to work. Stronger levels are better, but if the signal level was that strong outside, you probably wouldn't be having the issue inside.

There are also much better Repeater options at a $1900 price point than a Bridgecom.

IMHO Peaches come from a can, they were put there by a man in a factory downtown.

I think the real world difference between 2 watts and 5 watts comes down to noise floor. Outdoors in a quiet RF space, you probably would not see much difference. In a crowded urban area with tons of RF, the 5 watts will give you the tallest weed in a field of noisy grass. The 2 watts will still be down in the grass.

Look in your CPS - and make sure you are set for "Expert" view. The EVX-R70 has a built in CWID, there's no need for an external device.