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Everything posted by Lscott
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The never-ending Part 90/95 debate, and my discussion with the FCC
Lscott replied to a topic in FCC Rules Discussion
If you're interested in the Kenwood VHF models many will cover 136 to 174 MHz natively, no out of range warnings from the software. These are great for Ham 2M band, MURS, NOAA weather and the VHF marine channels. Of course the radios only have Part 90 certifications so user beware. They are also somewhat harder to find and seem to command a higher price used. The newer replacement for the TK-3160 is the TK-3360. It has a few extra features plus 5 watts output on UHF compared to the TK-3160's 4 watts. Both are 16 channel radios, but neither are Part 95 certified, just Part 90, however. If that doesn't matter they make great basic GMRS radios that a kid can use without screwing up the settings when programmed right. -
I've experimented with a thin walled fiberglass mast in a heavy duty speaker tripod mount for a temporary setup. There is an AL-800 dual band telescoping antenna on the top. The top tubing section was a bit thin so I removed. As it is now I get the antenna up about 20 feet when mounted on the tripod. If its a bit windy a few 6 inch tent stake spikes with some nylon cord works to guy the mast so it doesn't blow over. https://www.dxengineering.com/parts/mfj-1911 The antenna seems to match up OK on the GMRS channels when the coax is attached. No ground plane is needed thus reducing the wind load. https://www.dxengineering.com/parts/pry-al-800 The mast pops out of the tripod and will collapse to about 4 feet. The tripod folds up to about the same dimension. Without any guy wires I can setup the whole thing in about 10 minutes. I ran RG-58 cable up to the antenna. While a bit high on losses it is light weight and I'm not running the cable far anyway. I made the trade off with higher losses to get a light weight easy to setup and transport portable antenna system. If I have to I can use a 30 to 40 watt FM only amp that needs 4 to 5 watts drive power from an HT while drawing maybe at most 6 to 7 amps DC current, low enough to supply from a modest sized 12 volt battery. For Ham use a Mirage dual band BD-35 amps works. For GMRS a wide band amp is necessary. One from BTECH will work, however it is not Part 95 certified. https://www.dxengineering.com/parts/mir-bd-35 https://www.miklor.com/COM/Review_DMR-Amps.php https://baofengtech.com/product/amp-u25d/ If you look around you can find good deals on the above used. I picked up a BD-35 and a U25D for $100 total at a recent Ham Radio flea Market.
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I have a Ham Radio buddy that is interested in a cheap P25 radio mainly for monitoring public safety frequencies. The downside in many public safety departments run encrypted so you won't hear anything without the keys. I stumbled on a series of posts concerning NXDN. Apparently each radio has a unique ESN, electronic serial number, that a trunked radio system can verify. If I remember right a radio that is not authorized on the system will hear NOTHING. The software for setting up the system requires getting a key file for the radio and a license key from Kenwood to enable a radio on a trunking system. Sort of takes the fun out of using a radio just to monitor a system. I guess that was the goal to maintain security.
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I haven't made any of my own screen protectors. I do look for radio cases that have a screen cover. A number of my used radios obtained had noticeable scratches on the plastic screen. I found out that using tooth paste as a rubbing compound will take out the scratches if done right. It does take a lot of rubbing and the right technique to get good results but it does work.
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That just reminds me of a post elsewhere about a Ham who hated CCR's on his repeater so he setup the access tone to use exclusively MDC1200. He got a lot of negative comments along the lines of being a Motorola snob. It was his equipment. He can set it up any way he likes so long as it's legal. MDC1200 isn't exclusively a Motorola thing. Some of my basic 16 channel Kenwood HT's, TK-2360 and TK-3160, have it built in. I wouldn't mind getting a P25 radio to experiment with on the air. I just don't feel like spending $100 plus on a used one. One thing I have noticed the 800/900 MHz radios are not too expensive. The 450/490/520 MHz radios are more common and command a higher price used. The VHF radios is where the prices seem to get stupid high, likely because they are not so common and many get used on 2M in the Ham band. I would like to find another one or two TK-2170's but any I've seen have a ridiculously high price. In contrast I just got a clean looking TK-3173, the version of the TK-3170 which includes trunking, for $30 on eBay a couple of days ago. One of the reasons why I'm leaning towards DMR is I use my radios for scanning a lot, local business frequencies. A fair number have switched to DMR. With a mixed mode radio I can use on the Ham bands plus use as a scanner is attractive.
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The never-ending Part 90/95 debate, and my discussion with the FCC
Lscott replied to a topic in FCC Rules Discussion
Did you ever try to push it as far as you can down into the Ham 70cm band to see where it quits? I tried that the other day with one of the Kenwood TK-3160 16 channel radios I’ve got just for fun. The radio alarmed out around 433MHz, the PLL wouldn’t lock below that. Not too bad since the official low end is spec’d at 450MHz. -
I actually see 2 repeaters in Oakland county, 1 in Macomb county, 6 in Wayne county Michigan for D-Star. (9) There are 4 repeaters in Oakland county and 1 in Macomb county Michigan, 3 in Wayne county Michigan for DMR. (8) There are 5 repeaters in Oakland county and 3 in Macomb county Michigan, 4 in Wayne county Michigan for Fusion. (12) There is 1 repeater in Oakland county Michigan for NXDN. (1) There are 3 in Macomb county Michigan, 2 in Wayne county Michigan for P25. (3) The above I found in the on-line "repeaterbook.com" listings. It appears that Fusion, D-star and DMR, in that order, seems to be the ranking in the tri-county area where I live. D-Star and DMR are about even in repeater support. Other areas have different level of support. I know in Florida there is an area with a lot of NXDN repeaters. https://www.repeaterbook.com/repeaters/feature_search.php?state_id=12&type=NXDN https://ni4ce.org/nxdn-digital-communications/ I don't know how true this is but I heard Yeasu was giving huge discounts on their System Fusion repeaters. That was the reason given for the popularity, more of a marketing thing, cheaper to put a Fusion system with the discounts than one of the others.
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There are just too many digital voice modes for Ham Radio. Typically a radio will only support one. Yes I've seen some mobile LMR's that will do several but in general this isn't the norm. If you had to pick one digital voice mode which would you use? https://n5amd.com/ Also do you use or own radios for other digital voice modes? I'm not interested in any "Hot Spots". Myself I've played a tiny bit with DMR and leaning more towards it. My reason is the radios seem to be reasonably price with models available from multiple manufactures, and a healthy number of repeaters around. Kenwood terminated production on their analog/digital radio, TH-D74A, which does D-Star. So that leaves Icom for that mode. System Fusion is only available from Yeasu. https://www.dmrassociation.org/downloads/documents/White-Papers/DMR-Association-White-Paper_Benefits-and-Features-of-DMR_160512.pdf https://www.itu.int/dms_pub/itu-r/opb/rep/R-REP-M.2474-2019-PDF-E.pdf I have radios for D-Star, DMR and NXDN so far. I've thought about picking up a P25 radio, looks like the major choices are really old Motorola and some Kenwood gear. The newer stuff is expensive used and then finding the software to program them, Motorola mainly, is not as easy as the Kenwood stuff I have already. NXDN radios seem to be available from more than one manufacture.
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This is the version the notes mentions. 1952201234_KPG-49DV4.02.zip
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Look in the "Disk1" folder inside of the "KPG-49D 4.21" folder after unzipping. You should find a file with the name " Serial Number.txt" open it and then copy and paste it in to the serial number entry area. There is some interesting info I found a while back on this software. Since I don't have it installed I can't say if any of it works or not. KPG49D_Notes.txt
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The old DOS software likely will only work with a REAL RS-232 port using the 16550 chip. https://en.wikipedia.org/wiki/16550_UART DOS software typically programed the ports and other hardware directly. If the real physical chip register doesn’t exist then the software fails. The usual USB to RS-232 emulation cables work only because the software uses the drivers Windows installed. The drivers don’t emulate the physical serial chips. One other problem with DOS software is the speed of the computer. Timing routines were implemented in software so a computer that runs too fast also will cause problems. Experienced radio technicians are known to keep old slow DOS computers around with real serial port hardware to program old radios when necessary.
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The never-ending Part 90/95 debate, and my discussion with the FCC
Lscott replied to a topic in FCC Rules Discussion
"No GMRS transmitter will be certified for use in the GMRS if it is equipped with the capabilities to operate in services that do not require equipment certification, such as the Amateur Radio Service." That's rather confusing. I have my Part 95A FCC certified TK-3170 programmed with a bunch of Ham simplex and repeater frequencies in addition to GMRS stuff. Depending on how you interpret the above the radio may not be legally used on GMRS? -
I know this is a bit late but how much of the railroad communications takes place using digital NXDN? At one time I understood the railroads were switching over to it in place of analog. https://www.scannermasterblog.com/railroads-nxdn-and-ptc/ https://forums.radioreference.com/threads/railroads-and-nxdn.362261/
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The never-ending Part 90/95 debate, and my discussion with the FCC
Lscott replied to a topic in FCC Rules Discussion
The last rule change by the FCC they just "throw in the towel" in regards to what people were already doing, using those "dual service" FRS/GMRS radios without getting the required license. It was easier for the FCC to make the wide spread illegal practice legal by a rule change. Now they can ignore the issue. I expect at some point the same will be done with the use of Part 90 radios on GMRS. The FCC can't really say with a straight face they are enforcing the rules when they let the practice of using Part 90 equipment on GMRS go on, except were you pointed out, when its in conjunction with other rule violations. As discussed on the forum many times your typical name brand LMR/Part 90 radios meet and or exceed the technical specifications for GMRS. The only element missing is the official blessing by the FCC, certification. I personally expect to see the FCC sooner or later to again to "throw in the towel" on the issue. Likely with language along the lines of if it was certified for Part 90 with no front panel programming, and maybe a cut off date, its good to go, with no ambiguities. I suspect there are a LOT of Part 90 only radios being used everyday with no issues on GMRS. So long as the technical specifications, power - bandwidth - channel frequency - frequency stability - no digital - no encryption/voice scrambling, are met how would would one even know a radio was Part 90 only just from monitoring on the air? If you can't does it even really make any difference? -
I'll bet the cat killed the output for the string the panel is in where the cat is sitting. Or at the very least for the one panel if they are all connected in parallel. Big splashes of bird poop and other trash on the panels kills the output too. Big panel arrays need to be cleaned periodically, otherwise the output suffers after a while.
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Not only that but the metal sub-chassis of the radio along with your hand/arm combo forms part of the ground plane. https://www.hamradio.me/antennas/ht-antenna-comparisons.html I've tried checking the SWR on a bunch of HT antennas, well the results are mixed. I got widely varying results depending on how the antenna was mounted, directly to the analyzer - SMA type magnet mount on a ground plane (yes I found one at a swap) etc. About the only ones you can reliability check are 1/2 wave types since they don't require a ground plane. I've seen a few for the Ham 2M band. I don't recall seeing anything for UHF. https://www.smileyantenna.com/product-p/14686.htm
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I agree with your points. If necessary a short simple beep is enough. Personally myself I don’t use Roger Beeps either. I have used some Ham repeaters that had no courtesy tone. Trying to do a round table discussion with 3 or more people often resulted in somebody getting stepped on.
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Well that depends. If the radio supports operation through a repeater it may serve a useful propose. Most repeaters have a "hang time" which can be as short a a fraction of a second to several seconds or more. The hang time function is to keep the repeater keyed up and ready without the constant COR, carrier operated relay action. The Roger Beep lets everyone on the repeater know when the other party is done so you don't have to wait for the repeater to dropout, without the usual squelch tail, before commencing with another transmission. Of course it should be a common practice to wait a few seconds before jumping in anyway. That gives another party out there a change to announce their call sign and use the repeater. At least people are not using "echo mic's" with their radios, which seems commonly used on 11M. Now that's annoying.
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https://www.faa.gov/hazmat/packsafe/more_info/?hazmat=7 https://www.tsa.gov/blog/2013/06/11/travel-tips-tuesday-safely-packing-batteries-your-trip
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I traveled a lot through airports some years back, mid 2000's, and never had an issue with the radios. Now battery packs are another thing. I had a fanny pack with a 5Ah gell cell in it, for extended portable operation. That got a "lot of interest" because it showed up as completely black on the x-ray machine with wires coming off it to a round cylinder, 12 volt accessory socket, to use a battery charger eliminator. The TSA inspector almost had a heart attack when the accessory socket popped out like a Jack-In-A-Box, due to the coiled up wire cord, when he unzipped the fanny pack flap and slowly pulled it open. He forgot to let go of the fanny pack when it tried to throw it, otherwise it would have gone about 10 feet across the screening area. Oh well. Everybody saw what happened. And no I didn't get into any trouble and was allowed to proceed to the gate area.
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The Kenwood HT's I've had direct experience with are the following: TK-370G-1 https://mra-raycom.com/wp-content/uploads/simple-file-list/Specifications/portables/TK-270G-370G-Product-Brochure.pdf TK-3140 https://mra-raycom.com/wp-content/uploads/simple-file-list/Specifications/TK-3140-Product-Brochure.pdf TK-3170 https://5.imimg.com/data5/MT/AL/MY-2136226/tk-3170-handheld-portable-walkie-talkie.pdf TK-3173 http://www.comspecinc.com/PDF/TK-3173.pdf TK-3180 https://pdfs.kenwoodproducts.com/10/TK-2180&3180Brochure.pdf All are Part 95 certified. Either listed as "Part 95" or "Part 95A". The 95A was the older section for GMRS whereas the new one is Part 95E, same thing. It seems like the favorite is either the 3170 or 3173. Both use the same version of the programming software and will use the cheap Baofeng type Chinese radio programming cable and accessories like speaker microphones. The other two radios also use the same plugin accessories and programming cable too. The 3140, 3170 and 3173 all use the same type battery pack and charger so if you get the different models at least you can share them saving some money. The trick is find one of the above in good condition for a reasonable price. Don't forget you will likely need an antenna, new battery pack and charger too.
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They can’t let their license lapse either. If they do the FCC won’t renew it as a business and they lose any priority they enjoyed over secondary users. I have a similar issue by me. A local mall’s house keeping is operating a repeater on GMRS channel 16, yes it’s a repeater with PL tone, it’s been “tested”. The problem is their license expired in October 2015 per the FCC database. It was never renewed as far as I can tell while the house keeping staff continues to use their radios and the repeater. I’m waiting to see how long before somebody gets the idea to hijack the repeater and use it for local non mall related communications. If the mall complains to the FCC it likely will get shut down while the mall gets a $10k fine for unlicensed GMRS operations. Their other choice is pay for a regular business license, get a coordinated frequency, then get the repeater reprogram and tuned. The house keeping staff use those Motorola Mag One BPR40 radios which can easily be reprogramed. https://www.motorolasolutions.com/content/dam/msi/docs/business/products/two-way_radios/portable_radios/small_business_portable_radios/bpr40/_documents/static_files/mag_one_bpr40_brochure.pdf At least they’re not using those CLS1110/1410 radios. A number of the smaller stores their personal I’ve observed using those. You might mistake them for an FRS radio at first. https://www.motorolasolutions.com/content/dam/msi/docs/business/products/two-way_radios/portable_radios/small_business_portable_radios/cls1410/_documents/static_files/cls_specsheet.pdf
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Excellent point. Battery packs are something people are going to buy sooner or later. They don’t last forever. I wore out the lithium pack on my BTECH triband radio I use at work as cheap scanner while working in my office. Scan all day, then recharge overnight. After about a year it wouldn’t even make it through 8 hours before the radio shut down due to low voltage on the pack. The typical life of a battery pack is 300 to 500 charge/discharge cycles. Depending on the owners radio use a battery pack might last one to several years.
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As a point of reference the service manual for a Kenwood KSC-25 charger can be found here. https://manuals.repeater-builder.com/Kenwood/ksc/KSC-25_B51-8626-00.pdf Looking at the second page from the back it shows the circuitry for several different battery packs. I would imagine that battery packs from other manufactures likely do something similar. The "charging terminals" on the base of the battery pack is only accessible by the charger base while the "discharging terminals" are only accessible by the radio when it's installed. One thing about the Lithium Ion battery pack schematic are the cells are shown connected to a boxed area. That is a "protection" circuit. I noticed when running pack discharge tests using a simple power resistor, before using the E-load, if I discharged the Lithium pack much below the 6VDC I use for a cut off point the voltage will suddenly drop to zero. Lithium batteries will be permanently damaged if discharged below a certain voltage level. The protection circuit disconnects the cells internally from the discharge terminals to prevent this.
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The blocking diode is built into the battery packs, not the charger. Modifying the charger wouldn’t do any good.