Lscott
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Posts posted by Lscott
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11 hours ago, Flameout said:
I realize that this is an older thread, but I've been playing around with a few TK880's (2 are V1 and 1 is V 2.0) I just recently got the V2, programmed it and worked good for a few days, then I got the yyyyyyy screen. Reprogrammed it again and it was good. I noticed the display was brighter than my other 2 radios, so I swapped it to on of the better radios (the V2 was in bad shape, as far as crud on the PC board)
Was an easy swap and all was good, but then the V1 that I put the brighter display in got the yyyyyy screen. I then swapped the screens back and that is when I realized that it wasn't the radio causing it, but it was the display itself and the yyyyy display showed up on the previous good radio and the bad radio that was showing yyyyy was now fine
The V 2.0 radio was also showing VER: 1.5205 but that too follows the screen and nothing to do with the radio as it also was showing that when I had that screen in the other radio. How is that possible?
I still haven't found a way to fix that V 2.0 radio and the yyyyy. When I bought the radio, it was SUPPOSED to be the 880H but seller sent wrong radio so he refunded my money and let me keep the radio. I'd be a little more upset if it was the 880H and I put money out on it. BTW, still looking for an 880H
Do you have the service manual for the radios? Manufactures can and do change versions because of hardware design changes. That could apply to the display too. You simply might have a different, electrically, LCD display verses the other radio where they are not compatible. The service manual might show the differences.
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Some of the above sounds like a rehash of topics discussed before. I'm surprised more haven't downloaded a file I posted on 7/25, 3 so far and I was one of them to test it, in this thread detailing my thoughts on the topic along with a lot of links to prior background material. In there I go over some points where a couple of modes might be a good choice even if they are not the current favorite and why. The idea is what could be proposed in a filling with the FCC they will seriously consider. Before that happens there has to be sound arguments why it can and should be done.
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13 minutes ago, WRKC935 said:
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.
I wouldn't be concerned about FRS. It's a different service, and effectively unlicensed at that. If an FRS user wants to use digital voice, well let them pay for a license. It's another perk of getting licensed besides using higher power and access to repeater operation.
The repeater idea has merit. I believe that dual mode equipment is available, which will automatically switch between analog and digital modes.
The negative aspect is too many non-technical GMRS users have trouble figuring out what offsets and tones are judging by the frequent posts on the forum asking for help. Now throw in color codes, slots, talk-groups and user ID's, well even some experienced radio buffs have a bit of a problem with those.
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1 hour ago, WRKC935 said:
First thing that will be considered is the level of interference with legacy equipment. Since we are limited on bandwidth, FHSS is gonna be a no go. The popping it will cause in the analog receive of the legacy stuff and the fact it will effect ALL the channels not just the selected channel I just don't see it happening. The next logical thought IMO is DMR, using TDMA of a 25KC or 12.5 KC channel. Implementation would be simple enough in the channels could be designated with an A and B. Meaning CH 19 in digital would be 19A and 19B to split the two time slots per channel. The branded name for DMR of course is MOTOTRBO in Motorola speak, but there are a large number of manufactures that make DMR radios. This would basically DOUBLE the number of channels that could be accessed from a radio in the same allocated bandwidth for GMRS.
But so would going to 12.5KC channel spacing. Mind you the range would suffer greatly with going narrowband, but the interstitial channels between the repeater allocations could then become full repeater channels if the FCC was so inclined to make that change.
The other thing that's possible since we DON"T have the non-proprietary technology requirement in GMRS that the hams have, we COULD petition for some level of Tier2 DMR functionality like trunking for area's that have significant GMRS use. That would share 4 talk paths on 2 repeaters with a huge amount of possible group call designations (talkgroups). But planning and cooperation from ALL users of the system and the system owner would be key to getting that to actually work. But some level of a 'CLUB' membership with or without dues would almost be mandatory as the configuration of the subscriber radios and ID assignment for the individual radios would need to be controlled or it would simply be chaos. Tier 2 DMR allows for proprietary trunking methods like Capacity Plus from Motorola that will ONLY work from a Motorola radio.
P25, which I would actually prefer, does NOTHING for increasing bandwidth allocation, unless you went to a Phase 2 APCO25 standard. But the requirements for that are radios that are thousands of dollars and back end equipment that would be in the tens of thousands. So that is a pipe dream. And linking P25 is FAR more complicated than linking analog or DMR. DMR linking is simple, other than every device on the linked system needs a specifically assigned ID. Call routing mandates this. But outside of that, a Motorola repeater that is DMR has an Ethernet jack in the back. You configure the repeater a certain way, and connect it to the Internet. There has to be a C-Bridge somewhere as there is a hard limit of 15 repeaters that can be linked together with out the C-Bridge, but outside that, you can route talk groups with the bridge to limit the number of active repeaters by the talk group being used. Meaning a TG (talkgroup) could exist for each state, region, or a nation wide group simply by routing the TG to the repeaters in the footprint of the TG designated area.
Any of this would of course interfere with legacy analog equipment and communications in analog. There would almost certainly need to be some level of restriction of what repeater pairs could be used and how far they would need to be placed apart from current analog repeaters to minimize interference. DMR talks further, which increases the possibility of analog interference. And while I am all for it, and the conversion for ME is as simple as going to the tower and reprogramming my repeater (running an MTR3000 on the 462.675 machine) if you look at the coverage footprint of 675 on the map, running an analog repeater in that footprint would be near impossible as my transmitted output would tear the analog receive up for those operators.
So, given the current regulations, and assuming the FCC would change it's mind, what do you think has the best change of getting serious consideration? We have to be realistic here. The FCC isn't likely to make major changes that could have negative impacts on existing users. They made a mess of things previously by allowing the marketing of dual service radios, GMRS/FRS, and tried to clean it up with the 2017 changes. This is the conversion we need to have and have an open mind about it.
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The spec's for the 2730A are hard to compare to the 2821D since the sensitivity units are different. You need to convert the 2730A to uV units.
-10dbuV -> 0.32uV
-5dbuV -> 0.56uV
https://static.dxengineering.com/global/images/technicalarticles/ico-ic-2730a_sn.pdf
file:///C:/Users/kcs/Downloads/IC-2730A-brochure-12-01-17.pdf
- SteveShannon and Flameout
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5 hours ago, tweiss3 said:
Any further progress on this? I'm interested to hear if you do end up getting it to work as more than a 2 channel radio.
So far no. The programming software seems to set all of the “unused” channels frequencies to zeros if I switch between 8 to 2 channel models. It also sets those channel options to default values too. That’s VERY inconvenient. I had hoped it wouldn’t so I could do most of the channel setups through the software and just manually hex edit the code plug for the custom frequencies.
I need to experiment and see if hex editing the code plug for just the frequencies and load it into the programming software if it leaves them alone for the extra memory channels so I can write it to the radio. If it does I’ll have to reverse engineer the code plug structure for a memory channel completely to figure out where the options are set, bandwidth, power, scan etc. and hex edit those for each one.
If that works maybe I can write a utility to read in the code plug and make the changes, then save it.
Right now the frequencies are stored as packed BCD in little endian format in 4 bytes. The tones are stored as a 16 bit unsigned integer in 2 bytes, also in little endian format. Why the difference? Beats me. I didn’t write the radio programming software.
Some of Kenwood’s other radios the code plugs are encrypted using a simple XOR method. The key is stored in the code plug in a fixed location and might be different from one code plug to the next for the same exact model radio. I’ve seen the install key in the code plug along with radio serial numbers too for some models. I think this is done so Kenwood can trace where the code plug came from.
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21 minutes ago, MichaelLAX said:
Have you ever compared the range of an analog FM broadcast station to its HD-1 digital component?
The issue was looking at the range limit due to problems when the radios can't sync the time slots from signal delays. If the time slots overlap then communications basically fails. That was the focus of the mentioned section in the ESTI standard. I was curious if anyone has experienced this, or at least can be reasonably sure that was the cause.
The second issue was clock drift in the radios. Unless one is using extremely accurate clocks, like synchronized to an atomic standard, they will drift over time. BTW old cell sites used Rubidium atomic clocks but now use GPS disciplined clocks to maintain sync.
https://www.thinksrs.com/products/prs10.html
https://en.wikipedia.org/wiki/GPS_disciplined_oscillator
The clock would be the internal master oscillator reference used for the frequency reference. After some period of time, likely just seconds, after the initial slot synchronization for a transmission the slot timing may overlap between slots 1 and 2. Remember the frequency drift is for both radios at each end. Again communications fail. That seems to place a piratical limit on the transmission time length too.
If you look closely at the cheaper DMR radios, compared to the more expensive commercial versions, they have sort of crappy oscillator accuracy and drift spec's. For example the few Motorola XPR-6550's I have spec at +/- 0.5PPM, my Kenwood TK-D340's are +/- 1.0 PPM. The popular D878UV is +/-2.5PPM ! Ouch.
Some base radios, and or repeaters, could be using OCXO, oven controlled crystal oscillators, to maintain frequency accuracy and very low drift rates. The best hand held radios only have TCXO, temperature compensated crystal oscillators, because the power drain for the oven heater is far to high for battery pack powered radios.
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I've read about there being range limitations when using TDMA digital modes, like DMR, due to clock drift in the base and mobile stations. The issue seems to be the slot timing verses distance and length of transmissions. See section 10.2.3.1.3 on page 112 in the following link to one of the ESTI DMR standards.
https://www.etsi.org/deliver/etsi_ts/102300_102399/10236101/02.03.01_60/ts_10236101v020301p.pdf
Anybody have any experience with this or did the detailed calculations for their installation? I've seen comments where some have gone to FDMA type modes to avoid this issue.
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If "N" connectors are too big and you need something small that can be weather proofed, good luck with BNC's, and high frequency rated have a look at the RG8 mini UHF type.
https://www.everythingrf.com/tech-resources/connectors
https://www.amphenolrf.com/connectors/mini-uhf-connectors.html
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6 hours ago, KAF6045 said:
It will "work" for some definition of "work"... But if I may quote the grail knight from the Indiana Jones movie "... he chose poorly"
I've bootlegged my Tyt DMR HTs with GMRS frequencies (and MURS/Marine in the case of the VHF/UHF unit] (a few cycles taken for that as 1) decision on bandwidth confused with channel spacing -- they have 20kHz options [Hmm, just checked, and found about half were still at 25kHz]; 2) reserved for emergency usage as I have BTech GMRS-V1, GMRS-V2 HTs, and the aforementioned Midland MXT-115 -- and have a Wouxun (sp?) GMRS HT in shipment (not to mention Midland and Motorola bubble-pack radios that are now classified as GMRS after the 2017 restructuring [Power >2W and/or Repeater channel access; may still be 12.5kHz bandwidth though]. I'd like to bootleg the much more capable Anytone D878UVII DMR unit -- but it only offers 25kHz and 12.5kHz options, and is locked to transmit only on 2m/70cm (even setting the code plug from "amateur" [allows front panel programming of radio] to "professional" [programming only via software] doesn't unlock it -- I've not seen a secret key I'd be willing to trust to get it unlocked. Since most documents show the 25kHz bandwidth is still using a 16kxxx deviation mode, they may still be save at 25kHz.
If you check you'll see just about every radio that says it's "wide-band" really is spec'd for 16K0F3E, not the FCC authorized 20K0F3E for GMRS. The 16K0F3E was the old business wide-band specification. Just about every GMRS repeater on the air is build using old Part 90, business band, equipment with the 16K0 spec.
Many of the currently sold GMRS radios are old repurposed business radio designs, or amateur gear, with tweaked firmware to make them compliant with the FCC rules. The 16K0F3E spec seems to be particularly true of the new Chinese manufactured GMRS specific radios. One would have a difficult time telling the two apart, 16K0 verses 20K0, on the air. I suspect the FCC could have changed the rules to make 16K0 the "official" FM standard for GMRS and likely nobody would notice.
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My comments are to long to type so read the attached file. As stated in the very first post the idea is what rule changes are required and the probability of of getting the FCC to consider the idea. I have ZERO interest in any lectures about the technical merits. That totally derailed this thread from the beginning and I'm not going there again. I debated even responding to this thread and decided to give it one last try.
I make no apology for grammar, punctuation, spelling etc. My aim was trying to get some ideas down.
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Has to be rugged and reliable. If it dies from dropping on a cement floor it’s useless.
- gortex2, SOBX and DeoVindice
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You can buy a “cheap” Chinese Radio, CCR, and program it for receive only. Typically the transmit function is disabled by leaving the field for the transmit frequency empty. They come lock to the Ham bands for transmitting, receive isn’t a problem. There is a very simple way to change that using an undocumented command in the programming software and password.
I’ve been using a cheap TYT TH-350 tri-band radio as a scanner in the house to monitor local communications. I think it works better than the BTECH model and costs about the same.
http://www.randl.com/shop/catalog/product_info.php?cPath=370&products_id=74359
The programming software works reasonably well.
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Passwords for Kenwood radios are numeric only.
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I was concerned with GMRS specifically. Many of the popular radios I suspected are firmware tweaked versions of the commercial LMR versions. I found a list of some of the popular models for GMRS with their FCC ID's here.
https://www.buytwowayradios.com/blog/2018/12/wouxun-radio-fcc-id-and-type-acceptance-chart.html
Doing a spot check of the GMRS certified radios the ones I looked at are all 16K0F3E. That's sort of what I expected.
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I think that’s why the FCC left the spec’s for the interstitial channels between the repeater main ones at 11K0F3E and 0.5 watts to limit the interference to them.
I’m just wondering if the manufacturers are leaving the bandwidth at 16K0F3E on the higher power channels since many of the Chinese GMRS radios are based on either old Part 90 or Ham gear with tweaked firmware to make it legal for Part 95.
If the norm for the majority of the radios in use is 16K0F3E the FCC could just tweak the rules and make it official. That leaves a larger guard band between channels that could be employed to advantage for other uses.
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I’ve been thinking about an issue, which isn’t important at the moment, where the occupied bandwidth of the signal is a major concern. The FCC spec’s 20K0FE3 as the normal “wide-band” FM signal mode for GMRS. However many people, including myself, have Part 95 certified commercial radios that are spec’ed for 16K0FE3, the old Part 90 rules, we use. Also the vast majority of GMRS repeaters are built using commercial Part 90 gear, which has the slightly narrower emission. Likely wouldn’t even notice the differences on the air.
So the question is are the typical radios being specifically manufactured for GMRS are they certified for 20KHz or 16KHz occupied bandwidth? If the later it may make a difference for future proposed changes to the service. Just one less item for the FCC to raise objections over since it helps reduce the interference potential from adjacent channels.
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3 hours ago, WQZF786 said:
I agree but what if you are ignored or told to go censored yourself then what do you suggest?
With the rule changes in 2017, effective in 2018, business use of the frequencies is legal so long as they use FRS compliant radios. No call signs are required. Anybody who monitors the simplex channels will likely hear all sorts businesses on the air using them. Just have to deal with it.
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2 hours ago, tweiss3 said:
What does the radio do when you go to channel 3?
With the stopper in place you can't turn it that far. Normally on the Kenwood radios I the radio will generate a warning tone and flash/change color or the LED on unprogrammed channels. When I tried it on this one, with a knob missing the stopper bit, nothing happens like the above. I guess I'll have to screw around with it a bit more.
I'm also looking at seeing what changes between the 2 channel Protalk version and the 2 channel LMR code plug versions of the radio. It would be far easier to do all of the editing using the LMR version for all the settings, then switch the ID in the code plug to the Protalk version. Otherwise the software will complain. So far I can get the software to think the LMR code plug is for the Protalk radio but I noticed the free memory count showed "-16", oops. I need to see which byte(s) might control that if any. It might not even matter so long as I can write to the radio.
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Well an update on the TK-3200 Protalk. Just got home from work and loaded the hacked code plug in the radio. It seems to work just fine on the local repeater in the area for GMRS so I count this as a success.
Now all I have to do is figure out how to use the full 8 channels, at least the selector switch on top has detentes for 8 with a channel stopper after two. Have to think about that a bit.
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2 hours ago, tweiss3 said:
Getting down to 440MHz might prove difficult. I do wonder where the hard stop is at the bottom.
That's true. I tested a TK-3160 16 channel radio with the 450-490 band split. The radio started beeping around 433MHz, couldn't phase lock. I tried the same thing with a NX-320 with the 450-520 band split and it failed between 442MHz to 443MHz. I'm guessing the wider the band split the harder it is to get the radio to operate outside of it's official specifications. For the used radios I'm buying I try to get only the 400-470MHz band split version. For some models those are nearly, if not, impossible to find.
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42 minutes ago, KAF6045 said:
Well, the TK3230 was approved for Part 90 and Part 95 (in 2007, so pre-reorganization). According to the FCC type acceptance, that radio is only spec'd for 460-470 MHz which would allow GMRS usage (actually, if one doesn't use high power on the 467MHz interstitial it now falls into FRS territory). Given the acceptance number, (ending in 3200), that may apply to most of the series.
Also, per the PDF manual for the TD3200, it is NFM only (GMRS is still the wider FM -- distinguished from real WFM used for FM broadcast stations). The pre-set channel list does not include GMRS frequencies. GMRS primary span 462.5500 to 462.7250, TK3200 jumps from 461.3625 to 462.7625.
While it may be possible to hack the frequency table for GMRS, that 460-470MHz spec most likely means that you will not be able to hack it down to 440MHz 70cm band.
I've had some success with Kenwood Part 90 radios getting them to work down into the Ham 70cm band. If it will function down to around 440MHz that would be OK since that's where most of the repeaters are located anyway.
I'm using the KPG-88D software for the TK-3200. The version I'm using allows wide and narrow band FM. I do the initial editing using the software then save the file. The custom hacking is done with a hex editor. In the attached file you'll see I have the local repeater frequency, RPT-16, and tone entered, and also the simplex frequency for channel 20. The software won't allow different TX and RX frequencies, even from the allowed list, nor split tones. That's what I had to do by hand along with the GMRS frequencies. The software always forces the same tone for ENC and DEC columns, and the same frequency for RX and TX. The attached photo shows what you see when the hacked code plug is loaded into the programming software.
Digital Voice Mode on GMRS - Possible Rules?
in FCC Rules Discussion
Posted
That will be one of the issues with trying to get the FCC to approve the idea. There is an existing group of FM only users and how would allowing digital affect them? Many, I would guess, likely wouldn't have any need or interest in getting digital enabled radios. The current FM only radios fits their needs as is. The FCC would need to balance any proposed rule changes against the interest of those users. That will be the tricky part.