Lscott
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Posts posted by Lscott
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I address the specific question that was quoted. Rule exceptions under emergency conditions are another whole topic. Mingling the exceptions with standard operating conditions does nothing but confuse people.
People can decide themselves what to do with their equipment. What’s needed is clarity. You can have a radio that operates on both Ham and GMRS. So is it really a Ham radio modified to operate on GMRS frequencies, or is it a GMRS radio that can be programmed to operate on Ham frequencies? If it’s as you believe then why aren’t all GMRS radios out of the box designed to work on the Ham bands WITHOUT mucking with it first such as using manufactures undocumented software mod’s and “mode” changes. The same question can be asked about Ham equipment. After all what are the “MARS/CAP” mod’s?
Reading the rules for GMRS one requirement is the frequency determining controls are not accessible outside of the transmitter. This is necessary for Part 95 certification. The channel selector doesn’t count because all legal frequencies are preset and can’t be changed by the user. Enabling a VCO type operation violates that requirement and by definition no longer meets type certification. While you may not care there are others who do and shouldn’t be misled.
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Ah, a slight of hand bringing up emergency communications. That wasn’t part of the original question I quoted from your post.
Under emergency conditions the rules have a few exceptions. However as a general point, as one is lead to believe by your original question, it’s prohibited. That hasn’t changed. -
3 hours ago, MichaelLAX said:
Here's a hypothetical:
If a licensed Ham programs his 70 cm rig to transmit on 446.0 MHz and receive on 462.5625 and a licensed GMRS user programs his HT to transmit on 462.5625 and receive on 446.0, is their conversation within the FCC Rules for both services?
No. This I had thought about this exact scenario a long time ago and rejected it for the following reasons.
The rules state, last I read them, that stations in the Amateur service may only communicate with other stations in the Amateur service. The second I-got-you is doing what you propose is effectively making a one way transmission, see point above, which is only allowed for testing and in very few other limited conditions on an occasional basis, again for the Amateur service.
While the method would allow one to cross communicate between services without using modified radios the rules effectively shut the door on it.
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2 hours ago, Radioguy7268 said:
I would agree. Allowing any type of automated GPS updates will kill channel capacity even if you've got just 5 or 10 high power units reporting GPS location every 30 seconds. I haven't looked deeply enough at the rules - but is the FCC requiring units to monitor the channel prior to transmitting their "brief" data burst?
Automated location updates on repeater channels would be a disaster. I can see a point to allowing units to update automatically once every 10 to 15 minutes - or alternatively, tagging on to the beginning or end of a voice transmission like a PTT ID.
If there is no requirement for a BCL, busy channel lockout, that would be worse, automatic interference. I also think you wouldn't want this on a repeater channel. That has the potential to block a frequency out over a very wide area if the repeater was activated.
If were are going to tolerate GPS updates why not have it restricted to one channel only leaving everything else open for normal traffic? In the Ham world there are several frequencies in the band plans set aside specifically for packet and APRS. Keep it on one of the 8 low power, 1/2 watt, FRS channels. They are sort of useless for GMRS as it is.
- pcradio, wayoverthere and Radioguy7268
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6 hours ago, mbrun said:
As the settings affect the transmit characteristics, I adjusted them in the 905G used for Tx and observed the results on two other 905G as well as two other models of radio.
Michael
WRHS965
KE8PLMOk. Just wanted to be sure.
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2 hours ago, mbrun said:
I did explore this, and yes indeed the Tx time per digit and interval between digits can be changed. I made a variety of changes and still experienced unreliable decoding whereas my other radios were always rock solid regardless of which of the few combinations I tried.
Michael
WRHS965
KE8PLMOh, I hope you tried changing the timing parameters on the other radio(s) not on the 905G.
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2 hours ago, mbrun said:
I did explore this, and yes indeed the Tx time per digit and interval between digits can be changed. I made a variety of changes and still experienced unreliable decoding whereas my other radios were always rock solid regardless of which of the few combinations I tried.
Michael
WRHS965
KE8PLMIt was worth a shot if it fixed it. Perhaps a firmware update at some point might do the trick.
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On 10/3/2021 at 6:28 PM, wayoverthere said:
small expansion on this point; there are a few dual band antennas focused on the commercial/MURS end of VHF that are a decent match for GMRS as well. I have (but haven't tested) a Comet 2x4SR nmo that is supposed to play well with MURS, 2m, 70cm, and GMRS, but trades a little bit of a gain for the wider range. this again requires a nmo mount of your choice, and it's on the long side (~3ft). it DOES fold over, though, and there is a spring kit available to give it a little more flexibility.
I have one of the 2x4SR antennas, and a buddy here at work put one on his pickup truck using a lip mount on the front hood near the roof pillar. They work OK, but being a 5/8 wave design you need a REALLY good ground plane.
I did an SWR scan using a RigExpert AA-1000 and downloaded the data to a CAD package for plotting. As promised the SWR was under 2:1 around the GMRS frequencies and very surprisingly very low on the MURS frequencies.
https://rigexpert.com/products/antenna-analyzers/aa-1000/
The antenna is somewhat sensitive to mounting location even with a good ground plane. If you want one antenna to cover Ham and GMRS its a good option.
- 1977Hahn and wayoverthere
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1 hour ago, mbrun said:
DTMF decoding all my KG-905G is very poor (to the point of being completely worthless), but rock solid on some other models I have.
When another radio with DTMF sends out its ANI-ID/PTT-ID (usually 3-6 digits) the radio display should reflect the code it just received. Or, if the transmitting radio has DTMF buttons and sends out characters followed by #, the 905 should display them.
If you have two units you can perform a test. Use the software to program two different PTT-ID codes into the radios and enable it to transmit each time you press PTT.
So far the uses I have learned for DTMF include: Identification of the transmitting radio, use in some radio calling functions (to alert another radio), to control certain repeater functions, as an alternative to PL codes for opening squelch on another radio, for gaining access to a repeater, for dispatch software recognition of the radio transmitting.
Michael
WRHS965
KE8PLMDo the TX'ing radios allow changing the timing parameters for encoding the DTMF tones? I know on the commercial Kenwoods I have there are timing parameters I can tweak. Maybe your radio needs longer duration tones and slower sending rate to give it more time to decode.
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12 hours ago, wayoverthere said:
It's primarily something that carries over from the ham origins of the radio. There are repeaters set up to accept commands via DTMF tones, things like changing frequencies or turning off the transmitters. since much of the hardware can carry over to gmrs, this feature may be out there on gmrs repeaters as well.
The vestigial part (at least for gmrs) is that on the ham side, DTMF tones can be used to dial numbers on an autopatch equipped repeater to make phone calls....these are explicitly not allowed for gmrs though (interconnections to the telephone network).
On the Ham side DTMF tones have been used to access other linked analog repeaters using for example Echolink. I'm not sure if any linked GMRS repeaters use a similar system to access a specific linked repeater.
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8 hours ago, tweiss3 said:
While it is a compromise antenna, it is still the best one available (that carries 4 bands, I use 220 a lot), and is enough for the 6m repeaters in the area (I use 2 regularly) and have been successful with simplex contacts while hiking the local parks network. It doesn't nearly meet my vertical dipole 19' above ground that is powered by my 7300, but it works well overall.
If it’s working for you cool. Sounds like you’re one of the few people that utilizes the radio’s full set of features, most don’t.
Myself I would like to see Kenwood come out with a version of the TH-D74A but use DMR in place of D-Star. That would be a killer radio.
I’ve scanned 220 around here by me and it seems basically dead.
I have a cheap TYT TH-350 triband I use as a scanner at home. Mostly used to monitor the local mall security frequency, house keeping along with the neighborhood FRS stuff and the local GMRS repeater. For a CCR it’s an OK radio.
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Most Linux distro's have a VM function. If it isn't installed then you can add it. If you don't want to go that route then you can get the VirtualBox add-in for Linux here.
https://www.virtualbox.org/wiki/Linux_Downloads
Your next stop is to pick up a copy of Windows. An older version will likely work just fine for your needs. Look here.
https://winworldpc.com/product/windows-nt-2000/final
CHIRP will run on Linux. Some instructions are found here.
https://chirp.danplanet.com/projects/chirp/wiki/Running_Under_Linux
Good luck.
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1 hour ago, tweiss3 said:
Actually, it works quite well with the rubber duck on 6m, exactly like the 818/817 does.
I have an FT-817 and the included 6M antenna sucks. You realize for a 1/4 wave 6M antenna the required ground plane radials need to be about 60 inches long. The body of the radio is nowhere even close to that. Now holding the radio, well now your whole body might function as a sort of ground plane but the vertical element is still a crappy very short loaded helical design with high losses. Does the antenna radiate, yeah, but poorly.
There is a reason why you don't see a bunch of HT's with the 6M band included. Most 6M activity is during band openings and then it's typically on sideband anyway, not FM. I just check "repeaterbook.com" and there are a total of just 15 6M repeaters listed for the entire state of Michigan for example, it's not that popular for FM, at least around here.
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Those radios use an RJ-45 style plug I believe. I would check the connector that plugs into the radio. All the contact fingers should be clean. You can try to wipe the contacts down with alcohol, the programming cable, and use a Q-tip to do the socket in the radio.
Sometimes gently bending the contact fingers out a tiny bit helps if you can get to them.
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11 hours ago, tweiss3 said:
I do hike with my FT3DR and my VX7R, my current favorite being the VX7R for the inclusion of 220 and 6meters.
The antenna efficiency of an rubber duck 6M antenna on an HT is going to be really poor. Unless you plan on using an external 1/4 wave antenna with a ground plane it’s more of a marketing gimmick. The 2M VHF rubber duck antennas I’ve seen where it was stated as a negative 5 db gain in some cases too.
A 1/4 wave UHF antenna for Ham 70cm and GMRS is about 6 inches long. That’s small enough to fit on an HT where the body of the radio is just about big enough to make a reasonable ground plane. Even better when holding it.
I made a 1/4 ground plane antenna, with radials, using some heavy buss wire and a PCB BNC socket. The measured 2:1 bandwidth covered almost the 430 to 470 MHz range with a nearly perfect match around 448MHz. Good enough for Ham and GMRS.
I used the antenna zip-tied to a baseball cap while walking around the Dayton Hamvention a couple of years. That let me hang the radio on the belt using a short jumper cable and speaker mic. I only needed about 1 watt for good communications with the antenna up in the clear. I might have looked like a nerd but I wanted something that worked, cheap and simple to build. -
IF range was only determined by power then your range varies by the square root of the two powers. For example comparing 45 watts to 15 watts you get:
sqrt(45/15) = 1.73
In other words your range should increase by a factor of 1.73 going to 45 watts verses 15 watts. There are other factors that will conspire to reduce this.
You need to pay attention to the cable between the radio and the antenna mount. The RG-58 cable that’s typical used is fairly lossy at UHF. The loss can be compensated for by using a gain antenna.High gain antennas have their issues so they might not be a good fit for your application. If you mainly operate in very hilly or mountainous terrain a simple 1/4 wave antenna likely will work better. For flat open terrain a high gain antenna performs well.
There are a few antennas that require no ground plane allowing more options on mounting locations. Some of the other forum members likely have some good recommendations for this type of antenna.
A few people even keep more that one type in the vehicle and swap them out depending on operating requirements. Maybe a high gain one for use in a convoy while travailing on a highway then a short 1/4 wave for off road use.
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10 hours ago, BKmetzWRKZ843 said:
pcradio, good discussion. I'm also of thinking along the same lines you are in my need for a do-it-all HT.
First I'll address what you haven't said, do you have a ham license? I'll assume so because of the Yeasu radio you mentioned.
I own a Kenwood TH D74A. It's a tri-bander (2m/1.25m/70cm) and rather than list all it's features, I'll just post a link.
https://www.kenwood.com/usa/com/amateur/th-d74a/
It has everything you're looking for but it's discontinued and sold out everywhere. Used ones are going for stupid money. 6 months ago these radios were selling for $450 to $500. Then Kenwood unexpectedly discontinued it because of the chip shortage. Open box radios (if you can find one) are going for $800 to $1000. Prices of used radios are just as high.
I had the MARS-CAP mod done on my D74A by HRO so the warranty is intact. What this means is the radio was internally modified (removal of one tiny resistor) to open up those extra frequencies. What I have not done is get the firmware tweaked so I can take full advantage of those frequencies. I have a bunch of radios so it hasn't been a high priority.
Another radio, on the opposite end of the price spectrum, is the Wouxun KG-UV9P amateur band radio & scanner. It has everything your looking for except GPS. If you buy it from these guys https://bettersaferadio.com/wouxun-kg-uv9p-amateur-ham-two-way-radio/ they will pre-program all the scanner frequencies. That's why their price is a bit higher than other online retailers. This radio will only transmit on the ham frequencies and scan everything else. I don't know if the radio can be opened up to transmit on all its frequencies. There is probably someone out there who knows how to do this.
Good luck in your search and let us know what you end up buying.
Here's a photo of my Kenwood D74A. I'm monitoring my local NOAA frequency.
Yup. The D74A is a nice radio. I also got mine from HRO and had them do the MARS/CAP mod for the same reason. The only negative is the battery pack capacity, it doesn’t last that long.
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1 hour ago, BradfordD said:
Being a newbie - I heard the 905 has the "superheterodyne circuitry" (what ever the heck that means)
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2 hours ago, pcradio said:
Thank you. I did't realize that. I wanted GPS so I could note my coordiantes in real time while speaking with someone. However, I will have a GPS device on me, but was hoping I could get it in the radio too. Hmmm.
Yeah, check it out for the specific radio you're looking at buying. With all the features radios have now it's easy to overlook a detail like this and end up with something you can't use and paid a premium to get it.
Some of the Ham radios include a feature called "APRS". You can get the details of what that might do for you here:
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2 hours ago, mbrun said:
The key is the word ‘operate’. In radio lingo ‘operate’ is synonymous with transmitting. For part 95e certification I interpret that that the FCC does not want user’s having the indiscriminate ability to transmit in other services, and they do prescribe what is allowed in GMRS. If the radio firmware enforces the rules, regardless of mode, I think the intent of the FCC requirements are fully satisfied.
Michael
WRHS965
KE8PLMThe rules are written the way they are because the underlying assumption is the user is a non technical person who has no idea what the difference is between Hertz and Hurts. The rules are designed to prevent interference to other services regardless of how a user manipulates the radio’s controls, either deliberately or by accident.
Hams are held to a higher technical standard, and assumed to know where the bands are located frequency wise. There are few out there that would be challenged using two soup cans connected by a string, it’s not a guarantee somebody is competent just because they have a Ham license. It’s not a perfect world.
- wayoverthere and axorlov
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2 hours ago, MichaelLAX said:
As I pointed out the source was Amazon comments and that he should double check this feature, which you did for him.
A number of people recommend the FT-60R. About the only thing it doesn't have is GPS.
A number of radios that have GPS it ONLY works in the digital modes. So if the others in your party don't have similar radios it's sort of useless. Plus the GPS function simply TX's position messages that are displayed on a compatible radio. Again if the others don't have such a radio, that can display the text messages, the feature isn't going to be useful. Before spending the money you need to check into this very carefully or you'll end up with a nice radio with GPS nobody else can take advantage of on the air.
https://www.yaesu.com/indexVS.cfm?cmd=DisplayProducts&encProdID=6EC43B29CEF0EC2B4E19BB7371688B7F
Brochure.
https://www.radiotrans.com/archivos/catalogo/FT-60_EN.pdf
On line sellers.
https://www.hamradio.com/detail.cfm?pid=H0-007323
https://www.theantennafarm.com/catalog/index.php?main_page=product_info&cPath=115&products_id=432
For the RX/TX frequency expansion. If done by HRO they will warranty the radio.
https://www.hamradio.com/detail.cfm?pid=71-002354
https://www.theantennafarm.com/catalog/index.php?main_page=product_info&products_id=417
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I think gman1971 can answer that. He's pretty much the Motorola expert on the forum. He's help me out with some issues with a few XPR6550's I recently got.
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Per the FCC rules they state the following:
https://www.ecfr.gov/current/title-47/chapter-I/subchapter-D/part-95
"§ 95.1761 GMRS transmitter certification.
..... 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. All frequency determining circuitry (including crystals) and programming controls in each GMRS transmitter must be internal to the transmitter and must not be accessible from the exterior of the transmitter operating panel or from the exterior of the transmitter enclosure. "
Yes there are radios that "allow" FPP, front panel programming, but with conditions. Many require a deliberate hardware modification, typical diode, resistor or solder shunt removable, and enabling in the radio's programming software. Others require entering a "secret code" to switch operating modes, typical of the Chinese radios.
So, as long as the radio is configured to comply with 95.1761 it is operating under GMRS rules it's legal. The moment this is violated you're not compliant so the transmitter is now operating with illegal functionality and loses it's certification, even if it isn't being used. Of course it can be switched back, in which case the radio again would be in compliance, and the certification once again applies if it had it to begin with.
My Kenwood commercial radios can be modified for FPP, needs the hardware mod and the feature enabled in the software. There is a warning that radios MUST NOT be returned to the end user(s) with FPP feature enabled, so it's disabled in the software with the modified code plug written to the radio. Of course if the radio is ONLY going to be used on the Ham bands it's not a problem.
The problem revolves around the last sentence quoted above. Some feel just because the feature is there then there is no issue with enabling it. The FCC is clear that's not the case. There is no mention that one must be using the feature, the mere fact it's "possible" to access through some action(s) performed by the user is enough to void the certification. This includes changing the "mode" though any means accessible by the user external to the radio, such as pressing a sequence of buttons etc. during power up or any other time.
There is a VERY fine line with switching modes through a sequence of button presses. There is a reason why it's NOT documented, at least for anything an end user gets to read. The user isn't supposed to even know about it. This could be considered a violation of the above section of the FCC rules. If there is any debate it would be over this point alone. Everything else is fairly clear cut IMHO.
- Radioguy7268 and axorlov
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Don't forget about the effect from the apartment's building materials. If you have cement walls there is likely rebar in it, wood and brick may have foil backed isolation in the walls, metal tint on the windows, high lead content glass, metal blinds etc. Some newer construction has sheet metal wall studs in place of the old wood ones as another item. There is a pile of construction material that can screw with a UHF signal.
The building where I work has two of the above, poured concrete walls with a loose metal mesh and the office walls have metal studs. Needless to say the reception is rather poor for weak signals for anything other than a signal a mile or so away, and trying to TX is worse.
Midland petitions FCC for waiver to allow data Tx on non-handheld radios
in FCC Rules Discussion
Posted
They are a business and their main, only, interest is Profits.