KAF6045

The subject line is misleading. TYT is NOT part of Hytera -- and was even sued by Hytera when they were marketing under the name "Tytera". https://www.listcompany.org/Quanzhou_Nanan_Tyt_Electronics_Co_Ltd_Info.html Doesn't seem to have any company names related to the list https://www.fcc.gov/supplychain/coveredlist I couldn't find any sites in Google that implied Tyt was a subsidiary of any other company that might have been on the list. Hytera was put on the list in March 2021 (at that time, Hytera was banned from providing equipment to public service and security systems, but wasn't prohibited from general public -- the November 2022 report seems to change that to reject any filing for certification). Note that the FCC list includes Kaspersky anti-virus products. This all came about as part of an effort to protect the Internet (routers -- especially those with an ability to redirect packets to other addresses, I think; maybe DSL modems, WiFi access points) https://docs.fcc.gov/public/attachments/FCC-20-176A1.pdf

My Icom ID-5100 reports 14.1V when the engine is running -- and that's after going through the 10ft of heavy gauge wiring I had to splice into the provided power cable (total power lead run is something like 18ft --Battery in front left of Jeep Liberty, along fender, through firewall, alongside "running boards" (inside door trim), up through gap in back seat, into the middle of the covered storage well, where the radio itself is attached).

725 is listed as a MEMBERS ONLY repeater, with no posted tones. (Trying to find the 550 but I'm getting an error message on the database look-up) Northwest Houston 725 Name Disabled by Owner Access Requests Members Only (Free) Type 462.725 MHz Frequency Unlisted Input Tone Unlisted Output Tone Online Status 25 Miles Range (Estimate) 8 months ago Last Updated

Please cite those other sections -- I didn't see anything other than 15.247 covering communication devices, and the section heading explicitly states that it applies to the 902-923 band. Other parts of the regulations do cover the band, but NOT for communication devices (CAT scans, for example). I interpret it as: heading - (communication) devices in 902-923, (a) then restricts those devices to frequency hopping (or digital). It does not leave an opening (in my view) for non-frequency hopping (/digital) operations. Amateurs have access on a secondary basis and must accept any interference from ISM devices, and must not cause interference. They appear to be the only ones not required to use spread spectrum.

I strongly suspect the limit is imposed by the RF Exposure calculations: HTs are either body worn (with speaker/mic) or held within a few inches of the head -- SAR measurements are done to ensure the RF energy is below the limit for the frequency in use... In the most sensitive frequency bands, that necessitates a lower power.

Commercial air band runs from around 118 to 136MHz. (Military is around 380MHz) And yes, it is AM. There is reason for that. Unlike FM -- which has a "capture effect", where the strongest signal becomes the only signal that is "tracked" by the receiver; AM will let all signals on the frequency through. This is desirable because it means a distress call can be heard even while there is a communication going on between ground control and an aircraft.

You have confused frequency band (CB) with channel bandwidth (GMRS). GMRS operates on 462/467MHz (approximately 60cm). CB is ~17 times longer in wavelength, and with only 4W output, probably won't be seen by a GMRS antenna. Conversely, even with a 50W transmitter, the CB antenna is unlikely to capture too much of a signal. (The mag-mounts on my rust bucket are only about 18" apart). Of course, if you're really concerned, the solution is to STACK the antennas -- one a few feet above the other -- since the beam pattern is minimal off the end of the antenna, and maximum off the sides. And likely intended for mobile installations where flexibility is more important -- who has room for 9913 with roughly a 1ftx1ft area needed to make a 90deg bend.

The keyword is at the end of (c)(1)... That word is AND... It is not a case of either (1) or (2) -- Both clauses must be true. Since the authority of the individual license is limited to immediate family, they are identifying with the licensee's call sign... IOWs: ALL users of the repeater are operating under the single call sign, and those users are properly IDing. Third party users do not meet the requirements of (1).

First part of 15.247: Note that the purpose of frequency hopping is to minimize interference to other users; using a single frequency with a wider bandwidth may interfere with multiple ISM systems.

I'd have to concur -- that display has "LogMag" traces for both single port (s11) and dual port (s21), a Smith chart showing complex impedance, and something for phase (shift?). I'd suggest starting simple -- one trace, configured for SWR, and again -- test using the antenna only until comfortable with reading the device.

"PL" is derived from Motorola "Private Line" -- which is anything but private; a radio with no receive tone set will hear everything on the frequency. To the rest of the world, it is CTCSS (Continuous Tone Coded Squelch System). As that long name implies, radios with a receive tone set will not open squelch unless the transmitter is sending the tone. DCS (digital coded squelch) is a bit of a newer scheme -- rather than just a tone on a frequency that most receivers will filter out (so the listener doesn't hear the hum), DCS sends a digital sequence using some set of tones (1 and 0).

Use the antenna as a learning tool -- that's a single port connection. Duplexer might become a two port connection.

In the unified channel numbering scheme -- "channel 16" is a SIMPLEX channel transmitting on 462.xxx. That handheld either needs a channel marked something like: 16rp, or similar -- or the radio has repeater channels labeled as 23-30 (15rp-22rp), and you want channel 24 (16rp). Or was that "16 4" supposed to be "16 r" for repeater. If so, I have nothing to suggest. Your photo shows a green LED and signal strength meter; most radio's I own use green for RECEIVED SIGNAL, while the other rig is showing a red LED (typically used for transmit). It's as if the receive and transmit radios were reversed.

Most all traffic above 6m is FM. The 2m SSB segment is just 144.100 to 144.275.

Be advised that the /base/ RT97 does not have an ID system -- without it, the repeater is limited to "immediate family" using your callsign to ID (thereby IDing both themselves and the repeater). Note the "AND". Clause (1) "authority of the individual license" basically means "immediate family"; clause (2) thereby means users IDing with that license. Clause (2)

How are you connecting the unit? What sweep range did you set? What plot type? There's a lot that "can not get any reading" doesn't answer. We would need to know the exact steps you took with the device. For an antenna (reflected reading), you should be connecting to port 1, and port 2 should be left empty, and you need to ensure it is set for reflected measurements, not a through (port 1 to port 2) measurement.

450/455 likely indicates the frequencies that particular duplexer is currently tuned for. To use on GMRS may require retuning the input to 467.6 (approximately middle of repeater inputs) and 462.6 (repeater outputs). The other range indicates what it could be tuned to.

There is still the matter of educating the buyers of those bubble pack radios as to some protocol to follow... Something akin to https://www.mdarc.org/activities/emergency-communications/wilderness-protocol

What is not clear about... (page 5 of the manual) 22 simplex channels, 8 repeater channels. 87 receive only SCANNING channels Page 18-19: I suspect that "55" is a typo in the manual, and should be "31". ADDENDUM: Channels 1-30 are fixed frequency in order to keep them in line with the FCC consolidated FRS/GMRS channel numbering scheme. Modification is likely limited to bandwidth, CTCSS/DCS tones

Regardless of "club" or "group" -- the repeater operates under one individual license, and that licensee must manage use of the repeater. The funds to maintain the repeater can come from "club" members (are you making this a private repeater, or will it be open to the public during non-emergency periods? You might fall under both (3)(i) and (3)(ii) -- somehow). Note that your government entity does not qualify as a "participant" ("other persons eligible in the GMRS" -- the government entity is not eligible for a GMRS license -- and if they had a grandfathered license, it can not be modified for new frequencies). The government entity could provide a site (maybe for a nominal lease), could install a tower for antennas (especially if it has some LMR license and want to relocate their dispatch/repeater equipment), maybe a pair of shacks (one for their equipment, one for the GMRS repeater gear), have power run to the shacks (likely with independent meters so they can bill the GMRS group for power used by the repeater). They could set up a small EOC with a GMRS radio -- but that radio would only be usable by licensed individuals, not general staff. Then there is the negotiations on /how/ the equipment will be used in an emergency (net control, chain of command for moving traffic, etc.) with concomitant training of the participants in procedures.

95.305(e) doesn't exclude state and local governments -- but the rest would restrict them to grandfathered licenses... Such as the Grand Rapids 575 repeater (which is not "public" though did post a CTCSS tone for /emergency/ use [back in 1997 repeater guide]). https://wireless2.fcc.gov/UlsApp/UlsSearch/license.jsp?licKey=195998

I have a few radios using similar programming software, and the port selection dialog comes up greyed out for them. I had to use the Windows Device Manager to locate the COM device in question, and then manually change the Windows assigned port # to match the one the programming software defaulted to. As a result, I have something like two or three different adapter cables for the radios all assigned to COM 1 -- meaning only one cable at a time can be connected to the computer. Tones do nothing to prevent transmission... But mismatched tones can prevent /reception/! Tones are used to open the squelch on the receiving device. However, if the transmitter is set for repeater, the receiver will not hear it -- they are on frequencies 5MHz apart. Both devices need to be set for simplex -- try channels 1-7 in the unified channel listing as they are simplex only with a 5W ERP limit (you may also want to ensure both radios are set to the same bandwidth; wide FM, not NFM).

If said government entity has a grandfathered GMRS license (and maybe not even then -- if their license didn't specify a repeater [back in the day I believe such had to be declared on the license application], no changes are permitted) -- the FCC no longer issues licenses to organizations/businesses/etc. If they don't, the repeater will have to use the license of some individual person acting as the trustee of the license -- that individual would be responsible for the repeater's operation. The trustee will likely be an employee (possibly who ever is already in charge of tech stuff). If they leave, the government entity will have to find a new trustee (with different license) and update the repeater ID system.

While focused on marine band, http://www.boat-project.com/tutorials/vhfant.htm, may offer some insights. For ground-plane, it implies one needs a solid grounding route from antenna and/or radio through to the aluminum hull.

I'd prefer a larger ground plane for 1/4 wave. A 6.5" square or disk is about right (for the low end of GMRS, repeater inputs would be a tad smaller).