Lscott
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Posts posted by Lscott
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2 minutes ago, Sshannon said:
That’s pretty common. Some repeaters use phased antennas that direct the pattern downward.
You can see that in the antenna specifications referred to as "Down Tilt" angle. The purpose is to direct a bit more power closer in to the base area of the antenna. Otherwise the signal strength can be a bit poor close in but much better once you get some distance out from the repeater site.
Both of the antennas in the attached datasheets have no down tilt. However look at the beam width specification. The higher gain antenna has a VERY narrow one, 14 degrees, compared to the lower gain one at 27 degrees. Something to consider before buying.
DB408-B Product specifications.pdf DB404-B Product Specifications.pdf
- SteveShannon, gortex2 and VETCOMMS
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4 hours ago, gortex2 said:
Sorry but if a guy doesn't want someone on his repeater then he doesn't need to allow them on it. Granted profanity on it isn't correct but he has no requirement to allow users on his repeater. This isn't ham radio. Many forget about this.
There are some "closed" amateur repeaters. You have to be a "club member" to use them. Granted they are rare but not unheard of.
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9 hours ago, Sshannon said:
My wife gets around with Pride Elite GoGo scooter. As far as I can tell I never see any RFI and even when my 100 watt radio is transmitting it doesn’t appear to interfere with it.
That's good news.
I have stumbled across a story where a guy was running 1KW in their mobile. When he keyed up it would kill the engine of the vehicle next to them. Yes it's a very rare occurrence but does happen.
I'm surprised this topic doesn't get discussed more often. As the electronics contents of vehicles goes up the "potential" of interference to or from the vehicle's electronics increases. And with EV's that get even more concerning. I'm sure manufactures are doing a good job of EMC testing and shielding, but nothing is perfect.
- WRXB215 and SteveShannon
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10 minutes ago, Adamdaj said:
Thank you for giving me an answer! I was just trying figure out you typical Power Wheelchair or Mobility Scooter would issues with the use of Two-Way Radios.
The majority of Airports or Railroad Terminals use Terminal Carts, which are Electric Vehicles. Of course, the operator uses their 2-way radio. However, I'm not sure if I have facts right when it comes to a two-way radio while moving. Does it effect, all electric vehicles or only wheelchairs and mobility scooters??
Like I said in my question, I know that don't have any issues with talking and moving at the same time. I wouldn't use an old AM CB, because AM would definitely pick up motor RF and add hum.
If I'm rambling on, please shut me up. I apologize for sounding like why I asked this question in the first place. I
I would suspect that the use of an FM radio would be less of an issue from a receiver stand point. However the RF generated could, in theory, could even jam an FM radio. I guess the real way to find out is get a radio and just try it. Basically any kind of motor controller can cause RF trash to be generated. The higher the voltage the controller uses the more likely the noise will be greater in amplitude. Also the closer the radio is to the motor controller, motor or interconnecting cables the more likely you might experience a noise problem.
People have had issues with electric fuel pumps over the years. Usually a capacitor and or ferrite installed on the wires by it works in some cases to cure the noise problem.
Somebody else was asking about fuel injector noise. Fuel injectors use a moderate high frequency AC signal on the main signal that activates the fuel injector. The injectors use a solenoid to force fuel into the cylinder. The solenoid shaft has a habit of sticking. The moderate high frequency signal, manufactures call it a "dither current" I believe, that very slightly vibrates the solenoid shaft to keep it from sticking and could be a source for RF noise.
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20 minutes ago, Adamdaj said:
Specking from someone who uses a Mobility Scooter and has a bit of knowledge of RF and RFI, but I tend to ask how my experience is different than the manufactures.
I been using Hand Held Transceivers while driving my scooter for years without RFI to the motors. Of course, Manufactures warn owners don't 2 - way radios, because the RF from the radio can effect. Individuals use their Cell Phones while driving, Of course, they're not driving on streets and interstates like regular vehicles. then while crossing heavy traffic streets, I guess no one should holding anything, but the Tiller. I never had any issues that caused malfunction to the motors on any scooter that I drove.
That's a very good question.
Lately the auto manufactures want to eliminate AM radios from their vehicles. I strongly suspect there is much more to it than a simple cost cutting measure. I'm even more suspicious when an EV is involved.
My professional work experience involves designing high power switching inverters for metal heating at high frequency. I know first hand just how much electrical RF trash these things generate. I also consult with a buddy who does work over the years on EV motor drives, very similar in design principle to what I do. In his case they have to do extensive EMC, electromagnetic compatibility, testing.
The AM radios are amplitude modulated receivers in the frequency range of 550KHz to 1600KHz. Some of the EV motor drives operate up to 150KHz in some cases. The harmonics from the switching waveforms can easily end up in the AM radio broadcast band. I think the manufactures just want to eliminate the AM radio option rather than spending gobs of money trying to shield the motor drive inverter electronics so it doesn't trash the radio in the dash. If it's not there then there is no complaints they have to deal with fixing.
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1 hour ago, wqrh320 said:
I know this is an old topic, however I just purchased a TK-3173-K off fleaBay and its locked where I can't read it or write to it with a blank data archive allowing me to change frequencies. I have the Kenwood Version 2.40 of KPG-101D software but need details on the "dealer/engineer serial install key" mentioned at the start of this thread. Any input on how to make this radio programmable would be greatly appreciated. Thanks
See your private messages. I sent you the info on how to do it. I've had other password locked radios off or eBay. It sucks when you get one unless you have a way to remove them.-
Oh, the TK-3173 is a very nice radio for GMRS. Its basically the same, uses the same software as the TK-3170, but it also includes trunking. If you have a Ham license you can program out of band frequencies in the radio, the software with generate a warning but will accept the entry, allowing you to put in some Ham 70cm repeaters.
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After doing some reading I would not recommend a TYT TH-9800 radio for Ham or GMRS. While they are a neat radio they apparently suffer from various issues. One seems to be failure of the audio amp chips from an over voltage condition. I have a buddy and his just had the audio die on one side the other week. See the linked YouTube video for one such failure and how the tech fixed it and added the parts that TYT left out to save money.
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1 hour ago, Sshannon said:
Are there any digital voice protocols that don’t require a proprietary codec at least? (If I’m saying that right…)
Here’s one example of an open source codec.
https://www.rowetel.com/wordpress/?page_id=452
Note that the open source mode dPMR has bits that tell the RX radio what codec is in use. The mode allows up to 4. One could be an open source version like the above. See attached file.
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1 hour ago, NavyBOFH said:
I will check in as I can but look forward to seeing what everyone says about this.
I’ve posted this before. You might want to download it for a good read if you haven’t seen it before.
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9 hours ago, WRKC935 said:
I know that someone brought up using a trunking controller that would look at radio ID's
I'm on another forum where somebody asked about getting the frequencies used on an NXDN trunking system from just the radio handset. They wanted the frequencies used just to scan. One poster said that's impossible without access to the system key file, available only from the trunking system admin. It just so happened one used radio I purchased came programed from a trunking system. The normal radio software won't read it without the key file. Well, I had a hacked version of the software that allows me to read the radio and save the info as a service file. I posted screen shots of the frequency lists etc. just to make a point that nothing is hack proof or secure as you would assume as far as the trunking info goes.
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9 hours ago, Sshannon said:
2. If you don’t know what that screw is there’s absolutely no reason to think that it is related to your picket fencing problem.
Yup. Many radios have been wrecked by application of the "Golden Screwdriver".
- SteveShannon, WRWE456 and WRUU653
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On 10/10/2023 at 6:15 AM, WRKC935 said:
I would have to wonder how many of them tried to eat 'Tide Pods'.
When one of the young generation tells an older person they don’t know what they are talking about and gets reminded that eating Tide-Pods is not a good example of a high IQ. My question to them is what is their favorite flavor of Tide-Pod?
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19 minutes ago, WRTL946 said:
Could/would we be able to get a message from New York, all the way to California?
Well the national organization that represents Hams, ARRL, has its roots in just such an activity. ARRL stands for Amateur Radio Relay League. In the very early days of spark transmitting messages were passed from station to station cross country. That was just about the only way to communicate long distances in those days.
Even today there are emergency Net practice sessions on the VHF/UHF Ham bands, and on some HF ones, where one of the activities is traffic passing of messages.
- Raybestos, SteveShannon, WRXB215 and 2 others
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1 hour ago, WRKC935 said:
High gain antenna's will cause issues when close into the repeater if it's a lot higher in elevation.
That’s why some expensive high gain repeater antennas have a “down tilt” specification. These antennas are specially designed to direct a bit more of the power downward closer to the antenna site. That improves close in repeater coverage.
https://www.repeater-builder.com/antenna/downtilt.html
https://www.kpperformance.com/Antenna-Downtilt-A-Practical-Overview.html
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2 hours ago, AdmiralCochrane said:
Never thought of that.
Also neglected to understand capacitance load of plain open circuit paired wires until I watched a Youtube by AlphaPhoenix challenging people to predict the action of electron flow in a DC branch circuit with open and closed branches.
What you learn quickly the real circuit is not what the schematic shows. When you include all the parasitic elements it’s gets a lot more interesting. The higher the frequency or when transient events are important you can’t neglect them.
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4 hours ago, Sshannon said:
Ok.
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3 hours ago, Sshannon said:
I would use the coax. It’s not perfect but it’s not terrible. It’ll prevent you from getting an swr better than 1.5:1, but most people are satisfied with that.
You forgot about the necessity of cutting off those crummy F-connectors, replacing them with “N” type or PL-259, if you can find any that fit that coax size, or finding the correct adapter.
I think you’re better off installing the correct antenna and coax and save yourself the extra hassle. -
If you're definitely using your GMRS radio in Canada then you should be aware of the Industry Canada, their FCC, rules. They are closely similar to the US FRS rules. Per the Annex E specifications GMRS radios in Canada are restricted to no more than 2 watts ERP, effective radiated power. That's a significant restriction.
Canada GMRS-FRS Rules.pdf Canada FRS - GMRS Channels.pdf Canada Annex E - GMRS and FRS.pdf
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If you’re going to do any significant driving through the west side of Canada you may run into what are called “radio controlled roads” which are on VHF. That might be more of a use to you than the Canadian version of GMRS.
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It would be a very good idea to wait a few months on buying a TH-D75A. Let everyone else do the beta testing. By then Kenwood should have a good idea where all the remaining software and hardware bugs are and have a fix for them. I wouldn’t be surprised to see the radio go through several hardware revisions before getting to a stable design.
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10 hours ago, Sshannon said:
No, because the offset is always 5 MHz
There is nothing in the rules that requires this, but it's the general practice.
https://www.customsmobile.com/regulations/title47_chapterI-i4_part95_subpartE_section95.1763
A few repeater owners have selected a frequency pair from the 462 and 467 groups that are NOT an exact 5MHz offset. That was done to discourage some users, with fixed programed frequencies in their radios, from accessing the repeater. While that will "tie-up" what amounts to 2 "repeater channels" and may not be well received by other repeater owners it's not illegal under the current GMRS rules.
https://wiki.radioreference.com/index.php/Offset
Same with tones. A few owners have required the use of MDC to access the repeater in an attempt to limit unauthorized access. Most of the common Chinese radios can do CTCSS or DCS but not MDC, thus cutting them off from the use of the repeater. The are a number of the more expensive new/used commercial grade radios do include MDC functionality other than Motorola. See attached example brochures.
https://en.wikipedia.org/wiki/MDC-1200
TK-2360-3360 Brochure.pdf TK-5220_5320 Brochure - 1.pdf NX-1200_1300 Num 1.pdf NX-220_320.pdf
- AdmiralCochrane, WRUU653 and marcspaz
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5 minutes ago, Sshannon said:
The proposal Gil posted is a change because it will allow mobile radios to do similar functions.
It's bad enough people are trying to poke at their vehicle's touch screens, or playing with their smartphones, while driving. Do we really need another distraction for the driver?
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1 hour ago, WRXH658 said:
if so, how do I do it without distorting my audio?
You very likely can get a purpose built repeater controller for a lot less money unless you "happen" to have a PLC laying around someplace.
Otherwise the cheapest thing you likely can use is like the example linked to below.
https://www.robotshop.com/products/ardbox-plc-20-analog-modbus-industrial-arduino-module
Which would you prefer?
in General Discussion
Posted
By some reports it's already happening, unofficially. I guess FCC will have to deal with this sooner or later. One can either get on the bus, get run over by the bus, or just get the heck out of the way.