axorlov

RFI can also come from power wires. This is why I like to run both (+) and (-) directly to the battery, both fused, generous gauge. Even though it is not recommended way to power radio on modern cars.

You are overloading your other radio with your transmission from the first radio. Give other radio to somebody and ask them to walk 100 feet away, then repeat the test.

Posts #5 and #6 in this very thread. Contraption seems to satisfy the FRS requirements.

Modify the RX frequency? To make the pair valid. For example, set DIY-23 RX to 467.725.

The great starting point is here: https://www.repeater-builder.com Another great starting point is here (it is pinned!):

Commercial radios have the on- and off-hook behavior programmable in the software. Very often off-hook is programmed to monitor (i.e. squelch off, tone off), that gives the operator a second-two to monitor before transmitting. But it can be programmed to many other functions, home channel, off-scan, etc.

Yes, it can provide reflective plane to some extent. But important to realize that SWR is just a amount of mismatch between antenna and transmitter. In other words, SWR is not a measure of the efficiency of the antenna. Your transmitter will be happy now, but antenna pattern is unknown.

There is a mess with regards to the antenna models, I see three antennas mentioned, one a "ghost" another two whips. The printouts are for 4505S (what is that? 4503S?), another is for 4505NGPS. Hard to make sense, but lets try. - The shorter whip appears to be MUF4503S, which is 5/8 antenna; - The two-element whip appears to be MUF4505NGPS, which is 1/2 over 1/2 antenna? I can't find a good specs for it, but judging on the length of elements it looks like it's 1/2-1/2. If above is correct, the results for tuned antennas are not surprising. 5/8 antenna will work without ground plane, pattern will be messed up, and gain will be not what it should be when sufficient ground plane is present, but not by much. And, being a single element, it is much easier to tune. That is a virtue of 5/8 antennas: easy to tune for SWR, and they still work under non-ideal conditions. 1/2-1/2 is harder to tune to SWR, due to elements having an effect on each other. Btw, even 1/2 single element is harder to tune than 5/8, it is more sensitive to length. When properly tuned, it should outperform 5/8 with no ground plane, and should have better pattern. It very likely outperforms 5/8 already, with the current SWR 2.3. Do you want to use it as-is or want to tune it more, is between you and your transmitter. I would go with 5/8, it seems good enough. Edit: Looking at the printouts, it looks like tiny bit of shortening of the element of 1/2-1/2 will bring SWR down. You can try to do so when NanoVNA comes and you are familiar with it. And do sweeps and tuning in place, on your fender mount.

Worried about being watched by US and China governments? For the small amount of $120/year one can buy a peace of mind by subscribing to a system that uses quantum computing to protect your phone communications. It's activated on your phone number, and it's invisible! https://www.newcaliforniastate.com/product-page/deaf-1 Revolutionary system. I'm thinking about working with NCS51 to lease a part of their quantum computing time to bring badly needed protection to Baofengs of regular Americans. Price will be bit higher, though. The 11K0F3E emissions require special equipment and tons of research before being ready for full deployment.

China spies on companies, Tesla spies on owners and people around (https://arstechnica.com/tech-policy/2023/04/tesla-workers-shared-images-from-car-cameras-including-scenes-of-intimacy/), Ring spies on you and your neighbors and rats you to cops. Cops spy on you with their license reading cams. Alexa sits here and listens to everything, and never going to stop. One got to be careful these days.

DC blocker is not going to work for sure. Your radio already has this RF switch to protect it's own receiver. These switches are usually based on PIN diodes (here is more info: https://www.digikey.com/en/articles/how-and-why-to-use-pin-diodes-for-rf-switching). The practical solution would be to tap RF input for SDR after this RF switch in your radio. Search on the internet, there are solutions published for some popular radios. It may influence what are you going to buy. Below red arrow shows a good location for my radio (TK-880).

Some short lists were in these two threads:

Unsightly antennas are bad. Put up only good looking antennas, the more the merrier! Your cabin will be gorgeous, and an envy of all neighbors. Your mother-in-law will be glad and will brag about your antennas on her facebook! That's would be tough to cover these bands with one antenna. Tri-band 6m-2m-70cm antennas do exist, but lumping 10m, 11m and 1.25m would be difficult. Antenna tuners also exist but mostly down to 6m. I'm not aware of auto-tuner for 2m and shorter. If it exists, it's going to be expensive. There are manual tuners for 2m - 70cm, but KAF6045 mentioned losses in the coax. 11m-10m-6m could be covered with one antenna, 2m-MUSR-70cm-GMRS with another, and 1.25 is an outlier. Any antenna can receive, but if you want to transmit, you likely will need a dedicated antenna for it.

You are going to answer to Motorola Coca Cola company!

Channel spacing and occupied bandwidth are different things. On narrowband channels, spacing is 12.5 KHz, while occupied bandwidth is usually 11 KHz and even less on some chinese radios. On wideband channels spacing is 25 kHz, while bandwidth is 20 kHz, and on many radios is actually 16 kHz. This is how interstitial channels fit (barely).

Exactly right here^^^. There is a piracy and there is a piracy. I used to work for a multimedia company that suffered bad because of piracy. This is the reason I do not pirate software, movies or music. If I need that game/movie/album too bad I will have to figure out how to pay for it. True and right. But with all that said, Kenwood and Motorola are not in the business of selling software. The intellectual property is not in their software. Violating license for CPS for old model radio is one thing, and manufacturing and selling counterfeit PL2303 chip is different. Like going at 75mph on a freeway vs 65mph in a school zone. Both are illegal, but damage to society is incomparable.

For some reason the original link (https://www.onfreq.com/syntorx/dcs.html) does not work, great thing we have Wayback Machine!

No easy/cheap way to know for sure. The very first test is to disconnect from radio and antenna and use ohm-meter to check for short between center and shield. If there is a short, coax is damaged beyond any hope. You'd need to cut off the damaged section and put new connector. If no short and the coax is of RG type, not an LMR type, you can try to carefully unbend it. RG has much more robust dielectric. The way to test the coax is to plug SWR/watt-meter and dummy load to the radio, and then put your coax between the radio and meter. If there is a huge difference in SWR and/or watts, coax is toasted.

Yes, called DQT in Kenwood-speak. Digital quiet talk. It also supports advanced feature Operator Selected Tone, if you program it correctly.

If it is a stable, close knit group, like a family or hunting buddies, they may have their radios set up for dense areas and for woods. And they don't want to hear any other chatter. Set up once, use forever, assign a button for a "home" channel. It is very fool-proof setup, also safe and practical to give to 5yo. It is how my family radios are set up. If the question is about advantages of DCS vs CTCSS, bigger pool of codes to chose from comes to mind. I can't think of other advantages.

+246, +542, +653, -523, -647, -726 all are the same code. But it's unlikely Motorola will have any of them. More info here: https://web.archive.org/web/20220331074737/https://www.onfreq.com/syntorx/dcs.html

Yes, my experience is the same. UHF goes surprisingly far in the mountains, with no line of sight. But it is lousy in the forest and rolling hills. Better, higher antenna on the trailer would help for sure.

FTDX-101D can't do neither VHF nor UHF. It is certainly not a mobile, in a sense that it would not fit into single-DIN or double-DIN space. Try to look for 6 seconds, maybe?

Yes, you're right. You mentioned it in your other post anyway. Sorry for the noise.

467.xxx5 MHz channels are limited to 0.5W and narrowband for both GMRS and FRS. That are channels 8-14.