Alec

Hi Frank, I can understand your frustration but try to not get discouraged and stay excited. Things will get resolved. A random consideration: In many areas, depending upon the number of GMRS / FRS users in the area, communicating via simplex can be a real challenge. The 462Mhz/467Mhz frequencies used for GMRS channels are typically only capable of line-of-sight communications. Factor in buildings, trees, foliage, terrain and other things that tend to absorb signals in that frequency range and distance for 2 respective ground stations becomes quite limited. Obviously, this is why so many GMRS users tend to focus a lot on mountain/tower/building top repeaters. But in terms of getting an accurate signal check and test of your equipment, you are, IMHO, probably better off using simplex because when you do, people will be hearing your radio signal directly and not the signal of some presumably higher-powered, elevated repeater. If you can hear people talking on the non-repeater channels 1 thru 14 then you are almost certainly hearing simplex radio transmissions and chances may be good that if you are in range to hear them, they would be in range to hear you! If you hear someone on a simplex channel and attempt to communicate with them but do not get a response (assuming they are not just ignoring you!) the issue may be the other operators are using CTCSS or DCS sub-tones. IOW, it may not be your radio that is the issue, it may be the other person's radio that is the issue. The use of these sub-tones or "privacy codes" as they are often improperly called, restrict the user's radio to only hearing (breaking squelch) when that specific matching sub-tone is detected by the receiving radio. This creates the illusion that the conversation is private because unless the transmitting radio is sending out the correct matching sub-tone the receiving radio won't open squelch and play any audio. The majority of repeaters require a specific CTCSS or DCS sub-tone. So, your radio may be transmitting just fine in terms of distance, but the other GMRS users are not hearing you because of a specific setting on their respective radio. While the use of CTCSS or DCS codes on simplex is routinely discouraged many people do use them because they think it makes their conversation private. Additionally, some radios ship from the factory with CTCSS or DCS codes pre-programmed, so people just take the radios out of the box and start using them having no idea that these sub-tone codes are in use. So don't get discouraged too quickly. Some GMRS radios or scanners have the ability to display if a CTCSS or DCS tone is being transmitted by another radio and if you can detect this, it may allow you to set your radio to use the same sub-tone and make it "heard" by others. Doing tests of your mobile equipment with another handheld radio and a friend where you control the settings is the easiest path to take. If you need to rely on the assistance of other random people, then you must consider how the other person's radio might be configured. Good Luck! BTW, there is nothing wrong with talking to random people via GMRS! A random person may turn out to be a friend you just haven't met yet.

Hi Paul, Many radios on the market, including the Tidradio H8, ( I own one too) have the ability to receive on frequencies or bands that they do not have the ability to transmit on. This is why you were able to program frequencies into the radio that you can only receive and not transmit and it allows the device to be used as a frequency or channel scanner. At the risk of stating things that you may already know, here is a bit more explanation. The transmit frequency range(s) are locked by the manufacturer in the firmware or software of the radio. This is most often done so that the radio remains compliant with the certification for that device which has been granted by the regulatory agency for your country under their respective rules. I am not familiar with the regulatory entity in Australia so I cannot speak to that entity or their rules, but for example here in the USA frequency allocations and things such bandwidth, as how much transmitting power may be used etc. are defined and regulated by the Federal Communications Commission, aka the "FCC" and often radios sold here in the USA are FCC certified for use in a specific band that is defined by a "part" or section of the FCC rules code. For example, a GMRS radio here in the USA would be authorized under part 95 of the US FCC code and in order for the device to be Part 95 compliant or certified the radio would be required to adhere to certain frequency restrictions, band widths and power levels, etc. In many cases the radio might be capable of transmitting on other frequencies or bands or use more power etc., but these software imposed restrictions prevent that from happening so that the device can be compliant with those rules associated with specific uses. Some devices can be "Unlocked" to remove these artificial, software imposed, restrictions. You mentioned that you were considering getting your HAM radio license. In the case of the Tidradio H8, if you purchased the HAM version of the radio and not the GMRS version, that specific device does have the ability to be unlocked (Google it). However, while unlocking the device may allow it to transmit on the HAM frequencies and GMRS frequencies (or as you referred to the CB frequencies) that does not mean that the device is certified or authorized for such use by your communications regulatory authority, and you may or may not be licensed to use all the frequencies that the device is capable of working with, so be sure to do your homework about your local rules and requirements.

I agree with the previous posts that the most probable culprit is that the RT15 radios are using CTCSS or DCS Codes (see page 6 of your RT15 manual - I found it on the Retevis website here: Retevis RT15 Mini Lightweight FRS for Business Radio, usb charging, license free walkie talkie). Page 1 of that RT15 manual shows a diagram of the radio and according to that diagram the radio has a "Monitor" button on the side just below the PTT key. If you long press that button, it should, temporarily bypass any pre-programmed CTCSS/DCS tone code squelch. So, if you have all radios on the same channel (avoid channels 8-14 as your base station probably will not transmit on those channels) then long press that Monitor button on the RT15 while you transmit on the Midland GMRS base station and you hear the base station radio transmission come thru the speaker on the RT15 you will have pretty much confirmed that the issue is that your RT15 FRS radios have factory pre-programmed CTCSS or DCS Codes enabled. To solve this issue, you will need to reprogram these RT15 FRS radios to remove the use of CTCSS/DCS tone codes. As has been suggested by @AdmiralCochrane, you could also program your Midland 105 base radio to use the same CTCSS/DCS codes as the RT15 are using, but personally, I would not recommend that approach as doing so will limit your ability to communicate with others. Hope that helps.

Sorry, I should have been more specific. It's a 2018 GMC Sierra

From what I've observed magnet mounts seem to be rated in terms of "pounds of pull strength" which appears to be a rating of how many pounds of pressure or pull is needed to remove the magnet. Again, just casual observations on the various magnet mounts offered for sale via Amazon suggests that the larger the magnet mount diameter the more pull strength it tends to have. I would guess that getting a larger diameter magnet mount or one with more pull strength (or a smaller antenna with significantly less wind resistance) might allow you to overcome this issue of the mount slipping. FWIW, I've a GMC Sierra and use a magnet mount with a 32" whip, with no issues. But hey, I'm not a certified magnetologist, so your results may vary.