berkinet

It is interesting that note the LT-590 and TH-9000(d) UHF versions are not available on Amazon and it is unknown if they will become available. OTOH, There is a Retevis RT-9000D That appears to be almost identical to the TH-9000d and is in-stock. I mention the availability of the two Bond Telecom brands (Luiton and TYT) because it may hint at an upcoming change in the MXT400. In fact, the Retevis version may represent close-out stock that they purchased from Bond Telecom. Also, FWIW, the Retivis-9000D programming software appears to be the same as the LT-590. Also, just wondering if anyone here has tried to program their MXT400? I am sure there are a lot of interested people waiting to hear.

Could you note a couple.

Thanks for the additional information and the link. It seems there is a lot unsaid here. First of all, is use of the software by consumers even authorized? If it would allow the customer to set the radio to operate in a manner inconsistent with Part-95E. In trying to answer this question, I returned to a post from @Hans in 2018 in a discussion which suggests the MXT400 is really a Luiton LT-590 with modified settings for GMRS certification. With the Midland software already installed, I then downloaded the Luiton software. And guess what, they seem to be essentially the same, with some functionality removed from the MXT400 version. One difference is the Luiton version includes help files. So, I was able to determine that the two settings of the most interest were defined as: STEP = For scanning purposes, the change in frequency between activity checks. (Many options between 5kHz and 50kHz) CHANNEL SPACING = occupied bandwidth (narrow or wide): 12.5, 20 & 25 kHz A few other observations: I noticed PL tone 69.3 is still missing, I did not check for other missing tones/codesThere is a compander option which might help when talking Wide to Narrow band.There is an option for voice scrambling, but it is disabled (and not allowed in GMRS)There is an Optional Signaling option that is also disabled (DTMF, 2TONE & 5Tone)So, all in all I say there are two significant learnings here: The major limitations of the MXT400 (bandwidth and split PL) can be overcome. Any doubt that the MXT400 is a Luiton LT-590 on Prosac have been removed.BTW, I have no way of testing to see if the Luiton software will work on the Midland radio. But, I doubt it. For those who want to pursue this topic, here are a few key links from the Facebook posts MXT400 Programming software: https://www.dropbox.com/s/0lre3ljgt4nopf6/MXT400_Setup_1.05.zip?dl=1 Programming Cables. Original from Midland: https://midlandusa.com/product/dbr1-dual-band-radio-programming-cable/?fbclid=IwAR1Z-VbLD401AXmbUuGRHVHQFGKjURlY-MC709t1deGnfTDUPZQUGbPpyxI and a general purpose cable is available from: https://www.amazon.com/dp/B07D6S2P59/ref=cm_sw_em_r_mt_dp_U_tHfaFbXQ51QZK

It occurred to me after posting the above comment that there are some issues involved that may make the transition to GMRS from CB a bit harder to understand at first. Unlike CB, being roughly 6" long, installation of a basic 1/4 wave ground-plane antenna is easily achieved on GMRS. Likewise "gain" antennas and even multi-band gain antennas are all achievable in designs that will not break every light in a parking garage. This becomes even more straight-forward when you consider that (as noted previously) in the majority of cases, the basic 1/4 wave antenna will be more than adequate. However, the situation in mobile CB is very different. In that case, at 102", mounting even the basic 1/4 wave antenna is a compromise, and all the options involve managing loss, not gain. So, the choice of antenna design, mounting method and mounting location all become critical. This is especially true when you consider the maximum 4 watts of power out of the radio. Anyway, I hope this helps newcomers to GMRS and VHF/UHF in general, ease the entry to the new environment.

And further to @Tsavorite75's question. You can communicate between FRS & GMRS on any authorized FRS channel. That is, all FRS channels are authorized for GMRS, with the limitations @steveC7010 noted. However, be aware that the 8 GMRS repeater input channels are not authorized for FRS and will not appear on certified FRS radios.

When discussing antennas commenters often refer to their antenna as "working great." However, while I am sure the observation is subjectively true, it is a whole different question as to how "great" the antenna is in objective terms. In other words. Unless you test the antennas in a well equipped and controlled environment it is virtually impossible to draw any concrete conclusions. A big part of the difficulty in judging a UHF antenna's performance lies in the nature of how we observe them in use. It is pretty simple, do we get good connections to the stations we are communicating with? Given the nature of UHF, in most cases we are looking to contact stations relatively close to us and would probably succeed with a tuned coat-hanger. A secondary problem, especially for people coming from CB is that FM reception behaves quite differently than AM. AM tends to fade all the way to the point where the noise over-comes the signal. However, FM tends to go from intelligible to non-existent very quickly. Thus, if we receive the signal at all, it tends to be good enough for conversation. There are also a host of other issues, like bandwidth and propagation pattern that may be important in some applications and irrelevant in others. And, finally, there are the mechanical factors ((like corrosion) that are usually only observed after a period of a few months or years. All of which is to say, and this is strictly my own opinion: Unlike the ham low-bands where you can, and in some cased (low-power/QRP) must spend more on the antenna than the radio, for most GMRS uses, that is not the case. The perfect GMRS antenna is probably gong to be the lowest priced antenna that meets your basic communication needs* and is built by someone you trust to make quality products. Unfortunately, in GMRS there is no magic perfect antenna. * terrain (elevation changes), distance, mobil, fixed or portable, power, etc.

That is an interesting report. Unfortunately, I am not really sure what it is you are describing. I am guessing when you say make it split, you mean use different PL tones on transmit and receive. But, I am unclear about open up the band. If this were to allow reception from frequencies outside of GMRS, that would make sense. However, if it means allow transmitting on frequencies outside of GMRS, that would certainly nullify the Part95 certification, one of the major benefits of the radio. So, more information would be much appreciated. Thanks

As noted by Intermod above, reports seem to indicate they are on the main 2 watt/(high-power FRS channels: 1-8 & 15-22). This makes sense since the devices are being advertised as having 1.5 mile range. As to the on the air response. Besides being illegal, it is unlikely to be very effective. Keep in mind the real issue here is transmitters that are, for all intents and purposes, locked on. And, presumably most receivers will be close to the transmitters, probably in the same building. So, because of the FM capture effect, the receiving station would never even know you were transmitting.

This specific product has been reported to Amazon. Maybe something will happen.

It is quite possible the seller is trying to operate under FRS rules. Since we do not know the actual output power, it is possible the transmissions do meet the FRS standard. However, there are a couple of significant problems. First, if being used as a monitoring device, one-way transmission is implicit, particularly if VOX is enabled. But, FCC Part95-B states... § 95.531 Permissible FRS uses. ... ( One-way communications. FRS units may be used for one-way communications that are emergency messages, traveler assistance communications, voice pages or brief equipment tests. So, the promoted use as a monitor is not supported. However, more problematic is... § 95.561FRS transmitter certification. (a) Each FRS unit (a transmitter that operates or is intended to operate in the FRS) must be certficated for use in the FRS in accordance with this subpart and subpart J of part 2 of this chapter. and... § 95.587FRS additional requirements. Each FRS transmitter type must be designed to meet the following additional requirements. (a) Transmit frequency capability. FRS transmitter types must not be capable of transmitting on any frequency or channel other than those listed in § 95.563 [The FRS frequency list]. So, unless they are lying about the radio's frequency band, there is no way this device is legal. Even then, the specific intended usage is not legal on FRS.

I am not sure if this is the specific "duck" reported by Intermod. But, it walks, swims and quacks like it... https://www.amazon.com/gp/product/B07Z3D1N7D/ref=ask_ql_qh_dp_hza The product is described as: Frequency Range: UHF 400-470MHz ,Memory Channel: 16, CTCSS/DCS Using their programming software, available on request, they say it can be set to different channels and VOX operation can be enabled. If VOX operation is enabled, and there is a constant background source of noise, like a TV, it might appear to be on full-time. Since it can operate off of charger power, it could theoretically broadcast forever. It sounds like a basic cheap UHF CCR. Any recourse against the seller is probably gaunt to be fruitless, they will just fold their tent and set up a new one.. However, sales channels, like Amazon and eBay may be more sensitive to legal pressure from the FCC.

That is a commonly cited phrase, but is also not really true. Something that takes your time and energy and falsely increases your hopes, and then delivers zero is quite arguably worse than nothing. However, in the case at hand, it certainly looks like this is a well directed effort. The questions posed in this discussion have been about how it was managed and if it might have been managed more efficiently. Such a conversation is not intended to denigrate or criticize the group’s actions. But rather, to help others who might want to do something like this have a few more ways to think about their plans.

IF aspirin cured COVID-19, the pandemic would be over.

Keeping in mind, older part 90 radios are all wide band, while newer ones are narrow band. Though, some newer radios have the option to turn on narrow banding with appropriate software and/or permissions.

An antenna specifically designed for GMRS would typically be tuned for the middle of the band. Maybe somewhere around 464 MHz. But, a lot depends on the design of the antenna and it’s bandwidth. If you were making your own antenna or tuning one on your own, you might choose to favor the repeater section of the band if you exclusively used repeaters. On the other hand, if you only use simplex you would probably favor 462 MHz. I also wanted to note, though I have never used one, the Midland antennas have not gotten particularly good reviews on this forum. You might wish to look around and see what other antennas people have liked and then pick something that meets your radio and financial needs. But, keep in mind there is no particular advantage to using a Midland antenna with a Midland radio.

I think the core argument comes down to the fact the FCC has described the channel uses for GMRS repeater (and other main) channels as: having an authorized bandwidth of 20 kHz and a peak frequency deviation not exceed ± 5 kHz. However, the regulations go on describe § 95.1771 GMRS emission types. Each GMRS transmitter type must be designed to satisfy the emission capability rules in this section. Operation of GMRS stations must also be in compliance with these rules. (a) Each GMRS transmitter type must have the capability to transmit F3E or G3E emissions. ( Only emission types A1D, F1D, G1D, H1D, J1D, R1D, A3E, F3E, G3E, H3E, J3E, R3E, F2D, and G2D are authorized for use in the GMRS. In practical terms the only two useful types are F3E (FM Voice) and G3E (Phase Modulated Voice), which are essentially the same to the receiver. The other modes allow for AM and SSB and limited data, as permitted in the regulations. Personally, I have never heard on anyone operating AM or SSB on GMRS, but I guess it could happen. So, the FCC has defined maximum channel bandwidth, deviation and transmission types. But, here is the issue, they have not mandated those. So, it is totally permissible to operate narrow band (NB) on any GMRS channel. Now, in practical marketing terms, any company that only markets NB units for GMRS is obviously not going to push or promote wide band (WB) usage. However, since some GMRS channels are designated as NB, it is unlikely a WB only radio would be marketed as it could not transmit on the interstitial channels. Which brings us back to the two experts. In fact, if the statements of the two experts have been reported accurately, the answer should logically be neither or both. If by "is" they mean can be used as, they are both correct. However, if they mean is mandated as, then both are wrong. In fact, I would now say a true expert would not have defined GMRS in such a way and would have offered a better description as is provided by Part95E and the responses to the original question. So, in my mind, the answer is neither expert is correct.

To summarize WPXM352’s excellent response to your question… One of your club members is an expert the other is not.

While the use of an identifier is common, it is not require to meet FCC requirements. Each person operating under the license need only state the license number. Also, while most people follow the identification timing you noted. The actual regulation says every 15 minutes and at the end of each conversation. § 95.1751 GMRS station identification. Each GMRS station must be identified by transmission of its FCC-assigned call sign at the end of transmissions and at periodic intervals during transmissions except as provided [for repeaters] in this section. A unit number may be included after the call sign in the identification. (a) The GMRS station call sign must be transmitted: (1) Following a single transmission or a series of transmissions; and, (2) After 15 minutes and at least once every 15 minutes thereafter during a series of transmissions lasting more than 15 minutes. ...

just a note to those who did not know what field is. It is not just in the US, it is global. So radio operators around the world will be making contact with each other. Usually from temporary locations. I. e. The field.

I strongly suspect that with a good antenna 200 feet in the air attached to a decent radio, and extra isolation on the input, you will not see any improvement at all from a pre-amplifier. In fact, the most visible impact of the preamp will likely be to your electric bill. I would suggest you install the repeater with the extra cam and then start driving around and testing to make sure that your reception is balanced. Then, if you find problems, possibly you might consider adding amplification on the input or output.

This has already been tried and rejected. See: http://www.arrl.org/news/fcc-turns-away-petition-to-allow-hams-to-operate-non-certificated-transmitters-on-gmrs BTW, it has been previously suggested in this thread that price/cost is a factor in certified vs. ham equipment. I am not really sure that is true. It is hard to make a comparison since there are not many HAM single band UHF radios. But, for a rough comparison... GMRS - Midland MXT400 $250 Midland MXT115 & MXT275 $150 Btech 50X1 $200 HAM - ALINCO DR-435TMKIII $230 YAESU FTM-3207DR $169 So, I'd say while the GMRS radios are a bit more expensive, the price difference is not very significant and could well be accounted for by multiple factors like, lower demand, and certification costs. Also, you have to be careful to distinguish between radios manufactured for the ham radio market by vendors like Kenwood, ICOM, Yaesu, etc. and the low end radios labeled as "ham radios" because they are simply uncertified in any service. These include most of the CCRs

There is a MARS/CAP mod. YMMV http://www.hampedia.net/yaesu/ft-60r-modifications-extended-transmit.php

Then I'd keep it as simple as possible and go with the quarter-wave. Just make sure you give it a ground plane. Though, based on your description, even a mag mount quarter-wave on the truck roof should be fine.

1) Yes. It is that simple. just make sure you set the transmit frequency 5 MHz above the receive frequency. Also, initially you may not want to set tone on receive. That way you can hear everything on channel. 2) A repeater sounds like a good solution to your needs. Based on the advertised specifications, the Retevis might be a good candidate. However, I have no personal experience with the radio. As for the antenna, I would want to keep it as simple as possible. If you really are all line of sight to the repeater you will likely get by with a simple quarter wave. Also if the repeater is substantially higher in elevation then the stations that are accessing it, a gain antenna like the J pole might not be a good idea, since they reduce the amount of energy radiated downwards. In this case, the quarter wave would be ideal. Finally, the SamCom does seem to be certified for part 95. The grantee code is 2AIOQ

There are several ways to get elevation information from Google Maps. At the simplest you can just turn on terrain mapping with elevations and you get something like a topo map. But there are other schemes that will give you the elevation from any arbitrary point on the map. Just google something like: get elevation from google map I would have posted a couple of direct links but I’m on my phone and not the desktop so, I’ll let you do the work.