RickW

From my perspective, GMRS is reasonably equivalent to 440 FM ham radio, except the users in one extended family do not need to all be separately licensed. While full carrier AM would not be that useful, having the enhanced technology of SSB would be significant. I live in a fairly rural area, but at this moment am monitoring CB channel 39 LSB and can consistently talk to some stations 30+ miles away with me running legal power (12 watts PEP) with a Uniden Bearcat 980SSB rig. This is somewhat beyond what some might consider to be line of sight. I can sort of do it on AM, but SSB really helps. Same thing on VHF and UHF. The problem with SSB is that it is a bit more difficult for non technical folks and would significantly add to the cost of the rigs. I have talked to a station on 2 meter SSB with my 4 element beam at only 10 feet off the ground into northern Illinois from SE Wisconsin, if the other station has a fairly elaborate station with a high gain beam well up in the air. This is well over 100 miles simplex. And I can also talk to a station off the side of the beam around 25+ miles north of me when we had a three way. The FCC has loosened up the regulations on incidental use of ham radio for what we used to think of as commercial use. It would be completely acceptable to say, ask my wife to pick up some groceries via ham radio, but I personally would not make this an everyday practice. By the way, today is opening season of deer hunting and this has been the busiest I have heard the GMRS/FRS channels.

We recently purchased several Midland MXT400's and wanted to see how well they performed with different antennas and I thought that perhaps some members might find our test interesting. We used four antennas: 1- 2 meter/440 dual band ham antenna that was reasonably matched for GMRS 2- Modest 6 inch quarter wave mag mount antenna that comes with MXT115 radios 3- Midland MXTA10 12" 5/8 wave "3 dB" gain antenna with MXTA12 NMO mag mount 4- Midland MXTA11 27.5" "6 dB" gain antenna with MXTA12 NMO mag mount The MXT400 has a 6 segment LCD for relative received signal strength which gives at least some idea of the difference in how well you are receiving, in addition to how well it sounds by ear. The base station has a GP-9 2 meter/440 dual band antenna at 40 feet which puts it at close to 1300 feet ASL. The mobile is a Chevrolet Malibu and both rigs were run at Mid level power of about 20 watts. Because we live in the Driftless Area of Western Wisconsin, not far from the Mississippi River, the terrain has been unglaciated therefore has many "coulees" or narrow valleys caused by erosion. Our farm is located on the ridge top and by going only a mile, one can drop down hundreds of feet to lower elevations. Based on actual experience it can be difficult to even access our local 2 meter ham repeater (over 1400 feet ASL) at just 5 miles away when in a coulee at 865 ASL. I went down to the dam of a nearby lake at 900 ASL, about 2 miles out from the farm, but was just barely able to make contact with my wife at the home QTH using Antenna 1 with the antenna on the rear trunk deck with the first LCD segment flickering. This first bar has the imprint of busy. I actually expected no contact, so was pleased that we could at least make contact. Switching to Antenna 2, but now located on the center of the roof, the signals were much stronger and gave us a solid 2 bars at both locations. Considering the lossy and tiny coax, this surprised me since I expected the performance to be worse than Antenna 1. Antenna 3 was located on the rear deck and on both radios, showed 3 bars. Moving it to the roof seemed to make no difference. Antenna 4 was located on the rear deck only and showed 4 bars. This is the antenna I plan to use on the Malibu with plenty of garage clearance. I later set up Antenna 3 on my wife's SUV, but centered on the roof using one of our MXT115 radios which is quite compact and fits nicely in the dash "alcove" which just happens to have an auxiliary jack for powering the radio. Has anyone tested the microvolts of signal needed to light up the various segments on the MXT400 radio? I have an old URM-25D but I haven't done it for over a decade when testing an older Kenwood TS440SAT rig. But it would be interesting to see how many dB's between bars to get at least a rough idea of the antenna gain.

From my experience, when we first got the MXT400's, they only operated on simplex until you change the menu to allow repeater channels. This just adds additional duplicate channels, so that you have both simplex and repeater channels available. After doing this, as you rotate (or scan) through the channels, it displays the lower power channels 1 - 7, then the simplex channels 15 - 22, and then the repeater channels 15 - 22. Thus, if you transmit on a simplex channel, both rx and tx are on the same frequency, but if you transmit on a repeater channel, the required 5 MHz transmit offset is preset. It is different than what I have used for ham radio where a given frequency can be either simplex or a plus or a minus offset, or even a non standard offset. With GMRS since there is only the required 5 MHz plus offset and I suspect they did this to make it simpler for non technical users. If I am scanning, I will hear repeater outputs on either the simplex or repeater channels (15 - 22) assuming I have the correct tone (PL or DPL) set or no tone. If I then wish to stop scanning and use a repeater, I have to remember to use the repeater channels which display an rP on the lower left of the screen. The one shortcoming is that if you set a tone, it works for both TX and RX. I have never come across this in ham radio, but it seems that some GMRS repeater owners use different tones for input and output. If you really want to use a given repeater, the work around is to open the squelch for receive and ignore the repeater output tone, but, of course transmitting the access tone to the repeater. This means that if you are scanning, you will not hear the repeater if you have the tone set. If you do not have a tone set, you would have to select the tone before transmitting in order to access the repeater. This is a bit awkward but could be done.

We wanted to add some HT's to our Midland MXT400's and the BTECH GMRS V1 seems like a reasonable choice considering the extra features it has, especially for the price. There were a few things I wanted to know but you can not contact the dealer by phone, only by email. I did not get a response via their website email, but I later sent the following to Baofengtech.com: Questions on the BTECH GMRS V1 HT: 1. I am seeing comments on discussion groups that the HT no longer has the full 5 watt capability. Is this true? 2. If the power output has been reduced to only 2 watts (equal to the new standards for FRS) why was this done? 3. Wouldn't it be true that the HT can not be used on FRS since it has a detachable antenna? 4. Is there any way to use AA cells rather than AAA since AA cells have around 3 times the power at the same price and for much longer operating time? 5. Any new HT's coming available with AA batteries? 6. Do you sell adapters or short coax jumpers with ability to connect from the SMC to a BNC or PL259 connector? 7. Are you anticipating an imminent price change due to the tariff issues? This was their only response I received today: "The power is 2W on all units; FCC regulations allow 30 channels for GMRS usage per 2017 revision This is a GMRS only radio and is not sold or marketed as a FRA (sic) radio" While they did not answer all of my questions, it does seem that this HT transmits on the 467 MHz interstitials, and so indicates on the specifications.Likely, the power has to drop to the 0.5 watt level for those channels. I had thought that this could not be done with any radios having removeable antennas, but they imply that FCC does allow this. I still don't understand why they would reduce the power to a preexisting version unless they had found that using AAA cells under the higher power may have led to very short battery life. I wish they had made it possible to use AA cells and also avoid the need for the dummy cell if using higher voltage alkaline cells. But, I think we will purchase several and see how they work out. Does anyone have further thoughts on this? Also, can you recommend a source for a jumper to go from the SMC connector to a PL259 that you have ordered from and had good luck? Have any of you felt that just using an adapter is good enough or is that too much weight on the somewhat more fragile SMC (compared with BNC connectors we used to have on HT's)?

Update: I moved the GP-9 to my 30 foot tower, plus 10 feet additional pipe, so it is effectively 15 feet higher than the lower tower due to higher ground plus an extra section of Rohn 25. The feedline is longer, ~ 40 feet of RG-213 type coax to the lightning arrester, then ~ 70 feet of LMR 600 to the shack. The SWR is disguised a bit more, so now on the 462 channels, it is under 1.5:1, but on the higher 467 channels it is right at about 2:1. The sensitivity seems to be quite good on either tower. Even on the lower tower I was just able to detect a Midland 5 watt Micromobile with the magnetic antenna inside another individuals house at over 20 miles away. I am at a high point as is the other station, around 1250 ASL, but I would not have expected that. If I listen on MURS frequencies, I can copy some of the transmissions from HT's used at the "nearby" Walmart at about 7 miles and similarly another business next to them that uses one of the other MURS channels. I have looked for suggestions on tweaking the GP-9 to a higher frequency than the ham designed frequencies, but have never seen anything. In fact, I have never found any information on how to duplicate such an antenna. When I assembled it, I did take a peek at the construction and it is a springy wire that is folded various ways to get the phasing. I would expect that the difference for the higher frequency range antenna is slightly shorter "elements" in the wire, thus impractical to tweak without complete replacement of the wire. A J-Pole antenna has similar gain to a quarterwave groundplane, so perhaps not a practical replacement. The Tram 1486 is only 63" high, so gain is not quite in the same league. Maybe my question should be: What omnidirectional high gain antenna do you actually use for GMRS? And have you compared it with other antennas in an A/B comparison?

Do any members have experience between these two Comet antennas? Or compared with other antennas intended for fairly significant gain on GMRS frequencies? As mentioned in a previous post, I have a Comet GP9 (base antenna) but the SWR is excessive since it is so far out of band and I don't think the Midland MXT400 rigs have power "fold back" for protection so we have been only running the mid power level at the most. The GP9NCA may possibly be discontinued from what it looks like, but it has substantial gain for a consumer priced vertical base station antenna and several vendors indicate some inventory. One other question. Has anyone rigged up an in-line tuner to flatten out the SWR on UHF antennas? I would expect that this would introduce losses, but the GP9 actually performs reasonably well at 25 feet height above ground and I could move it to 40 feet. I have never tried UHF tweaking , but, of course, there are many antenna tuners that we use routinely on the HF bands, but in that case it is more of tuning the antenna "system." Rick

Our family recently purchased a couple of Midland MXT400's. I am trying them out using my GP-9 dual band antenna, but of course the SWR is very high (2.5:1) since it is far from the design frequency. The heat sinks don't get very warm with say a minute or so key down at high power setting, but I wonder if anyone has run this type of rig and damaged the finals at these SWR levels. Although I recently joined the group, I have been reading the mail for the past year or so and I know that there are some very accomplished technical experts here with a lot of practical experience. Thanks for any help or suggestions. Rick W