Lscott

That’s a wee bit outside of my threshold of financial pain. I guess I’ll have to do some more poking around on the USGS site and see if there is anything remotely like the service you have.

What source are you using for the topo maps to get the elevation data?

There is an open source project for solving transmission line problems using Smith charts. I was alerted by a fellow Ham and EE who uses it. https://www.w0qe.com/SimSmith.html

You might want to check with a local Ham Radio club. Many members have various types of antenna measuring equipment and one of them likely would he happy to help check it for you. You may be in for some luck. The last weekend of June is Field Day for Amateur Radio. Many groups, even single operators, setup in local parks, parking lots etc. and operate off of portable/emergency power power. It's a good place to meet other radio minded people and somebody I'm sure has the equipment on site to check your antenna system out. Oh, don't be surprised if somebody suggests getting your Ham License. http://www.arrl.org/field-day

Run 4 watts.

That's a nice chart you did. Anyway what you pointed out you'll see elsewhere with the FCC rules where the language isn't clear. There is another area on the forums for FCC rule discussions. If you have further questions that area that would be the place to get answers and a lot of opinions.

I believe that is correct. The FCC has them reserved exclusively for repeater inputs. This link is a nice summary. https://en.wikipedia.org/wiki/General_Mobile_Radio_Service The link below is the most current version of the Part 95 sections. For GMRS you want subpart E. https://www.ecfr.gov/cgi-bin/text-idx?SID=85a15d2032f9f51fa68cef9b9657e610&mc=true&node=pt47.5.95&rgn=div5 I have stuff like this printed out as PDF files, stored on the computer and smart phone along with all my radio operating manuals for easy reference.

This is what the FCC has to say about it when the rules were last changed: § 95.1767 GMRS transmitting power limits. This section contains transmitting power limits for GMRS stations. The maximum transmitting power depends on which channels are being used and the type of station. (a) 462/467 MHz main channels. The limits in this paragraph apply to stations transmitting on any of the 462 MHz main channels or any of the 467 MHz main channels. Each GMRS transmitter type must be capable of operating within the allowable power range. GMRS licensees are responsible for ensuring that their GMRS stations operate in compliance with these limits. (1) The transmitter output power of mobile, repeater and base stations must not exceed 50 Watts. (2) The transmitter output power of fixed stations must not exceed 15 Watts. ( 462 MHz interstitial channels. The effective radiated power (ERP) of mobile, hand-held portable and base stations transmitting on the 462 MHz interstitial channels must not exceed 5 Watts. © 467 MHz interstitial channels. The effective radiated power (ERP) of handheld portable units transmitting on the 467 MHz interstitial channels must not exceed 0.5 Watt. Each GMRS transmitter type capable of transmitting on these channels must be designed such that the ERP does not exceed 0.5 Watt.

Sort of a silly question but did you check to see if the repeater requires a PL tone to access? If it does and you don't have one set, or the correct one, the repeater won't do anything.

I have 4 of the TK-370G-1’s and 2 of the TK-370-1’s. The later are just 32 channel regular FM only. Both are Part 95 certified I believe. The TK-3170-1 are nice, Part 95 certified, if you can find any at a reasonable price. The antennas are either the ones they came with, eBay or local Ham swap, the rest are from a cheap 5 pack I purchased from an eBay seller. I did do an SWR scan of the cheap 5 pack ones and was surprised the SWR was comfortably below 2:1. I was hoping I didn’t get a “50 ohm resister in a rubber stick”. Yea there are a few like that around. When mobile I use a high gain dual band antenna. It has low enough SWR across the Ham bands and the GMRS frequencies. The antenna is almost 60 inches tall. Comet no longer makes this model. I wish they did. I’ve had two for nearly 20 years. One is on the Jeep’s roof rack the other is used inside when I lived in an apartment. That one has never been out doors. Still looks new. CA-2x4MB, 4.5 dBi on VHF, and 7.4 dBi on UHF

Thanks for the info. I was fairly sure there wasn't a problem. I was interested in tweiss's opinion since he seems to think it's an issue based on a rather broad comment in his post. I used myself as an example where I was sure it wasn't doing exactly what he said likely was. Maybe there is something that he's seen, read or whatever where it could be. The FCC's rules are not always that clear cut about what's permitted and prohibited. No harm in trying to find out.

Were would the problem be for example in my case out of curiosity since I’m doing exactly the above? I’m licensed for both services and use a Kenwood TK-370G-1 which is Part 95 certified, unmodified and has a full front panel keypad. The radio is not enabled, through hardware and software, for front panel programming. However it is programed for both GMRS simplex channels, a couple of GMRS repeaters and various local UHF Ham repeaters.

I have the D878UV HT. The radio itself seems to be mostly OK and not a bad value for an analog - DMR HT. The main issue I have is with the darn programming software. One version they fix a number of outright bugs. It's good for a version or so then they bugger it up again. It's really frustrating. It's like there is no quality control and no version control. You would figure once they fix a bug it would stay that way, nope. I reamed their tech support out over this issue several times by email. Of course it's all in China so how much do you think they are going to care. I haven't even bothered to load the latest firmware release. I did try the radio programming software. Some stuff they fixed the other things that I noticed they didn't bother with fixing. 8-/ Normally when they do an update they issue both a new firmware file for the radio and a new version of the programming software. They likely need to do this because the memory layout changes from one version to the next for the code plug. The notes say to save the code plug using the old version then reload it using the new one. The last update was so bad they had to issue an update just for the radio programming software. Right now the radio sits around and I'm not actively using it. I'm waiting to see if they finally get their act together. I'm just about done with the bugfest. Now about the 220 band. The activity seems to be hit or miss depending on the area. Where I'm at, Detroit metro location, I haven't noticed much use. Other places I hear it's popular. If you can get a radio that includes it without a significant cost premium I would say go for it. The reason why it's not more common is the band is not a world wide armature allocation like 2 meters or 70cm bands. Most manufactures don't want to include it because it is pretty specific to ITU region 2 which is where the US is located. That leaves out about 2/3'rd of the world wide market. One other thing. You can find amplifiers easy enough for 2 meters and 70cm. Good 220 amps are hard to find. I've looked for used ones at Hamfests and haven't had much luck. The ones I have seen are beat to crap and or the seller thinks it made of gold with a price to match. The only cheap FM one I have seen is from Btech. I've read some mixed reviews on them. Basically it's just to boost the power from an HT. I've thought about getting one for my Kenwood tri-bander, TH-D74A, the price is cheap enough considering. https://baofengtech.com/amp-v25 Dual band antennas for 2 meters and 70cm are also easy to find. The two bands are harmonically related, 70cm frequencies are approximately 3 times 2 meter frequencies. That makes designing dual band antennas reasonably easy to do. However 220 is not. So finding a tri-band antenna for 2 meters - 220 and 70cm are not that common. One example is the SBB-224/SBB-224NMO. http://www.cometantenna.com/amateur-radio/mobile-antennas/ma-tri-band/ Most likely you will get a good dual band 2 meter and 70cm antenna and a separate one for 220. Then you use triplexers and patch cables to split out the 220, or just use a coax switch to flip between the antennas. https://mfjenterprises.com/products/mfj-4936s?_pos=2&_sid=060a07025&_ss=r

If you want something smaller and likely cheaper look at this one. This one is a bit over 6 inches tall. https://www.pctel.com/wp-content/uploads/2018/11/Product-Datasheet-25.pdf Check out the model PCTCN4347. This is pre-cut, tuned, so you don't need to do anything. A generic one where you have to cut the whip to tune it is here. https://www.theantennafarm.com/catalog/pctel-maxrad-pctcnmft-5913

I'm not sure about the exact model radio you installed. Many of the Kenwood's will program down into the Ham Band even if the software pops up a warning about the frequency being out of range. Most of the simplex and repeater operations on the 70cm Ham band are between 440 MHz and 450 MHz. I have a collection of HT's, 4 watt radios TK-370G-1's, that work down to a bit above 440 MHz I use for both Ham and GMRS. With a 1/4 wave antenna the bandwidth can be rather large. I built a small one out of some stiff bus wire and a BNC connector. The SWR was below 2:1 from 430 MHz to 470 MHz covering the usable section of the Ham 70cm band and all of the GMRS frequencies. If you can do that with the antenna you installed, and the radio will program down low enough, you can have access to both services on UHF with just one antenna and radio. Most radios work fine as long as the SWR is 2:1 or less. Not a bad deal if it tunes right. You can do a frequency sweep and see where you're at. If the low SWR point is a bit too high you can get a replacement whip and cut it a bit longer to try to cover the GMRS frequencies and as much of the Ham 70cm band as practical. Good luck on trying to get your Ham Tech Class license. The test is pretty easy. I went to a Ham swap once many years ago with my brother, who was already a Ham, just to look at some test gear, and he offered to pay the fee if I sat for the Tech Class test. I had no idea he was going to ask me try try it. I said OK it's your money. Surprised, I passed with no studying!

That does look like a neat install. How easy is it to get up on top to remove the antenna when necessary? I assume you have a cap to screw on the mounting base when the antenna is removed to keep out the elements.

The problem with a virtual machine is only the Pro versions of Windows 7 has the necessary features. Same with Windows 10. If you have the Home versions then you need to install a 3’rd party virtual machine manager. There is an excellent open source, free, you can down load called VirtualBox. I’ve run Windows 3.11 on DOS, Win98SE, Win NT4, Win2000, WinXP, Win7 Pro and Win10 Pro in it. I’ve also ran several versions of Linux too and one of the last releases of IBM’s Warp4 OS. All worked. https://www.virtualbox.org/

Here is another post. "The last release of 1225 for conventional and 1225LS for trunking available on MOL both work with Windows XP but will NOT work with XP 64bit or any flavor of Windows 7 (and probably Vista if anyone is foolish enough to own that OS). You can, and I do, run every legacy version of Motorola software except DOS versions in an XP virtual machine on Windows 7 and they work just fine. You need the last release of both LS and regular, earlier versions won't do it. I do this for a living where time is money and radios have to work every time. Trust me. If you need to retain DOS compatibility there are literally hundreds of very nice laptops, including Toughbooks on broken-stolen-radios.com (ebay) that will do what you need for under $100. Dedicate a laptop, format it for DOS 6.22 and be done with it. This is why when local hams need their Syntor X9000s programmed they know where to come, I have the correct gear, and it works."

I found the following posts elsewhere that might help you. "f this is still of interest to anyone, I just used a full day in trying to program one of these. Finally, W7 or its XP mode did not work in any guise or compatibility mode. The only way I got this Ver. 3 program to work was to install a virtual Windows 95. Even then, only the serial port -based Chinese RIB worked, my RIBless USB-to-RJ45 did not work even if Win95 recognized it. This took a day to learn on my own cost. Microsoft changed their understanding of RS232 communication in DOS 4.1 and again in abandoning the DOS kernel in XP, this is how I try to comfort myself. My lament is that when my Dell 5100 laptop wears out, programming of many 'legacy' telephone exchanges and radios etc. that only accept DOS operating system -based programming software becomes challenging." "Get version 4.0. Although I havent tried it with Windows 7, it works just fine on Windows 98 and XP."

Think carefully about drilling a hole for an antenna mount. Most recent manufactured vehicles the sheet metal is rather thin. A through hole mount such as an NMO has a small diameter hole to support it. If the antenna gets whacked by a tree limb or from a low overhanging obstruction etc., the torque from the antenna exerted on the base and thus the surrounding sheet metal can be huge. There are stories where the mount ripped through the sheet metal or severely warped it. There has been damage reported just from the torque due to wind resistance driving at highway speeds when large really stiff antennas were used. If you do drill a hole I would first research for a good way to reinforce the area around the mount location to eliminate damage to mount and or vehicle sheet metal from driving and minor antenna strikes.

That's likely very true. I'm in the Detroit area and there is a wide coverage area linked repeater, UHF - VHF, on top of the tallest building around, the GM head quarters building. The antennas are up at 728 feet. You might get into the repeater at 40 miles more or less. That should give you some idea. http://www.gmarc.org/wp/ This is the estimated UHF coverage zone map. http://www.gmarc.org/wp/uhf-repeater-coverage/ And this is the estimated VHF coverage zone map. http://www.gmarc.org/wp/vhf-repeater-coverage/

Just a guess but the QYT is likely restricted to only transmit on the Ham bands. If that’s the case radio may generate an error tone or flash some kind of visual signal, screen message etc., the frequency is out of range.

You can go to this site and experiment with putting in different heights for the antennas. http://www.hamuniverse.com/lineofsightcalculator.html The resulting range is just an "estimate" of what you're likely to get. There are a number of hard to define factors that also figure into range calculations. So take what you see with a grain of salt.

When looking at an antenna system you need to consider at least two things, coax loss and your antenna gain. At UHF coax loss can be rather high for the typical type most people tend to use. It's a trade off between cost and cable loss. Less cable loss the bigger and more extensive the coax will be. I see many going for LMR-400. The loss at 450 MHz, GMRS is 462 MHz to 468 MHz approximately so we're close enough for this example, is 2.7 db per 100 feet. So if you have a 30 to 40 foot high tower or mast on the house you could easily use 75 feet of cable from the antenna to the radio. That works out to 2.03 db of loss so only 63 percent of your transmit power makes it to the antenna! What you would like to do is pick an antenna that has enough gain to make up, so to speak, for the cable losses at a minimum. A quick note here on gain, or loss, of every 3 db represents an increase by a factor of two, or a loss by 1/2. So a gain, or loss, of 6 db would be an increase by a factor 4, or a loss by a factor of 1/4. Now we have some things to look at very carefully with antennas. You will see antenna gains shown as some gain followed by "dbi" or "dbd". If it isn't shown or mentioned it's most likely in "dbi". The two gain spec's are NOT the same. The gain spec'd as "dbi" is the gain above a theoretical and impossible to build isotropic antenna. The gain spec'd as "dbd" is the gain above a dipole, really amounts to a 1/4 wave antenna on a ground plane. Think a cheap 1/4 wave magnet mount. The gain in "dbd" for a dipole is 0 while using "dbi" it's 2.15. Remember this is exactly the same antenna! Manufactures like to use the "dbi" spec because it inflates the gain by a couple of db. If you're not paying attention a cheap antenna rated in "dbi" may appear to be as good as a more expensive one rated in "dbd". Dishonest, no, but you need to be educated about what the spec's mean to make a good purchasing decision. So for example you might see a 1/4 wave antenna spec'd as 2.1 dbi. Hummm... Now getting back to the issue with cable loss you need a real gain of at least 2 dbd just to break even due to coax losses in the above example. Ideally you would like a lot more. Of course the antenna will be larger, longer, and more expensive. As the gain increases, it's usually at a spec'd center frequency, as you depart from that ideal point the gain tends to drop off. You want one designed and tuned close to center of the band of frequencies you want to operate on. In you case around 467 MHz to 468 MHz which are the repeater input frequencies for GMRS. I'm sure some members here have good recommendations. Also search past posts on the forums here for info.

Just for fun I looked for some info on the Kenwood TK-8180 or TK-8180H radio. It looks nice. What I noticed from the Kenwood brochure there are two band splits depending on model "type". Either one will work for GMRS, however if at some point you have a desire to get your Ham license, the Tech Class is very easy, then the "type 2" is what you want. It will work over the complete Ham 70cm band AND the GMRS frequencies. https://pdfs.kenwoodproducts.com/28/TK-7180&8180MPTBrochure.pdf From some notes elsewhere on the Internet you can program the "type 1" radio down into the upper part of the Ham Band, 430 MHz to 450 MHz, but the VCO has problems locking to those frequencies. Seems like the trouble starts around 441 MHz to 442 MHz. Below those frequencies the radio likely won't work. The "type 2" radio is spec'd from 400 MHz to 470 MHz. GMRS runs from about 462 MHz to just under 468 MHz. So this model could be used for both services when programmed correctly. That saves having two radios. If it was me I would get the "type 2" since I'm dual licensed, if you can find one. I'll guess most are the "type 1" radios. Looking at a few eBay listings the sellers don't make it explicitly clear what model they are selling. Sometimes the description is just plain wrong. Look very carefully at the FCC and nameplate stickers in the photos. The model number may show something like "TK-8180H-K" which doesn't appear in the manufacture's brochure so its a bit questionable which "type" it is. My guess would be a "type 1". Oh, you do want to make sure it has an FCC ID tag. First with the FCC tag, and the certification number on it, you can check to see what parts the radio is certified for. Additionally in the grant the frequency ranges the radio is certified for along with the bandwidth and power are listed. That's serves as a check on whatever the seller claims as the spec's for the radio. Second as an example I ended up getting a hand held radio a while back that was a European model, didn't notice it had no FCC ID tag. The radio needed a hard to find version of the programming software. The radio worked fine once programmed. Further the code plug for the European model and US model I have can't be swapped. There were some feature differences that made the code plugs incompatible so now I have two separate codes plugs instead of one for the two radios.