Lscott

Some virus software will falsely flag perfectly OK files as infected. I had Norton AV years ago kept deleting the main EXE file for a $4500 microcontroller development environment I tried installing several times that I needed to use at work. I finally had to but the name of the file in an exclusion list to keep Norton from screwing with it. Very aggravating.

Looks like you need to trim your antenna. The question is it too long or too short. If the antenna provides a means to adjust the length a bit try that first. As far as the SWR going up after cutting the coax length down a bit isn't surprising. The SWR depends on how much power is output by the transmitter and what fraction of that at the end of the coax is reflected back by the antenna. A longer length of coax results in less power reaching the antenna and the reflected power, as a fixed function of the antenna match itself, is further attenuated by the extra coax length. The end result is a lower SWR as seen at the transmitter end.

All valid good points. When I was running around the country doing service for a few years I also took my FT-817 with me. Tried to get hotel rooms up on the top floor where possible. Used a small camera tripod to support some VHF and UHF antennas. Made a few surprising contacts on 2M SSB that way.

I was just thinking based on your story about getting out of the path of a hurricane and keeping track of everyone perhaps APRS would be the ticket. You can find info on it here. Basically APRS uses a GPS receiver connected to a radio which will periodically, and automatically, transmit you current GPS position to any compatible radio in the area. This data can also be displayed on a map accessible on the internet so anybody can see your location if one or more of the RX'ing radios has an internet connection. Even if there is no internet access close by APRS can use special APRS digital repeaters to propagate the APRS packets over a very large area. http://www.aprs.org/ Mapping. https://aprs.fi/#!lat=42.6206&lng=-82.9608

If the FT-818 has about the same output filter as the FT-817, I own the original version with the MARS/CAP mod, the power drops fast above the upper limit of the Ham 70cm band. Around 462 MHz it does about half power max, and at 467 MHz lucky to get 1 to 2 watts out of it at best if you are thinking about GMRS access for emergency comm's. Also the radio won't tune above 154 MHz on VHF so even on RX you can't get any of the NOAA weather stations. The later seems to be a big complaint with even the unmodified radios since the market for is is QRP operation while camping, hiking etc.

This is the mod to open up the RX and TX on the above radio. https://radioaficion.com/cms/th-d74-modification-of-the-us-version/

Try looking at the Kenwood TH-D74A if price is not a problem. I have one with the mods to open up the TX and RX ranges, https://www.kenwood.com/usa/com/support/pdf/TH-D74A.pdf I ordered mine from here and they will also do the MARS/CAP mod for you as an extra cost option. https://www.hamradio.com/detail.cfm?pid=H0-015269 You might want to look around a bit for a better price. I paid $550 with no mods when I got it a while back.

If you don't have a good ground plane for the 5/8 wave then the only alternative is using a 1/2 wave antenna, they don't require any kind of a ground plane. You need a really good ground plane for any 5/8 wave antenna to get a good match and realize the slight gain you get from using one.

Oops. The one link is for the repeater. Editing and copy paste isn’t the best on a smart phone when you’re tired. But you get the idea.

One of the first things I do when interested in a model of radio I’m not familiar with is look for any manufacturers brochures. That gives a quick run down on the features. If no luck then look for the user manual, service manuals etc. https://www.ameradio.com/doc/Kenwood_TK-7180_TK-8180.pdf http://www.repeater-builder.com/kenwood/pdfs/tkr-740-840-brochure.pdf

A bigger handheld isn’t necessarily a bad thing. If you use your handheld radio with a moderate to high duty cycle it’s going to get real hot! Some time back a Ham wrote, on another forum, he failed the output stage on his TWICE from over heating due to a high duty cycle. A larger radio has a larger metal sub-chassis, thus more thermal mass and more area to radiate heat. If you look at the typical specifications it shows 5-5-90. That’s 5 percent TX, 5 percent RX and 90 percent standby with no audio for battery life but it can also be applied roughly for thermal consideration.

I don't have any experience with the Kenwood mobile radios so I can't address that question. The Kenwood TK-3170 is a good radio. You should also consider the TK-370G-1, TK-3140-K (Type 1) and the TK-3173-K (Type 1). I have all these models and they work fine on GMRS, repeaters, simplex, split tones (analog and digital) and will program down in to the upper part of the Ham 70cm band. I have a TK-3180 that should be showing up in the next few days from an eBay purchase so I'll see how that works out. The TK-3173 is a TK-3170 but has built in trunking functions, which you don't care about for GMRS, but otherwise they are almost the exact same radio and use the same software. When you buy a used radio try to find out if it's password locked. One of my TK-3170's showed up with a data read and a data write password. That prevented me from reading or writing anything to the radio. It took a while to track down a real "engineer's" version of the software which allows you to blow by any passwords in the radio to read it and then write your own code plug to it. The software also seems to have provisions for "hex editing" the radio's memory and a few other things the normal dealer or end user software won't allow. I also have the "engineer's" version of the software for the TK-3180 just in case there are some "surprises" when I try to program it when it arrives.

If you go that route, two radios, the separate 2m and combo Ham 70cm with GMRS is a recommendation. All of the Kenwood commercial HT’s radios I have all will program down into the repeater section of the Ham 70cm band and most of the simplex section. So I can use just one radio for both services so long as it’s on UHF. When I’m not going to the gym I go for long walks so having just one radio is a big convenience for access to both services.

If the radio supports a STUN function but the user doesn’t have a code entered that won’t work. Of course you would have to know what that code was before hand, which if it’s an unknown user you won’t have it. Changing input PL codes works for a very short time with a determined jammer. It only takes a few minutes curchunking the repeater using different analog PL tones until they hear the squelch tail. There are only around 38 to 40 of them. As far as using an output tone that isn’t that effective either. All my radios, CCR’s - Ham - commercial, there is a provision for entering a RX tone, which I never use. In that case I don’t even care if there is a tone on a repeater output, I’ll hear anything that’s there. The purpose of STUN codes is to disable a lost or stolen radio that you own and programmed. On all of my radios I get used that’s one of the first things I make sure is cleared out. I would suggest using a digital tone, there are more of them. Also using an uncommon repeater access method, like MDC1200, might work out better. The later isn’t that common outside of Motorola radios. Only a few of my commercial Kenwood radios have it for example. One other idea is to also use a non standard repeater split. There is nothing in the FCC rules that requires the repeater split to be exactly 5MHz. The requirements are one frequency from the 467.xxx input group be used and one from the repeater output group, 462.xxx, be used. Any radio that has preprogrammed repeater channel frequencies won’t be able to use the system setup using an odd spilt. In the Ham world I’ve run across a few odd repeater spilts so it’s been done there.

Yup, I have my TK-3170's and TK-3173's programmed up with Ham simplex and repeater frequencies along with the GMRS stuff.

These seem to be rather rare to find, at least for the times I've looked. There was one on eBay a while back but I didn't want to pay the asking price. The TK-3180 with the 450 to 520 split I'm getting looks in very good condition and the seller wanted $55 which includes shipping, battery pack and a somewhat broken antenna, which I have aftermarket replacements. By the way there are a couple more he's selling listed. I have the software installed with the "engineer's key" so I can bypass any passwords that might be on the radio.

I'm thinking about getting a used Kenwood TK-3180-K (450-520) radio to experiment with. How much luck has anybody had getting the radio to work down into the Ham 70cm band? If so how far and any issues with power or sensitivity? The KPG-89D software will allow the out of band entry after clicking the button in the popup warning window.

1) Correct. You do need a good metal ground plane immediately under the magnet mount. It doesn't have to be magnetic, just conductive. If it isn't magnetic then of course it's a bit more of a challenge figuring out how to keep the mount in place. 8-) 2) Not necessarily. A well coupled ground plane on UHF can perform similarly to an NMO type. A crappy NMO install, didn't scrap away the paint etc., may perform worse than a magnet mount. The issue with magnet mounts is they are not recommended for huge mobile antennas. For example I have a dual band on a luggage rack mount on my 04 Jeep. The antenna is nearly 60 inches tall. The wind resistance at 70 MPH is rather high. If I used a magnet mount I would have needed one of those tri-magnet or quad-magnet mounts to keep it on the roof. Also if you read the fine print some antenna manufactures state "Not recommended for magnet mounts" on their large vertical antennas. If you don't want the hassle of worrying about a ground plane for your antenna then look for one that is a 1/2 wave, also the spec's may say "ground independent" too. Those you can stick just about anywhere, they don't need a ground plane, so long as you keep the vertical radiating section away from things like roof pillars etc.

Actually it’s capacitive coupling. The base of the magnet mount is one side of the capacitor and the sheet metal under the paint is the other plate. At times to much of a gap between the magnet mount and the sheet metal results in poor coupling and high SWR. As the frequency goes down, UHF -> VHF -> HF, the problem of poor coupling get worse. Also very thick paint coatings and adding extra padding under the magnet mount base also decreases coupling.

Nothing like have multiple ultra wide-band spark gap transmitters under the hood. Even people who installed two way radios in their vehicles have problems with ignition noise.

Congratulations! You just opened up a world of opportunities to explore. One thing that give me satisfaction is mentoring others by answering their questions and always encouraging others to at least try. It seems that self doubt is what holds back many from trying to take the license exams.

Some AV software allows you to enter a specific file name to leave alone. I had to do this a few times with an expensive embedded micro-controller development package at work and some custom written utility software. Same thing as you, installed it then a few seconds later, poof, all gone. 8-/

As axorlov mentioned the Kenwood TK-2170/3170/3173 radios have a table for 40 tone entries so those aren't much of a problem. The radios do offer "Operator Selectable Tone (OST)" you can assign the function to one of the PF keys on the radio. This allows you to select one of the pre-stored tones in the tone table. The Kenwood TK-270G/370G, TK-2140/3140 radios have only 16 entries for the tone table. Those are of course more restricted. The radios I'm looking at to revise the code plugs are the TK-2140 and TK-3140 radios. With only the option to program in 16 tones I wanted to pick ones the are most likely to be used. By the way the TK-270G, TK-2170 and TK-2140 are VHF radios while the TK-370G, TK-3140 and TK-3170/3173 are UHF. And yes these radios could be programmed through the front panel, BUT you need to remove a small surface mount component off a circuit board inside in addition to enabling the function in the programming software. This is all covered in the service manuals for the radios. After looking at the very inconvenient multi button pressing while powering up the radio plus the rather cryptic multi layer menus you have to go through it really isn't worth the trouble.

I've got several commercial Kenwood radios with provisions for operator selectable tones in a list. The list only has room for 16 tones for the radios I'm interested in at the moment. The question is what are the most popular tones used for repeater access?

Yup, used commercial gear has a lot going for them. I just helped another gentleman on the forum the other day by PM with some sample code plugs for several Kenwood TK-370G-1's, certified for Part 95, he purchased for a group wanting to do search and rescue work using GMRS. Some of those people are licensed Hams and the radio will work on the Ham 70cm band too after ignoring the warning message about entering out of range frequencies each time. And yes the radio will work on simplex and repeaters this way. https://mra-raycom.com/wp-content/uploads/simple-file-list/Specifications/portables/TK-270G-370G-Product-Brochure.pdf A number of people like the newer versions, TK-3170/3173's. http://www.swscomm.com/kenwood/TK-2170_3170.pdf https://www.manualslib.com/manual/2329/Kenwood-Tk-3173.html If you can find any of the TK-3140's they are worth a look too. https://www.ameradio.com/doc/Kenwood_TK2140_3140.pdf