Lscott

I’ve got a couple of DMR radios. I haven’t really did much with them to date. The D878UV has another firmware release out and been too lazy to do the update. The other radio is a TK-D340, a 32 channel (2 zones of 16 channels each) commercial radio. The small amount of monitoring I’ve done I ran into a VERY ANNOYING problem where people don’t get their audio levels adjusted right. One station comes in at a low level, crank up the volume to hear them, then the next station’s audio blows me out of the chair. That gets old after a few minutes.

I’ve got a couple of DMR radios. I haven’t really did much with them to date. The D878UV has another firmware release out and been too lazy to do the update. The other radio is a TK-D340, a 32 channel (2 zones of 16 channels each) commercial radio. The small amount of monitoring I’ve done I ran into a VERY ANNOYING problem where people don’t get their audio levels adjusted right. One station comes in at a low level, crank up the volume to hear them, then the next station’s audio blows me out of the chair. That gets old after a few minutes.

Oh, I advised a buddy at work to buy a new battery pack for a used radio he just got. I recommended he let me test the used pack that came with the radio. He mentioned it lasted all day scanning so he wasn’t that interested in having it tested. It’s very easy to get fooled by a crappy pack if you judge it by how long the radio stays alive scanning. When the radio is scanning with no audio the power drain on the pack is at the minimum. Even a pack with 20 to 30 percent capacity may work that way for hours. One of my NiMH packs I thought was good, because I can let the radio scan nearly all day, tested at only 732 mAh on a 1800 mAh rated pack! I ordered 2 new 1800 mAh packs since I have 4 UHF radios and 5 VHF radios that use them. They don’t sell Lithium Ion packs for these radios and the OEM chargers only handle NiCAD or NiMH types. All my other radios can use the Lithium Ion packs and the OEM chargers work with them.

Oh, I advised a buddy at work to buy a new battery pack for a used radio he just got. I recommended he let me test the used pack that came with the radio. He mentioned it lasted all day scanning so he wasn’t that interested in having it tested. It’s very easy to get fooled by a crappy pack if you judge it by how long the radio stays alive scanning. When the radio is scanning with no audio the power drain on the pack is at the minimum. Even a pack with 20 to 30 percent capacity may work that way for hours. One of my NiMH packs I thought was good, because I can let the radio scan nearly all day, tested at only 732 mAh on a 1800 mAh rated pack! I ordered 2 new 1800 mAh packs since I have 4 UHF radios and 5 VHF radios that use them. They don’t sell Lithium Ion packs for these radios and the OEM chargers only handle NiCAD or NiMH types. All my other radios can use the Lithium Ion packs and the OEM chargers work with them.

How did you evaluate the cells? I started off cheap using a bunch of paralleled power resistors with a 3-1/2 digit multimeter to measure the voltage on the pack. I timed how long it took to run the pack down to my lower voltage limit with a stopwatch. Since the pack’s voltage drops during the test I just used the average pack voltage and resistor value to calculate the average discharge current. It wasn’t very accurate but it told me if a pack was worth keeping or headed for the trash bin.

This is a topic I haven't seen discussed very much. I've been testing a huge pile of used battery packs accumulated from purchasing used radios. Two main types I have are Lithium Ion and Nickel Metal Hydride. They range in capacity from 2000 mAh to 1480 mAh for the Lithium type and 1800 mAh to 1200 mAh for the Nickel type. I don't want to have anything to do with the old Nickel Cadmium types. All the sellers that include battery packs typically state the packs are in unknown condition, meaning they have no idea of the remaining usable capacity. Because of that I usually don't consider it of any extra value in evaluating the sellers price for a used radio. If I get a good one I consider myself lucky. The testing was done using an electronic load, which has a built-in battery test function. I found about 40 to 50 percent of the packs tested at 80 percent or better of the specified rating that appears on the battery case. The rest were at 60 percent to a low of 23 percent, basically good for a quick radio test or just junk status. Typically the accepted value of anything below 80 percent of new the pack is considered EOL, end of life, and should be replaced. While that's OK for business use it gets expensive for hobby uses. For me at least I have an idea of how much use I can expect to get out of a given pack. I marked the measured capacity in mAh's on the pack, the percent of the nameplate rating and the test date on each pack I have. So given a fair number of people use HT's how many really have evaluated their "fleet" of battery packs? I know some of the more advance chargers can "recondition" packs and test them for usable capacity. I see all sorts of sellers of OEM battery packs on eBay, typically very expensive, and far more economical battery packs sold as "unbranded" and direct replacements for the OEM ones. The better prices of course are from the Chinese sellers, or from US importers of Chinese battery packs. I have read stories where it's not uncommon to buy one of these cheap battery packs and discover later they "don't seem to have the capacity" claimed on the case. However without some quantitative testing it's just an opinion. So has anybody done their own testing and found a seller that has a good price and the battery packs really do meet the specified ratings and are reliable? You might have the best radio manufactured, but if the battery pack is crap, dies just when you need it, what good is the radio?

Were the testes performed using the OEM supplied antennas or did you use any aftermarket types?

Read the manual for the radio first.

Most likely they do. I have some Kenwood TK-3160's and the some what newer replacements for them the TK-3360's. They definitely will do repeaters along with wide and narrow band on a per channel basis. The programming is fairly easy but you do have to understand what all the options do in the radio. For that you can read through the help file for the programming software. For a simple to operate radio you can't beat these. http://www.longislandradio.com/Kenwood%20Product%20PDFs/Portable/TK-2160_3160.pdf https://www.kenwood.com/usa/Support/pdf/TK-2360_3360.pdf If you buy one be VERY CAREFUL which sub type you get. These radios come in several different frequency ranges on UHF. You want one that covers at least the 462 MHz to 467 MHz range. With only 16 channels this isn't a big limitation since channels 8 to 14 the power is limited to 0.5 watts and narrow band only. Not really that useful. That leaves 15 GMRS channels left. You can program those in the radio with one spare memory slot left over.

The TK-3173's are the same as the TK-3170's except they also do trunking, which for GMRS you don't care about anyway. Both use the same software to program them, KPG-101D Version 2.40. http://www.secomwireless.com/KWLIT/LIT_TK-3173.pdf I really never consider the inclusion of a battery pack that great of an extra value unless the seller states it's new. I have at least a dozen used Lithium Ion battery packs that fit the above radios, from past purchases, and several more Kenwood models. I'm in the process of testing them for capacity using an "electronic load" with a built-in battery test feature. So far the best pack tested at 79% of the spec's on the back of the pack while the worse so far is at 23%. The typical figure of 80% of new rating is generally considered the EOL, end of life, for a battery pack. This is the equipment I'm using for the pack testing. https://www.amazon.com/Siglent-Technologies-SDL1020X-Programmable-Electronic/dp/B07RS2B8VT The packs are tested at a "C/5" rate with the low cutoff voltage of 6.00 VDC. There isn't much variation in capacity if a lower discharge rate is used with Lithium batteries. The 6.00 VDC cutoff is where the Kenwood HT's will shut down so there is no point in testing to a lower voltage.

He got that deal about a week or so ago on the TK-3170 as an auction. I picked up 3 TK-3173’s, 2 at $40 each with shipping and one for $30 with shipping. The $30 one needed a volume knob, which I had. None had antennas or battery packs. I already had those. If you want a good deal on eBay you have to check several times a day. Then jump on a good deal when you see one.

Excluding the specific low cost radios, typically of Chinese manufacture like the 805, Baofengs and their derivatives etc., which HT's from the major manufactures seem to be popular choices to use on the GMRS band? I'm more interested in the use of commercial, LMR (Land Mobile Radio), types. I typically use Kenwood radios because I have the programming cable and accessories for them, and they are mostly interchangeable between the radios. Also I've had very good luck finding the manufacture's programming software, which seems to work up to so far on Windows 10 with no real issues. The radios I do have for use on GMRS are: TK-370G-1 (128 channel, wide and narrow band) TK-3170-K (128 channel, wide and narrow band) TK-3173-K (128 channel, wide and narrow band) TK-3140 (250 channel, wide and narrow band) TK-370-1 (32 channel, wide band only, Chip seems to work OK for this radio to program it) A buddy, licensed GMRS only for the moment, here at work was complaining about his high power Baofeng radio. He felt the receive wasn't working well on it, poor sensitivity. I explained the radio uses a cheap "radio-on-a-chip" design and the poor performance wasn't unexpected. After all what do you expect from a $25 radio? I suggested he get a good used commercial quality radio model I recommended. He picked up a good used TK-3170 which included the antenna, battery pack, speaker microphone and charger package on eBay for $65. I gave him a code plug I built for my radios and the software to get him started. The Baofeng programming cable works just fine on these radios. He immediately commented on the quality of the radio and he doesn't get the interference he experienced frequently with the Baofeng. He travels frequently, mostly driving, for work and I'm sure he is going to be happy with how this radio works compared to the Baofeng.

I've been collecting HT's for the past year or two. If I find a good deal on one I can't help myself. I have enough to equip a small army.

You can try looking here. https://www.repeaterbook.com/gmrs/index.php?state_id=none

Well you'll likely EMP proof in that case as long as you're indoors.

I've had good luck using my old dual band Comet CA-2x4MB, no ground plane required, on the Jeep. On the GMRS frequencies I get 1.3:1 at 462 MHz, 1.05:1 at 464 MHz and 1.5:1 at 468 MHz. On the 2M and 70cm Ham bands the match is good. Surprising it's OK on the 5 MURS frequencies too. I have another one I've used indoors, never been exposed to the outside weather, and performs about the same.

On another note I have heard of Hams building a cross band repeater using a couple HT's and a small duplexer. Fly the drone up really high on field day for some DX contacts. Also ran a power cord up to the drone from the ground to give it more "air time". I think some cell phone companies do this on an emergency basis to restore service at times too.

You would reed a really long mic cable for that. 8-))

I second berkinet's points. The fastest way to get the attention of the local FCC is running high power on the 0.5 watt FRS frequencies. When they can hear you 10 miles away with full quieting they'll know something isn't right. You'll know when you've been found out when the knock on the front door occurs with the black SUV parked out front.

Have you considered a ground mounted push-up mast? If you don’t use the radio often you leave it down when not operating. https://mfjenterprises.com/products/mfj-1906hd

This just came out on YouTube, a review of GMRS hand held radios. https://youtu.be/TYUZJUhVCuk

That's why I recommend people use the official manufacture's software, at least for the commercial radios, since Chirp doesn't cover many of the features the radios offer. For other radios it's just plain buggy. I tried it with a Kenwood TK-270G and TK-370G radios. No good. Channels wouldn't program or disappear when trying to use the zone feature. The import function didn't work etc. As far as I know it's still broken.

Well on the antenna side for the mobile you can look at the following: https://cometantenna.com/wp-content/uploads/2013/09/CA-2x4SR.pdf I have a buddy at work with one installed on his pickup truck. The SWR is under 2:1 where he operates on GMRS when I checked it for him. The match is better towards the Ham band on 70cm. On VHF the match is really good on the Ham 2M band and on the 5 MURS channels. The trick with this antenna is it needs a really good ground plane since it's a 5/8 wave design. If you don't want to go that route then get a good Ham dual band antenna and a cheap simple 1/4 wave for GMRS. A 1/4 wave GMRS antenna is about 6 inches tall. By the way 1/4 wave antennas have a wide bandwidth and the radiation pattern is much broader giving better coverage when in hilly terrain. Some people go with a 1/4 wave for GMRS for just that reason.

Me, I got into GMRS after having my Ham license for some years because it was “there”. It’s another means of communications. Now I find it easier to get people interested in radio if they don’t need to “take a test”. Later some change their mind and want to get their Ham license so taking the Tech Class exam isn’t so intimidating and there is a motivation to do more than talk on a few channels on a UHF only radio. I have a buddy at work who got his Tech license after talking to him about it for a while. Another buddy at work has his GMRS license. I can talk to either one but they can’t really to each other except on the CB. Now the Ham buddy is looking at getting the GMRS license too. The GMRS buddy is still thinking about getting his Tech license. Then we all can sit around and talk on the CB. 8-(