Lscott

I would leave it alone. To trim a dual band antenna for another frequency involves more that just shorting the radials. I would recommend you look for a GMRS specific base antenna. Members here have some very good recommendations they can offer.

I think the concession counter is still open.

Good question. This is one of those areas that can be very subjective. Some people will find the audio response satisfactory for a given test sample while another may dislike it. One sample may sound OK on a given radio's RX while on another it won't. Just another wrinkle to think about. The one thing that is important is the microphone's sensitivity. I have a soft voice so I tend to set the "gain" higher, there is a setting for this in my commercial radios, and I don't know if there is anything like that for some of the inexpensive radios. Some radios have an auto gain control function. There is also an audio equalizer for both TX and RX audio in the analog/digital radios I have. Just IMHO the larger speaker microphones the RX auto does tend to sound better due to the larger speaker. The smaller speakers tend to distort the audio at higher volume levels. This is a consideration when the radio must be operated in a high noise environment. In the end it's all about "communication" and so long as the party on the other end can understand your speech clearly that's what really matters.

That's true with every DMR radio I've ever setup. The 16 channel limit, per zone, on the 6550's was a PIA besides trying to figure out what Motorola called stuff verses the Kenwoods I've done. Besides being time consuming it's tedious. Make one small mistake and it doesn't work.

I went back to look at the photos on the site he linked. Sort of weird the radio has a Kenwood belt clip on it. https://reibert.info/lots/radiostancija-r-168-0-5um-akveduk-spec-svjaz.956129/

I guess it could be. I only see one knob or screw thing on the side. The link shows the photos and there are two on the one side. Of course one could be missing. The video resolution isn't high enough to see more details.

Any more theories about the radio? Is there a list of what radios are known to be used by all sides in the conflict there? I've looked at the spec's for the radios used in WWII, Korea and Vietnam. When I watch some old war movies I try to see what kind/model of radio they used. It's shocking how little power output the manpack radios had during those times. Anywhere from a few hundred milliwatts to a watt or so. The radios were really the size of a backpack. Now you get more power and performance out of something that fits in a shirt pocket. https://en.wikipedia.org/wiki/SCR-300 https://en.wikipedia.org/wiki/AN/PRC-77_Portable_Transceiver

Note that a 5/8 wave is NOT a "No Ground Plane" antenna.

Sad, but some inner city school districts wanted to hire teachers who could speak Ebonics so they can communicate with the kids. https://www.pbs.org/speak/education/curriculum/high/aae/ https://www.latimes.com/archives/la-xpm-1996-12-20-mn-11042-story.html

On the NX-200/300 series radios the programing cable should work for the data communications too. The programming software uses the serial port. The wrinkle is when the port is used for data exchange. The port works a bit different. Since it's used to program the radio it's obvious it can't be a "full time" serial data exchange port when you setup the port in the radio programming software. Apparently what Kenwood's firmware does is looks for commands from the programming software running on the computer to start a radio write operation for code plug loading. That has to happen within the first 10 seconds after the radio is powered up. After that the port reverts to the serial data exchange mode. You have to be quick and ready to click that write button when you turn on the radio if you want to load a code plug, or read one out.

I've seen stuff like the item in the link below at swaps from time to time. Has anyone played with one? https://www.ritron.com/dtxm-nx-series-radiomodem-transceiver-nxdn-data-only-protocol

Technically the base of the mount and the metal under the paint form a capacitor. The RF current, for the mirror imaged half of the dipole, flows through that capacitance. The capacitance you get is a function of, the area of the base, space separating the base of the mount and vehicle body metal and the dialectic constant of the material between the two. You would ideally like the that value, capacitance, to be as high as possible resulting in a low capacitive reactance. The lower the effective capacitance, higher reactance, the more it will affect the SWR. You can try shimming up the mount using anything that’s none conductive then check the SWR. Once you get enough space between the vehicle’s body and the antenna’s base the SWR will rapidly go to crap. Some people have experienced poor SWR using cheap magnet mounts with a tiny base on a vehicle that has a thick coating of paint on the metal body. Oh, the increased space between the magnet mount and the metal body will reduce the holding force too. Having the mount break loose at highway speeds usually doesn’t end well.

It's a hobby. People will comment about the money I've spent on my radio collection and electronic test gear. I ask them how much did those new snowmobiles motorcycles and boat, they use just a few months out of the year, cost them. The silence from them is pure gold.

I don't think I've notice that. Next time I get around to playing with the XPR's I'll look for it. Anyway that's cool you can do cross band and cross mode repeat. Do you know if the audio is sent in digital format between the two radio decks or is it analog? I'm assuming it is. Another question can those radios be setup for an auto ID using CW? Just about every radio with builtin cross band repeat I know about has the same problem. No way to do an auto ID. The NX HT's I have include a CW ID function, but it's not automatic. You have to assign it to a function key then press it to send. The screen shot is from a NX-200/300 HT setup. I looked at the P25 radios I have, TK-5220/5320, and they don't have this feature. Sort of odd since at one time you could get Kenwood convert your radio, NX-200/300 <-> TK-5220/5320, from one to the other. I'm told that's no longer offered. I though about how cross band would work using a couple of hand held radios. The coupling would have to be done using analog audio. A lot of processing is done on the analog signal in the course of conversion to digital, then couple that with another from digital to analog, then the reverse on the second radio would result, I would assume, in some serious degradation in audio signal quality. On a different topic how much has this setup cost you so far?

I've played a tiny bit with Motorola's RM just to see what it does. It was automatically installed along with CPS 16. I only have a few radios so the extra work isn't worth it for me. I just have to save the code plugs by radio serial number. I've though about using the Depot software to change the SN on the radios to be the same. Then I don't need to track the code plugs by SN. I'm not using anything that's specific to a radio that's enabled using an entitlement key, I believe, so that might work for me saving the tracking by SN hassle. I did bugger up one of the XPR6580's I have. Somebody had used V2 on it. I saved the tune data for the radio to a file. Then used the Depot tool to force a downgrade in firmware which also eliminated the trunking crap. At this point I had nothing to lose. Apparently you have to get rid of the trunking stuff to use the in-memory edit software hack with CPS 16 to get the radio on the 33cm band. I tried to reload the tune data and found out there is a difference in the number of parameters so it refused to load. WTF!! Boo-hiss. Now Motorola in their infinite wisdom uses the auto tune feature, in their test gear, to setup some of the parameters in the radios. The tune utility won't let you manually adjust those specific ones. Anyway I used the Depot tool to change the serial number to match the good XPR6580 I have. I saved the tune data from the good radio and wrote it to the buggered up one. Yeah some stuff very likely is not optimally set but at lest I have a radio that sort of works I can beat around and try stuff out on. This is why I sort of stick with the older Kenwood stuff.

Even one cable likely isn't enough. I just purchased another cable for some of my radios. I keep a set at home, at work and some to take along on road trips. Then I a have a few spare cables put away. Yes I've had programming cables fail. Oh well,you spend a bunch of money buying radios a few extra for a cable or two, or three...

Just when you thought this would end. We need a wooden stake. This vampire just won't stay down.

At least you get paid for the trouble I assume. Me, it's all on my time.

This is an export for an experimental code plug from KPG-166D for my TK-D300 radio. KPG166D_TK-D300 Export.itm.csv You'll notice none of the zone names are in the file, only identified by the zone number, so importing this data will wipe out my zone names at a minimum. Also other crap gets changed, I think the memories all get set as added to the scan list for example, then I have to go through each one to uncheck the scan add box. PIA. The only thing I found useful about the import function is it saves me the trouble of reentering a bunch of frequencies when building a new code plug from scratch for a new radio model I got. The radio used is in the link here. https://forums.mygmrs.com/gallery/image/255-tk-d300e-fmdmr/

Your idea might have some merit. Doing the manual editing in Excel might be easier than flipping through various windows in the programming software. Reimporting the data also has a nasty habit of wiping out the zone names I’ve assigned and resetting some options back to their defaults. I have to renter all that again by hand.

Not all of Kenwood’s software has an export function, which seems it just a CVS file. I can change the file extension to CVS and Excel reads it just fine. Sorting in Excel won’t help. I’ve already tried this. The exported data had the list entry number on the same line as the user ID’s and talk group numbers. Yes there are two lists. The big one is the talk group one. If you do a sort it looks petty in Excel. When you reimport the data the talk groups get stuck back in the list corresponding to the list number you see in Excel. You end up with exactly what you started with, a mess.

I don’t program up any of my digital radio unless I need to make a change, or making a code plug from scratch, which lately in about never. That can be a PIA when the repeater owner(s) change talk groups and or networks. You discover that when previously working stuff quits working. Then trying to find the info on what is currently supported is a crap shoot. Sometimes Repeaterbook.com helps, if not then you’re off looking for the repeater’s website, if there is one. Sometimes I think the repeater owners change stuff around just to torment people. The way I currently try to keep the mess organized is using one “zone” per repeater. In each zone I use one memory entry per talk group and slot number. The commercial radios I use don’t support front panel programming, like you get with Ham gear, so this all has to be done ahead of time. Some of the radios have the ability to select user ID’s and talk groups from the internal lists stored with the code plug through a menu function you assign to a PF key. The fun starts when adding in more talk group numbers. Those go into a list. The list is numbered from 1 to whatever size the radio software/hardware limits are. When a memory is programmed you use the list entry number corresponding to the entry for the talk group you want. Having a lot of talk groups in the list means constantly scrolling through the list looking to see where it’s at to get the list entry number. Sooner or later the list is a mess of out of order talk groups. Moving the talk group numbers now means your memory setting for the talk group list entry now refers to the wrong talk group. Now you have to manually go through every programed memory and update the talk group entry list number. I’ve done that more that once. There doesn’t seem to be a way to let the software sort the list and update the memory programming.

You might be right on this one.

I feel sorry for them if they are reduced to using cheap Chinese radios in war time. You are literally betting your life on a $25 radio that will likely fail the first time you drop it on a hard surface. It's as sad as these guys at the following link too. https://radiofreeq.wordpress.com/2016/01/19/militia-radio-frequencies/

You may need to do a model if the metal structures are a 1/4 wavelength or larger in size in the immediate area of the antenna. Things like roofs, hoods and so on can affect the radiation pattern. Those structures are approximated using a grid of wires in the model. This is an old model I did looking at the radiation pattern for a 2 meter horizontal loop antenna using a magnet mount on the roof of my old Jeep. I wanted to see if the 18 inch mast they sell with the magnet mount was sufficiently high for good performance. Doesn't look very good. Both photos have the same exact 3D orientation. As you can see there are two main areas of high signal radiation. One is mostly directed skywards, useless. The second in in a horizontal plane, which is where you want it. Because the roof is a rectangle the horizontal part is not symmetrical, more signal in the direction of more metal in the roof.