axorlov
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Posts posted by axorlov
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Seems to work pretty well on the video linked below..
Obviously, I can't give full credibility to anybody as I actually don't know anybody..
Start watching at about 9:00 mark on the video.. and let me know what you think i guess.
Mine SW-33 is a lemon for sure. The video demonstrates 3 power measurements (at 4.3W) that are consistent. Mine never gives consistent results when doing several measurements on UHF.
However, I will stand with what I said before about SWR measurements shown in the video: meaningless. Especially on GMRS frequency, where inserting SW-33 lengthens the antenna (actually half of the antenna, check the article posted by Lscott) by roughly 1/8 wavelength.
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Great article! Clearly shows how things change when HT is held vs sitting on the table.
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You cannot measure SWR of HT antenna by simply attaching the meter between HT and antenna. The body of HT coupled with your body is a part of antenna. You need measuring apparatus inside the HT to have a meaningful measurements. Attempts to use regular SWR meter to measure SWR of HT antenna are futile. SWR numbers measured this way are meaningless and junk science (junk engineering).
And on top of that, SW-33 is not to be trusted on UHF, according to my personal experience.
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The good thing about Wine is that you do not need Windows install, unlike when using VirtualBox or VMWare Player. But, yes, it's totally hit and miss with a lot of WIndows software.
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I tried years ago KPG-49D in Wine and failed. I do not remember the exact reason. The first thing to check, especially with USB devices, to identify the /dev/ttyUSB_ that is your cable, and check if the user account has read/write permissions to it. Maybe you will be luckier than me.
Btw, Wine is not DOSBox, but I understand what you are saying. Or maybe I don't. KPG-49D is a Windows application, will not run in DOSBox without Windows installed.
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Not sure if this is the correct place to ask this question.
I have a Kenwood TK-840 I bought new. It is not programmed. I am trying to find out how to program it with reliable information. I did buy a cable that I think will work to program it. I need the software etc and don't know where to turn to do that and any tricks etc that would be helpful to program it.
Any help would be appreciated.
Idajoe33222
WRJZ278
It looks like KPG-25D is the software needed. It's DOS software, so you may need DOS install native or in VirtualBox. Kenwood software is usually can be found on the Internet laying around sad in the rain, waiting for being picked up. Unlike Motorola software.
Chirp does not seem to support it, looks like support starts with 860/360 series. Always worth a try.
And are you sure it's new? The radio was discontinued in the past century or shortly after. If new old stock, however, you maybe have a unit that will continue to work into the next century, for the amusement of your grand-grand kids. Research this MS-DOS or FreeDOS install.
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There is very little science or craft in using GMRS as a tool. Just press a button and yada yada yada till batteries are empty. 5yo can do that. GMRS designed this way, as a service.
There is a lot of science and craft into radio, in general. One of possible good first steps (only if you're interested!) is ARRL study material for Technician license. Most of regulatory stuff does not apply, all technical stuff directly applicable to GMRS.
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One of my tk-880 came with channels labeled like Sheriff-1, Sheriff-2, FD-tac and such. Seller was from Louisiana. It also has a scrambler board inside. I wiped all the programming and did not think of it.
Good idea to put Ham callsign to message block, just in case.
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If you both on mountain tops. Repeaters in Sacramento area can easily be worked from Emigrant Gap in Sierra Nevada with 40W mobile, and that's about 70 miles as bird flies. In fact, I can hear mt Diablo repeaters (K6POU) way into Sierra, that will be more than 100 miles. Though, never tried to work it from that distance. Certainty not reliable, because as the road turns, you lose line-of-sight and communications. But strategically places fixed station, or long hike to the top of local hill will make comms reliable.
- berkinet and wayoverthere
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Interesting article. Some new freqs to put into my scan list.
Side note: the radio on the chest or on the belt provides mild intimidation effect on general population. Even when worn alone and not paired with guns, badges or tactical vests. When I ride my MTB in group or alone, I usually carry TK-3170 (when out with family) or FT1XD (when alone), because of spotty or no cell connection where I usually ride. When others notice the radio on my belt or handlebars, politeness level goes +1.
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Alinco DJ-MD5 and its variants. It is similar to Anytone 686 to the point where some say it's redesigned Anytone. PCB is clearly different (according to pics from internet), but RF/electronics looks identical. Not waterproof.
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The repeater snobs here will quickly point out the weak link in your setup: $70 duplexer + GMRS-V1 front-end. You may end up with massive desense of the receiver. Another potential problem (not obvious!) is LMR-400 - search this forum for details about using it for the repeater duty.
Did you have a chance to test your system already? If it works and you really get 7 miles from base(repeater) antenna to HTs that's great! In my case 7-8 miles is a limit from by base (40W TK800H + antenna at 25') to Kenwood HT. No repeater, just simplex in 1-2 story suburban setting.
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Not everybody has the same goals, or is in the same situation.
Totally true. Usages cases are different for different people. Cobbled-together repeater with cheap diplexer works wonders in the mountains or in the woods where there is no RF interference. 10 miles - sure possible with tall antenna. Even more if you place your repeater in a good place, up the tall tree or high on the hill. Same system will be deaf and mute in urban or suburban setting.
- gortex2, DeoVindice and smalpierre
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bluemax49ers only sells genuine FTDI chipped cables. The cheaper knock-offs are using pirated Prolific chips that rarely work.
He also sells Prolific-based cables, somewhat cheaper than FTDI. I have one CAT interface from him with Prolific. But his Prolific chips are genuine and do work in Windows without problems.
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Lightning arrestor on the coax is an ideal, with short run of #8 wire to the ground rod nearby, but check local codes!
Grounding mast and shield of the coax is a bare minimum, to discharge static electricity, that builds up just from wind blowing. It's not up to electrical codes, though.
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People not answering calls for radio checks is a normal situation. It's not a Ham band, and even on Ham band good luck finding anybody on 446.000.
- Is it Tram 1450? What manual says about adjusting length of the radiators?
- Is your meter appropriate for the 460MHz? Do you use it correctly? Meters require calibration for SWR measurements. It's often easier and better to measure forward and reflected power. You want reflected power to be as low as possible.
To check the feedline integrity, attach dummy load instead of antenna, on the far end of the feedline, check SWR or reflected power at the radio, should be 1:1 or close to it. If you don' have dummy load, Move radiators to shortest and to longest positions, check SWR (or reflected power), see if there is any difference. If there is difference in measurements when moving radiators, chances your feedline is ok. Experiment with radiator length.
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... It is now my understanding that Unity gain would actually have been a better choice for hilly areas?
Depending on how tall the hills are and how close you are to them. It's likely be fine, if they are hills and not El Capitan (https://en.wikipedia.org/wiki/El_Capitan) and you are not at the bottom of it.
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I honestly do not understand fascination with Ed Fong's J-pole. It's clever design, true. It's easy to build yourself if you know how to measure velocity factor of the coax and twin-lead and have tools to do so. But in the form Fong sells it, it lacks important feature: common mode choke. J-pole design is very susceptible for common mode current on the outside of the coax, it's inherent in the design. When you add suitable choke (and do a lot of research if you a newbie), add PVC and mounting hardware, your total cost is about $80.
For GMRS forget Fong's antenna and buy yourself a nice Browning BR-6140. It is unity gain (like Fong's dual band), it has RF choke integrated (unlike Fong's), has N connector (unlike Fong's), has mounting hardware included (unlike Fong's). It's plug-and-play and fool-proof (totally not like Fong's). It's about 24" length (Fong's is 5 feet). What not to like? It's $36 on Newegg! Go buy two, for yourself and your aunt.
And if you're Ham, options are plenty. For example, Diamond X50. It's dual-band (like Fong's), 5 feet long (like Fong's), it's 4 or 5dBi on 2m and 7dBi on 70cm (unlike Fong's), has common mode choke, N connector (X50NA variation) and mounting hardware. It's also plug-and-play. Available at different places for roughly $100. Yes, it's not tuned for GMRS. You will get perfect SWR on ham bands and 1:1.7 on GMRS. So what? Fong's antenna will give you any SWR from 1 to infinity depending on where wind blows from, and alignment of the stars on particular night.
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Do not use RG58U, loss is very significant on 460MHz. Just look at what Lscott listed. Another reputable company that sells cables with connectors is dxengineering.com They have 25', 50', 75' runs of their LMR400 equivalent with with N-connector or PL259. Coax loss charts: https://w4rp.com/ref/coax.html
If radio-cable-antenna-connectors system is well-matched through all the components, the length of the coax will not matter. The 1/2 wavelength cable allows you to tune your device (usually antenna) more precisely with some equipment. Once match achieved, coax can be any fraction of wavelength. So, don't worry about it unless you plan to invest into instruments and knowledge. And 1/2 wavelength on GMRS is roughly 325mm, so quarter-inch less or quarter-inch more and you are out of optimal length anyway. Velocity factor is also needed to be considered... Do not worry about coax length. The shorter the better, but that's it.
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Yaesu VX series are submersible. VX6 is currently available new, VX7 and VX8 are discontinued. These are ham, not GMRS radios. I have Yaesu FT1XD, it is not submersible, but fairly good weather-protected. Build quality is on par with commercial radios.
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There are some (many!) mobile Kenwood radios that are Part 95A (pre-2017), you can refer to this thread for a few examples:
https://forums.mygmrs.com/topic/2183-brand-name-radios-proscons-thread-usednew/
I do not have anything against Motorola or Vertex or Icom, really, it just the original post mentioned KENWOOD. Motorola (thanks Gman, lol!) and Kenwood are covered well on these forums.
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Actually, after re-reading your original post, Steve, I have some additional comments.
I do not have 2m Ham equipment in my cars. I have Kenwood TK-880H-1 (40W) that I use for talking to family when camping and for 70cm repeaters in my area. With Part 95 (and Part 90) equipment you are not going to have VFO, but that seem to be a very minor problem. Repeaters are programmed in advance, 446.000 MHz and few other freqs are pre-programmed too. Lscott covered this already few posts above. There is a front panel programming option with some radios, that do not require a hardware mod, thus not violating Part 95 even in it's stricktest-ever sense.
Linux Users Programming Kenwood 880s
in Technical Discussion
Posted
Solid advice. However, in the specific case of KPG-49D (which is only for Windows) it covers all features of TK-880, like OST, off-hook monitor, button programming, front-panel enabling, firmware uploading... etc, that aren't covered by Chirp.