Does good for what it does, and cost $$$. Not a Yaesu or Kenwood of course, but keep the transmissions short, and common sense on SWR's..3+ years, almost daily use..never a problem.
I wouldn't say it does what it claims though. Box might claim 25w, but i doubt it peaks over 8 watts when hooked to a power meter. But that is pretty typical for chinese radio's.
Almost all these Chinese radios do about 10% below claimed power. I measure 22.5 watts at high power on my KT-8900D. It sounds like you have a blown final and you're just seeing the driver output power (if you actually measured anything at all). @@nikushim6665
@@va3-gfy618 Wow! What an incredibly ADULT response you gave to this guy. I'm just a General class operator in the USA, probably half your age, and I couldn't fathom typing like that to somebody - at least not since I was like 13. Based on the ad-hominem insults you threw at Papa Alpha Tango, seems like he struck a nerve.
Not that a ham license means jack anymore. It was just something the FCC passed off to a bunch of hobby groups to run so they could circle jerk one another. The hobby in it self is kinda dead. Most people i see going out for a license nowadays are either infosec or RC hobbyist who just want it to operate outside the normal bands.
If the foam has the right stuff in it, it could be efficient at transmitting the heat to the heat spreader then to the case, I have installed a few newer computer CPU's and they use a similar material, but it is much thinner and, in the radio, you have a smaller fan.
it is special non inductive heat pad silicone. samsung tv procs are cooled by this all the time, not saying this is the best solution. or that this is okay. but it is not simply foam.
Lol I updated both my qyt 7900s with heat sink pads from Amazon and a small copper heat sink for a raspberry pi. Zero issues daily users as they are a small used as a small repeater I use on my property
That "foam" is probably a thermal pad. Same stuff is used all kinds of electronics where thermal paste or epoxy cannot be used. The quality of that thermal pad, or the spec of the components used in the final, are another matter.
@@oliverkhoo Not necessarily, just because there is indeed some thermal transfer material there doesn't mean the specs of the finals transistor are good quality and properly rated or that the thermal pad is of any quality. It just means that this guy's ranting on how there is this random "foam" is wrong. If you are wanting one of these radios, I'd point you in the direction of the BTECH UV-25X2. It is the same radio design, but supposedly beefed up to resolve these issues with the finals that the 8900D has and with custom (supposedly better) firmware. And only slightly more expensive at ~$120.
@@gixxygamma Well stated. I have used thermally conductive foam on many designs. There is another video showing that there is also another heat sink on the other side of the board. And there is the fan. I was ready to tear mine down and replace the final but I then saw the video where the guy fixed 2 radios by simply re-flowing the solder. Given the heat sink on the other side of the PCB, I'd believe they do have a potential reflow problem. I'm going to try that first.
Any thermal pad over 5mm thick is pretty much useless, and ideally they are dense like putty to actually transfer heat, that looks like someone grabbed the wrong thing to use or had no idea, i mean they are probably assembled by child labour... if that is foam, then its literally worse than air, as foam would be insulting the heat
Given that people are replacing these finals with 6 watt-rated transistors, it's no wonder they blow up. The proper transistor (AFT09MS015NT1 about $6 from Mouser) will withstand 65:1 SWR at 150C operating temperature at max rated voltage (17V). They will also supply 20+ watts at 870 MHz.@@gixxygamma
These are "real" radios, this guy probably did something really dumb. My daily driver for VHF/UHF is an anytone at778UV - I talk on it every day of my life, I get it RED HOT, and have done so every day for multiple years. I also own a QYT, and a few others. Save your "real radio money" for an HF rig (you know, REAL radio)....... but these cheep chinese mobile VHF/UHF rigs work amazing for me and literally everyone in my club, and i'll go one step further, and say they work out for the majority of the hams I talk to.
