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Many years back, before these CCR became the rage, it was a common complaint of ham users of Japanese handhelds that when replacing the factory supplied "rubber duckie" antenna with a 5/8 wave dipole or a base station antenna that the receiver sensitivity would erode. This was quickly identified as being a combination of both poor RF front end selectivity and poor dynamic range and IMD . It would be interesting to subject these CCR radios as well as known good commercial grade radios to the rigorous testing of TIA603D. Lacking the complete facilities to do so, it occurred to me that a UHF TEM cell could be put to use to combine a desired signal (12dB SINAD reference) and undesired noise spectrum (rejection notched at desired) from an amplified noise diode generator to perform a Noise Power Ratio test of these various radios having integral antennas. This set up could be used to quantitatively measure radios and rank them on a dB scale of best to worst. This setup would simulate the "real world" environment of powerful emitters in and out of band of the receiver.

Yeah, I know about the software bugs with the D878UV. Hardware wise it's a nice radio. At least the front end seems better at rejecting out of band or off frequency signals compared to the other cheap Chinese radios I have. The downfall is the firmware and the customer programming software. If you look about every 1 to 3 months they come out with a new version of both ever since the radio was first released. They fix something in one version, then it's broken in the next. I don't understand why when they fix a bug it doesn't stay fixed in later releases. The last one, V1.17, that just came out a few weeks ago I just sent off another bug report about a couple of things that don't work I stumbled a cross or just plain annoying until they get fixed. Now by contrast my TH-D74A has only a few updates and when the bugs get fixed they stay that way. Yes its an expensive radio but you get what you pay for too.

Look at how little filtering the RT-22 has. There's all sorts of unpopulated pads on the production model that aren't on the FCC submitted model. I bet those harmonics aren't 50dB down on production models. Again, you're in a highly unconventional RF environment, RF power coming from the Candelabra transmitters through a typical UHF passband (370-530 MHz) should be in the ballpark of 0dBm. Most people are around -50dBm. That's a HUGE difference. That said, CCRs aren't meant to be used on fixed antennas; they're designed to be used as portable radios. Most handhelds will show measurable desense on a high-gain base antenna, CCR or not. The typical CCR construction with a wide-open frontend happens to have a lot more desense. In open spaces away from other transmitters, they have a slight advantage due to less filtering loss. They have their place, and that's on-site business use on the hip; can't desense if the strongest transmitter is the repeater you're using. They also work good enough for amateur use that people keep buying them. Few people in reality will cite receive performance as a reason to upgrade from a D878UV or something to a Motorola or Kenwood, it's mostly for audio quality. Over here, where the noise floor is high on VHF, I get better coverage on GMRS than MURS, and better 800 MHz Part 90 reception than 460 MHz Part 90 reception. In my experiences with line-of-sight conditions, the higher gain from UHF antennas gives better audio (helps to make up for deep fades, which are briefer on UHF), while in mobile-to-mobile situations with some separation VHF has an advantage in punching through terrain. UHF has much better spot coverage. For mobile-to-mobile operation, ~50W out into a gain antenna on GMRS should give universally better coverage than your Part 95 compliant MURS setup. Portable-to-portable simplex will be much more variable due to terrain. Noise floor is also an important consideration in urban environments, and lower frequencies will have more noise than higher frequencies.

Gosh, Doesn't anybody have an opinion here.