Wednesday, 20 September 2017
Cheap Handhelds vs Outdoor Antenna
The Baofeng GT-3 dual bander was completely overloaded right across the 137-174MHz band. I don't think it was paging, even the paging on 153MHz sounded like it might have been getting some interference. I'm guessing strong broadcast signals (FM or DAB) as it was non-stop desensing of the receiver. It's hardly worth going outside with this radio on VHF or connecting anything but the stock antenna, it was the worst of the lot. Receiver sensitivity is as good as any other handheld though. S-meter isn't just 0 or full, but seems to be linked to the squelch level (with squelch of 0, there is no meter reading on any signal).
Puxing PX-777 VHF was much better than the Baofeng at coping with strong signals, even though it was one of the first cheap handhelds on the market (they came out in about 2007 for £35). At 165MHz, there were no problems, but near the bottom of the frequency range there was some pager breakthrough on mid-level signals. I wouldn't take this very close to a transmitter site and expect decent contacts on it but it's definitely an improvement on the more modern Baofeng. I've had problems with the battery life in cold weather so maybe not one to rely on for a hill top activation on it's internal battery only.
Uniden Bearcat UBC3500 is a handheld scanner covering 25 - 1300MHz and despite the wide frequency coverage, this didn't have any great problems with strong signals anywhere in the 137 - 174MHz range. The 3500 isn't quite as sensitive as the other handheld radios but in everyday use this doesn't really matter.
UHF isn't usually as hard on radios as VHF for strong signal handling, apart from Airwave around 390MHz, most transmitters are low powered and on roof tops rather than hill top masts.
The UBC3500 had no problems with overloading, but you could definitely tell the lower receiver sensitivity. This could have been better, as some of the other handhelds were much better on weak signals without any interference from nearby transmitters.
The UHF version of the PX-777 and the Retevis RT-3 (TYT MD-380 rebadged) were both able to cope with any strong signals and more sensitive than the Uniden scanner. The S-meter on the PX-777 wasn't realistic, giving full scale on a slightly noisy signal which was about S1 on my FT-7900 mobile radio. I hadn't used the RT-3 on FM very much on an external antenna and it's hard with DMR to tell if a signal has either gone below the noise or has been wiped out by something else. The RT-3 has a thing with the S-meter where it goes up to full scale for a few seconds after changing channel, which makes it look a bit like there is some interference in the background.
Once again, the Baofeng GT-3 was worse than other handhelds, and around 456MHz was being overloaded by something which didn't affect the others, making it struggle with the weakest signals. Lower down the UHF band it seemed OK, so may be usable on UHF even when VHF isn't.
The Puxing PX-2R (photo below) was as good as the others on UHF, it's only 2 watts though so not something I'd really be connecting to an external antenna any time. There is a few seconds delay on the S-meter, which usually reads full scale or nothing. It has a Nokia type charging socket and the battery looks like a mobile phone battery.