Sunday, May 15, 2011

Inside the UV-3R

Many people have been buying the cheap little dual band Baofeng UV-3R handheld radios from China. Some people have been pulling them apart, such as Fabrice, F4AVI, who has discovered that it is really quite a state of the art radio.


Fabrice found that the VHF/UHF transceiver functionality is provided by an RDA Microelectronics RDA1846 chip. This is a single chip fully DSP based transceiver capable of covering 134-174, 200-250 and 400-500MHz and supports CTCSS, CDCSS and DTMF with an 8dBm on-board PA. The Band 2 broadcast FM receiver uses an RDA5802E chip, also from RDA Microelectronics, which is a single chip broadcast FM stereo tuner. The UV-3R doesn't cover the US 220MHz band, of course, nor is the FM broadcast audio in stereo. But future models might well do.

Some buyers of the Boafeng have experienced minor issues with their radios that suggest the quality control is not all it could be. Still, it is interesting to see innovative designs coming out of China. One can only wonder what next?

9 comments:

Hakan said...

Ordered one last night while doing boring overtime work. I hope it arrives by the time of my birthday! :)

Hakan said...

Btw, I wonder if there are any chinese base stations. I haven't seen one in ebay yet.

Julian said...

I've not seen any on eBay but there are some, such as the AnyTone (sold by a couple of dealers in the UK) and this new dual bander from Vero Telecom.

Peter, M3PHP said...

Interesting been wondering about these handhelds and after reading your post decided to risk it and ordered one!

Wonder if they could be used along with an APRS tracker?

Pete, 2E0SQL

Julian said...

I don't see why not. I havent tried it with the FoxTrak I built - one reason being it is several times the size of the radio!

Peter, M3PHP said...

I'll give it a try once it arrives along with the FoxTrak which will hopefully be turning up in the post soon too.

Might make a compact APRS system while out cycling/walking.

James said...

Looking at the datasheet for the RDA1846, it strikes me that the block diagram basically shows this as a SDR in a chip. I wish the company who makes this chip would let people get at the DSP code to add additional modes, or at least bring the In-phase and Quadrature signals out to a couple pins. You could very easily have a pocket sized all-mode HT. I'm sure that would shake things up a bit in the industry. A pair of chips, with the 220 capability workable and the ability to rebias the PA for class C or AB would make a nice small sized satellite station, IF radio or rover radio.

Additionally both this chip, and the RDA 1845 in the Puxing PX-2R support DTMF. That gives me hope in a hack one day to add it, at least to the Puxing.

MrJoshua said...

James - I just thought exactly the same thing when reading the spec pdf for the chip... A 2w FM/SSB 2m/70cm HT would be an absolutely storming success in the amateur community! Think of the possibilities for SOTA etc :) :)

Julian said...

Yes indeed. I would buy one immediately.