| First Look: Baofeng UV-3R Review - What Makes It Tick? |
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| Written by Gary, KB2BSL | |||||||
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What Makes It Tick?
The entire radio, CPU is under the LCD on the other side. More pictures are available on the UV-3R Yahoo Group. This radio is undoubtedly a SDR (Software Defined Radio) and has a relatively low part count. I will not cover every part used as a full list is available in the UV-3R Yahoo group file section (Thanks to PY2BBS), but will cover some of the major ones. The heart of the radio is a RDA Microelectronics RDA1846 single chip transceiver for walkie talkies. This single CMOS chip provides frequency synthesizer, VCO/VFO, AFC, AGC, pre/de-emphasis (selectable and can be disabled), RSSI indicator, CTCSS/DCS encode/decode, DTMF, 8dBm PA (about 6mw), and more. Basically everything a radio needs is provided by a single chip. A programming guide can be found here. Personally, I think this is an amazing chip, and I'm thinking up some project ideas. If you read the spec sheet, you will note that this chip is also capable of 200-260 MHz. Next up is the CPU to control the SDR. This chip is unmarked on the circuit board, but the MCU it is believed to be the Abov Semiconductors MC81F8816. This radio contains two distinct RF pre amps, one for VHF and another for UHF. They are provided by NXP Semiconductors, and Hitachi respectively. As the firmware is presently programmed, their appears to be no way to control these preamps. Judging by my earlier findings, they might be automatically controlled and not on full time. The final amplifier is provided by Renesas RQA0009TXDQS MOS FET. This final seems to be capable of 6 watts of output at a 65% efficiency, something you are unlikely to obtain in a 3.7 volt operating environment. The charge control is provided by a Linear Technology LTC4054-4.2 one of these little chips should have been provided in the docking stand but wasn't. Next up we have a short disassembly type video from Brick O'Lore.
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Comments
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What is the FCC ID on these?
73, Steve, K9DCI
https://apps.fcc.gov/oetcf/eas/reports/ViewExhibitReport.cfm?mode=Exhibits&RequestTimeout=500&calledFromFrame=N&application_id=186528&fcc_id='ZP5BF-3R'
I'm a retired Motorola EE and and know the desire (and talk) for a SDR radio has been talked about for probably more than 30 or so years and this IC is one of the bigger significant steps that way. The real performance is the true test. A local that is "connected" talked to a rep and found out that that IC won't do HF. Too bad it doesn't do other modes otherwise an up converter would allow HF operation. Of course, there's always 10 meters...
Thanks.
73, Steve, K9DCI
OOPS. That link says the NC-5H is double conversion Superhet.
26.450 -> 450.
73, Steve, K9DCI
From the FCC filing pictures, I can see that the antenna connector center conductor is soldered to the board.
Unfortunately, the FCC filing pictures are not good enough to blow up. The bare board image you have on your site is much better than the FCC pictures.
In your picture, it is the hole about half an inch this side (in front of) the LED, close to the mounting hole at the lower right corner. I can't make out enough to tell if there is anything else.
73, Steve
MANY HT's will key when you place the ear/mic plug into them, not just this one, it's quite common.
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