A quick and unscientific spectral analysis of two Baofeng radios.

The November 2015 issue of QST contains an article by Larry D. Wolfgang, WR1B, entitled “ARRL Laboratory Handheld Transceiver Testing,” which contains information about some of the Chinese radio manufacturers and whether their products actually comply with Part 97 rules.  I own two of these radios, so I became curious – are my Baofengs  legal to use on the ham bands? So, with the help (and equipment) of a friend, I did a quick and unscientific test using a spectrum analyzer.

Note that there is no Part 97 certification like there is for Parts 90 or 95, but there are still regulations on spurious emissions – and unlike other radio services, in amateur radio, it is up to each operator to ensure their equipment meets these regulations.

The relevant portion is in 97.307, paragraph (e):

(e) The mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency between 30–225 MHz must be at least 60 dB below the mean power of the fundamental. For a transmitter having a mean power of 25 W or less, the mean power of any spurious emission supplied to the antenna transmission line must not exceed 25 µW and must be at least 40 dB below the mean power of the fundamental emission, but need not be reduced below the power of 10 µW. A transmitter built before April 15, 1977, or first marketed before January 1, 1978, is exempt from this requirement.

The QST article – which I highly recommend you read – does all the math, but the result is this: a 5 watt handheld on the 2 meter band needs at least 53dB of suppression.  4 watts needs 52dB and 3 watts needs just under 51dB.

So let’s get to the good part.  For testing, I used two Baofeng models, a UV-5RA and a BF-F8+.  I connected the radios to an Agilent E4402B spectrum analyzer through a 20dB attenuator. I’ve included photos of each radio below (you can click on the photos for more detail):

UV-5RA FrontUV-5RA BackBF-F8+ FrontBF-F8+ Back

First, I tested on UHF with a transmit frequency of 449.625 – I use UHF much more than 2 meters.  Let’s take a look at the UV-5RA on UHF:

UV-5RA UHF

You can clearly see a spur around 1.3GHz and it’s just over 40dB down from the fundamental frequency.

The BF-F8+ on UHF looks roughly the same (note that the bottom frequency has been moved down from 200MHz to 100MHz for this shot – remember, this is a quick and dirty test):

BF-F8+ UHF

Again, we have a spur around 1.3GHz and it’s maybe 35dB down from the fundamental.

Now we move to VHF.  To get better detail (and make it easier to see), we expanded the Y-axis and shrunk the X-axis for the VHF readings.  Here’s the UV-5RA:

UV-5RA VHF

This transmitter is all over the place.  Tons of spurious emissions, some as little as 30dB down from the fundamental.  This transmitter is definitely misbehaving or not properly filtered.

And the BF-F8+ on VHF – same settings on the spectrum analyzer:

BF-F8+ VHF

This transmitter is also pretty bad, but it’s not as bad. The worst spurious emission is just under 35dB down, but the others are much farther down.

And finally, for reference, we tested a 25 year old Motorola commercial HT in the 2 meter ham band:

Motorola VHF

Zero spurious emissions – this is because higher-end radios have filters that prevent these emissions from making it out of the transmitter.  This is what a transmitter should look like, and you can find one of these radios used on eBay for not much more than a Baofeng.

Final Thoughts

I will no longer transmit from my Baofengs because they do not meet Part 97 specifications.  Additionally, I will no longer recommend Baofengs to new hams. Even though the ARRL found that only about half of them fail to meet the emissions standards, I don’t want new hams to have to play that lottery.  I will likely recommend radios like the Yaesu FT60.  More expensive? Sure.  But they’re legal.

I have read some comments that the knockoffs are the ones failing these emissions standards and the real ones do not.  But how can you know if you’ve gotten a knockoff? I bought mine from sellers on Amazon: “ETEKCITY CORPORATION” and “Foscam Digital Technologies LLC.”  Seems legit to me, but I have no way of knowing for sure.

Look, I get it: They’re cheap, available, and they work. But are you willing to violate FCC regulations just to save a few bucks?

A quick and unscientific spectral analysis of two Baofeng radios.
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