Spectral Displays of Numerous HTs
Over the last few years I've checked numerous HTs to see how clean or dirty they are. "Do they meet FCC specs for harmonic attenuation?"
My main concern was with these cheap Chinese HTs. They seem to be flooding the market and most of what I have checked over the last few years do not comply with FCC specs. I did not save the displays so I had to start from scratch starting Nov 2024. Here are my results.
When it comes to harmonic attenuation, all VHF and UHF radios outputting less then 50 watts, harmonics must be down greater then 40 db. Radios over 50 watts all harmonics must be down greater then 60 db.
To read the displays, you must read the delta between the fundamental frequency and the harmonic frequency you are comparing it to. Each radio was tested using the same two frequencies. VHF = 145.555 mhz and UHF = 445.555 mhz. All HT's were tested at the output power of 5 watts.
Since the radios supplied by The Big Three always meet FCC specs, I figured showing two Kenwood HTs first would really set the benchmark for what to expect from an HT.
HT's tested as of 29 Nov 2024
Kenwood TH F6A Kenwood TH D74A Baofeng UV-5R TIDRadio H3
Anytone 878-UV2+ Radioddity GC-5 Baofeng BF-B8HP Pro Baofeng UV-5R Rush Iron
Baofeng UV-21R Explorer QRZ-1 Baofeng BF-T1
Click on any of the displays to expand the view.
You will notice that all of the harmonics not only pass the FCC requirements, but are in the noise floor of the spectrum analyzer. Both bands the harmonics are more than 60 db down.
You will again notice that all of the harmonics not only pass the FCC requirements, but are in the noise floor of the spectrum analyzer. Both bands the harmonics are more than 60 db down, the same as the Kenwood TH F6A
This Baofeng UV-5R passes FCC requirements. On the VHF side, the second order harmonic is down by 52.5 db. On the UHF side, the third order harmonic is down 51.1 db. All harmonics on both bands are down by at least 50 db.
Take notice to the H3's UHF spectral display. All harmonics are down more then 50 db. Some are even lower than 60 db. This radio is super clean when it comes to the UHF side. The VHF side not as good. This H3 does in fact meet FCC requirements when it comes to harmonic attenuation but only by the skin of its teeth. I say this only because I've seen others that do not pass.
Look closely to the second harmonic. The requirement is better then 40 db and this makes it by only 1.5 db. The second order harmonic is 41.5 db down. The third order harmonic is down 59.7 db. The fourth order harmonic is down 49.6 db.
This radio does in fact comply but what I find strange is the second and forth order harmonics are higher then the third order harmonic. Usually even order harmonics are down more then odd order harmonics. This is not an issue with the radio, but interesting. Pass is pass and this H3 passes.
The Anytone 878 UV2+ more then meets FCC specs for harmonic attenuation. All harmonics shown are well below 60 db on both the VHF and UHF frequencies.
The Radioddity GC-5 does not meet FCC specs of 40 db down on the VHF band on this radio. The second order harmonic is only down 31.5 db. This radio should not be used on the VHF band but is perfectly clean on the UHF side and can be used there.
The Baofeng BF B8HP-Pro does not meet FCC specs of 40 db down on the VHF band on this radio. The second order harmonic is only down 18.5 db. This radio should not be used on the VHF band but is perfectly clean on the UHF side and can be used there. All harmonics on the UHF side are down better then 60 db.
The Baofeng UV5 Rush Iron easily passes the FCC requirement of better then 40 db down on both the VHF and UHF bands.
The Baofeng UV-21R does not meet FCC specs of 40 db down on the VHF band on this radio. The second order harmonic is only down 19.5 db. This radio should not be used on the VHF band but is perfectly clean on the UHF side and can be used there.
The Explorer QRZ-1 more then meets FCC specs for harmonic attenuation. All harmonics shown are well below 60 db on both the VHF and UHF frequencies.
The Baofeng BF-T1 is a UHF only little radio. It more than meets the FCC specs.
Check back from time to time. More tests will be posted as I test more Chinese HTs. Last update: 29 Nov 24.