Category: RF

Baofeng UV9R Plus (UV-9R+) measurements & programming

Can be ordered from ebay / Aliexpress, cost ~40€. Unknown if this model is genuine Baofeng radio or some knock-off. There seem to be different versions of the UV-9R Plus, with different keyboard color (orange brim). Some seller’s advertised data (20W TX power, 10.000mAh battery capacity) seems pretty implausible. No UV-9, UV-9R+, or similar is listed on Baofeng’s website. Cheap programming cables (CH340 based) are available and work fine for me with Windows10. Due to the completely different “waterproof” interface equipment from the popular UV-5R can not be used (headphones, programming cable, etc). Comparable to UV-5R, no frequency / channel mode button. No dedicated VFO-A/B selection button (press “EXIT” button to switch between the two selected frequencies / channels)

Programming

As of 11/2021 the popular free software “Chirp” can be used to program memory & settings of the UV-9R+. Selecting the “UV-9R” as radio model did not work properly. However, inputting “UV-82WP” solved the problem and let me program the channels with names and adapt necessary setting (power-up message, …)

Select UV-82WP to up- & download data from a UV-9R+ !

After switching the UV-9R+ to Channel Mode (switch off radio, hold “Menu”-button, switch on radio) I had to set “MDF-A” (upper display line, Menu-21) and “MDF-B” (lower display line, Menu-22) to the setting “NAME”. (Select “CH” for channel number and “FREQ” to display the frequency of the corresponding VFO.

Measurements

GPS ceramic patch antenna (Aliexpress) S11

Some time ago I ordered a lot of (cheap) and small GPS patch antenna from Aliexpress.

DUT:

I was very interested in the resonant frequency so I decided to connect it to my HP8753C to evaluate the match.

Result:

    • Minimum S11 -13.4 dB (VSWR: 1.544:1, reflection coefficient gamma: 0.214) at approx. 1070 MHz
    • Antenna resonant peak far off GPS L1 center frequency (nominal 1575.42 MHz). Usually, a sufficient ground plane is required for patch antennas, but these usually shift the resonant frequency to lower values.
    • Nevertheless the match looks better than 10dB at the 1575.42 MHz which is sufficient

Side Note: A good match does not necessarily lead to a “good antenna”. Although a good match is a basic requirement for all energy being transported from (and to) the antenna it is not guaranteed that the energy will be radiated in an effective way. S11 (or VSWR) only quantifies the amount of energy being reflected back from the antenna into the transmitter. It is up to the antenna (material and geometry) to efficiently radiate the delivered energy. Just think of a dummy load as an extreme of this phenomena: Nearly all energy is transferred (very good match, S11 minus many dB) but nearly nothing is radiated. Beside impedance mismatch losses, ohmic conduction losses (copper etc.) and mostly dielectric losses of surrounding material (like FR4 etc.) massively degrade antenna efficiency. The belonging measure is called “antenna efficiency” mostly given in %. (For RX operation the same applies analogous due to the antenna reciprocity theorem).

Equipment:

    • HEWLETT PACKARD 8753C, SW: 4.02
    • HEWLETT PACKARD 85047A
    • APC-7 – SMA (f)
    • SMA (f) – U.FL (m) MULTICOMP MC000984
    • RG 58A/U 0,5m SMA (m) – SMA (m)
    • Kirkby Microwave 85033, ‘50Ω SMA Calibration & verification kit’

Download:
Touchstone file (*.S1P)