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TenaTesta

TenaTesta is a compact tool for indicating antenna SWR. It can also be used as a RF signal generator to over 1GHz & now, measure low level RF signals!

  Easy single-handed operation!
Designed with ease of use in mind, 3 buttons control all functions. Great for single handed operation - up a ladder, behind or under the bench is a snap. The colour illuminated display is not only cool, its great in dark places!

  SWR sweeper
The Sweeper indicates the SWR of an antenna from 
100kHz to 150MHz. It is very easy to use – just set start & stop frequencies and double click control button to start th
e sweep. The TenaTesta then plots 150 points of forward, reflected and SWR data on the colour display. When completed, it reports the very first frequency with the lowest SWR. For clearest results, start and stop frequencies should be fairly close.

  Sweep data
The 150 points of sweep data is output through the USB port at 115,200 baud. It is comma delimited with each new line showing "Frequency, FWD, REV, SWR" (FWD & REV are forward and reflected DAC values from 0 to 1023). Fantastic for creating PC plots!

  RF generator

The RF generator tunes from 100kHz to 150MHz in 100Hz steps with 4 selectable output levels from about -3dBm to +7dBm. As the output is a square wave, it is rich in harmonic
s to well over 1GHz. To take advantage of this, the display also shows all harmonics up to the 7th. TenaTesta also displays actual wavelength, in meters, down to 1/8th λ. Both the displayed harmonics and wavelength automatically update if the frequency is changed.

  Trim & measure
Another great generator feature is that when 4mA is selected, the SWR is shown for the current frequency. This is great when you need to trim the antenna at a specific frequency. With the harmonics display, it may be useful past UHF.
  RF power meter
Wideband RF power measurement is a new feature. It accepts levels from around -14dBm to just over 2dBm. Reading is an arbitrary ADC voltage (not dBm) and works well past 500MHz.

  Arduino sketch & circuit available
Arduino is the popular open-source electronics prototyping platform intended for designers and hobbyists. The TenaTesta source code and schematics are available for personal, non commercial use when you purchase one.

Save your settings & calibration

The calibrations screen allows you to adjust the TenaTesta reference clock. A simple way to do this is by zero beating the TenaTesta generator to a time signal like WWV on 10MHz (set generator 10.0000MHz & adjust calibration for zero beat). To permanently save sweeper start and stop frequencies, calibration and RF generator frequency, simply hold the * button down until it exits to the main menu. Press and hold * again until 'Saving...' is displayed. Now your default setting are saved and will be recalled each time you power up TenaTesta.

  Micro USB powered

TenaTesta is powered directly from its micro USB port and draws up to about 90mA. So a single cell 18650 2000mAh power bank will last a long time!

  How it works & accuracy
TenaTesta uses a 50Ω Wheatstone impedance bridge for measurement. Forward and reverse RF voltages are converter to DC, amplified then measured by 10-bit ADC. The results are calculated by the microcontroller then displayed. The design is compact, cost effective and fulfils the goal of 'useful shack tool'. This approach however does not allow the accurate reporting of antenna impedance or RF power levels.Analyzer Specifications
  • SWR Detector: 50 Ω Wheatstone impedance bridge

  • SWR RF Drive: Fixed at 4mA = 2.3dBm

  • SWR Frequency Range: 100Khz to 150MHz

  • SWR Measurement Range: 1.0:1 to 8.9:1

  • Chart Plots: Yellow (SWR), Blue (FWD) & Red (REV)

Generator Specifications

  • Frequency Range: 100Khz to 150MHz + harmonics past 1GHz

  • Frequency Step: 100Hz

  • Output Level: 2mA, 4mA, 6mA & 8mA selectable (about -3.5dBm ~ +3.5dBm from 1MHz to 150MHz)

  • Harmonic Display: f2, f3, f4, f5, f6 & f7 (dynamically updated with frequency change)

  • Wavelength Display: 1λ, 1/2λ, 1/4λ & 1/8λ (dynamically updated with frequency change)

RF Power Meter Specifications

  • Type: Wideband (Schottky diode RF rectifier)

  • Useful Frequency Range: from about 1MHz to over 500MHz

  • RF Displays: ADC voltage from 0.000 to 2.560 (2.56 vRef / 1023 10-bit ADC)

  • Approximate dBm Range: varies from -25~15dBm to +1~+3dBm

General Specifications

  • Processor: Atmega32u4 (Arduino Leonardo compatible)

  • Development Environment: Arduino IDE 1.6.10

  • Screen: 1.8” 128x160 TFT Colour Display

  • User Interface: 3x Tact Switch for easy single handed operation

  • Oscillator Reference: 27MHz ABM3B (10ppm tolerance & stability)

  • RF Connector: SMA Female

  • RF Connector Impedance: 50 Ohms

  • Operating Voltage: 5V @ 70mA (90mA at full RF output level)

  • Power Connector: Micro USB

  • Dimensions (W x H x D): 58mm, 35mm, 18mm

  • Weight: 40g

When I have stock, TenaTesta is available on eBay

Assembled & Tested,
Bare circuit board (PCB),
From time to time, full kit with PCB and all parts.

To purchase, please search eBay for 'TenaTesta'.

TenaTesta is hand assembled in Oamaru, New Zealand by Chris Day, ZL1CVD.


Ċ
Chris Day,
May 18, 2017, 4:43 AM
Ċ
Chris Day,
May 18, 2017, 4:44 AM
Ċ
Chris Day,
May 18, 2017, 4:43 AM
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