FA-VA6 Antenna Analyzer
The FA-VA6 antenna analyzer is the successor to the well-known FA-VA5 and FA-VA4 analyzers. It is a completely new design with significant enhancements in both hardware and software.
In addition to a professional keypad, a TFT color display, power supplied by an industrial-grade Li-Ion cell, and a working range up to 1 GHz, the FA-VA6 stands out especially due to its extensive features, including time-domain measurements and applications.
The FA-VA6 was introduced in FUNKAMATEUR issues 05/2025 and 06/2025 and is available at FUNKAMATEUR-Shop and at SDR-Kits as a 99%-preassembled kit. Instructions and numerous additional resources are also available there.
The following images show the FA-VA6 in its robust aluminum housing, the included carrying case, and the back side of the circuit board:
The following are several display images showing SWR, impedance (Z), and S11 measurements:
Additional display images showing the LCR meter, measurement details, and 5-band mode:
Additional display images showing time domain measurements — fault location and impedance — as well as a cable application:
Additional display images showing the menu system, help system, and USB operation with VNWA and other software:
Technical Data
| Component | Remark |
|---|---|
| Frequency range | 10 kHz to 1 GHz (resolution 1 Hz) |
| Measurement result Single Frequency | SWR, scattering parameter S11, magnitude and phase S11, return loss, mismatch loss, impedance Z by real and imaginary part, magnitude and phase of the impedance, resistance, capacitance, inductance and quality for series and parallel equivalent circuit model of the impedance |
| Measurement result Multi Frequency | SWR, impedance Z by real and imaginary part, scattering parameter S11 as Smith chart, scattering parameter S11 in dB, all values from single frequency at the position of the marker |
| Measurement result 5-band | SWR |
| Length ranges Time Domain (TDR) | 6.3 m, 12.6 m, 25.3 m, 50.6 m, 101.3 m, 202.7 m (with velocity factor 0.66) |
| Measurement result time domain (TDR) | Impulse response over length, impulse response in dB over length, step response over length, step response magnitude of impedance over length |
| Time Domain resolution (TDR) | Adjacent interference points: 0.5 ns, corresponds to 0.1 m at VF = 0.66 Individual interference points: < 0.05 ns, corresponds to 0.01 m at VF = 0.66 |
| Current applications | Cable length according to known velocity factor Velocity factor according to known cable length Characteristic impedance of the cable (characteristic impedance) Cable attenuation at 10 MHz, 30 MHz, 50 MHz, 100 MHz, 200 MHz |
| Display | 320x240 2.8" IPS TFT color display with 1000 cd/m2 brightness, Refresh rate (depending on application) 60...120 Hz |
| Dynamic range measuring chain | In each case up to 200 MHz, 200 MHz to 600 MHz, 600 MHz to 1 GHz Precise mode: > 80 dB / 69 dB / 57 dB Balanced mode: 80 dB / 64 dB / 54 dB Fast mode: 80 dB / 60 dB / 51 dB |
| Frequency stability | 0,5 ppm |
| Signal processing | 24-bit ADC, 32-bit DSP, 64-bit calculations |
| Measurement input | BNC socket 50 Ω |
| Output signal | rectangular f = 1 MHz, R load = 50 Ω 𝑃1 = 3,2 dBm (1. harmonic, fundamental) 𝑃2 = -6,4 dBm (3. harmonic) 𝑃3 = -10,9 dBm (5. harmonic) f = 200 MHz, R load = 50 Ω 𝑃1 = 2,1 dBm (1. harmonic, fundamental) 𝑃2 = -10,0 dBm (3. harmonic) 𝑃3 = -17,6 dBm (5. harmonic) |
| Firmware | New versions free of charge, update via USB |
| Operating current and times | 260 mA, approx. 12 h, 100 % brightness 165 mA, approx. 19 h, 50 % brightness 130 mA, approx. 24 h, 30 % brightness approx. 42 μA, switched off state incl. real-time clock |
| Currently supported languages | German, English |
| Power supply | Lithium-Ion industrial cell 18650 |
| Battery type | Panasonic NCR18650BD 3.6 V 3180 mAh |
| Battery protection | Against reverse polarity, overcharging, deep discharge, short circuit, charging outside the operating temperature range |
| Battery charge | Via USB and built-in CI-CV charge controller with load balancing, simultaneous operation of the device possible |
| Operating and storage temperature | -20 °C bis 60 °C |
| Dimensions | 135 mm x 85 mm x 28 mm (L x B x H), without keypad and BNC socket |
| Weight | 270 g incl. battery |
This section provides frequently asked questions (FAQ) and discusses requested changes and errors in the current firmware.
FAQ
Accessories including USB cable missing
Q: My kit is missing screws, rubber feet, and the USB cable?
A: These items are located underneath the upper foam insert in the case.
Alignment of the front and back panel of the case bottom to the top cover
Q: On my case, the front or back panel protrudes or sits too far inward. Can this be aligned?
A: Despite CNC manufacturing, tolerances can occur. Without the circuit board installed, you can manually bend the front and back panels to align them perfectly.
Inserting and removing the circuit board from the case
Q: How can I insert or remove the circuit board without risking damage to the USB-C socket?
A: Face the case with the BNC socket toward you and use your thumbs and index fingers to gently lever the board in and out. Gloves may help.
Insertion: Index fingers on the bottom edge of the board, thumbs on the inside bottom of the back panel.
Removal: Index fingers against the battery holder, thumbs on the inside top of the back panel.
Alternative: Use 2–4 old credit cards or similar between the board and the back panel on both sides to help lever it out.
Display shows vertical red line
Q: My display shows a vertical red line?
A: That is the protective film on the display. Remove it by peeling from the green corner.
Loose screws on the keypad
Q: The M2 screws on my keypad are loose — should I tighten them?
A: No, the screws need some play to allow proper alignment of the keypad. The nuts are glued in place.
Keypad alignment to upper case shell
Q: The keypad buttons aren’t perfectly aligned with the holes. Can it be adjusted?
A: Yes, slightly shift the keypad sideways using as many buttons as possible until the alignment fits.
Usable 18650 Battery / Part 1
Q: Can a different 18650 battery be used?
A: The FA-VA6 uses the MCP73871T-2CCI/ML charging controller, which is designed for a 4.2V charge cutoff. Batteries with a different cutoff voltage may be overcharged or not fully charged. The internal protection circuit is also set for this voltage. We strongly recommend using the specified battery type NCR18650BD.
Usable 18650 Battery / Part 2
Q: Can a 18650 battery with internal protection be used?
A: Protected 18650 batteries are generally mechanically longer and may not fit in the holder. The FA-VA6 has its own internal protection circuit. We strongly recommend using the specified battery type NCR18650BD.
Frequency used for measuring the velocity factor (VF) in cable application
Q: What frequency is used when measuring a cable's velocity factor?
A: The frequency is variable and depends on the cable length. The electrical length (and thus the VF) is determined using a quarter-wave (λ/4) transformation approach.
Feature requests for firmware updates or application ideas
Q: How do I submit a feature request for a firmware update?
A: Ideally by email to support@dg5mk.de. Please check here first to see if your request has already been listed.
Firmware
Current Version: 1.0
Feature Requests / Additions:
- Cover 23 cm band (1.3 GHz) using 7th harmonic
Status: Open - Display more than 5 frequencies (>10) in the style of the 5-Band measurement
Status: Open - Add additional frequency bands, e.g., 8-meter band
Status: Open - Selection by frequency band also for single frequency and 5Band modes (center frequency)
Status: Open - Simplify frequency entry in kHz and MHz, e.g. by long-pressing zero during input, or entry in Hz by ENTER and kHz by Arrow-Down
Status: Open - Increased measurement rate for single frequency mode, e. g. using an additional parameter
Status: Open - Add additional cable types into the catalog
Status: Open - Merge cable applications into one application
Status: Open - Implement a rudimentary spectrum analyzer operation mode
Status: Open - Extend callsign to two lines to add name
Status: Open - Extend frequency span using ham-band selection to factor 1.5 or 2
Status: Open - Implement reference trace from current trace capability
Status: Open - Implement zoom function for Smith chart
Status: Open - Add return loss view with bar in single frequency mode
Status: Open - Implement impedance matching application
Status: Open - Implement balun / unun matching application
Status: Open - Implement often used Ham radio calculation tools
Status: Open - Adapt cable applications to measure symmetrical feedlines
Status: Open
Known Errors / Workarounds:
- Vertical lines may show up for SWR measurements in multi frequency mode with open or shorted port, because a calculated negative SWR is set to zero instead of positive infinity.
Workaround: None, as this does not affect any practical measurement.
Status: Open - Wrong measurement values may show up in multi frequency mode (mostly using continuous measurement) with a center frequency of 150 MHz / 450 MHz and a small span.
Workaround: Use a larger span and/or single measurement.
Status: Open