TekBox EMC pre-compliance and RF accessories
Five TekBox products we stock for Siglent spectrum analysers: an open TEM cell and a near-field probe set with preamplifier that put radiated-emissions testing on your own bench, and three cased sets of attenuators and adaptors for the RF bench. All chosen and supported to work with the Siglent instruments.
Why a Siglent distributor stocks TekBox
More than half of all products fail their first EMC compliance test, and every failure costs a test-house booking, a redesign and weeks of schedule. The cure is to measure before you go: a spectrum of what the product radiates, taken on your own bench, before and after every change. Siglent makes the spectrum analysers for that. TekBox makes the pieces that go in front of the analyser: the TEM cell that turns radiated emissions into a signal on an N connector, and the near-field probes that find which trace or component produces them.
TekBox Digital Solutions, Ho Chi Minh City, has built its range around exactly this kind of bench: affordable, well-documented EMC pre-compliance equipment that works from the tracking generator and USB port of a mid-range spectrum analyser rather than from a chamber. We stock the two instruments that matter most and three of TekBox’s cased accessory sets, and we support them together with the Siglent analyser they connect to.
Every product here comes with TekBox’s measured plots — coupling loss per probe, S21 and VSWR per attenuator, return and transmission loss of the cell — so you know what the accessory does to the measurement.
How a pre-compliance test runs on the bench
Four steps, two TekBox products and one Siglent analyser. The cell gives the repeatable measurement, the probes give the diagnosis.
Measure the whole product in the TEM cell
Board under the septum, one port terminated, the other into the analyser through the DC block. Max hold, 9 kHz resolution bandwidth, peak detector first. The trace is the product’s radiated spectrum on your bench — not the test house’s number, but the same spurs at the same frequencies.
Find the source with the near-field probes
Scan the H20 loop over the board at the frequency the cell flagged; the trace rises as it passes the source. Switch to the 10 mm, then the 5 mm loop and the source narrows to a component, a via or a trace. The E5 finds the high-impedance nodes the loops miss.
Fix it, measure again, compare
Ferrite, filter, layout change, a lid on the enclosure: back into the cell with the same settings and the before-and-after traces tell you how many dB the change bought. Any dB a spur loses in the cell it also loses at the test house.
Immunity, with the same cell
Replace the analyser by a swept generator and an amplitude-modulated amplifier and the cell generates the field instead of receiving it: about 5 mW for 10 V/m, 1 W for 141 V/m across the board. TekBox’s modulated amplifiers are available on request.
EMC pre-compliance on the bench
The two instruments that turn a Siglent spectrum analyser into a radiated-emissions test bench: the cell measures how much the product radiates, the probes find where it comes from.
Radiated emissions and immunity on the bench. 50 mm septum, room for a 19 × 13 × 5 cm board, usable to 3 GHz. 25 W termination and DC block included.
Three H-field loops (20, 10, 5 mm) and an E-field probe, with a 20 dB or 40 dB preamplifier powered from the analyser’s USB port. 2 MHz to 6 GHz.
RF bench sets in a box
Attenuators and adaptors as cased assortments. Each piece has its own cut-out, so the set stays complete and the adaptor you need is in the box rather than in somebody else’s drawer.
3, 6, 10 and 20 dB N-type attenuators, DC to 6 GHz, 2 W, VSWR below 1.2, in a beech-wood box. Fifteen values from 3 to 39 dB when stacked.
44 adaptors in 25 types between N, SMA, BNC, SMB and RCA, all 50 Ω, N and SMA rated to 6 GHz, in a beech-wood box.
Seven pieces: BNC to 4 mm banana plugs and jacks, BNC to screw terminal block, and a 50 Ω feed-through termination.
Which one do I need?
Start from the situation on your bench.
| Situation | Product | Why |
|---|---|---|
| A product failed radiated emissions at the test house | TBTC1 | Measure it in the cell before changing anything, note how many dB are missing, fix until the spur has dropped by that amount. Add the probes to find the source. |
| I want to know which part of the board radiates | TBPS01-TBWA2 | Near-field probes, loop by loop, with the analyser on max hold. The 40 dB amplifier for the quietest emissions, 20 dB when the analyser has its own preamplifier. |
| I design for EMC and want to test every prototype myself | TBTC1 | Cell plus probe set is the complete bench. The cell gives the repeatable before-and-after; the probes give the diagnosis. |
| The analyser’s noise floor hides the emission | TBPS01-TBWA2 | The TBWA2 in the probe set adds 20 or 40 dB in front of the analyser, 2 MHz to 6 GHz, powered from the analyser’s USB port. |
| I need to protect the analyser input or set a level | TBAS4 | 3, 6, 10 and 20 dB N attenuators, 2 W, to 6 GHz; fifteen values when stacked. |
| The cable has the wrong connector for the instrument | TBCAS1 | 44 adaptors between N, SMA, BNC, SMB and RCA. The four N-male to SMA-female pieces are the ones every analyser bench uses most. |
| A BNC instrument has to meet banana leads or bare wire | TBBNC1 | BNC to 4 mm banana, BNC to screw terminal block, and a 50 Ω feed-through termination, seven pieces. |
The Siglent analysers it pairs with
Every TekBox product here connects to the N input of a Siglent spectrum analyser. For each family an EMI measurement option adds the quasi-peak detector and CISPR bandwidths that the standards specify.
The entry analyser for a pre-compliance bench: tracking generator and the EMI measurement option (quasi-peak detector, CISPR bandwidths) available.
Lower noise floor and faster sweeps than the SSA3000X; EMI option available. The usual pairing for the TEM cell and the probe set.
Real-time spectrum analysis catches the sporadic and pulsed emissions a swept analyser misses between sweeps; EMI option available.
For products with emissions well above 3 GHz, and the lowest displayed noise of the family; EMI option available.
All spectrum analysers · SVA1000X spectrum & vector network analysers
Questions about TekBox and pre-compliance testing
Who is TekBox?
TekBox Digital Solutions Vietnam Co. Ltd., Ho Chi Minh City: a designer and manufacturer of EMC pre-compliance equipment — TEM cells, near-field probes, LISNs, amplifiers — and of cased RF accessory sets. The products on siglent.eu are the ones that complete a Siglent spectrum analyser into a test bench, and we support them together with the analyser.
Can a TEM cell replace the test house?
No. The voltage at the cell output cannot be converted into the field strength an antenna measures at 3 or 10 m, so the cell gives no pass/fail against a limit line. What it gives is a repeatable measurement on your own bench: the same spurs the test house will see, and the before-and-after of every change you make. Products that have been through the cell go to the test house with far fewer surprises.
Which Siglent analyser do I need?
Any SSA3000X, SSA3000X Plus, SSA3000X-R or SSA5000A works with the cell and the probes; set attenuation to 0 dB, switch the preamplifier on and use max hold. The EMI measurement option for each family adds the quasi-peak detector and the CISPR 6 dB bandwidths that the standards specify, which matters once a spur is close to a limit.
Do I need the amplifier with the probes?
Near-field probes deliver very little signal, so the set comes with the TBWA2 amplifier. With an analyser that has its own preamplifier the 20 dB version is usually enough; the 40 dB version is for the weakest emissions. The probes also work alone with the analyser’s preamplifier on and 0 dB attenuation.
Can I do immunity tests?
With the TEM cell, yes: terminate one port and drive the other from a generator and an amplifier, and the field across the board follows TekBox’s table — about 5 mW for 10 V/m, 1 W for 141 V/m. The standards call for modulated signals, so the source is usually the analyser’s tracking generator feeding a modulated amplifier from TekBox’s TBMDA range, which we supply on request.
Are the attenuator and adaptor sets only for EMC work?
No. The TBAS4 attenuators, the TBCAS1 adaptors and the TBBNC1 BNC set are general bench accessories for any Siglent oscilloscope, generator, analyser or network analyser; they are in this category because TekBox makes them.
What else does TekBox make, and can you supply it?
Larger and smaller TEM cells (TBTC0, TBTC2, TBTC3), a GTEM cell, LISNs and current probes for conducted emissions, modulated amplifiers for immunity testing and the EMCview PC software. Ask us; we quote any TekBox product.
Putting together a pre-compliance bench?
Tell us what you build and which standard it has to meet. We put together the cell, the probes, the analyser with the EMI option and — for immunity — the amplifier, and quote the set.
Prices ex VAT. Specifications from TekBox’s product manuals (TEM cell V1.5, TBPS01/TBWA2 V2.2, TBAS4 V1.0, TBCAS1 V1.2, TBBNC1 V1.0); errors & omissions excepted.