Junction Box Family — BNC Patch Panels, JB04T to JB80T

Nine channel counts, two build options

Every unit in the family routes one BNC bulkhead connector per channel through a numbered, silk-screened panel — the same convention on the smallest bench box and the largest floor unit. The difference between models is channel count and, above roughly 32 channels, whether the panel is worth dividing into zones.

Model	Channels	Panel layout	Confirmed from
JB04T	4	1 row × 4	Studio render
JB08T	8	2 rows × 4	Studio render
JB12T	12	2 rows × 6	Real bench photograph (6 angles)
JB16T	16	2 rows × 8	Studio render
JB24T	24	3 rows × 8	Studio render
JB48T	48	4 rows × 12	Studio render
JB60T	60	5 rows × 12	Studio render
JB64T	64	4 zones × 16	Customer tender specification
JB80T	80	5 rows × 16	Studio render — panel numbering has legibility defects; channel count and layout are reliable, but fine per-connector digits are not

Every model above uses the same panel legend format: model code top-right, TIERA logo top-left, channel numbers beside each BNC, {N} CHANNEL JUNCTION BOX along the lower edge, and a serial number S/N JB{NN}T26001.

Two build options, not two product lines

Standard build — screw-fixed cover. Every model, JB04T through JB80T, is built this way as standard: black powder-coated steel, a top panel held down by corner and edge screws, rubber bench feet, no hinge, no lock, no lid-support stay. It is the cheaper, simpler cover — a screwdriver removes it during setup or a wiring change, and there is nothing to fail on a bench unit that lives in a lab and isn’t opened and closed under time pressure.

Chassis-configured build — hinged, lockable, zoned. Available as an upgrade from 48 channels up, and standard on the 64-channel tender configuration: a folding lid-support stay that holds the cover open without a hand on it, a key-operated or hasp lock with two-point handles, the panel divided into zones with dividing graphics, one cable gland per zone sized to that zone’s cable bundle, and an optional wheeled castor stand for field or site deployment. Port numbering is printed on both the outer and inner face of the cover, so a technician can read channel numbers with the lid open or closed.

Why the boundary sits near 32 channels. Below that, one technician can scan a single flat panel and keep the wiring in their head — a screw-fixed cover and bench feet are the whole story. Above it, the panel is wide enough that grouping channels by structure zone or DAQ card measurably reduces wiring errors, and a box that gets opened and closed repeatedly on a test floor benefits from a lid that stays up on its own and locks when the test is unattended. JB48T and JB60T are built to the screw-fixed convention as standard — the chassis build is the configurable option at that size, not the default. JB64T is the case where a customer specified the chassis build outright, and its zoning (4 × 16) is the only zone grouping evidenced in the source material for this family.

Configuration matrix

Specify against this table when requesting a quote. Not every combination applies to every channel count — ask sales to confirm fit for your model.

Option	Choices	Applies to	Notes
Cover	Screw-fixed panel (standard) · Hinged, lockable, with lid-support stay	All models; hinged/lockable typically only justified from 48 ch up	Hinged build adds lock hardware and two-point handles
Mounting	Bench feet (standard) · Rack ears · Wheeled castor floor stand	Bench feet: all models. Rack ears and castor stand: chassis build	Castor stand supplied with the unit on tender-grade orders
Cable glands	Sized and counted to the cable bundle	JB12T confirmed at 2 glands, one side wall. Others confirmed at order engineering	Chassis build: 1 gland per zone (JB64T: 4 glands, 16 coax each)
Connector make	Amphenol · Neutrik · TE Connectivity · Fairview Microwave	All models	Approved-vendor list; make and part number stated in the offer
Panel marking	Outer face only (standard) · Outer + inner face	Outer-only: standard. Outer + inner: chassis build (mandatory on JB64T)	Inner-face marking needed once a lid can be opened and read from inside
Zone grouping	None · Grouped by structure/DAQ zone	Meaningful above ~32 channels; confirmed only on JB64T (4×16)	Zone width follows the customer’s sensor layout, not a fixed rule
Test-report scope	Standard (≥10% of connectors or 8 channels, whichever is higher) · Full 100% channel test	All models	Full-scope test available on request, at added cost

Electrical specification

±0.1 dB flatness, 10 Hz–20 kHz is the specification that actually defines this family — it is the one number a buyer should compare across suppliers, and every model meets it across its full channel count.

Parameter	Value
Flatness	±0.1 dB, 10 Hz – 20 kHz
Contact resistance	≤ 5 mΩ
Insulation resistance	≥ 1000 MΩ
Connector	BNC, female-to-female, panel-mount bulkhead — one per channel
Contact material	Beryllium copper or brass, nickel-plated
Insulator	Delrin (Acetal / POM)

A note on THD and noise floor. These are passive assemblies — a panel of connectors and coaxial runs, with no active device anywhere in the signal path to generate distortion or noise of its own. A THD or noise-floor number measured on a box like this characterises the test system at least as much as the box: it is a null-result measurement, and a good one. TIERA reports ≤ 0.001% THD (≤ −100 dBV ref. fundamental @ 1 kHz) and ≤ −120 dBV broadband noise floor on every delivered unit, on request — read those figures as confirmation that the assembly adds no detectable distortion or noise above the calibrated analyser’s own floor, not as a spec the box “achieves” the way an active instrument would.

Two footnotes worth carrying into a tender response:

• 50 Ω impedance and a DC–4 GHz connector rating (where specified) are outside the family’s 10 Hz–20 kHz usable band — an IEPE accelerometer chain isn’t an impedance-matched RF line at audio frequencies, so 50 Ω vs 75 Ω makes no measurable difference here. The requirement is harmless but narrows the approved-connector list.
• Delrin (POM) is specified as the connector insulator rather than PTFE. PTFE has a marginally better dielectric at RF; for this band the difference is not measurable, and Delrin is standard and less costly. Flag this with the customer if PTFE is a fixed BOM requirement rather than a technical one.

Test report and compliance

Every unit ships with a test report generated on a calibrated audio/RF analyser, covering a minimum of 10% of connectors or 8 channels — whichever is higher — with worst-case values reported in both dBV and percent. The report is delivered with the unit, not after.

The 64-channel configuration was engineered against a customer tender specification. Its model page reproduces the full compliance checklist so a tender response can be mapped line by line.

Applications

• Aircraft-structure vibration and modal testing
• Modal test arrays and impact/shaker campaigns needing many simultaneous points
• Acoustic and microphone-array measurement chains
• Structural health monitoring (SHM) installations
• End-of-line test benches where a fixed sensor layout is tested repeatedly

Warranty

12 months from acceptance, covering replacement of defective connectors, cover hardware, cable glands or finish at no cost.

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Pairs with:

• PhonoVibe Series — multi-channel DAQ to receive the routed BNC channels
• TVIB Software — analysis suite for the sensor data these boxes route
• Sensors & Accessories — accelerometers, cables and mounts feeding into the panel
• Signal Conditioners — IEPE conditioning ahead of the junction box where needed