Siglent ASP-18 — Adjustable single-ended TDR probe, DC–18 GHz
The Siglent ASP-18 is an adjustable single-ended (50 Ω) TDR probe for measuring the impedance of circuit-board traces, components and wires. A built-in wheel sets the tip spacing from 0 to 6.5 mm, so one probe adapts to uneven pads and traces — no custom fixture needed. With a flat DC–18 GHz response, an SMA connector and better-than-2% repeatability, it delivers fast, consistent time-domain reflectometry measurement
Product overview
The ASP-18 is an adjustable single-ended (50 Ω) TDR probe for measuring the impedance of circuit-board traces, components and wires. A built-in adjusting wheel sets the tip spacing anywhere from 0 to 6.5 mm, so a single probe adapts to uneven pad and trace spacing — no custom fixture required.
With a flat response from DC to 18 GHz, an SMA connector and a 50 ± 0.5 Ω cable, the ASP-18 delivers fast, repeatable time-domain reflectometry measurements — better than 2% repeatability over a hundred probings — for signal-integrity and PCB characterisation work.
Key highlights
DC – 18 GHz bandwidth
Wide, flat response from DC to 18 GHz for accurate TDR and impedance measurement.
Single-ended · 50 Ω
Configured as a single-ended, 50 Ω TDR probe to match your device under test.
0 – 6.5 mm adjustable pitch
A built-in adjusting wheel sets the tip spacing from 0 to 6.5 mm, so one probe fits uneven pad and trace spacing.
SMA connector, 50 Ω cable
SMA probe connector with a 50 ± 0.5 Ω cable — one end SMA to the probe, the other end N or SMA.
Repeatable & stable
Better than 2% repeatability (R ≤ 2%) over more than 100 consecutive measurements.
For boards, traces & wires
Quickly probe circuit-board traces, components and wires where fixed fixtures do not fit.
Adjustable spacing, no custom fixture
Set the pitch
Turn the built-in wheel to set the tip spacing from 0 to 6.5 mm — matching the pads, vias or traces in front of you.
Probe & measure
Touch the single-ended tips to the device under test and read impedance directly with your TDR-capable instrument.
Repeat with confidence
Better than 2% repeatability over 100+ probings means consistent results across a board or a batch.
Specifications & dimensions
Mechanical dimensions (mm)
- Probe model
- ASP-18
- Probe type
- Single-ended TDR probe
- Bandwidth
- DC – 18 GHz
- Probe impedance
- 50 Ω
- Probe spacing
- 0 – 6.5 mm, adjustable (built-in wheel)
- Probe connector
- SMA
- Cable impedance
- 50 ± 0.5 Ω
- Cable connector
- SMA to the probe; N or SMA at the other end
- Repeatability & stability
- R ≤ 2% over 100+ measurements
- Cable outside diameter
- 5 mm
- Dimensions (L×W×tip)
- 134.2 × 36 × 21.9 mm
- Warranty
- 6 months
The adjustable-probe family
ASP = single-ended (50 Ω) · ADP = differential (100 Ω); 18 = DC–18 GHz, 26 = DC–26.5 GHz. All share the same 0–6.5 mm adjustable body.
Ready to order the ASP-18?
In EU stock, shipped from the Netherlands with full warranty and expert support.