RF Metrology — Filtered amplifier

The right gain,
on the right band.

The FA-1 is a filter-first amplifier with passive fail-safe, powered by DC-feed. Four selectable gain steps (BP / +6 / +9 / +12 dB), four standard 50 MHz blocks across the film UHF band, or any filter built to spec. If power disappears, the filter stays in line — no dropout. Made in France.

Standard blocks

470–520 · 520–570 · 570–620 · 620–670 MHz

Selectable gain

BP / +6 / +9 / +12 dB

Filter BW

20 / 35 / 60 / 120 MHz @ −3 dB

Power

DC-feed 10–18 V

Weight

100 g

Highlights

Filter-first topology

Signal is filtered then amplified: out-of-band interferers (walkies, DECT, Wi-Fi, GSM, 4G, intercom base stations) are killed before the gain stage, not after.

Filter → amp · not the other way

Four gain steps

BP (bypass, filter only), +6 dB, +9 dB, +12 dB. You compensate exactly the coaxial cable loss — not too much, not too little.

BP / +6 / +9 / +12 dB

Passive fail-safe

Lost power? The FA-1 keeps passing signal in pure-filter mode. Typical −2 dB loss: a power failure doesn't break the recording.

0 V = passive filter

Powered by DC-feed

No separate power lead: the FA-1 draws current from the receiver's or splitter's DC-feed (AS-62, AS-122). Better still: it lets DC-feed pass through to power an active antenna upstream.

DC-feed in · DC-feed through

An aluminum cigar

94 × 20 × 24 mm, 100 g: the FA-1 slips into an existing link without clutter, machined from solid aluminum to dissipate heat and last.

94 × 20 × 24 mm · 100 g

Custom filters available

The four standard blocks cover 470–670 MHz in UHF. For specific bands (high VHF, upper UHF, narrow industrial bands), BSRF builds filters to spec.

4 blocks + custom

Specifications

The numbers that matter.

Condensed excerpt. See the datasheet for detailed conditions.

RF

Standard blocks470–520 · 520–570 · 570–620 · 620–670 MHz
Custom blocksVHF / UHF supérieure / bandes étroites — sur spécification
Filter bandwidth20 / 35 / 60 / 120 MHz @ −3 dB (personnalisable)
Selectable gainBP (filtre seul) / +6 dB / +9 dB / +12 dB
Unpowered loss (fail-safe)−2 dB typ. (dépend du filtre)
RF handlingJusqu'à 1 W en entrée (filtre seul)
Impedance50 Ω nominal

Power & mechanical

Power supplyVia DC-feed sur BNC · 10 – 18 V · 200 mA max
Typical consumption100 mA @ 12 V
DC-feed passthroughOui (alimente une antenne active en amont)
ConnectorsBNC 50 Ω (option N)
Dimensions (L×W×H)94 × 20 × 24 mm (connecteurs inclus)
Weight100 g
HousingAluminium usiné
ComplianceCE · RoHS · DEEE

Use cases

Dense RF environment

Clean up an HF reception polluted by 4G

Right at the antenna, the FA-1 cuts nearby cellular emissions before they contaminate the receiver. The noise floor drops, reception breathes.

Cable compensation

Recover 30 m of coaxial loss before a rack

A +12 dB FA-1 at the antenna output compensates for a long coax run (LMR, RG213) and restores nominal level at the splitter input without degrading noise.

Reliability engineering

Drop in a filter that never fails

Thanks to fail-safe, even if the FA-1 loses power, the filter stays active and signal keeps flowing. One link doing two jobs — one of which survives failure.

Documentation

Everything you need before buying.

Datasheets and user manuals available in PDF format.

Need a specific band?

Standard blocks 470–670 MHz, custom at order.