Ten-Tec Model 218, 9 MHz 8 Pole 1.8 KC SSB Crystal Filter NEW in Box

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MPN:

218

Condition:

New

Shipping:

$8.00 (Fixed Shipping Cost)

Description

Description

Ten-Tec Model 218, 9 MHz 8 Pole 1.8 KC SSB Crystal Filter NEW in Box

Ten-Tec Model 218 is a 9 MHz 8-pole crystal ladder filter with a 1.8 kHz (1800 Hz) bandwidth at -6 dB, serving as an optional narrow SSB (or wide CW) filter. It provides sharper skirts and better adjacent signal rejection than the standard 2.4 kHz filters in many Ten-Tec rigs, making it excellent for crowded bands, contesting, DXing, or when a tighter SSB passband is preferred (e.g., for clearer voice or reduced QRM while maintaining good audio quality). It's part of the classic 9 MHz filter family (217/218/219/220 series), with an 8-pole design for superior shape factor compared to 6-pole versions.Key Details and Specifications

Bandwidth: 1800 Hz (nominal at -6 dB).
Poles: 8-pole ladder configuration.
Center Frequency: Approximately 9.0015 MHz (some sources note slight variations for offset compatibility with rig sidetone/PTO centering; e.g., designed around typical 700–750 Hz CW offsets but optimized for SSB use).
Shape Factor: Excellent (sharp skirts due to 8 poles).
Installation: Plug-in internal option board (slots into the IF filter position per the rig's manual; may require jumper settings for gain in some models like Omni VI+).
Era: Late 1970s/1980s onward, compatible with many classic Ten-Tec HF transceivers.
Build: High-quality shielded module with ladder crystals; reliable and long-lasting in vintage gear.

Compatible RadiosThe Model 218 is designed for Ten-Tec transceivers with a 9 MHz IF stage that support these optional ladder filters. Compatible models include:

Omni Series: Omni A, B, C (Model 546), early Omni models.
Omni V / Omni VI / Omni VI+ (Models 562/563/564; usable in 9 MHz positions, often with low-gain jumper setting).
Corsair / Corsair II (Models 560/561).
Argosy / Argosy II (Models 525/525D).
Delta 580 (and Delta II in some setups).
Orion / Orion I (Model 565; optional roofing or IF filter position).
Paragon / Paragon II (in 9 MHz slots).
Others: Early Omni series, some Argonaut mods, and cross-compatible with rigs using the same 9 MHz ladder filter family (e.g., documented in manuals for Omni B/C, Argosy, and later like Omni VI+).

Not all later models (e.g., Jupiter, Omni VII, Eagle) use these exact 9 MHz plug-ins (they often have DSP/digital filters or different IFs). Always confirm with the specific rig's manual or TentecWiki for slot, centering, and any required modifications.