Ten-Tec Model 217, 9 MHz 8 Pole 500 Hz CW Crystal Filter NEW in Box

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MPN:

217

Condition:

New

Shipping:

$8.00 (Fixed Shipping Cost)

Description

Description

Ten-Tec Model 217, 9 MHz 8 Pole 500 Hz CW Crystal Filter NEW in Box

Ten-Tec Model 217 is a 9 MHz 8-pole crystal ladder filter with a 500 Hz bandwidth, designed as an optional narrow CW (continuous wave/Morse code) filter for improved selectivity in crowded bands. It's an 8-pole design for sharper skirts and better rejection of nearby signals compared to 6-pole versions (like the Model 216). This filter was a popular upgrade for Ten-Tec rigs with a 9 MHz IF stage, providing excellent performance for serious CW operators (tight passband centered around typical CW offsets of ~700–750 Hz, though exact centering varies slightly by model/era).Key Details and Specifications

Bandwidth: 500 Hz (nominal at -6 dB).
Poles: 8-pole ladder configuration.
Center Frequency: Approximately 9.000 MHz (some references note slight offsets like 9.0015 MHz in certain units, but generally compatible as 9 MHz standard).
Shape Factor: Excellent due to 8 poles (sharp skirts for rejecting QRM).
Installation: Plug-in board (internal option slot in compatible transceivers; requires following the rig's manual for insertion and alignment if needed).
Era: Introduced in the late 1970s/early 1980s, part of the classic 9 MHz filter family (217/218/219/220 series).
Build: High-quality crystals in a shielded module; durable and reliable for vintage gear.

Compatible RadiosThe Model 217 is specifically designed for Ten-Tec transceivers with a 9 MHz intermediate frequency (IF) stage that accept these optional ladder filters. Compatible models include:

Omni Series: Omni A, B, C (Model 546), D series.
Corsair / Corsair II (Models 560/561).
Argosy / Argosy II (Models 525/525D).
Delta 580 (and possibly Delta II 536 in some configurations).
Paragon / Paragon II.
Omni V (Model 562/563/564).
Omni VI / Omni VI+ (Models 563/564; usable in 9 MHz slots, though 6.3 MHz filters often preferred first).
Argonaut 509 (can be added for narrow CW; documented in homebrew/mod guides).
Others: Some references mention compatibility with early Orion I (565) in 9 MHz positions, but check manuals—later rigs like Omni VII or Jupiter often use different filters or have built-in options.

Always verify with the specific rig's owner's manual or Ten-Tec archives (available on tentec.com or qsl.net/tentec) for exact slot/centering compatibility, as some models have fixed CW offsets that affect filter performance.

Specifications

Center Frequency

6 dB BW, Hz

Shape Factor, 6/60 dB

Insertion Loss, dB

Ultimate Rejection, dB

Z in & out, Ohms

Number of Poles