Robert Lucky's own 2006 first-person retrospective essay on inventing the adaptive equalizer exists but is paywalled, with no open-access copy found

Robert W. Lucky is credited as sole author of "The Adaptive Equalizer," a first-person retrospective on inventing the Bell Labs adaptive equalizer (claim-lucky-1965-adaptive-equalizer-steepest-descent-transversal-filter), published in IEEE Signal Processing Magazine. Semantic Scholar's indexing record gives the DOI as 10.1109/MSP.2006.1628883 (Semantic Scholar Corpus ID 15008740; DBLP cross-reference journals/spm/Lucky06), and Unpaywall's API record for the same DOI gives the venue as IEEE Signal Processing Magazine, published 2006-05-01, with oa_status: "closed" and no open-access location found. The DOI itself resolves — https://doi.org/10.1109/MSP.2006.1628883 returns an HTTP 302 redirect to http://ieeexplore.ieee.org/document/1628883/ — confirming a real IEEE Xplore record exists at that identifier. IEEE Xplore's own page, however, returned no readable content to this session's fetch tool (consistent with a paywall or bot-block), so the article's actual text — including its exact volume/issue/page numbers, given only by aggregators as vol. 23, pp. 104–107 — was not independently confirmed against the publisher's own page.

This is, on current evidence, the single most promising still-unread source bearing on question-lucky-own-account-of-widrow-hoff-awareness: Lucky's own account, in his own words, of how he invented the equalizer, and a natural place to expect a statement of what he did or didn't know of Widrow-Hoff's 1960 LMS work (claim-widrow-frames-lucky-equalizer-as-independent-invention-lms-later-graft). It joins Lucky's 1999 ETHW oral history — also named, also findable, also blocked — as a second first-person source that exists without yet having been read.