I've been reviewing the 'conversion' document, found here: https://nerp.net/~legendre/heathkit/3400/ET-3400_ET-3400A/Heathkit%20ET%203400_modification_manual.pdf
Which describes how to modify the ET-3400/A to mate with the ETA-3400 accy unit. For some reason, a number of details - pictorials, it seems - are missing from the document. All of the missing details seem to involve modification and connection of an 'RF shield' component, which might refer to a copper tape strip which is part of the ET-3400 package. Apparently, the they intend for a wide copper strip to interconnect the ground planes of the two chassis..? My sense is that the info was left out as it's unnecessary to achieve correct operation.. more of a "the FCC made us do this" sort of thing. Can anyone comment on the omission, and any importance it might have? ----------------------------------------------------------------------------- (My complete Heathkit 3400 series document set is here: http://nerp.net/~legendre/heathkit/3400/ It includes all of the scanned 3400 materials I have collected, and I believe it is complete, less the BASIC programming course materials. All other documents, including the self-taught courses should be present. Please advise if anything is missing, or if you can supply the BASIC course documents. ------------------------------------------------------------------------------ On Tue, Jun 7, 2016 at 3:58 PM, drlegendre . <[email protected]> wrote: > Hey, thanks for the catalog link. It confirms that the 'W' designation > indicates factory-wired units, in the case of both the trainer and the > accessory unit. But note the difference in assembly costs between the > ETW-3400 and the EWA-3400 accessory, I'm surprised that the latter would > take any more time to build than the former, but I'm sure they had their > reasons. > > And it appears that the $47.00 chip option is for the extra 3K of SRAM > that the accy. board can hold (for the max total of 4K). Both the tiny > BASIC and monitor ROMs are standard equipment, and included in the regular > price - or at least they were in 1979. > > On Tue, Jun 7, 2016 at 7:06 AM, william degnan <[email protected]> > wrote: > >> CORRECTION >> >> I am wrong. The W means assembled in the factory apparently. >> >> http://heathkit.garlanger.com/catalogs/1979/Heathkit_Catalog_845.pdf >> >> For another $47 you could by the chipset for either the W or T versions. >> >> Sorry about that. >> >> b >> > >
