Hi Dave, I am now looking at the service manual of TR7. It lists two versions of digital board. One uses PROM and one uses without. The Drake part number for the prom is 3040082 at location U201. If the part number is the same on the R7 manual, I can safely assume they are the same.
With the version of the schematic without the prom and patience, the logic states should be able to be derived. Hope this helps, QRP3K On Wed, Jan 13, 2010 at 10:07 PM, Dave Childs <wireadd...@operamail.com>wrote: > Because of an accidental solder bridge [that I put] between the +5 & 10 V > buses on the underside of the parent board I fried the PROM IC, U201 [P/N > 3040082] on the digital control board. Everything else appears OK but all > the PROM outputs stay low although the enable-not input is low & the [4] > band select inputs are changing state properly. I need to get another > [properly programmed] PROM, another 02 board or the truth table for this > PROM so I can possibly hard wire something in its place. I've looked for > R7/TR7[A] parts on EBay but all I could find was a complete R7 for over > $1200. I'm not sure if the digital control boards for an R7 & a TR7 are the > same; I've been told both that they were & also that they weren't so I'm not > certain. Does anyone have these parts for sale of a truth table for U201? > [I may need to disclose my e-mail address if there's no other way make > contact.] Thanks in advance & regards. > > Dave > > > _______________________________________________ > Drakelist mailing list > Drakelist@zerobeat.net > http://mailman.zerobeat.net/mailman/listinfo/drakelist >
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