Oh, man! Clayton, you're my hero. The prom is a 28-pin, and is UV programmable,
rather that EE programmable. I believe the programming of my prom is good. It's
just an input gate that's stuck low. If that's not a problem for downloading
(if input gate states are not needed), then my prom should be good for
acquiring the program.
I can't imagine that TT would have a problem, given that they may not even have
the capability, and cannot supply the programmed prom. But I can check with
them on Monday. Do you have the hi-intensity UV lamp, or is your fixture for EE
proms?
Thanks! es 73,
Allen-----W7GIF
----- Original Message -----
From: Clayton Brantley<mailto:clayton_n4ev@yahoo.com>
To: Discussion of Ten-Tec Equipment<mailto:tentec@contesting.com>
Sent: Friday, February 14, 2014 5:53 PM
Subject: Re: [TenTec] Corsair II UV EPROM failure
Allen: I have a programmer and can read a good eprom and make a duplicate.
I'll check it tomorrow to see if your eprom is on the list. If someone has a
good
one, I can make you one providing my programmer can handle the chip.
The only caveat is will TenTec look the other way? The only $$ would be the
mailing on my end.
73
Clayton N4EV
On Friday, February 14, 2014 7:44 PM, A R
<raf_3@msn.com<mailto:raf_3@msn.com>> wrote:
My recently acquired Corsair II has a failed logic board UV eprom
(MC68705P3S) that prevents me from operating CW. The eprom failure is the keyer
"dit" input stuck close enough to a "low", that about 30 minutes after
power-up, the eprom temp reaches 50C, and the "dit" input is low enough that
all I have is a continuous, uninterruptable transmitted string of dits.
Unfortunately, the architecture doesn't have provision to defeat the keyer
function in CW mode. The eprom temp reaches the 50C temp after about 30
minutes, with an ambient temp of 22C.
I've talked to Garry Green at TenTec, but they don't have any proms for this
ancient Corsair II. But, the unprogrammed MC68705P3S's are available elsewhere,
and Garry agreed to search the TenTec operation to see if they have the
programming fixture and the Corsair II program. I'm hoping that Garry can find
the fixture and the program. But, I'm not very optimistic he'll be successful.
So, my options are to either find a "surplus" programmed CORSAIR II
MC68705P3S (anybody have a spare or surplus one?), or modify the Logic Board
enclosure to provide forced air cooling in an attempt to keep the processor
temp below the critical 50C.......and hope the processor "dit" input doesn't
further deteriorate.
Does anyone have a spare or "surplus" programmed processor for the CORSAIR II?
Thoughts on cooling/controlling the temp of the processor? Forced air may get
the job done (maybe in combination with a dip heatsink bonded onto the
processor). But I recall (from a former life) that ss heat exchangers for dips
may be a solution that's not as messy as shoe-horning a 25mm pc fan onto the
logic board enclosure, but would necessarily contribute a slight ? temp rise in
the CORSAIR's interior.
Any help or suggestions welcome.
73,
Allen---W7GIF
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