I looked up the X24C04 in my Xicor Data book. It is a 512 x 8 Electrically
Erasable PROM with a 2 wire serial I2C interface. You read and write to it
by sending and receiving serial packets with control commands, addresses,
and data.
I'm surprised that the tuner control system would have a problem with the
EEPROM "filling up", but I suppose its possible. There is nothing special
about getting full. It should just wrap around and begin overwriting the
first locations. If the tuner starts acting flakey, sounds like a bug in the
control software. In theory, you could manually erase the chip if the tuner
won't handle that, but you would have to send it serial commands to write
all the locations, there doesn't appear to be a block erase command, so it
would be a bit of a hassle requiring some digital breadboarding.
- Tom
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Tom Scott - Wyle Electronics - KD7DMH
10300 SW Nimbus Ave #PB, Portland, OR 97223
503-603-1931 - TEL 503-684-6620 - FAX
503-504-1583 - Cell 503-604-8651 - Pager
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-----Original Message-----
From: owner-tentec@contesting.com [mailto:owner-tentec@contesting.com] On
Behalf Of Charles Jack Hawley
Sent: Sunday, January 10, 1999 9:57 PM
To: Rick Williams
Cc: TenTec List
Subject: Re: [TenTec] 253 Tuner Chip?
Rick Williams wrote:
> That's chip-NOT chirp.
>
> I have been seeking information about TT model 253 automatic antenna
> coupler. It seems to be a love it or hate it opinion.
>
> One thing some have mentioned is the memory chip that is used to store the
> several combinations of presets. The question is what happens when the
> memory chip is full? Is it eraseable? Can it be replaced? Is the part
> proprietary or is it available "off-the shelf".
It's a Xicor X24C04 and is available from the chip maker or TT. It costs
about $5. It "fills up" if you do a lot of tuning. If you do mostly returns
to stored memory locations, it lasts a long time. TT provided a socket as
their solution to the problem. When it "fills up" it causes the tuner to
hunt forever on some (usually several) of the memory addresses but works
normally on all the rest.
Another thing that annoys me is that when I turn the tuner on and I have
selected a different antenna position or band, the tuner goes to some
setting that is not correct for the antenna or band it is set to. This also
causes the micro to lose tract of where the roller coil is and you have to
do a "realignment" by pressing the up inductor and cap switches. The other
thing is that if you leave it where you turned it off, then you still have
to cycle it through a different ant or band because it comes on in the
bypass mode instead of whatever memory address it was set to.
Other than that.......it's ok. I wish I had a manual reversible el network
that had 5000 pf of hi Q cap and about 35 uh of roller inductor. I would
like that better instead of the 253.
Chuck
--
Charles Jack Hawley
Amateur Radio Operator
Chuck, KE9UW
Alias "Jack" to my BMW Motorcycle Friends
BMWMOA # 224 Black '86 K100RS
President, IBMWR
Viki rides...
BMWMOA # 18120 Black '86 K100RS
c-hawley@uiuc.edu
Sr. Research Engineer Emeritus
University of Illinois, Urbana-Champaign
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