[TenTec] Paragon 2 Memory Battery Back-up Solved

[LEE BAHR]

Jerry:

Thank you very much.  You put light on a lot of data for me to digest.  I 
appreciate the effort.  Keep COOL!  I'll try and absorb all this now!

Lee, w0vt




> Digging deeper in the HOT attic, I found a Motorola Data Book with a 
> section on the MC146805E2P. There is NO battery in that part. Digging 
> deeper in the Paragon II manual, I found a board with a DS1220Y-200 
> Nonvolatile Static RAM and a DS1287 Real Time Clock. THOSE ARE THE 
> packages with batteries that can die with old age. I knew about the DS 
> devices, I didn't know Motorola did the same and I don't think they did.
>
> Anyway, googling DS1287 I found a page about replacing the battery with a 
> link to another opinion about how to do it. 
> http://www.walshcomptech.com/ps2/dallasrework.html That was on the first 
> page of 8190 hits. The first 30 hits averaged 2 opinions per page on 
> carving into the DS1287. It might also be replaced with a DS12887 its 
> said.
>
> As for the DS1220Y-200, its still a valid Maxim/Dallas part number, though 
> Digi-Key hints the ROSH DS1220AD-200 would be more appropriate. Either is 
> under $12 but they will order one of the AD but want an order for 56 
> minimum of the Y.
>
> Thing that might prove useful is that Maxim will sell samples direct. 
> Maxim (www.maxim-ic.com) recommends the AD part because the battery 
> doesn't begin to age until its used where the Y part ages from the date of 
> manufacture. They might send a free sample of the DS1220AD-200+ part which 
> should fit fine or will sell it for $17.85 on their web page.
>
> Appears to me that since the DS12887 and DS1220AD-200 are good 
> Maxim/Dallas part numbers with NEW batteries, there isn't a significant 
> problem. Might cost $35 from Maxim or one of their distributors if you 
> can't get them to send you a sample. Most companies like to send samples 
> to engineering students. I've not tried for specific samples from 
> Maxim/Dallas, but I had more than an apple box full of similar samples 
> from decades of samples arriving unsolicited that I've already moved. I 
> need to get back to the moving, the computer hasn't moved yet but the 
> attic and bedroom here are running about 90 degrees and the new place is 
> so much more comfortable, I'm sleeping there now.
>
> 73, Jerry, K0CQ
>
> On 5/30/2010 4:00 PM, LEE BAHR wrote:
>> Jerry:
>>
>> Thanks for the input. This makes sense. My concern is for a Paragon 2. I
>> don't have one yet but plan to buy one if/when I can find one to my
>> liking. Maybe there is someone on here who actually did this. I would
>> suspect it has been done many times since the manual says the "cell"
>> within the microprocessor chip will maintain memory and work for around
>> 10 years. These cells must all be dead bye now. I have never had a radio
>> without a small outboard battery which could be slipped in and out of
>> it's holder. For those radios I routinely change them after a few years
>> of service. That is easy and fast. This idea of having an internal
>> "cell" good for 10 years being built into a microprocessor mystifies me.
>> I can't imagine why this would be done. I have not heard of anyone being
>> annoyed by this, so there must be some remedy for the problem.
>>
>> Lee, w0vt
>> Houston, Tx
>>
>>