[ICOM] R71A Problems

[Gary P. Fiber]

Roger,

In the day these products were designed there were no EEProms, There 
were EPRoms but they cost about $25.00 each and did not hold up well in 
RF environments in the early 1980's. In my 11 years at Icom the majority 
of failures to this ram unit was when people were trying to do 
maintenance on their rigs and changed out the ram battery as part of the 
maintenance. And of course the clipped on leads jumped off and the ram 
lost power.
I suspect now days that many are getting onto 25 years old we may see 
some failures, but the ram unit draws micro amps and the battery 
supplies milliamps of current.
I think one time we figured out if all things were ideal, the battery 
should last over 80 years. However there is no such thing as a circuit 
operating under ideal on paper conditions.

Gary K8IZ

On 4/8/2011 10:18 AM, K8RI wrote:
> It's been a long time since I had a 751 but I knew the back up battery
> was getting weak (measured it in place) and knew better than to just
> replace it by pulling the old one out and replacing it.
>
> I called Icom and they suggested I get the new memory module from them
> already programmed with updates. Then all I'd have to do is swap them out.
>
> Things have changed. Back then the entire module was relatively
> inexpensive at well less than half of today's quoted prices.  Too bad
> they didn't use an EEProm or some form of static memory, rather than one
> that required a backup battery.
>
> Of course with the dead batter and loss of memory as indicated by the
> readouts there was nothing to lose by pulling the battery, but nothing
> to gain either.
>
> If the second source module is reliable I would think it would be
> desirable over the Icom module as the present, or future owners would
> not have to be concerned about a $3 battery replacement turning into a
> $75 project plus labor.
>
> 73
>
> Roger (K8RI)
>
> On 4/8/2011 12:20 PM, Stephen Budensiek wrote:
>> Hello,
>>      Guess the bad new is (if my memory is correct), the R71 has the OS
>> in RAM, you need to keep voltage on it while you replace the battery.
>> If you don't, it loses the OS.   You can either send it back to Icom
>> for reprogram, or buy another memory moudule from them, or go to a 3rd
>> party vendor who makes a memory replacement module with more memory
>> locations, and the OS is eeprom.  Any way you go, it will be around
>> $75 to get it back up.  There use to be one internet site with the OS
>> code, and if you had a ROM burner, you could reload the RAM module
>> with it.  Same problem in the 751, 271, 471, etc if the memory battery
>> failed.
>>
>> 73's de Stephen, K0SD in TX
>>
>> ******************************************
>>
>> On Fri, Apr 8, 2011 at 11:08 AM, Gary H. Harmon, Jr.
>> <gharmon at idworld.net>   wrote:
>>> I have a friend's R71A on the bench and before I get too crazy I thought I
>>> would check the list.  I replaced the battery IAW instructions on the web.
>>> The removed battery measured 0.3 volts.  It comes on with a frequency
>>> display of either 466.666.6 or 666.666.6.  There is a little hum in the
>>> speaker but no rushing noise.
>>>
>>>
>>>
>>> Are there any other obvious issues to check?  Is there a service manual
>>> available online?
>>>
>>>
>>>
>>> Vr,
>>>
>>>
>>>
>>> Gary H. Harmon, Jr. - K5JWK
>>>
>>> 6003 Archwood
>>>
>>> San Antonio, TX 78239-1504
>>>
>>> 210.657.1549h / 210.884.6926c
>>>
>>>
>>>
>>> "Retirement means every day is a Saturday except Sunday"
>>>
>>>
>>>
>>>
>>>
>>> ----
>>> Your Moderator: Dick Flanagan K7VC: icom-owner at mailman.qth.net
>>> Icom Users Net: Sundays, 1700Z, 14.316 MHz
>>> Icom FAQ: http://www.qsl.net/icom/
>>> To support QSL/QTH.net: http://www.qsl.net/donate.html
>>>
>> ----
>> Your Moderator: Dick Flanagan K7VC: icom-owner at mailman.qth.net
>> Icom Users Net: Sundays, 1700Z, 14.316 MHz
>> Icom FAQ: http://www.qsl.net/icom/
>> To support QSL/QTH.net: http://www.qsl.net/donate.html
>>
>
> ----
> Your Moderator: Dick Flanagan K7VC: icom-owner at mailman.qth.net
> Icom Users Net: Sundays, 1700Z, 14.316 MHz
> Icom FAQ: http://www.qsl.net/icom/
> To support QSL/QTH.net: http://www.qsl.net/donate.html
>


-- 
Gary P. Fiber K8IZ

General Radio Telephone Operators License PG-19-6691,
with Shipboard Radar Endorsement.
Washington State Resident.

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