parnass@ihu1h.UUCP (Bob Parnass, AJ9S) (02/27/85)
x
LOSS OF ICOM BACKUP BATTERY FORCES
REPROGRAMMING OF RAM
A friend from Wheaton (MD) asked me to post this war-
ning:
If you own an ICOM R71, 751, 271, or 471,
don't disconnect the lithium battery on the
memory board!
All these models use a common $17 memory plug-in board
which contains 2 IC's (one a Japanese 2114 RAM) and a
lithium battery.
This fellow wanted to experiment with the memory cir-
cuit, so he disconnected the battery in order to
install a socket for the RAM.
His radio didn't work when he reconnected everything,
and a call to ICOM confirmed that the RAM contains the
microcode which gives each model radio its own per-
sonality. His board is on its way back to ICOM for
reprogramming, which can't be done at the dealer's.
For ICOM owners, this means that when the lithium bat-
tery runs down (7 year life), the memory board must be
sent in for reprogramming.
For those interested in the R71A service manual, a
disappointing note: the manual does not contain schema-
tics for the speech synthesizer or IR remote control.
This fellow is contemplating using his home computer,
which uses 2114s to determine the contents of the ICOM
RAM, and is looking for other suggestions. It would be
useful to modify the contents of the RAM to permit out
of band reception.
--
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Bob Parnass, Bell Telephone Laboratories - ihnp4!ihu1h!parnass - (312)979-5414 ptb@Mitre-Bedford (03/01/85)
Does anyone know if they use that same microcode setup for the ICOM 02AT handy-talkie too? In other words, if you get one, are you going to have to send it back in 7 years to reprogram it too? This does have a lithium battery to do the memory, but I am not sure about any "personality" setups on the rig. Thanks in advance, Peter Baldwin, WA1SNH ptb@mitre-bedford (617) 271-2886
BISBEY@USC-ISIB.ARPA (03/04/85)
I would recommend changing the Lithium Battery with the radio powered on, i.e., let the radio hold up the ram while you're swapping batteries. Last week, Bob Parnass posted a message on setting frequencies outside the band limits of the R71A. The computer interface can be used for this purpose on the 751, 271, and 471. If I remember correctly, the radios only cover 1 MHz above and below the band limits before folding takes place, and you can only tune towards the band limits. For greater coverage, you need to change the band limits themselves; I changed my 271 from the standard 143.8-148.2 MHz to 140-150 MHz. Finally, for satellite users, the computer interface makes working satellites a delight. Just tune the receiver and let a computer calculate and set the transmitter frequency. Richard NG6Q -------
pcarah.es@XEROX.ARPA (03/07/85)
No, the 02AT, 04AT use diodes soldered onto the processor board for
their personality. I have the impression that the reset button works by
disconnecting the battery.
-- Pete, K6JRR
PCarah.es@Xerox.arpa
{...,ihnp4}!vortex!pelican!pete