SV: [PCR-1000] no receive

Sun Jun 19 01:36:23 EDT 2005

Speaking about slow starting and stopping powersupply. 
I have a simular problem with my AR-3000. The powersupply is a quite heavy
duty 
10Amp unit with large capacitors, and there are lots of other radios beside
the 
AOR AR-3000, but this radio need to be switched off/on with it´s own switch,

otherwise at 1 out of 3 times it drops the memory, all channels and
frequencies 
has to be reprogrammed. It has a lithium back-up memory but this is checked
OK (and
replaced). Another strannge problem has followed this radio since it was
nearly new:
>From time to time it starts to oscillate internally, often when receiving a
somewhat
weak and noisy signal. This can be heard as a strange and roaring sound in
the speaker
but as soon as you only set the hand about 10cm in front of the radio it
stops. Very annoying..
There could be several weeks between the faults, or several times on a
day.... Any tips on
the cause and solution for this is most welcome.
I have a PCR-1000 to, it has not so far (3 years) failed.

/Folke   SM7HMS 

-----Ursprungligt meddelande-----
Från: pcr-1000-bounces at mailman.qth.net
[mailto:pcr-1000-bounces at mailman.qth.net] För Darrel Emerson
Skickat: den 18 juni 2005 17:40
Till: INTERNET:pcr-1000 at mailman.qth.net
Ämne: RE: [PCR-1000] no receive

About the PCR-1000 going deaf:
   I still have an early PCR-1000 receiver, and have been following this
list more or less since the beginning.  I think that the business of
third-party software causing the problem was something put out by Icom as a
way of blaming someone else. From following this list,  I believe there have
been quite as many EEPROM corruptions from people using Icom's own software,
as from use of any third party software - but Icom always denied that.
  I still use the same PCR-1000 essentially daily.
   I had no problems with the PCR-1000 for 6 years, and then one day the
EEPROM corruption struck,  At the time I was using Win98, and had been doing
so for some time.  Fortunately I had an EEPROM backup, and after EEPROM
restoration the PCR-1000 was back on the air, as good as new, in no time.
It's been running since then for a couple of years.  Before restoration I
made a temporary backup of the corrupted EEPROM and examined it.  It wasn't
just a single byte here or there, but essentially all of the EEPROM bytes
had been replaced by Hex#80.
  I never found what had caused the corruption after 6 years of no problem.
 It might
have been Windows interrogating the serial port.  Another theory is that it
was my power up sequence; I use relatively heavy duty 12 V power supply, and
was in the habit of leaving the PCR-1000's own power switch turned on, and
just powering up or down with the 12V PSU switch.  I could imagine that,
particularly after I turn off the PSU power, the nominal 12 V output
decreases fairly slowly as capacitors discharge.
You could imagine then that the slowly falling low voltage that's still
applied to the PCR-1000 might cause the logic to get into some strange state
which could occasionally erase the EEPROM.  "Occasionally" could be once in
every 2000 power cycles, or about once per 6 years.  
  This is just a theory.  Since that one EEPROM corruption, I've made a
point of only turning on the PCR-1000 at its own switch after my PC has
booted up, and after the 12 V PSU has been turned on.  Similarly, before
powering down, I first turn off the PCR-1000 at its switch, before shutting
down the PC and powering down the
12 V PSU.  Since doing that, there have been no further problems - at least
for
2 years or so.  But then, it took 6 years for the first and only problem to
appear, so I guess I have to wait for a few more years to know if my better
power up and power down sequence actually makes any difference.

         Good luck,
                     Darrel Emerson.

Original message: -----------------------
Message: 1
Date: Fri, 17 Jun 2005 17:46:21 +0100
From: "Dave Hancock" <dave at davehancock.org>
Subject: RE: [PCR-1000] no receive
To: "'Discussion of PCR-1000 by Icom'" <pcr-1000 at mailman.qth.net>
Message-ID: <20050617164705.B0C97859C28 at mailman.qth.net>
Content-Type: text/plain;       charset="us-ascii"

Hi Chuck,

My unit was deaf on 137mhz but was receiving FM broadcasts ok. I cured the
problem by loading on a copy of a working EEPROM I got from
http://sean.wenzel.net/lists/PCR1000/0413.html. I then used TalkPCR to make
a backup of my original, renamed it and then renamed the downloaded version
so TalkPCR thought it was my backup and restored it. 

This certainly cured my problem and as long as you can make a backup of your
original you are not going to be any worse off.

Drop me a private mail if you have trouble finding any of the above on the
web and I will send you a copy.

Good Luck!
Dave
Dave at davehancock.org

-----Original Message-----
From: pcr-1000-bounces at mailman.qth.net
[mailto:pcr-1000-bounces at mailman.qth.net] On Behalf Of Chuck Nitsch
Sent: 16 June 2005 01:11
To: Discussion of PCR-1000 by Icom
Subject: RE: [PCR-1000] no receive

Here is what I know for sure... It's not the cable and it's not the
computer.

I have tried to tune both AM and FM broadcast stations, but I get nothing
other than speaker hiss / noise.

I've considered perhaps it's the EPROM, but I don't have a backup.

Has anyone here had the experience of having an Icom go deaf (excluding
white noise from speaker) and subsequently do an EPROM restoration and fix
the problem?
<

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