[PCR-1000] PCR-1000 Scan Rates

Tue, 23 Sep 2003 13:30:20 -0400

[All opinions expressed are those of the author alone. He's crazy, you
know...]

Ahhhhh, use caution in the quest for speed!
That path may lead to EEPROM corruption.
I've had  PCR-1000s for 4 years now.
My first lesson with ANY new or different software is BACK UP YOUR EEPROM.
Do it now.
No excuses.
It will cost you $90 plus shipping to an Icom service center if you scramble
your EEPROM.
There are several free programs out there that will make you a backup copy.
Google "pcr-1000 eeprom backup"

----[What limits scanning speed? ]-----
The time it takes the radio to process each command is the limiting factor.
. Any recent Pentium computer with a 19,200 baud serial port is capable of
sending commands faster than the radio can process each command and respond.
The processor in the radio isn't all that fast, as the radio wasn't designed
to be a 'scanner' in the sense of a dedicated scanner radio. It works well,
but if I'm just going to listen to the local keystone kops, I've got a
cheapie Radio Shack scanner that does a much better job-- But the Radio
Shack scanner won't do AM, it won't do WFM, it wont do USB, it won't do LSB,
it won't cover below 30MHz or over 900MHz and it sure won't do a spectrum
analysis or fine-tune like the PCR-1000 can.

-----[How does the EEPROM get corrupted? ]-----
When you send a command to the radio, the radio responds after it completes
the command. It's possible to send another command without waiting for the
response from the previous command. Sometimes you can get away with not
waiting for the radio to reply and sometimes not. If there are several
pending requests to the radio and they begin to overlap, the radio starts
getting garbage mixed in with data. The garbage is what triggers corruption.
If in the quest for speed the software does not wait for the response from
the radio after sending a command,
and sends another command,
and another,
and another,
the radio may get 'confused' and write garbage to your EEPROM.

-----[Symptoms of EEPROM corruption include: ]-----
AFC in NBFM mode causes the radio to tune downward forever.
Bandscope shows small signals all the way across or doesn't work at all.
Radio is deaf in many VHF/UHF  bands.

I've had it happen to me several times. The first time it cost me $90.
Then I learned and backed up my EEPROM.
I've had to use the backup several times after trying new software.
There have been dozens of programs written to run the PCR-1000. I've
probably tried them all.
Several nice programs never got popular because they didn't wait for the
radio to respond before sending the next command and would scramble your
EEPROM..

I have two PCR-1000s - one is four years old, one is two years old.
The newer one will scan slightly faster than the older one. About 1 1/2 or 2
channels a second faster than the older one.
The older one seems to resist EEPROM corruption better than the new one, but
it will 'lock-up' and require a power off/on to restart. (different
processor chip revision?)
Anyway, I like my PCR-1000s and wouldn't trade them for anything else
comparable.
I use TalkPCR 99% of the time and have never had EEPROM corruption using
TalkPCR. (I can't say the same thing with other much more expensive
software..)

Radios in the house:
Icom R-8500
Icom PCR-1000 (2 of 'em)
Icom R-10
Lowe HF-150
Pro-92 scanner
Pro-2045 scanner
A couple CBs and FRS radios
A whole attic full of antennas (neighborhood rules: no outside antennas)

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From: "Julian Blandford" <[email protected]>
To: [email protected]
Date: Mon, 22 Sep 2003 21:44:48 +1000
Subject: [PCR-1000] PCR-1000 Maximum Scan Rates
Reply-To: [email protected]

In the recent flurry of messages about TalkPCR I noticed that Probe1k laid
claim to having the
fastest scan rates of any software that can drive the PCR-1000.

Apparently this is due to it being DOS based, nice and simple and having a
great database
engine under the hood which enables Probe1k to churn through the frequencies
quicker.

So what is the limiting factor on the maximum scan rate of the PCR-1000? Is
it simply the
comms interface speed?

Presumably with faster and faster PC hardware out there that can execute
code quickly (no matter
what GUI or database engine is being used), the limiting factor would not be
the program
that generates the ASCII going down to the PCR?

Do those little USB-to-serial interfaces improve the throughput over just a
plain DB9 connection?

best rgds, Julian