From: parnass@cbnewse.cb.att.com (Bob Parnass, AJ9S)
Newsgroups: alt.radio.scanner
Subject: Re: ICOM R7100
Summary: I like the R7100.  Repost of R7100 vs R7000 comments
Keywords: Scanner
Date: 12 Dec 92 19:55:56 GMT
Organization: AT&T Bell Laboratories, Naperville, IL

In article <Bz471z.p60@austin.ibm.com>, mcinnis@austin.ibm.com () writes:
> 
> Any opinions on an ICOM R7100?

My e-mail response to you bounced and I tried 2 different paths.
I replaced my R7000 with an R7100 a few months ago and liked
both radios.  Here's a repost of my comparison:


       COMPARING THE ICOM R7100 TO THE R7000 RECEIVER

                    by Bob Parnass, AJ9S

The radio RF/IF/AF portions of the R7100 are similar to  the
older  R7000,  but  the  R7100  is constructed using surface
mount parts.  Consequently, the R7100 is smaller.  A-B tests
indicate  both  the R7100 and Radio Shack PRO-2006 receivers
are about equally sensitive, and more sensitive than  the  6
year  old  R7000.   Both  the  R7000 and R7100 are much more
immune to intermod than the Uniden/Bearcat  760XLT  and  the
portable PRO-43.

Many of the functions controlled by separate rotary switches
and potentiometers in the R7000 are controlled by pushbutton
switches and firmware in the R7100.


              Deleted Tuning Meter, Added AFC

Too bad the R7000's analog center reading meter function was
replaced  with  3  indicators  on the R7100, a left arrow, a
square, and a right arrow.  In my R7100, the  square  lights
if  you are tuned within 2.5 kHz of center of an FM station,
a larger window for WBFM signals.  The arrow  indicates  the
direction  in  which the tuning knob should turned to center
the receiver on the signal.

The R7100 has an interesting AFC circuit,  controlled  by  a
front  panel  switch.   The  AFC will automagically tune the
receiver close to the center frequency if you tune  near  an
FM  signal.   You  can watch the frequency change as the AFC
steps the receiver in 100 Hz increments (on NBFM).  The  AFC
never  quite  tunes  to the exact center, but tunes within a
window set by a difference amplifier circuit, so the station
sounds  good  even  though  the R7100 is slightly off center
frequency.


                           Modes

R7000 and R7100 users have the same  choice  of  modes,  but
they  are  easily selected from front panels controls in the
new R7100.  A rear mounted slide switch is used for  USB/LSB
selection in the R7000.


    Fancy Firmware for Memory Organization and Scanning

The firmware in the R7100 is much more sophisticated, and  a
brief  article wouldn't do it justice.  There are 9 banks of
100 channels.  Further, you can associate each channel  with
1  of 10 groups.  There are many possible ways to scan, more
than listed here.  You can scan:


   all channels
   all channels in a given bank
   all channels in a given group
   all channels in a given group in a given bank

   all channels in a given emission mode
   all channels in a given emission mode in a given bank

As with most other scanners, there is a lockout bit for each
channel,  so you don't have to scan the NOAA weather channel
even though you have it in memory.

There are 10 pairs of search limits.  The search  and  store
("memory  write")  scan  mode lets you store 100 frequencies
instead of the 20 in R7000.  Another  R7100  improvement  is
that  you  can  program  up to 100 channels for the R7100 to
skip while searching.  I used this for searching for federal
stations  in  the  162-170 MHz range while skipping the NOAA
weather channels 162.55, 162.4, and 162.475 MHz, as well  as
some veteran's hospital paging channels.

The R7100 has 2 VFOs, but Icom calls  them  windows.   There
are  several  window  scan modes, but they resemble priority
scan modes in a Bearcat scanner.

Both the R7000 and R7100 scan slowly compared with  PRO-2004
and PRO-2006, and that's a drawback.  Perhaps a bigger draw-
back is that both the R7100 and R7000 employs a noisy relay,
activated  when  the  receiver is tuned to frequencies above
520 MHz.  Scanning a mixture  of  VHF  and  UHF  frequencies
serenades the Icom user with a very annoying clickety-clack,
clickety-clack!


                  New Memory Query Feature

The R7100, like the Bearcat  200xlt,  has  a  feature  which
allows  you to detect memory channels programmed with dupli-
cate frequencies.


                   Tuning Step Selections

The R7000 tuning  step  size  is  selected  using  a  rotary
switch.   The  R7100 tuning step size is selected by using a
pushbutton to step through the selections.   The  R7100  has
more  choices,  including  a 100 kHz step, useful for tuning
around the aircraft bands.

Another new R7100 feature is that a tuning step size can  be
stored into each of the 900 memory channels, so when you use
the tuning knob to tune off  a  memory  channel,  the  R7100
tunes  in  reasonable  increments (e.g., 12.5 kHz in the 450
MHz range, 10 kHz in the VHF-low band, etc.).


           Rescan Delay Added, but Nondefeatable

Icom finally included a decent 2 second rescan delay in  the
R7100  which  owners  complained was missing from the R7000.
Ironically, you cannot defeat the rescan delay in the R7100,
so  it's now more difficult to scan trunked systems in which
the frequency changes with each new  repeater  transmission!
Using  the  VSC voice squelch helps shorten the rescan delay
unless scanning noisy stations.


                   Power Supply and More

The internal power supply in  both  radios  runs  hot.   The
R7100  comes with a 12 VDC power cord included, an option in
the R7000.

The R7000 comes with a  handy  carrying  handle  and  rubber
feet, an $8.50 option on the R7100.


                   Added Clock and Timers

Unlike the R7000, the R7100 contains  a  digital  clock  and
timers  which  can be used to turn the radio on and off, and
tune to different channels, several times each day.  I prob-
ably won't be using timers, though.


                     Which Radio to Buy

For fast, reliable scanning, you still  can't  beat  a  PRO-
2006.   If  you  want  SSB reception, computer control, or a
radio with a tuning knob and lots of features,  I  recommend
the Icom radios.

The R7100 is more complicated to use than the R7000.   There
are  so  many  firmware  controlled  features  and there are
several 2 key sequencies.

Faced with choosing between an R7000 or an R7100 in a  simi-
lar  price  range,  I  prefer  the newer R7100.  Sensitivity
aside, both are about equal  communications  receivers,  but
the  R7100  is  a better scanner, especially for finding new
frequencies and organizing memory.
-- 
==============================================================================
Bob Parnass, AJ9S  -  AT&T Bell Labs  -  parnass@ihlpm.att.com - (708)979-5414
Newsgroups: alt.radio.scanner