Ham Radio/Ham Radio CD-ROM (Emerald Software) (1995).ISO/reviews/sony2010/sony2010.txt

Text File | 1991-09-26 | 11KB | 261 lines

                    The Sony ICF-2010
                    ------------------
                    by Sheldon T. Hall

Before I tell you about the setup I have for my Sony ICF-2010, let
me tell you that my experience really does not support my making
suggestions or in any way taking on the role of "guru" in this
matter.  I've been in and out of SWLing for about 30 years, ever
since I built a HeathKit AR-3 receiver I got as a Christmas
present, but I've never had much of a radio, or really done much
listening, until recently.

When I bought the 2010 I justified the expenditure to my
Danish-born wife on the basis that she would be able to hear the
occasional broadcast from Denmark, and I was quite chagrinned to
discover that the 2010 would barely pick up Radio Danmark's
pipsqueak transmitter even with the wire antenna Sony supplies.

Thus, I justified the purchase and construction of a "real" antenna.

My antenna is now the $8.95 Radio Shack SWL antenna kit, erected
full length (about 75') between two trees about 65' up.  The
antenna runs ENE-WSW, which is a little askew (my major interest is
Europe) but the trees are too big to move.  Worse still, we are on
the southwestern slope of a small ridge, so even the 65' altitude
of the antenna does not give me a clear shot to the North and East.
We can pick up Radio Danmark with it, though.

The antenna is suspended by high-strength nylon twine, the twine
running through small sailing-dinghy blocks (pulleys) at both ends,
suspended weights being used to tension the antenna yet allow the
trees to sway without putting undue stress on the rigging.  The
blocks are themselves attached to some more twine thrown over the
trees by the simple expedient of tying it to a spare auto-battery
cable clamp, spinning same at the end of a short length of the
twine, David-style, and pretending the trees were Goliath.  This
was remarkably effective, as the weight cleared the tops of the
trees by quite a few feet.

This arrangement has stayed aloft during several good breezes, and
has allowed me easily to lower the antenna for modifications and to
remove a small branch lodged in it during a storm.

Since the antenna's insulators and the blocks are just within the
foliage crowns of the trees, the antenna is quite inconspicuous; it
would be more so if I dyed the twine so its whiteness didn't show
against the largely grey-green colors of the pines and oaks that
march up the ridge.

Although the antenna itself has been the same since I put it up,
I've connected it to the radio several different ways, and I think
the way I have it now is the best I've tried.  I'm quite willing,
however, to admit that my knowledge of electronics is fairly
spotty, and my understanding of RF in general and antennas in
particular almost nil.  To round out my ignorance, I don't have a
piece of electronic test equipment to my name, so any claim I make
as to "best" must be understood to be entirely subjective.

VERSION 1.0

My listening room is on the opposite side of the house from the
electrical service attachment, but only about 20' from the house's
main fuse box, and 10' from the washing machine, the outdoor half
of our heat-pump/air-conditioner, the cable-TV connection, and the
telephone terminal box.  I also have three computers, two modems,
and a printer in the listening room.

So, brainwashed by all the impedence-matching cautions in the
various antenna handbooks, and hoping to subdue any electrical
noise loose in the vicinity, I originally used RG-58U coax as a
lead-in, connecting the center conductor to the antenna (at the ENE
end) and leaving the shield unconnected.  The connection was
carefully wrapped to prevent the shield from absorbing water.  The
coax dropped vertically toward the listening room, clearing the
gutter and assuming a catenary curve to the window, where it came
in through a small hole drilled in the storm window frame.

I've always been told that the antenna is only half of the signal
path (the ground being the other), so I have a galvanized iron
strap, about 1.5" x .125" and 5' long, driven into the
perpetually-damp red Georgia clay just under the listening room
window, and I led a solid wire clamped to the strap up to the
aluminum storm window frame and attached it.  The shield of the
coax was also attached to the window frame, and thus to ground.

The coax was attached to a mini-phone-plug in the conventional way
and plugged right into the 2010.

The result was a tremendous overload on the 2010, until I put the
Antenna Attenuator in the 'local' position, when I got pretty good
results, logging numerous out-of-the-way countries and any major
broadcaster who happened to be on when I listened in.

Then someone pointed out that this rig had no lightning protection,
and that the 2010 is very sensitive to static build-up in outside
antenna; too much and the FETs in the front-end go 'poof.'

Another kill-joy told me that antenna impedence really doesn't make
much difference for receiving, and that a long-wire is high
impedence anyway.

A third well-meaning meddler mentioned that signals arriving here
in Atlanta, regardless of their original polarization, were not
really polarized any more, the various skips and bounces having
thoroughly scrambled the polarization along the way.  He suggested
that an unshielded leadin might be considered a vertical antenna.

My wife suggested that I invent some arrangement that might let me
close the window all the way.

All of which led to ...

VERSION 2.0

I replaced the coax with the unshielded leadin wire from the Radio
Shack kit, suitably lengthened with some hook-up wire of about the
same diameter.  It follows the same path as the coax, and comes in
through the coax-sized hole in the storm-window frame; I used a
rubber grommet to protect the wire from the sharp edges of the
hole.

The leadin is terminated at a barrier strip (also from Radio
Shack), as is the ground wire, and a 2.2 megOhm resistor connects
the leadin to ground to drain off static electricity.

Since the barrier strip is between the storm window and the sash,
and since this is all (reputedly) high-impedence stuff, I used
three feet of 300 Ohm TV twin lead from the barrier-strip antenna
and ground connections to the radio.  The twin-lead is thin enough
that I can close the sash.

The twin-lead ends at the high-impedence side of a 300 Ohm to 75
Ohm television balun coil, whose 75 Ohm side is a mini-phone-plug
that plugs right into the 2010.  The balun is marked Sony, so I
suppose it came with one of their small TV sets.  They probably
have these at Radio Shack, too.

I'd like to think that the balun provides both impedence matching
and static-electricity isolation services.  It doesn't seem to
decrease the signal level.

Compared to version 1.0, this setup seems provide slightly more
signal with no more noise than before, allowing me to run the
2010's RF gain control at half-mast most of the time, lopping off
much of the noise and some of the QRM, yet letting the broadcast
signals through.

I'm sure this whole setup flies right in the teeth of all that is
sacred in Antennadom, but I'm quite pleased with it.  I think the
signal strength is more than enough, the noise level is low on most
bands, and I can just sit back and listen.  I've logged stations
on all continents except Antartica, including domestic services in
the USSR and Africa, and some real low-wattage peashooters in South
America.

As is so often the case, I think I'm the limit, not the hardware.

-Shel Hall [76701,103]
 SysOp, CompuServe Gulf Crisis forum.


Here are the specs on the Sony, adapted from a file I found on a local
BBS:


                    Sony ICF-2010 Specifications
                    ----------------------------

Circuit system: FM:      Superheterodyne
                AIR/AM:  Dual conversion superhet
                Quartz controlled PLL frequency synthesis.

Frequency range: AIR     116-136 MHz
                 FM      76-108 MHz
                 AM      150.0-29999.9 kHz

Aerials:  AIR/FM/SW      External Telescopic
          MW/LW          Built-in ferrite/coil
          External terminal for AIR/FM
          External terminal for AM

Audio: 380 mW at 10% harmonic distortion.

Output: Built-in speaker
            Disconnected when earphone plugged in
        Recording output jack (minijack)
            Level:       0.775 mV (-60 dB)
            Impedance:   1 kohm
        Earphone output (minijack):
            Impedence:   8 ohms.
            Stereo output on FM
            Mono output on other bands
            "Walkman"-type headphone compatible

Power Requirements: Radio 4.5V (Three D size batteries)
                    Computer/clock 3V (2 AA size)
                    Supplied ac power adapter for radio (4.5V) operation.

Features:

*  AM has 5 modes: Wide, Narrow, Sync, USB, LSB/CW. Sync is the synchronised
   operation which has been mentioned before. There are two advantages using
   this:

     (1) It can generate a carrier for weak signals subject to fading,
     this carrier is synchronized to the original carrier and improves
     reception for weak signals (really does work!).

     (2) It can eliminate interference from adjacent stations. This can be
     achieved by tuning to either the USB or LSB of the station being
     received, whichever is not being subject to the interference.
     Wide/Narrow I think uses IF filters to change the bandwidth of the
     tuned signal. Useful in crowded bands for weak signals.

* Tuning achieved through rotary manual tuning knob, direct digital entry,
  memory recall and scanning. AM has a 0.1 and 1 kHz resolution for manual
  tuning. FM has a 0.05 MHz resolution and AIR has a 0.025 MHz resolution.
  In addition for scanning, other scanning intervals are defined. There is
  also a 9 kHz / 10 kHz switchable scanning interval for the MW band.
  The manual tuning knob can also be electronically locked.

* Scanning has too many features to list like band skipping, station skipping
  defined frequencies scanning, two scan types, memory scanning functions
  and so on.

* 32 memory presets possible which stores all characteristics of the station
  including both the mode and frequency.

* Timer: Sleep timer as well 4 programmable prioritised timers which can
  be programmed to 0, 15, 30, 60 minutes of operation (0 min disables the
  timer). The station must be stored in any of the 32 memory locations.

* Other features:

    DX/Local switch and RF gain control.
    12/24 hour clock
    Battery check
    Signal strength indicator
    Sync indicator (USB, LSB)
    Tone selector (High, Low, News)
    Volume control, of course!
    Display light

* Accesories:
    Supplied:
       AC power adapter
       Single earphone
       Shoulder strap
       SW long-wire aerial
       2 External aerial connectors
       Wave handbook
       Memo sheet and info sheet

    Optional:
       Car battery cord DCC-127A
       Connecting cord RK-69A
       VHF aerial AN-3
       LW/MW/SW wide range aerial AN-1

Price: approx $290 - $310 (mail order) - $395 list.