Re: Radio/Communications FAQ  
Author: Wombat <larryn@ozemail.com.auDate: 1999/03/08Forum: alt.survival Posted on: 1999/03/08Message-ID: <370e8fde.38813190@news.ozemail.com.auContent-Transfer-Encoding: 7bitContent-Type: text/plain; charset=us-asciiMime-Version: 1.0Newsgroups: alt.survivalOrganization: OzEmail Ltd.References:   sponsored by:
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On Sun, 07 Mar 1999 17:59:43 GMT, RadioKrafter@hotmail.com wrote:

There have been the on and off requests for "which radio receivers to
buy?"  Maybe I can help.   I have been a licensed ham for just over 25
years and I thought a contribution based on my own experience would
begin to balance the scales just a bit for what I have received here
from so many thoughtful people.

I live about 150 miles north of Cape Hatteras, NC, an area which can
be pummeled by hurricanes.  Naturally, radios and communication are
important to the general public here.  Hams of course, are pretty much
"the first ones in" during and after a hurricane or other disaster.
Thus, we worry a bit more about radios that can transmit, a
consideration not all may share.   

1== Very happy to see a radio amateur on the group!   

This treatise will be about receivers.  

If anyone wants do discuss receiver, transmitters or "radio kraft"
(how to do it) etc.... I would suggest that we get together on the
Preparedness chat channel at some mutually agreeable time.  I may even
use the personal www space that my ISB provides and do a longer
treatise there.    Any suggestions or thoughts would be appreciated by
private e-mail.

-----------------------------------------

Emergency Communications - Receivers

During an emergency , or any time really, being able to hear and
digest news is important; during emergencies, especially so.  Imagine
sitting through a hurricane, tornado or flood in an information
vacuum. An often overlooked attribute, during extended problems,
radios can lend moral support and help maintain "mental balance"
through their entertainment value alone.  Having a quality, reliable
radio receiver on hand is an important component in the inventory of
forward thinking individuals.

2== IMHO, all excellent points.   In a disaster situation, not
knowing what is happening is far worse than knowing.

To help with your selection, just a bit about basic communications
theory...  There are 4 areas of frequency coverage  to consider, each
with special attributes.  These are:

Long Wave 	150-300 Khz
Commonly used in Europe, northern Africa and the Mid-East  for
commercial broacast.  Signals propagate 3000 miles + during darkess.
Can be heard well after dark on the East Coast.  Transmissions are
made in conventional, double sided AM with carrier (A3). Planning to
include coverage of this band has little "preparitive value."


2== We don't get any long-wave broadcasting in Australia, and agree
that VLF band is of limited usefulness, with one possible exception.
It includes airport radio beacons between 200 - 415 KHz.  Larger
airports give continuous weather reports in voice.  Smaller ones may
just have a morse identification signal.  

Portable receivers, even cheap ones, are pretty directional.  If
someone takes the trouble to find out the frequencies of the airports
in their area, and has a map, would be possible to roughly determine
location by plotting  the direction of strongest signals.

Possibly of limited use in these days of portable GPS receivers, of
course, but could conceivably be useful.  Of course, can usually do
the same with BC band stations.

Medium Wave        530 - 1.7 Mhz

This includes both the conventional and extended (1.6 - 1.7 mhz) US AM
broadcast band.  Reception VIA ground wave to distances of 300 miles
during daylight hours and 2,000 miles at night via skywave is common.
This band has a combination of large, network owned stations such as
the 50KW WCBS in New York City on .880 mhz and small, 500W local
stations.  During an incident, you can expect to hear the "company
line" from the large network stations contrasted with very "up front
and personal" accounts from the locals.  Coastal listeners can hear
stations in Europe at dusk on occasion.    Transmissions are made in
conventional, double sided AM with carrier (A3). Planning to include
coverage of this band has much "preparitive value."

3== Are you planning a later post on emergency antennas to 
get the best reception?   

4==Those with a shortwave receiver with coax antenna connector might
want to consider an active antenna such as the Datong AD270 or AD370 .
[Indoor & outdoor models.]  I recommend the weatherproof outdoor
model, which is a weatherproof sealed plastic box with 2 x demountable
stainless steel whip antennas each side.  These whips are each  1.5
metres [ 59 inches] long, so unit is around 10 feet  wide [or long]
when assembled.   Mounted vertically, acts as a vertical dipole and is
omni-directional.  Used horizontally, has same directional
characteristics as ordinary dipole, and signal is strongest when
orientated at right angles to source of signal.  Stations off the ends
of the antenna, even strong local stations, can be nulled out.   This
is a *very* useful feature when in a situation where other stations
may interfere with the one you are trying to listen to.
Specifications follow:

Frequency range:  Sensitivity is constant from 200 KHz to 30 MHz.
Useful performance is also obtained from 100 KHz to over 70 MHz.

Output impedance:  50 ohms nominal

Differential voltage gain of head unit: 6 dbs (into 50 ohm load)

Gain of interface unit 0 dbs (preamplifier out of circuit) or 12 dbs
switchable.

Supply voltage::  11 to 14 volt

Supply current: 140 mA

Features include:
* Available in two versions, one for indoor use only (model 270), the
other for outdoor mounting (model 370)
* Overall length only 3 metres yet gives signal-to-noise ratios
comparable to full-size conventional antennas in the 200kHz to 30 MHz
range.
* The response is broadband and no tuning or adjustment is required
when changing frequency, therefore ideal for mounting in remote
positions.  e.g. loft, attic, roof or chimney.   
* Designed to professional standards of low noise level and strong
signal performance.
*Dipole configuration gives choice of polarization plus useful
directivity and eliminates need for ground plane or earth connection.
* Excellent balance and constant output impedance minimize
interference pick-up by the feeder.
* No need for expensive accessories such as antenna tuner units or
matching units.

I've used one for over a decade and very pleased with it.  Should be
very useful for a short wave listener who isn't allowed an outdoor
antenna due to zoning regulations.  It comes with a 4 metre [13 foot]
cable from head unit to interface unit, one meter interface cable from
interface unit to radio.  This is enough for most applications.  

It can be used as a receiving antenna for a 27 MHz transceiver.
However, would strongly suggest that if do this, remove the microphone
from the transceiver.  Otherwise you, or your children, might forget
and key on the transmitter.  If do this, your "active antenna" will
instantly become a permanently "inactive antenna". ;-  


Shortwaves   2.0 - 30 Mhz

The shortwaves contain the full gammett.  Large, easy to hear,
government owned international broadcasters are typically found in the
49, 41, 31, 25, 19 and 16 meter International Broadcast bands with
multi-language transmissions including English.   While you can hear
different perspectives on a given event, the information will be
skewed to the broadcasting governments official position. 
little exception, transmissions are made in conventional, double sided
AM with carrier (A3).

5== In some countries the only broadcasting is government controlled.
In others the broadcasting is completely independent.    American
friends tell me that US sources aren't always very good in reporting
what is happening outside the US.  

Since the international date line zigzags down through the Pacific,
those of us on this side of it will experience any Y2K problems that
come up at the end of the year.  World time is usually reckoned from
GMT (Greenwich Mean Time), or London time.  

When is midnight in London, will only be 1900 hrs [7 PM] in New York
[ GMT  minus 5 hrs] and 1600 hrs [4 PM] in Los Angeles.   [GMT minus 8
hours].    In Australia, we will be on daylight savings time, and it
will be 1100 hrs [11 AM] as we are 11 hours *ahead* of GMT.

So anyone who really wants to follow the action should know where to
find shortwave services from NZ, Australia, Japan, etc.   which can
give US listeners several hours lead time on what is happening here.

Although the date line is a couple of time zones east of New Zealand,
NZ will be one of the first countries that is heavily dependent on
computers to be affected.  When it is midnight on Dec.31 in NZ, 
will be 2200 hrs [10 PM] in Sydney, 0600 [6 AM] in New York
and 0300 [3 AM] in Los Angeles.  

Smaller, regional broadcasters throughout the world can be found in
the 120, 90 and 60 meter "Tropical Bands."  Similar to our AM
Broadcast Band, the tropicals are used in many 3rd world countries to
allow full country radio coverage using only 1 or 2 transmitters with
programming typically in the country's native language.  Only about
10% of programming found on these stations is in English.  The
tropicals are so named because international treaty allows their use
by stations commonly located between the tropics of Cancer and
Capricorn.    Transmissions are made in conventional, double sided AM
with carrier (A3).  There is little value in planning listening to
broadcasts on the Tropicals unless you are skilled in a foreign
language.  Spanish would be my 2nd language of choice here as there
are hundreds of small, independent latin stations on the Tropicals in
the evening transmitting from our neighbors to the south.

Amateur Radio voice communications can be found on the 160, 75, 40,
20, 15, 17, 12 and 10 meter bands.  These transmissions are generally
made using either lower or upper Single Sideband (SSB) as the
transmitting mode (A3J).  Selection of sideband is frequency
dependent.  EG:  Lower on 41 meters and below, upper on 20 meters and
up.   The 160, 75 and 41 meter bands are usefull locally by day but
primary use is at night with  signals propagating across the country.
The 20, 15, 17, 12 and 10 meter bands are typically useful by day
although our currently increasing sunspot numbers support propagation
at night.   Count on first hand information from hams that might
benefit from second source confirmation.

The Citizens Band (CB) frequencies are found at 27 mhz.

Planning to include coverage of the shortwave bands, especially the
amateur bands has "preparitive value."



VHF bands 30 - 300 Mhz and UHF 400-900 Mhz

Of course, the 88 - 107 mhz conventional FM broadcast band is found
here along with Television.  Typically, the physics of these
frequencies do not allow for propagation over distance, especially
beyond the amateur 6 meter band (54 mhz).  The 2 meter amateur band is
found at 146 mhz, the 70cm band is at 440 mhz.   These are for local
(<50 miles) use and narrow band FM (F3 something-or-other) is the
transmission mode.    Cellular phones occupy a good bit of space on
800 Mhz but listening there is illegal and receivers have not been
commercially available for some years.  There are older scanners
available (Radio Shack et al..) which will listen to cellular when
modified.  800 mhz enabled receivers are available in Canada.

The police, fire, FBI, DEA, BATF, et al use frequencies in this range
for local communications and "event" coordination.  Listening to these
is not (yet) an area of expertise here  but  the wise planner will
ferrett out the various frequencies and program them into their
scanner. It would be nice to know who was-where-doing-what in your
local area.

NOAA weather radio broadcasts in FM on several frequencies around 162
Mhz.  Choice of which on is determined by region.  Ours is 162.55 mhz.

Planning to include coverage of the VHF bands, especially the amateur
and police frequencies has "preparitive value."


Armed with that basic knowledge, a choice of choices can now be made
as to equipment.  This can be as involved or not as you wish.  Price
is determined by level of performance and for the average person using
radio equipment as a stand by, I would suggest not buying $1,200 table
top shortwave radios.  For preparadness, lots of wizz-bang gadgets and
freatures along with lab-level perfomance is not required or
recommended. 

What is most important is price to performance ratio, simplicity of
operation (who wants to re-read the book in and emergency) method of
power and power consumption and of course, reliability.  I am not
recommending crank up generator powered radios.  While I appreciate
their design and utility, I am not convinced as to their reilability
during daily use over the long haul.  Plus, their price/performance
ratio is smaller than like featured conventionally powered units.
When you add a flipping LED light, its even more skewed. 

5== Not that it has any fancy digital readout, but what do you think
of the old Yaesu FRG-7 as a survival radio?  Wadley Loop circuit
enables tuning to plus or minus 1 KHz..   Was a fairly popular general
coverage receiver here.  Many of the features of an amateur receiver
without the complexity.  Will operate from mains, 12 VDC, has
provision for optional inbuilt battery pack. 
Frequency range:  200 KHz -29.9 MHz
Type of emission: AM, SSB, CW  
Sensitivity: SSB/ CW  :  Better than 0.7 microvolt at S/N 10 dB
	      AM:   Better than 2 microvolt at S/N 10 dB
Selectivity :  plus or minus 3 kHz at minus 6 dB, plus or minus 7 kHz

		at minus 50 dB
Stability:   Less than plus or minus 500 Hz at any 30 minutes after 	
		warm up.
Antenna impedance:   High impedance for  .2 MHz ~ 1.6 MHz
			50 ohm unbalanced for 1.6 ~ 29.9 MHz
Power Requirement:  100/117/200/220/234 VAC 50/60 Hz, 12 VDC external

			or internal.  [Battery holder is option]
Power consumption  AC 14VA
Size:  340 mm wide x 153 mm high x 285 mm deep.
Weight:  Approx. 7 kg without batteries.

6== Very  obsolescent these days, of course, but the survivalist on a
budget might be able to find an old one if looked around a bit.   
As can see from size and weight, though, not something one tosses in a
backpack.   

For all of these radios, consider having a solar battery charger plus
a back up with several sets of either Ni-Cad or nickel hydride NiMh (I
believe thats it) on hand and rotate them.  Yesterday, I saw one of
these $59 Far East mfg Bay-Gen knockoffs that you see advertised.  One
of these would be far from my choice.  

7== Not familiar with these, but a problem have seen with many low
cost analogue [non-digital] receivers is that tuning is so crowded is
difficult to find a specific frequency.   The FRG -7 is analogue, but
solves the problem by bandswitch, pretune to select a 1 Mhz segment,
then bandspread calibrated from 1 to 1000 to tune down to 1 Hz within
that one Mhz.   


Below are some specific model suggestions with a brief discussion.   I
am including URL's for sales companieswith some outright
recommendations.

Right up front, I do not sell nor do I have any monetary interest in
the suggestions made here.  All the URL's are that of Universal Radio,
in Reynoldsburg Ohio.  I have delt with these folks for 15 years and
have ALWAYS been satisfied.  As important as products, they also have
a wide selection of books and a helpful sales staff  to help you best
configure and enjoy your radio.

So, its pure info, folks.  No sales stuff.


For basic AM and FM coverage

Not widely known, the GE Super Radios are excellent.  They are very
very high performance units covering our AM and FM broadcast bands.
Strong points are incrediably low battery consumption and excellent,<
hi-fi quality audio.  I have personal experience running one of these
12 hours/day for 4 days during the last hurricane (Bonnie?) then
intermittently for a year beyond that on the same 3 "D" cells. Other
owners share the same observations.   At $59 US discount, the
price/performance ratio is superb.  

You can see it at :
http://www.universal-radio.com/catalog/spcialty/0547.html



Receivers for Shortwave coverage include these suggested portables:

While I have not used one, I know many of those who have and speak
highly of the Grundig Yacht Boy 400.  It offers Long Wave, Medium Wave
Shortwave and FM coverage.  It also includes SSB mode (A3J).  At $169,
they are not bad.  At $129 for a reconditioned unit, even better.

See it at:

http://www.universal-radio.com/catalog/portable/0040.html



The Sony ICF-2010 receives Longwave, Meduim Wave, Air-Nav and FM.
Having owned one, I can tell you that it is the standard by which all
portables under are judged.  The 2010 receives AM (A3) Sideband (A3J)
and wideband (comercial broadcast) FM (F3) modes.  It also includes a
very handy and effective<  tool for receiving conventional AM
signals, a sideband selectable synchronous detector and 2 IF
bandwidths for counterint interference.  The  '2010 was first
introduced in the 80's and over that time, slated to be discontinued
several times.  However, Sony keeps responding popular demand and
making more.
  
It runs on a wall adaptor or AA batteries and is a little power
hungary.  Plan to have a solar charger fo this one.

To see one, go to:

http://www.universal-radio.com/catalog/portable/0841.html



Probably the "top end" of a receiver only I might suggest is the Drake
SW-8 portable.  I currently own one of these and can share that it is
the best general coverage (Longwave - FM) portable receiver on the
block.  It can receive AM, FM and SSB modes, has synchronous side band
selectable AM detection, adjustable AGC and 3 interference fighting IF
bandwidths.   100 memory channels and 110V AC or power from 6 "D"
cells is possilble.  Shortwave and Medium Wave DX (reception of weak
station) performance rivals multi-thousand dollar table top receivers.

From a first hand perspective, I can share that the audio quality from
this receiver is superb.  It even has stereo FM capability (though
headphones).

On the downside are price.  At $779 its not very cheap at all.
However, worth the money from a performance standpoint.  It also
consumes batteries at a enthusiastic rate.  The 6 "D" cells last about
6-8 hours at room volumes.  Thus, you would find that you were
operating it  from the 9V "wall wart" adaptor more often than not.   I
plan to build a 12V to 9V regulator and run mine from a car
battery/solar cell set up.

You can see this at:

http://www.universal-radio.com/catalog/commrxvr/0088.html

8== Hmm, bit thirsty for power, then.  Is that using alkaline "D"
cells or just standard carbon-zinc?  

9== Measured power consumption of FRG-7 under varying conditions as 
follows:

a:  Volume at minimum, dial lights off  109 milliamperes [mA]
b:        "        "   maximum,  "        "        "    350 mA
c:        "       minimum , dial lights on ,   300 mA
d:       "      maximum     "         "      on	    400 mA.

10== Liquid crystal digital digital displays consume very little
power, but some LED type displays are very power hungry.


Scanners for VHF/UHF can be easily found at Radio Shack.  They are
about the same and price will be determined by number of memories,
scanning rate and frequency coverage.  Don't by the most expensive,
nor the cheapest.  Your local Radio Shack dealer also has intimate
knowledge (in most cases) of local frequencies used.

Hope this helps.  Any questions, write me but be sure to "unmuggle"
the address.


11== Very nice post, hope to see more of them.

~ larryn

SPAM Foiling in effect.

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