The Unsorted BBS Collection/thegreatunsorted.tar/thegreatunsorted/texts/pirate_radio/412

Text File | 1993-12-18 | 44KB | 1,212 lines

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An Interactive e-mail Journal In Service To The Radio Broadcasting Community
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                   (Formerly the Internet Radio Jorunal)

Our Internet Email Addresses:

    Submit Articles:            [e-mail]
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... Thank You For Subscribing  .....  William Pfeiffer: Editor/Moderator ...
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   For Archive and Other Information, See Info Section at End of Journal
             --------------------------------------------------

            Articles in this issue include:

Elevating vertically produced news widely        (San Francisco Fractal)
Re: Seeking Radio Station cal                (Dan Patrick)
Re:  Car Radio    Question                (Will Martin )
Re:  Prarie Home Companion: Why the name change?    (Will Martin )
Re: Why    Bash Rush?                    (Rob Schaller)
Highwater #8 final                    (San Francisco Fractal)
technical discussion on    DAB - CRA            (Bruce Girard)
Unlicensed FM fine info?                (dbelson)
Re: Digital Audio Broadcasting (DAB)            (Sean Keric Murphy)
Minneapolis/St.    Paul Ratings, etc.            (SGRIFFITH)
Washington, D.C., summer ratings are in!        (Tom Lacko )
KSHE/St. Louis heard in    west-central Indiana        (jwg)

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


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

Subject: Elevating vertically produced news widely
From: [e-mail] (San Francisco Fractal Factory)
Organization: NETCOM On-line Communication Services (408 241-9760 guest)

I produce this weekly radio 1/2 hour spot from postings
to misc.activism.progressive.  Besides mailing copies of
the tape around to noncommercial, college, and unlicensed
broadcasters, I have recently contracted
for six weeks of 1/2 hour spots with NPR satellite.

I hope to provide this resource to the community for
observation and experiments. Our first test is acceptance.
The 'typical' NPR program director would like what?

Our second is appeal.  Does inexperience or cultural
difference blind us to obvious shortcomings and slights?

Then community building.  The current format allows for time
for local news, from the broadcasting site, for calendars,
announcements, contacts, reality checks, and fund-raisers.  The
'branch' distributor may add programming or calander, civic stuff,
etc.  E.g. I send to Ontario, who adds Canada News and Calendar and
sends to Halifax, Hamilton, and Montreal.  Montreal throws down
some francois, and an ad for a hot-tub place.

Plant some seeds.

Then latency diminishing.  Instant gratification, perpetual flow.
Actually, I mean digital audio e-mail and the beginning of the
e-mail 'man' age.  (Walkman like device).


Send SASE 632 Cole SF CA 94117 for stickers

-a

--
-37-

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

Subject: Re: Seeking Radio Station cal
From: [e-mail] (Dan Patrick, EC3 F5 ??, 997-6193, DCP2)
Organization: Texas Instruments, Inc.






Some additional radio calls and what they stand for. These are mostly from
the Southern US.

Dallas area stations....
KDMX - Dallas Mix
KJMZ - JAMS
KLRX - Lite Relaxing
KMGC - Magic (defunct)
KEGL - Eagle
KPLX - metroPLEX
KDGE - EDGE
KSNN - Sunny
KERA - Equal Rights Amendment (?)
KLTY - Light
KYNG - YOUNG country

Other Southern Stations....
KISS - KISS - San Antonio
KLBJ - Lyndon B. Johnson - Austin
KTYL - TYLER, Tx
WJMI - Jackson, MS
WRNO - Rock of New Orleans
WMSI - Mississippi Country (Jackson)
WRVR - RIVER - Memphis

______________________________________________________________________________________
Dan Patrick                                       Insert Standard DISCLAIMER here!!
Design Automation Division
Texas Instruments
Dallas, TX
WSTR - STAR - Atlanta

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

Subject:  Re:  Car Radio Question
From: Will Martin <[e-mail]>
Organization: NONE

A follow-up to my earlier note about the car radio question:

Note the enclosed. While the "official" price is back up to
$279, you CAN get it at the $195 price IF you cite it and ask for it
specifically (and beggingly! :-).

Will

----- Forwarded message # 1:
>Date:         Wed, 13 Oct 1993 15:08:06 GMT
>Sender:       Short Wave Listener's List <SWL$[e-mail]>
>From:         Lee Castellion <[e-mail]>
>Organization: Hewlett-Packard Fort Collins Site
>Subject:      Re: Philips 777 Car Shortwave/AM/FM/Cassette

Some good news, bad news corrections are in order regarding my last
posting.

Lee Castellion ([e-mail]) wrote:
: Passport gives a phone number to call 1-800-544-0618, which is Philips
: North America.  I called today and can offer the following information:
:       They are not planning on discontinuing the DC777 but are
:               just clearing the shelves for the 1994 version of
:               the DC777.   The person I spoke with said there was no
:               difference between the 1994 and the 1993 version.
This is definately true and is now official, they are NOT discontinuing
the DC777.

:       The DC777 has sold quite well for them.
Still true.

:       The current closeout price is $195 plus about $6 for shipping.
:               This price is $100 less than what EEB is currently selling
:               the radio for.

Unfortunately NOT true.  Because they have decided to NOT discontinue
the unit, the price is now $279.  However, this is still a good price.

Oh well, I guess we can't have it all :-)

: The opinions expressed here do not in any way shape or form, represent the
: policy of the company I work for.
Still true.
--
Lee Castellion                                                       ___
Telecomm. Engineering      |Internet: [e-mail]        |HEWLETT/  /
3404 E. Harmony Rd., MS#12 |HPDesk  : lee_castellion@hp4000 |      /hp/
Ft. Collins, CO 80525      |(303)-229-6540, Telnet 229-6540 |     /__/PACKARD

----- Forwarded message # 2:
>Date:         Thu, 14 Oct 1993 01:12:19 GMT
>Sender:       Short Wave Listener's List <SWL$[e-mail]>
>From:         Joseph Jesson <[e-mail]>
>Organization: Netcom - Online Communication Services (408 241-9760 guest)
>Subject:      Re: Philips 777 Car Shortwave/AM/FM/Cassette

  If you ask the sales woman PLEASE get me the $197.00 price, you will
get the better price.  Be nice, as she also told me the price WAS MUCH
HIGHER during the initial conversation.

I am looking at my new car radio (shipping was in TWO days!)...
--
-------------------------------------------------------------------------
Joseph Jesson   [e-mail]  Day [phone]  Eve [phone]
21414 W. Honey Lane, Lake Villa, IL, 60046
-------------------------------------------------------------------------
----- End of forwarded messages

(I don't know why one says "$195" and the other says "$197". Try for
$195! - Will)

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

Subject:  Re:  Prarie Home Companion: Why the name change?
From: Will Martin <[e-mail]>
Organization: NONE

>From: [e-mail] (Charles S Kerr)
>I was wondering if anyone out there knows why the American Radio Company
>of the Air has changed its name back to Prarie Home Companion

I happened to see a blurb about Garrison Keilor in one of those
newspaper fluff-news "people" columns, wherin he explained the change
back as trying to re-emphasize and return to the "midwestern" aspects of
the program, qualities which he felt had made it a success initially,
and which were lost (or at leasted weakened) when he had moved to NYC
and changed the name.

I have no info on the cast, though.

Will

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

Subject: Re: Why Bash Rush?
From: [e-mail] (Rob Schaller)
Organization: Motorola Inc.

In article <29mu0r$[e-mail]>, [e-mail] (William A.
Goldsmith) wrote:
>
> In article <29gd66$[e-mail]> Scott Seely <[e-mail]> writes:
> >I have been reading this journal for a while now.  I am amazed at the numbers
> >of people lambasting Limbaugh.  Believe it or not, the man speaks about things
> >that a large portion of the country believe is true.  His idealogy is that
> >of the majority of talk radio listeners.  That is why he is so popular.  The
> >country may be evenly split politically speaking, but for those who really



Anyone who calls themself the truth is real arogant and pompus.  Maybe they
should give Rush paid airtime with Billy Graham.  Talk is cheap and with
the growing number of syndicated talk shows on radio, and TV, it is getting
cheaper by the minute.  Save radio!  Support your local radio personalities
which are becoming endangered.

Rob
I speak for myself and std. disclaimers apply

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

Subject: Highwater #8 final
From: [e-mail] (San Francisco Fractal Factory)
Organization: NETCOM On-line Communication Services (408 241-9760 guest)

Welcome Bloomington Indiana, Swarthmore Pennsylvania,
and Redwood Community Radio.

Highwater #8 went to Ames Iowa for uplink to Nat'l
Public Radio Satellite Channel 11, Wednesday 0100-0129,
Highwater will go for Oct 27, Nov 3,10,17, and 24.

Listen for John "Black Dog" Ridnell in the mix this week.
His new CD, Valley of the Jive is available from Real
Rock Records through Dutch East India Trading Co. at a
local store.

Several carriers missed #6 and #7 because of lack of
tapes.  Please return cassettes to 632 Cole SF CA 94117.
Interested in donating: We love FUJI DR-I Extraslim
IEC i/ TYPE I Normal.

I have enclosed #7 on #8 tape for those that missed it
and new subscribers.

FYI 9/15 #3
0:00    Food Not Bombs
2:32    NRDC, recycled paper
4:38    NYTN Terrorist Plot, Reno!
6:46    Havana Green Cities Conference
7:45    Lakota vigil
8:45    NYTN Domestic abuse related to economy
10:12   IPS rio 9/2 500,000 child prostitutes
11:45   Leonard Peltier denial
14:40   end cue

 9/ 22 #4
0:00    Sharon Bottoms, Prop 174 gives $ to bigotted schools
2:17    Chomsky quote Isreal-Palestine
3:10    IAC Somalia
5:43    Nicarague, Jesse Helms
6:33    Boycott List
9:00    PepsiCo Guatemala
10:35   New World Order, "decarceration"
11:30   Hollywood uses rainforest wood
12:21   HandsNet Digest: headstart,leland,tarao'toole
14:12   Guatamala - Jen Harbury Hunger Strike
15:01   out cue

#5  9/29
0:00    Picketing steel workers
1:34    Rainforest Action Network, MAXXUS Huranami Nat'l Park
2:42    WHO - violence vs. women
5:05    AFSC, Reno - border patrol
7:20    FCNL Nuke
7:50    AI Djibouti
10:00   Cuban Quality of Life, compares favorably, UNICEF
11:37   FCC ID's Edmunson San Francisco Liberation Radio
14:15   out
15:01           Highwater news quiz

#6  oct 5
0:00    Black Dog music
0:37    Forestry conference Delhi
5:23    Pro NAFTA Environmental groups
6:10    UFW boycott, Chataeu St Michelle, Columbia Crest
7:17    Phones cut by Yeltsin gomnt, cut radio, tv, everything
9:20    Phosdrin suspended WASHINGTON - UFW
10:27   IAC 10/29       Protest Somalia
12:18   GLAAD demands DC RALLY
14:08   FCNL China nuke
15:09 out


While the NPR link allows for many more stations
to 'pick up' the Highwater report, it has not lessoned the
burden of copying tapes, because none of our present
subscribers have access to this service (as far as I know).
I am still researching the use of the net as the carrier for
the show.  In the mean-time, if you are interested in acting
as a 'mail branch', and could copy and mail tapes, the break
even point is 6 addresses.  This is 75cents (post) + 80cents
(tape) and 1 tape overnight for $9 FedEx.  So it would be
worth my time to FedEx you a tape when I send NPR's and
if you'd deal with making six copies and sending them, we'd
still be on time and we could serve more people (I max out
at 25 tapes).  To be clearer about $, the tape would cost you
nothing to get and keep.  I ask that you make 6 copies and
send them to some addresses I can supply you.  I can reimburse
you for tapes and stamps.


Two people for the east coast, one for midwest, and I'll handle
CA and INT'l, will do it for now.  So GET INVOLVED (yeah!!)

If you know anyway of hearing NPR CHANNEL 11 1AM Wed Morning
listen for the Highwater Report.  And please inform me if
you can receive the show this way rather than by tape.

Send tapes back! 632 Cole, SF CA 94117 I really like
FUJI DR-I, TYPE I, NORMAL EXTRASLIM if you've got some spare $
If you like the tape on a higher quality. just send the
blanks, we do specials!

There are now TWO bucks.  One is COMMERCIAL (with commercial
breaks) and one NONCOMMERCIAL.  If you would like breaks in the
show to sell air time to local businesses, just send me the
timings of when you want the breaks and for how long and I will
custom fit your spaces.

The commercial product can be provided with a
tax deductable
donation to the Coalition on Homelessness, just
write Food Not Bombs/Highwater Radio on the memo line.


So.......
#8 Oct 20  NPR 93-u66-00001
0:00    Black Dog, Spread The News,  John Ridnell
1:00    Haiti, why US and UN should get out
7:25    Chomsky quote
8:35    1-800- ECOLINK has 60,000 record database
9:45    War on DRUGS
12:50   Mahagony forests getting cleared
15:25   Nukes -US, FRANCE, Tara O'Toole confirmed
17:15   HandsNet Digest: Violence Against Women
19:00   Food Irradiation sticks to GATT
21:30   Pot Warfare costs CA lots
24:15   Clinton reduces environmental agency, worse than Bush

Music:  Crazy (Just Ain't Right) and Keep That Train a Movin',
John Ridnell.

Contact you local NPR station and request that they carry the
Highwater Report.  Now's a good time, 'cause I'm making some
noise on their electronic message-sender doohickey.

Thanks everyone- keep those cards and messages coming!
Love the art work!!!

Viva Tesla!


--
-37-

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

Subject: technical discussion on DAB - CRA
From: [e-mail] (Bruce Girard)
Organization: NONE

/* Written  6:21 pm  Oct 16, 1993 by peg:pbaatech in web:amarc.radiotech */
/* ---------- "technical discussion on DAB - CRA" ---------- */
DISCUSSION PAPER

ENSURING A BRIGHT FUTURE FOR INDEPENDENT DAB

Dr Brian T Evans     Tantara Tek Ltd    30 September 1993

   Tel [phone]
   Fax [phone]
   E-Mail tantara@gn  (GreenNet UK)

Introduction

I first saw DAB in action at the 1989 Montreux TV show.
In those far off days the French explained that the
waveform was so complicated that the receiver chips could
manage to decode only one sound programme at a time - the
other carriers were ignored.  The original Rennes DAB
transmissions therefore modulated PROGRAMME A onto
carriers 1, 9, 17 etc,  and PROGRAMME B on carriers 2,
10, 18 etc.  If eight programmes were to be broadcast
then each programme permanently used an eighth of the
available carriers.

The same modulation system used for DAB, COFDM, is also
being used to broadcast Digital Television.  NTL, who are
the UK proponents of SPECTRE, have demonstrated HDTV
transmissions using COFDM and tell me how easy it is to
delete many individual COFDM carriers from the overall
multiplex.  Although it might at first sight appear
wasteful it is relatively easy to delete seven eighths of
the carriers. The remaining carriers need not be bunched
together but can be spread out over the whole available
bandwidth.

DAB developments now define three principal modes of
operation.

DAB Mode 1 defines a set of carriers set 1 kHz apart
DAB Mode 2 defines a set of carriers set 4 kHz apart
DAB Mode 3 defines a set of carriers set 8 kHz apart.

The successful identification and demodulation of such
close carrier spacings can prove difficult in fast moving
vehicles.  Theory suggests that a 4 dB increase in
transmitter power is needed to overcome the demodulation
difficulty when the Doppler frequency shift, caused by
the moving vehicle, approaches a twentieth of the carrier
spacing.

High speed motoring

This theory has been diligently applied to the speeding
motorist.  At 120 miles per hour the resultant worst case
Doppler shift (50 Hz) will limit the Mode 1 DAB systems
(with 1 kHz carrier spacing) to frequencies below about
350 MHz.  This is one reason why Mode 1 and VHF
broadcasting have become synonymous.  The wider carrier
spacing of Modes 2 and 3 make them 4 and 8 times more
tolerant to Doppler shift and therefore allow operation
at 4 and 8 times the (nominal) 350 MHz frequency limit of
Mode 1.

The magic of 1.5 MHz DAB frequency blocks.

Today's implementation of Mode 1 DAB stacks up about 1500
individual carriers every 1 kHz thereby fully covering a
spectrum of 1.5 MHz.  There has been a debate as to how
much - or little  - bandwidth is needed for DAB to work
well.  The limiting factor is how much bandwidth gets
"taken out" in a multipath selective fade, the sort of
fade that dogs the reception of everyday VHF FM
broadcasts.  Propagation studies indicate that the fade
bandwidth at VHF lies between 30 and 300 kHz.   A
transmission bandwidth of 1.5 MHz seems to leave just
enough of the signal unaffected by the selective fade so
that a faithful reconstruction of the missing bits can be
made.

The use of the extended guard interval between symbols is
a delightfully easy way around the need for an active
equalizer in the receiver.

It provides two benefits :

1.   It allows for the not entirely destructive
     reception of multipath signals
     and/or
2.   It caters for the "symbol spreading" that results
     from a Doppler shift of up to a twentieth of the
     carrier spacing from a moving vehicle.

We need to take special care when implementing good DAB
reception in a car.  The extended guard interval takes
care of the Doppler shift but cannot deal with the
quickly changing signal strength of a dense urban
environment.

There are a number of special techniques that claim to
overcome these problems.  It has been practice, in both
the Mark 1 (FDMA) and the Mark 2 (TDMA) implementations
of DAB, to spread the digital coding of each syllable of
speech over a time interval of a few tenths of a second.
This breaks up the bad reception spots into even smaller
pieces which prove easier to correct.  However, the
American DAB IBOC papers show that their time-spreading
techniques break down when speeds drops below 15 miles
per hour.  Bad luck if you are in heavy traffic, their
DAB only works properly at high speed.

Although the time spreading does improve reception in
cars it is not meant to work when the receiver is
stationary.  It is therefore important for us to sort
out the criteria for good fixed reception first and then
add the "moving" bits later.

Frequency or Time division Multiplexing.

Two multiplexing techniques have been used.


Mark 1 - FDMA.   Used in the Rennes/Geneva DAB
demonstrations.

   Programme A permanently uses interleaved carriers (1,
   9, 17 etc) and each carrier carries continuous data on
   that programme.

Mark 2 - TDMA   Used in the BBC/NAB DAB demonstrations.

   At first Programme A uses all the carriers (1, 2, 3, 4,
   etc) on a time interleaved basis.   It is then the turn
   of Programme B to use all the carriers and so on.

It is quite probable that the Mark 2 technique offers a
few dB theoretical advantage over the Mark 1 technique
but this may not be important in practice.  I have not
seen any figures detailing what improvements occur in
BER (Bit Error Rate) when switching from the Mark 1 FDMA
to the Mark 2 TDMA interleaving technique.

Starting again.

DAB developments have shown that

The Good News

1.  Spreading a number of digital carriers over at least
a 1.5 MHz block of VHF frequencies can, by the use of
clever error correction techniques, provide a programme
service that does not fall prey to the horrors of
selective fading.

2.  The addition of a guard interval to each digital
symbol ensures a tolerance to pulses which were distorted
by multipath effects or Doppler frequency shifts.

3.  The further addition of a time spreading technique
will improve reception in the speeding car or train.

The Bad News

1.  Setting the intercarrier spacing at the minimum
theoretical limit needs special techniques and takes a
lot of effort.

2.  All programmes must be pre-assembled before encoding
and transmission.

3.  The mutual help that the guard interval provides for
on-channel repeaters turns to dust when the programme
multiplex needs to be changed in an adjacent area.

4.  The advantages of single frequency networking (SFN)
have been lost on independent and local broadcasters,
both in Europe and the USA markets.

Can we build on the items of Good News and minimise the
effects of the Bad News?   Item 2 of the Good News might
hold the clue.

The guard interval technique allows a trade off between
the frequency displacement of up to a twentieth of a
carrier spacing and the output power of the transmitter.
For a 4 dB increase in transmitter power the frequency
offset amounts to 50 Hz for a (VHF) Mode 1 system.   For
L band (1,500 MHz) the Mode 2 and Mode 3 systems offer
frequency offsets of 200 and 400 Hz.

Could we steal a small part of this tolerance margin in
order to use it for a different purpose?

Let us look at some possible variations on the Mark 1
FDMA technique in which different broadcasters are
assigned different carriers in the same 1.5 MHz DAB
frequency block.

-  The first local broadcaster could operate a single-
   programme frequency-interleaved service on carriers 1,
   9, 17 etc  and permanently delete carriers
   2,3,4,5,6,7,8  10,11,12,13,14,15,16, 18,19,20 etc from
   his transmission.

-  The second local broadcaster, a few miles away, could
   operate an independent single programme service on
   carriers 2, 10, 18, etc and would never use carriers
   1, 3,4,5,6,7,8,9, 11,12,13,14,15, etc.

-  Both broadcasters thus offer a skeleton set of carriers
   that do not interfere with one another, whether
   transmitted from the same mast or not.

However, unlike the Rennes transmissions, there is no
need to pre-assemble these programmes prior to
transmission.  We can use a part of the 50 Hz frequency
tolerance of the Mode 1 DAB system to interlace two or
more quite separate transmissions.  If we aim to match
each broadcaster to within 10 Hz then the frequency
tolerance of each broadcaster's VHF (100 MHz) transmitter
needs to be within 1 part in 107.  This is well within
the standard tolerance of a crystal oscillator and adds
no more than 1 dB to the link budget.

We have knocked out items 2 and 4 of the Bad News

GOOD NEWS   No inter-broadcaster synchronisation is
required

There are three prices to pay for this independence.

1.  A 10 Hz offset between broadcasters will need an
extra 1 dB of power to overcome the pulse distortion.

2. The Mark 1 FDMA coding across fixed carriers per
programme is probably not as efficient as the Mark 2 TDMA
approach.

3. It is no longer possible to reach the theoretical
minimum spacing between carriers.

Let us deal with each issue in turn.

1. Whereas the output power of a VHF FM transmitter may
be in the kiloWatt range.  the output power of the DAB
transmitter will be tens of Watts.   Changes in power
level between 10 and 100 watts are less significant than
for medium and high power FM schemes.

2.  Spacing local broadcast Mode 1 carriers every 2 kHz
is "inefficient" but the alternative - central
synchronized transmissions - is a nightmare.

3.  Co-located non synchronised Mode 1 inter-carrier
spacing will need to be greater than 1 kHz.  As an
example let each local broadcaster use carriers each set
8 kHz apart in the 1.5 MHz block.  He would suppress the
other carriers normally present in a Mode 1 system.   It
is thus relatively easy for four local broadcasters -
from separate transmitters and/or from separate masts -
to interleave the four signals every 2 kHz because the
frequency stability need be no better than 10 Hz and
there is no need for expensive atomic reference clocks.
A temperature controlled crystal oscillator would provide
a stability of a few Hz at VHF thereby leaving the
quality of reception of the 120 mph motorist unaffected.


Programme A    *       *       *       *        *  etc
Programme B      *       *       *       *
Programme C        *       *       *       *
Programme D          *       *       *       *

1 kHz markers  .................................  x 1500

   DAB frequency interleaving of 4 independent local
   broadcasters every 2 kHz

Frequency interleaving offers both the central and the
independent broadcaster a lot of flexibility which is
missing from current implementation strategies.

A mixed scheme would allow a national SFN and a number of
local commercial/community broadcasters to all operate
within a standard 1.5 MHz block.  Yes, some care needs to
be taken to match receiver signal strength service levels
but this could be planned for.


Single programme RDS

Existing FM RDS technology can be used to tell a
receiver, which may be tuned to one local programme, that
other services are available a few kHz away.  There is no
pressing need to centralise this programming choice
facility into one RDS "super-header".

Independent per-programme RDS signals are easier to
administrate and offer more flexibility than an RDS
super-header.  This independence would enable different
commercial operators to strike and re-strike "hand-off"
deals with their colleagues or marketplace rivals in
contiguous coverage areas.


Mixed mode fun.

The 8 kHz carrier spacing of local broadcast Mode 1 has
a remarkable similarity to the 8 KHz carrier spacing of
Mode 3.   The "Satellite" Mode 3 is designed to use 8 kHz
carriers but at 8 times the data rate of Mode 1.
However, there is no need to operate at such high speed
if there are relatively few programmes to distribute.

-  It would be straightforward to provide a fixed receiver
   L band cellular coverage by means of a direct frequency
   translation of an 8 kHz Mode 1 (800 Baud) service.

-  Vehicles could listen to the same programming on either
   VHF or L band.

-  Alternatively some VHF local services might use other
   Modes if an 8 kHz spacing became commonplace for
   independent local or commercial broadcasting services.
   For example current experimental Digital COFDM HDTV
   broadcasts do not restrict themselves to QPSK.  The
   adoption of a wider DAB inter-carrier spacing would
   facilitate the introduction of other PSK modulations
   that may become commonplace for digital TV services.


Wider choices.

But why should everyone listen to exactly the same
programme?

Could we not offer different advertisement on the VHF and
L band service for example that might target different
market niches?

Stand-alone transmitters and masts offer exciting
possibilities for the commercial broadcaster.  Their
individual per-programme RDS headers could customise and
direct fixed and moving receivers to different sub-
channels so that different areas or cells receive
different advertisements and jingles.

This idea might also be applied in a different way.
Service areas could be extended in a quasi-SFN mode by
shifting the output frequency of the repeater by a few
kHz.  The main transmitter could broadcast on Carrier 1,
carrier 9 etc whereas the repeater could rebroadcast
these signals by shifting them up or down 2, 3  or 4 kHz.

Just like the frequency shifted audio at a live pop
concert this "Quasi-On-Channel"   QOC    repeater
technology offers a welcome extra margin of transponder
gain before the onset of howl around.

Just like a real on-channel repeater the transponded DAB
signal can be reflected or "mirrored" back into the main
service area ** but without the need for an expensive
synchronised microwave or satellite feed **.

The four colour map theorem can give us an instant feel
to the coverage of such an 8 kHz spacing/ 2 kHz
interleaving scheme.  Two examples are given at the end
on this paper.

QUESTIONS

1.  We need to know how well two or more DAB transmitters
can work together in the same 1.5 MHz slot when each of
them offers a clutch of carriers spaced 8 kHz apart.

2.  Can four such transmissions interleave so as to form
a 2 kHz "comb"?

3.  What inter-carrier variation in signal strength can
be tolerated by the domestic receiver?

4.  Can the domestic receiver lock onto a distant 8 kHz
sequence x dB below the level of an interleaved local 8
kHz sequence?

5.  What increase in transmitter power is needed to
maintain Bit Error Rate (BER) performance if we use
permanently assigned skeleton carriers instead of the
more recent "Mark 2" TDMA approach?


Footnote

When I spoke to Dr John Forrest of NTL at Montreux in
June he suggested that digital transmission had now come
full circle.  Whereas HD-MAC TV used a digital "helper"
signal to sharpen the picture he thought that we now
needed an equivalent analog "helper" signal to allow
digital systems to degrade gracefully.

Here is an idea.  How about using one of the 8 kHz spaced
carriers (at the edge of the 1.5 MHz DAB bandwidth) to
carry an analog AM programme instead of part of the
digital bit stream.   If applied to DAB at L band this
has similarities with the Irish use of AM MMDS TV service
which operates at about 2.3 GHz.   A low power AM carrier
could be just what we need at the edge of the service
area and would not interfere with the digital multiplex.


CONCLUSIONS

We have been presented with a particular set of
parameters that, although technically excellent,
needlessly favour the centralised broadcaster.  We must
find out whether, for a few DAB dB more,  we can have the
same freedom and independence that is currently enjoyed
on FM.

The broadcast industry is struggling with the idea of
central synchronisation because that is how the Eureka
DAB system has been presented to us.   We do not have to
accept this initial "central broadcaster" solution when
it may prove possible to build on the existing research
work to develop an independent solution.


Dr Brian T Evans          30 Sember 1993

Example 1

1 Primary Programme Service and 7 Repeaters
in a 1.5 MHz DAB Block


============
  Service 6     Third Layer
============
      *
      *
      *
============
  Service 4     Second Layer

============
         *
         *
         *
===============          Second Layer       Third Layer
    Primary              ============       ===========
    Transmitter  ******   Service 3   ******  Service 7
    CHANNEL 1                               ===========
===============          ============
         *
         *
         *
============
 Service 5      Second Layer
                                      Non-linked
============                          Independent
      *                               ============
      *                                Service 8
      *                               ============
============
  Service 2     Third Layer
============

***********  denotes possible connection routes

The Second layer service areas may be set 3,4 or 5 kHz
away from the Primary Service transmitter.

The Third layer service areas may be set 2 or more kHz
away from the Second layer transmitters.

In this way each of the secondary and tertiary
transmitters may be used to provide either an
independent service or may be slaved off a
neighbouring transmitter.


Example 2

2 Primary Programme Services and Repeaters
in a 1.5 MHz DAB Block


============
  Service 4   -  Second Layer

============
         *
         *
================      Second Layer        Third Layer
 Primary              ===========         ===========
 Transmitter    *****  Service 3  ******* Service 6
 CHANNEL 1                                ===========
================      ============

Co-sited Primaries

================      Second Layer        Third Layer
 Primary              ============        ==========
 Transmitter    *****   Service 7  ******* Service 2
 CHANNEL 5                                ===========
================      ===========
         *
         *
============
  Service 8   -  Second Layer

============

The Second layer service areas are set 2 kHz away
from the two Primary Service transmitters.

The Third layer service areas may be set 2 or
more kHz away from the Second layer transmitters.

In this way each of the secondary and tertiary
transmitters may be used to provide either an
independent service or may be slaved off one of the
two primary transmitter.



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

Subject: Unlicensed FM fine info?
From: [e-mail]
Organization: Stevens Institute Of Technology


    As part of an assignment for a journalism class, I need to find out
the legal ramifications of being a "pirate fm" station, if you will.  Where
would i be able to find info on the fines that are levied for broadcasting
fm w/o a license, and where the responsibility falls for paying them?  If
you can refer me to a section of fcc rules, I would appreciate it, or if
anyone out there knows, or has the info handy, please e-mail me with it.

    Thanks in advance.

                    -David Belson

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

Subject: Re: Digital Audio Broadcasting (DAB)
From: [e-mail] (Sean Keric Murphy)
Organization: Princeton University

In article <29sdt6$[e-mail]> "Dave Marthouse N2AAM" <[e-mail]> writes:
>I know that a few standards have been put forward for digital audio broadcastin
>in the US. I would be interested in a technical overview of the systems. I
>would in addition love to hear from anyone who has caught a demmo of any of
>the systems. Any information would be appreciated.
>g
>--
>Dave Marthouse
>Internet: [e-mail]

Well, reports to the FCC are due at the end of this year (12/31/93) of
test results.  I don't know of any tests to date in the US, but they
will be happening soon.  Different systems to be tested include:

- in-band, on-channel: the digital signal can theoretically be buried in
the noise floor of an analog signal, thus allowing broadcasters to use
one frequency slot for both FM and DAB

- in-band, adjacent-channel: the digital signals would run "in the gaps"
between current FM frequencies (with a ceiling of 1.5 megahertz, there
should not be too much interference except for areas which are already
packed to the brim, like the entire Northeast Corridor)

- out-band:  this would require the use of a new chunk of the spectrum
for this broadcasting (much like that which is proposed for HDTV, as I
understand it).

The FCC apparently favors the "in-band" systems, especially the
"in-band, on-channel" concept.  But the tests have not yet been done, so
nobody knows if these will work.  That's all I've heard so far, but I'm
looking forward to learning more (even if it could be a bad turn for
smaller broadcasters and community radio, as discussed in the posting on
European testing).  Interestingly enough, DAB could be the "savior" of
AM, since the broadcast technology seems to geared to AM xmtrs rather
than FM.  Imagine these 50,000 W clear-channels with digital clarity on
a good night...

Sean Murphy
[e-mail]


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

Subject: Minneapolis/St. Paul Ratings, etc.
From: [e-mail]
Organization: NONE


Courtesy of the Friday, October 15, 1993 Minneapolis Star-Tribune:


          Age 12+               25-54               18-34

Station   SU93  SP93  SU92    SU93  SP93  SU92     SU93  SP93  SU92

WCCO-AM   15.2  15.9  17.2    9.5   10.3  12.7      3.3   3.6   5.3
(830-AM, News/Talk, Mn Twins Broadcasts)

KQRS-FM   10.0   9.8   8.3   11.8   11.4  10.5     18.0  18.3  15.8
(92.5FM, Classic Rock, Tom Barnard & Morning Crew)

KDWB-FM    7.3   6.8   6.7    4.7    4.8   4.2      9.7   9.7   9.1
(101.3FM, CHR/Dance/Urban)

KSTP-FM    7.1   6.2   7.1    8.7    8.2   9.8      8.8   8.6   8.5
(94.5FM, A/C "Always 95 and Sunny, KS95")

KEEY-FM    6.9   9.2  10.2    7.8   10.4  12.4      6.5   9.0  12.4
(102FM, Country, "K102 - The FM Country")

WLTE-FM    6.7   7.2   6.5    8.1    8.0   7.6      5.7   5.6   5.3
(103FM, A/C, "The Lite FM" - Co-owned with WCCO-AM)

KTCZ-FM    6.7   5.7   6.5    8.3    7.3   5.6     10.8   9.3   5.1
(97.1FM, NAC, "The Cities' 97)

KRXX-FM    6.6   5.8   5.8    3.3    4.6   3.5     10.9  10.3  10.4
(93.7FM, Hard Rock, "93X")

KQQL-FM    4.5   5.6   6.7    6.6    7.0   8.4      2.4   3.4   4.4
(108FM, Oldies, "Kool 108")

KSTP-AM    4.3   5.2   3.4    4.5    5.3   3.5      3.6   4.2   3.9
(1500AM, News/Talk, Limbaugh 12-2pm)

WBOB-FM    3.9   1.5   ---    4.8    1.5   ---      5.0   1.9   ---
(100FM, Country, "Turn Your Knob To Bob")

KJJO-FM    2.6   2.7   2.3    3.2    3.2   2.5      3.4   3.2   5.3
(104FM, Country, "Country Thunder")

KLBB-AM    1.6   2.1   1.8    0.1    0.8   0.3      0.3   ---   ---
(1400AM "The Music Of Your Life")

KFAN-AM    1.3   0.9   1.1    1.7    1.0   1.4      1.1   1.1   1.2
(1130AM, All Sports, co-owned with KEEY-FM by Shamrock)

WDGY-AM    0.8   0.6   0.5    0.6    0.2   0.1      0.1   0.1   0.2
(no idea)

KCFE-FM    0.5   0.4   ---    0.8    0.6   ---      0.4   0.1   ---
(105FM, Soft Jazz/Light New Age, "The Cafe")

WWTC-AM    0.5   0.3   ---    0.7    0.5   ---      0.3   0.5   ---
(1230AM, Children, "Radio AAHS")

There you go.  No time for more now...will write again and, in the words of
our friend Rush, "Tell you what to think about it".

Til then,

Steve Griffith
Studio Engineer
Mn Public Radio
[e-mail]

p.s.  Yes, Bill, I remember about your airchecks!!!!

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

Subject: Washington, D.C., summer ratings are in!
From: Tom Lacko <[e-mail]>
Organization: NONE

Here are the summer 1993 Washington, D.C., ratings for commercial stations
overall.

    STATION                SUMMER '93    SPRING '93

 1    WPGC FM95.5 Urban/CHR        10.7        9.4
 2     WMZQ AM1390 FM98.7/Country    6.6        7.2
 3     WKYS FM93.9/Urban        4.9        4.7
 4    WRQX FM107.3/AC/Mix        4.1        5.0
 5    WMAL AM630/Talk (Local & net.)    4.0        4.0
TIE    WMMJ FM102.3/Urban AC        4.0        4.2
 7    WHUR FM96.3/Urban        3.9        3.6
 8    WTOP AM1500/News + Orioles BB    3.8        3.5
 9    WGAY FM99.5/AC            3.7        4.7
TIE    WBIG FM100.3/Oldies(1st book w/oldies 3.7    2.4 (Jazz)
11    WJFK FM106.7/Talk/Stern/Don &    3.5        4.2
        Mike Liddy/Greaseman/Jazz on weekends
12    WWDC FM101.1/Rock        3.3        3.9
13    WASH FM97.1/AC            3.1        2.7
14    WHFS FM99.1/Alternative Rock    2.7        2.6
15    WCXR FM105.9/Classic Rock    2.5        2.6
TIE    WXTR FM104.1/Oldies        2.5        3.4
17    WGMS FM103.5/Classical        2.3        3.2
18    WLTT FM94.7/AC/Jazz @ night    2.0        2.2
TIE    WOL AM1450/Talk (Local)        2.0        1.2
20    WWDC AM1260/Big band        1.3        1.2
21    WWRC AM980/Talk (Local & net.)    1.1        1.6
22    WAVA FM105.1/Religous        1.0         .9
23    WTEM AM570/Sports talk/Imus/    1.0         .7
        + Redskins FB


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

Subject: KSHE/St. Louis heard in west-central Indiana
From: SEDV1.acd4.acd.com![e-mail] (jwg)
Organization: /u/jwg/.organization

I was on the road Friday morning heading southeast from my home base of
Terre Haute, Indiana on Indiana State Road 46.  I was listening to
Bob & Tom on Q95 (WFBQ/Indianapolis, 94.7 MHz) as I cruised along
that winding, hilly road.  Between Bowling Green and Spencer, where the
road is its windiest and hilliest, Bob & Tom would occasionally cut out
and I would clearly hear another radio station.  The station was playing
some Pearl Jam or Alice in Chains song (all that Seattle stuff sounds
alike to me).  At first I was mostly annoyed that some local yokel
station out in the middle of farm country Indiana, no doubt doing the
satellite boogie, was interrupting Bob & Tom.  But then a jock came on
and started talking about Busch Stadium.  "Hm," I thought, "St. Louis."
This station cut in and out with Q95, mostly appearing at higher elevations
along this road.  I even pulled over and listened for a few seconds.
I never heard the station identify itself, but as I listened, I became
convinced I was hearing St. Louis radio.  When I got home, I consulted
my Broadcasting and Cable Yearbook, and found that KSHE, St. Louis's
rock station, is firmly nestled at 94.7 MHz.  Wow!  I was two hundred
miles away!

[Moderator's Note:  Of course, 100,000 watts at 1,026 feet helps a tad,
no?  Bill]

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


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End of Internet Radio Journal issue 412.

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