September 1993 posts from qrp-request@Think.COM

REMINDER: These posts are more than a decade old. They were retrieved from QRP-L archives after a May 2006 Google search for 'colorburst' and '79er'.

From qrp-request@Think.COM Wed Sep 1 13:15:51 1993
Date: Wed, 01 Sep 93 17:08:02 GMT
From: jkearman@arrl.org (Jim Kearman)
Subject: September Thurs Nite 3579/3684 Sprints

I posted this yesterday, but haven't seen it,
so here 'tis again:

While your neighbors are warming up their TVs for
the new Fall season, you can check the stability
of their colorburst oscillators, and meet other
weird QRPers at the same time! Yes, you too can
DX the colorburst frequency of 3579.5 kHz, hunting
other participants in the

***** SEPTEMBER COLORBURST SPRINTS *****

sponsored by the New England QRP Club.

When? Each Thursday night (Eastern time) in September
9-10 PM. We're on EDT here, 4 hours behind UTC.

The frequency is easy to find: just look for the
colorburst howls and screeches around 3579 kHz.

Exchange name, QTH, RST + "X" if you're crystal controlled
(Yes, that's the opposite of the way X is supposed to be
used, but nobody uses it the traditional way anymore.
This system has worked fine so far.), name, power output
and other info you feel is relevant. I may start using a
new Q signal I made up, QCB. QCB means "These colorburst
oscillators are killing my hearing." QCB? means "Are the
colorburst oscillators killing your hearing?" What?
Could you speak up, please?

If you're a member of NE-QRP, send your membership number,
too. Having a QRP club number is really important if you're
going to hang out in QRP QSO parties like this one. Having a
low number is very prestigious. I had to join the Czech QRP
club to get a 2-digit number, and I just squeaked through (#94).
My NE QRP number is even better, though: #5! Good thing,
because my memory is going and that's easy to remember.
Experienced participants in NE-QRP QSO parties know that
putting my call and NE-QRP number in their log is the
only way their scores are given any recognition at all.
What's good for politicians is good for contest managers.

Since this is a QRP club, you're not supposed to run more
than 5 watts output, okay? The idea of this contest is to
test the ability of the NE-QRP contest manager to withstand
tortuous shrieking noises, and also to promote the
construction of rigs that use colorburst crystals as the
frequency determining element.

The time was selected to work around W1AW on 3581 kHz.
This may not be a problem where you live, but at my place,
1/2 mile (0.8 km) from W1AW, they're even louder than the
colorburst oscillator downstairs. Unfortunately for me,
W1AW, in an attempt to be a good neighbor, has begun
sending warnings 5 minutes before bulletins and code
practice start, so I have to be off by 9:55 PM. I can
usually tell when they're close to blasting me off the
band by the increase in white noise when all those solid-
state KW amps are powered up. Whoever heard of working an
operating event around the unfortunate choice of QTH of one
member? Hey, I'm not contest manager for nothing!

NE-QRP has published a transmitter design that uses the
colorburst oscillator, but any old QRP circuit for 80
meters will work. You used to be able to get these crystals
at Radio Shack, but they don't carry them anymore. Extra
points if you steal the one from your neighbor's TV! Being
able to "swing" the crystal is nice, as the area around
3579 gets a bit crowded. Sometimes you just have to wait
for KN1H to get around to you. Whatever you do, don't turn
on the TV while you're waiting!

It's not my fault the colorburst frequency is outside the
Novice/Tech subband, right? Fortunately, the Europeans were
more thoughtful, and chose 3684 kHz for their banshees to
haunt. Look on 3684 for N/T QSOs. If you don't hear anything,
please call CQ NE. Who knows what will come back?

If you hear W1FMR, give him an especially good signal report.
He's so far north, he has to start transmitting on Wednesday
afternoons to get his signal down here on time.

Work each station once per week, and don't forget to put me
in your log, too. At the end of the month, send your logs,
comments and bribe attempts to me:

Jim Kearman
83 Main St #13C
Newington, CT 06111-1330

Put my call in your log, but please don't put it on the envelope.
The mailman is already somewhat unstable, and I don't want to tax
him further. Also, seriously, I really am keeping a low profile
at home, so none of the neighbors knows that I'm a ham. Joys of
apartment living.

Note that there really are no points (I lied earlier), scoring
formulae, awards, fame or glory associated with these events.
We just want to get acquainted and keep in touch.

See you Thursday nights in September.

72/73, Jim
KR1S

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

From qrp-request@Think.COM Wed Sep 1 16:01:19 1993
Date: Wed, 1 Sep 93 10:01:08 HST
From: Jeff Herman
Subject: Project 6: 80M QRP colorburst xmtr

Gang,
In preparation for tomorrow's 80M QRP Colorburst Contest, here's a quick
80M xmtr you can throw together in 5 minutes; the 3579 kHz xtal comes,
naturally, from the colorburst oscillator board in your color TV (if you've
got a junked TV, or if you think TV only contains junk, yank the xtal out).
The rf output is not much - about 25 mw. Tuneup is simple: just bring a
field strength meter into vicinity of L1/L2 and tune L1 for peak deflection
of the meter. If you really want to get fancy, you can substitute a 100 pF
variable for C3 and optimize a bit further; this involves a bit of experi-
mentation to determine a `norm' setting for L1/L2. After this has been
established, all further tuning can be accomplished with C3.

Parts List:

C1 .047 mF capacitor
C2 .0015 mF
C3 100 pF
L1 18 turns of No.30 wire closewound on 3/8 in. diameter slug-tuned form
L2 5 turns of No. 30 closewound around middle of L1. Experiment with posi-
tion of this coil over L1; in some circuits performance will be increased
by moving L2 towards cold end of L1. Once exact position has been
determined (with ant. hooked in and FSM for monitoring), glue in place.
L3 2.5 mH rf choke (National R-100 or equiv.)
M1 3 volt battery
M2 6 volt battery
M3 80 meter xtal
Q1 HEP-2 transistor
R1 330 ohm resistor
R2 27K resistor
S1 spst switch

---------M3---------- ANT
| | |
| | |
*------E-Q1-C-------*------------*------- --------------
| B | | |
| | | | |
L3 *-------- C3 L1 L2
| | | | | |
| | | | | |
R1 R2 C1 *------- GND
| | | |
| | | |
| GND GND |
| |
| *----------KEY------M2+----GND
----------S1---M1+---GND |
|
C2
|
|
GND

Note the polarity of M1 and M2. Hope to hear some of you on the `official
colorburst frequency' of 3579 kHz!

Jeff NH6IL

Jeffrey Herman, University of Hawaii Mathematics, jherman@Hawaii.Edu

===============================================
From qrp-request@Think.COM Fri Sep 3 15:55:25 1993
From: jfw@ksr.com (John F. Woods)
Subject: Re: Colorburst?
Date: Fri, 03 Sep 93 15:54:01 -0400

> I have read a bunch of things on this mailing list abt Colorburst
> Xmtr?QSO party? etc. What is this abt?
> Tnx es 73 de kb1amb/ae
> PS - Hope u people don't mind these questions. Ive been a ham for < 10mths
> and into HF CW for 2 mths. tnx

No problem. The "colorburst" in question is the reference frequency for
TV color, referred to as the "colorburst" frequency for that reason. That
frequency is 3.759-and-lots-of-change MHz (I think). There tends to be
a fair amount of QRM there on the air, due to TVs with leaky chassis
radiating their color reference signals, but thanks to this, there is
relatively little *ham* QRM, making it a fairly good spot for moderately-
hardy operators who don't mind dodging a few local TV sets but find it harder
to dodge a couple of dozen rabid DXers... ( :-) for the rabid DXers on
the list here :-) ). It's also popular for crystal-bound operators, since
colorburst crystals are widely available (at least until Radio Snack dropped
them :-( ), and are cheap. The Colorburst QSO party is (I guess) a way of
making it easy for people to find each other, so that everyone tries to
operate at once (instead of all but one avoiding the frequency at any
given time :-) ).

Hope that helps.
John, WB7EEL/1

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From qrp-request@Think.COM Fri Sep 3 18:33:31 1993
From: laurahal@microsoft.com
Subject: Re: Colorburst?
Date: Fri, 03 Sep 93 15:29:00 PDT

John writes in response to Swami:

>No problem. The "colorburst" in question is the reference frequency for
>TV color, referred to as the "colorburst" frequency for that reason. That
>frequency is 3.759-and-lots-of-change MHz (I think).

The number is 3.579545 MHz. It was chosen so that color subcarrier
information could fit in between the sidebands of the chrominance (black &
white) subcarrier. Since the main feature of the video signal is sidebands
at multiples of the horizontal sweep frequency, the NTSC folks chose a half
multiple of the sweep frequency for the subcarrier frequency
(3579545/15734=227.5) to put color information in between the black & white
information. This interleaving is why color tv sets sometimes have
difficulty separating color information from fine detail.

Since these crystals are mass produced for color tv use, they're cheap and
fairly easy to come by. As well as being a useful 80m frequency.

When the Europeans decided that they did want the same colors to recur
(critics claim NTSC stands for Never Twice the Same Color :-), they went
through a similar exercise and came up with a color subcarrier of
4.43something MHz.

73 from Burnaby,
laura VE7LDH

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

From qrp-request@Think.COM Sun Sep 5 00:13:49 1993
Date: Sat, 4 Sep 93 22:13:11 -0600
From: tjf@beta.lanl.gov (Tom J Farish)
Subject: Re: NN1G Again

Hi...Got to Olympia Wa on one Watt from Los Alamos, NM ... 1800+ Km.

Tell me about this 1000 mile/Watt award! ;^)

He was running 100 W and gave me a 579 to his 569! This on the
MFJ 20m rig and helical PVC pipe antenna. I seem to have a
pipeline to Washington State on 20m. Florida on 40m (evenings).

Heard Hawaii on 20m but couldn't raise him. Hawaii is unusual for
me on 20m...anyone else notice unusual propagation last night (Fri)?

Thanks Jeff for the antenna Plans! Rig is going deer hunting with
me next weekend. I'll be up around 11,000 ft in the Manzano Mountains.
should be some DX evenings! Ahhhh...deer liver & onions & dx! ;^)

Tom

KJ5LT