DOUGLAS COUNTY AMATEUR RADIO CLUB NEWSLETTER
Vol. 30, No. 6, JUNE 2000
Articles and information for the Newsletter may be submitted up to the 25th of the month before the next meeting.
Ken Blair, KC0GL, Editor
1711 West 19th Terrace
Lawrence, KS 66046
Phone: 843-8826
e-mail: kc0gl@arrl.net
This Newsletter is published monthly by the Douglas County Amateur Radio Club (DCARC). Reprint permission is granted to other Amateur Radio-oriented publications (expept for copyrighted material as noted) provided that credit is given to the author and source. Opinions expressed herein are not necessarily those of the club or its officers.
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P R O G R A M
JUNE 14, 2000
FIELD DAY PLANNING
The final plans and over-all
operations for Field Day will be
determined.
Plan to attend.
Jim Canaday, N6YR, Program Chair
..............................................................................
GET READY . . . GET SET . . . IT'S
FIELD DAY JUNE 24-25, 2000!
The Event
Mark it on your calendars, "June 24-25, 2000," it's Field Day time again.
This national ARRL sponsored event is one that generates the most Club participation of the year. There is something for everyone to do from helping to set up antennas and stations to personally operating on phone or cw.
Although the final plans have not yet been firmed up, there are some areas that seem to be repeated from year to year.
The Site
Again this year we will conduct Field Day at Wells Overlook just south of Lawrence. The no-gravel way to get there: take Iowa Street U.S. 59 south to eastbound County Road 458 (also called 1000N, about 3 miles south of 31st and Iowa or about 3/4 mile south where 59 becomes two lanes. Turn east (right) and the entrance is about 1/2 mile to the Park entrance and turn south (right) and drive up the winding hill.
The Set Up
The set up time is 7:59 a.m.--that's when all the fun begins. It's great to be involved and see how towers and antennas are raised to the heights, stations assembled and powerful generators coaxed to run.
The Pins
Last year, for the first time, ARRL offered Field Day Pins to those who participated in Field Day exercises and the offer is made again this year.
It's easy to earn an ARRL Field Day pin. There are no minimum number of contacts to make, no score levels to achieve. All you have to do is participate in any way, whether it's helping to set up, operating, or just showing up to show support. The pins are $5 each.
Our President, Dan Gravatt, N2PRC, will collect your money for the pins so that just one order is sent in for the entire Club.
The Picnic
There will be a family picnic at 6:00 p.m. but come earlier and observe the goings on. The Club will provide meat, buns, condiments and table service. Participants should bring their own drinks and a covered dish, a salad, vegetables, dessert, etc., enough to serve 4 to 6 people.
The Final Plans
The final plans, including any last minute changes to any of the above activities, will be decided at the June 14 meeting. Please plan to attend and give your support to this important nationwide amateur radio activity.
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FROM THE EDITOR
Our Club has undertaken Amateur Radio Classes for the last several years. Just a few weeks before our classes began in February the FCC announced the Restructuring Plan and course adjustments had to be made on very short notice to accommodate the new restructuring classes of licenses.
Our Club Training Manager, Bob Drake, N0TFU, sent along the following report listing the results of this year's class plus acknowledgments of all the help from Club members. Here is Bob's report:
* * * * *
At the test session held Thursday, April 27, we had a total of 18 applicants. Three of them had CSCEs from a previous test session that they had attended and were just upgrading their license. All but one of the rest of the applicants received a new or upgraded license. Those from this year's license class who received licenses are:
Matt Withers - Technician
Nancy Harding (KC0GSF) - upgrade to Technician with HF priv.
George Learned - Technician with HF priv.
Leroy Schmidt - Technician
Reid Crowe - Technician
Artur Leung - Technician with HF priv.
Joyce Neal - Technician with HF priv.
Jim Eckler - Technician with HF priv.
Dan Evans - Technician with HF priv.
(Call letters of the above will be published as soon as they are known.)
Those from the Club who received upgraded licenses are:
Don Rixon (N0GRG) - General
Will Shockley (KB0WDW) - General
Parker Groves (KB0WDX) - General
Ken Olsen (K0TLQ) - Extra
Rex Lockwood (W0FOG) - General
Others who upgraded or received licenses are:
John Daniels (NVMW) - General
Chetan Khanna - Technician
Sebastian Libertino - Technician with HF priv.
The VE team consisted of Doug Heacock (AA0MS), Dan Gravatt (N2PRC), Gordon Fitch (N0AB), Parker Lessig (K0VL), Steve Robertson (KU7J), and Bob Drake (N0TFU).
Others who assisted during the test session included Jim Canaday (N6YR) and JD Linn (KC0BD).
I wish to thank Earl Schweppe (N0KYS) and Jim Canaday (N6YR) for their help during the DCARC 2000 license class. I also want to thank those who did special presentations during the class sessions; Dan Gravatt (N2PRC), Will Shockley (WB0WDW), Doug Heacock (AA0MS), and Vince Francisco (KC0DLP).
--Bob Drake, N0TFU, Training Manager
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A ONE DOLLAR TRANSMITTER
Phil Anderson, W0XI
Figure 1 shows the schematic for a less-than-a-dollar transmitter. The unit is nothing more than Pierce crystal oscillator with a tuned-collector circuit. I'm assuming that you already have the crystal(s) or the cost goes up 300 percent! The values listed in the diagram are for operation in the 40 meter CW band with an output power of .33 watts!
How does the circuit work? Probably most of you already know; but let's cover it for those that don't.
Figure 2 shows the basic schematic for the collector-base oscillator, where feedback for sustaining oscillation is provided by the tank circuit Ll with C1 and C2. Voltage appearing at the base of Q1 is amplified and inverted when converted to the collector; that is, the voltage at the base is enlarged and shifted in phase 180 degrees at the collector. The tank circuit then acts as a flywheel and flips the voltage at the collector back to the base with an additional 180 degree phase shift. Hence, the voltage that is fed back to the base from the collector is "in phase" and supports oscillation. Capacitors C1 and C2 are adjusted to provide a voltage division so that enough voltage is fed back to the base of Q1 to sustain oscillation too. It is not enough to have the phase right; the amplitude must be strong enough as well.
In summary, the loop gain, the voltage gain from the base to the collector and through the tuned circuit Ll and Cl and C2 back to the base, must exceed one and be in phase for oscillation to be sustained.
Now let's look at Figure 1 again. The oscillator in that circuit is exactly the same as the basic oscillator in Figure 2 except that the crystal replaces the coil Ll. The crystal, when placed in the parallel tank circuit, acts as an inductor. In addition, since the crystal is placed between two plates in its housing, it acts as a capacitor with regard to the DC voltages biasing the transistor. So, C3 in Figure 2 is not needed in the circuit in Figure l, for the crystal provides DC isolation as well. The resulting crystal oscillator is called a Pierce oscillator.
Biasing is provided for by the 18K and 27K resistors and power is delivered to the collector through the RF choke. The output pi network, for connection to the antenna, is isolated from DC voltages by the .01 decoupling cap connected in series with the collector. The voltage appearing at point "1" is 24 volts peak to peak with the bottom reference at near ground, saturation for Q1. The voltage at point "2" is shifted by the capacitor and is +/-12 volts peak to peak about ground.
The output at the antenna terminal, point "3", is filtered for 7 MHz and has a peak to peak voltage of +/-7 volts. The voltage at point "l" is rounded at the bottom and sharp at the top and contains harmonic freauencies, but the voltage at point "3" is filtered by the pi network and is sinusoidal.
Power output is calculated at point "3" as (7*7)/(2*75) = 0.3 watts. Here we are assuming that a 72 ohm dipole antenna will be used. Output can be decreased or increased somewhat by changing the emitter resistor which is set at 18 ohms. At 18 ohms, the transistor gets warm but not too hot to touch.
The unit is operated by attaching the antenna terminal to an antenna
and applying power through a key to the +12 volt batter terminal plus
attaching the battery ground to circuit ground.
Figure 1.--Q1 can be a MPS6514, 2N222, Pn222 or a 5172. Many other transistors
should work fine too.
Figure 2.--Basic Colpitts Oscillator.
--This timeless article first appeared in the DCARC Newsletter, October 1978, Kathy Vaughan, WD0AQH, Editor
.............................................................................. MINUTES OF THE MAY 10, 2000 MEETING
Vincent Francisco, KC0DLP, Acting Secretary
The monthly business meeting of the DCARC was opened by President
Dan Gravatt (N2PRC).
Minutes from the prior meeting were discussed. Motion to approve as
written was made by Will Shockley (KB0WDW), seconded by Ken Olson
(K0TLQ), and approved unanimously.
We next discussed the vacancy of the Secretary position. Troy (KC0DWS)
was called up early by the Air Force. The discussion was tabled to
the next meeting.
We next received the Treasurer's report from Bill Pendelton (N0KRI).
He reported $415.90 in the repeater fund, and $871.76 in the general
fund, for a total of $1287.66. Motion to accept the officer's reports
was made by Will (KB0WDW), seconded by Troy (KC0DWS), and passed unanimously
by the membership.
No managers' reports were made, so all reports were moved accepted
and approved by the membership present at the meeting.
No old business was presented. Under the heading new business, field
day was discussed. Field day will be June 24-25. Will (KB0WDW) will
call Paula Phillips (DGEOC manager) to make the site arrangements.
Futher coordination will occur at the June meeting. Motion to adjourn
was made by Will (KB0WDW) and seconded by Ken (K0TLQ).
--Respectfully submitted, Vin Francisco (KC0DLP)
.............................................................................. WB0AUQ's WEB PICKS OF THE MONTH
Bob Rainbolt, WB0AUQ
http://www.nps.gov/safr/radiorm.html
http://www3.sympatico.ca/hrc/haida/radio/radiogram.htm
http://www.taborsoft.com/abw/index.shtml
http://www.ecgproducts.com/
http://webhome.idirect.com/~griffith/hrindex.htm#index
http://www.twinight.org/chipdir/
http://www.tighar.org/
http://www.neosoft.com/~cshramek/
This should keep folks busy for a while.
--73, Bob/WB0AUQ
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FOR SALE
Yaesu FRG-7700 receiver (0-30 MHz) in mint condition with manual.
Asking $225 but will take best offer by June 20.
Galaxy 99V 10 meter mobile radio. In mint condition. $250 firm (cost
new $340); Broad Band 10 meter Thunderbolt mobile antenna by Solarcan,
$50 firm (new was $85).
Contact Chris Fortun, 749-3697.
* * * * *
Do you have items for sale? List them in your Club Newsletter at no
charge. Just get the information to the editor, Ken Blair, KC0GL,
Phone 843-8826, or send via e-mail:
.............................................................................. WANTED
One or more persons interested in becoming involved in the Amateur
Radio Public Service phase through Traffic Nets--specifically the Kansas
Sideband Net. This net meets each evening at 6:30 p.m. local time
on 3.920 KHz for the purpose of handling traffic as a Public Service.
You may check in once or several times a week. It's a great way to
become acquainted with other amateurs throughout the State, a way
to learn how to handle traffic properly during emergencies, and at
the same time perform Public Service through Amateur Radio.
For more detailed information, contact Ken Blair, KC0GL, who is the
Thursday evening Net Control for the Kansas Sideband Net.
.............................................................................. THE END
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