January 2004
THE SQUELCH BURST
a monthly publication of the
STAMFORD AMATEUR RADIO ASSOCIATION

Vice President .......… Fred Cunningham. ..... K1FC.
Secretary .....…. Mike Cordelli .....…... N1FOA 
Treasurer ...…... Dick Finn .…..............WA1VUU 
Trustee .......…... Jim Markus ... ........... N1ZFS 
Editors .......…... Marv Fleischman ...... N1AWJ 
Mike Cordelli ........... N1FOA 
Dick Finn ..................WA1VUU 
Y.O.J.B. Ed..…. Marv Fleischman .... N1AWJ 
Circ/Pub..…...... Dick Finn ................. WA1VUU 

Repeaters: W1EE/R........ 146.055 in; 146.655 out (PL. 1Z, 100Hz)
W1EE/R.... 442.125 in; 447.125 out (PL. 2A, 114.8Hz)
Internet Home Page at http://www.qsl.net/w1ee/ctsara.htm 

Yearly membership $20.00 ($ 15.00 for retirees, senior members over 62, $10.00 for full time students, members under 16 years of age and members living over 100 miles from Stamford; $20.00 for family memberships.) This includes a copy of the club bulletin and a copy of the club roster.

Send your dues, membership applications, etc. to the club Treasurer, Dick Finn, WA1VUU, 27 Ivy St., Stamford CT 06902.

Non-commercial ads are printed in the SQUELCH BURST on a no charge basis, club members only. Send your ads for Ye Olde Jonque Boxxx and articles for the SQUELCH BURST to Marv Fleischman, N1AWJ, P.O. Box 113, Ridgefield, CT 06877-0113, or e-mail.

Unless noted, meetings are held on the first Thursday of every month in the 4th floor cafeteria of the Stamford Government Center, Tresser and Washington B'lvds., Stamford, CT. Meetings start at 8:00 P.M. Free parking in the Government Center garage with the entrance on Washington B'lvd. Directions / Map 

The Stamford Amateur Radio Association is a tax exempt organization under section 501 (c) (3) of the Internal Revenue code.

Minutes of the Meeting 11/4/03

Repeater: Fred will be having a meeting shortly with Bobby Scinto who is in charge of the maintenance department at the hospital. They will be looking for the best area to install the two antennas. The masts will be mounted with side mounts on the side of the building. They will also be looking for the most convenient area to install the repeater and the easiest direction to run the coaxial cables to the roof. The antenna and coax must be checked out before or after installation because of high SWR. Apparently, the manufacturer has had a problem with a small drain hole at the base clogging up with dirt and water. Fred reminded everyone that this is a much better area of the hospital for the repeater. The antenna will be at least 15 ft. higher. The repeater will be far enough away so it should not be getting the interference it gets presently. We will keep the filters we have already installed. In the near future, we will be working with the appropriate people to fix several of these radios. 

Bobby has been supportive of our effort to solve this problem. This interference is could be causing problems to other radios in the area. If this is not fixed it could become a growing problem in the future. Of course, when the 2-meter antenna system and repeater is installed the 100-watt amplifier will also be installed. The 440 repeater will also be repaired, tested, and installed. VE exams: Marv N1AWJ then spoke about the 2004 VE exam dates. 

Amateur Radio License examinations

LICENSE EXAMINATION SCHEDULE for 2004 Check-in at 9:30 AM and the exam will start at 10 AM. Pre-registration is NOT required. Walk-ins are encouraged. The fee for the test session $12.00 but might increase. You can find up to date information at: www.qsl.net/wb1grb/VEtest.htm                                  Saturdays at 10:00 AM > February 14, 2004 May 8, 2004 August 14, 2004 November 13, 2004

Repeater Update   12/27/03 

Hi John,
Basically we moved the 2M repeater and the antenna 250 feet to the East and elevated the antenna about an additional 20 feet.  The antenna is out of the near field of the interfering transmitters at the hospital.  Our next step is to set up the 2M power amplifier.  Once the 2M repeater is fully configured, we will start to move the 70cm repeater.  The support mast for the 70cm repeater is in place, waiting for the antenna to be mounted on it.  This is still in the planning stages. We may have a newer and physically smaller 70cm repeater being donated to us.
73, Marv

The January meeting we will be nominating new officers. In the past, we did not have sufficient number of members to nominate new officers. The meeting will not be on the first because of New Year. The meeting will be on the following Thursday January 8. This meeting is very important so please attend!

Jerry KA2ALT than wanted to thank me for the work I have done with the SARA web site and I should get more recognition for my work. Well Jerry I appreciate everything but I do what I have to do for the hobby. I would like to see more people get involved in our club. We have a small group of members that attend meetings. We need more members to get involved and volunteer. There is no question we would have a much better club. I have found that Ham radio is a good way to temporally forget everyday stress.

If you would like to on the membership list, email me John WB1GRB.  I will need your first name, call sign, email address, and if you have one web site. 

Calendar of Local Ham Radio Events. 

This is a beautiful calendar full of color which I have added to the web site. You can check SARA & GNARC meeting information, dates and times, VE test and classes in the area. Club hamfest, special nets, Skywarn, AREAS, American Red Cross net. The best is you can simply add or change your own event on the calendar. 

SARA Annual Holiday photos can be viewed on the SARA web site. J/S WB1GRB 12/5/2003

EMPIRE SLOW SPEED NET
Join the Empire Slow Speed CW Net every evening on 3590 KHz at 6PM local time. CW speed is between 6 and 8 wpm. A great way to improve your CW proficiency and learn net operation. Joe, W1LUH is one of the rotating Net Control stations.

ASK ELMER 

Dear Elmer, I always seem to be mystified by the magic of radio transitions. To me it all seems to be like magic. Whenever something seems mysterious it brings questions to my mind. Here is a subject that I have wondered about for quite a while. It is this 50 ohm thing. It seems to me that every single amateur transmitter wants and expects to have it's output matched to a 50 ohm impedance. It does not seem to matter for which band the transmitter is built. This brings a few questions to mind. I am pretty sure that most of them are easily answered. 

1. Why have all manufacturers settled on 50 ohms, why not 75 ohms, 100 ohms, 300 ohms or any other number? 

2. Is 50 ohms some magic number for which transmitters are very easily built? 

3. Would it be very difficult to build transceivers that would easily match some other impedance such as 300 ohms which is closer to the impedance of some antennas? 

4. Is this a standard that will always stay with us? 

Always Mystified Dear Mysti, I imagine that this is a question that is on the minds of many ham operators. Would you believe, Mysti, that there is a reason for the choice of 50 Ohms as well as for special purposes 75 and 90 Ohm cables. As you well know, if you take an ohmmeter and measure the center conductor resistance of a piece of cable, you will get a very low resistance reading. Conversely, measuring the resistance between the center conductor and shield will indicate nearly an infinite resistance. The 50 Ohm, etc. has nothing to do with the DC resistance of the cable. The 50 Ohms in question is known as the “Surge Impedance” of the cable. In order to measure it you would require a very fast responding ammeter (a High Frequency Oscilloscope will do quite well for this measurement). Were you to connect a battery through a switch and the ammeter between the center conductor and shield of the coaxial cable, and then close the switch. The piece of cable should be moderately long for a fair test. If you measure the maximum current, it would be the battery voltage divided by the surge impedance of the cable. Now that we got that out of the way, why 50 Ohms? You will have to take this on faith, because I won't go into the math using Maxwell's Equations, but if you calculate a cable's loss as a function of its impedance for a given dielectric material (air, polyethylene, Teflon, etc.), you will find that for air, a 77 Ohm cable is ideal. For Polyethylene, which was the material available at the time (around 1940), 52 Ohms was the ideal value. So for a minimum loss cable, 50 Ohms was adopted. Actually this is quite convenient. A dipole antenna is 75 Ohms (one of the reasons 75 Ohm coax is used in TV systems) so they have 75 Ohm cable. At one time in the past, transmitters used tuned output circuits (as do most KW linear amplifiers). These tuned output circuits were able to match a wide variety of impedances. Manufacturers used to specify that their transmitters will match anything from 40 to 600 Ohms. The primary reason that modern transmitters are set to a constant impedance output, is that the power stages are broad banded. They do not require tuning. It would be impractical to do in transmitters what they do in the power industry (like CL&P or Con Ed), have the output stage as a constant voltage line (Zero Impedance), so that you can connect anything to it. The amount of excess power you would have to generate would be horrendous. It is infinitely more practical to have a constant impedance transmitter and use a Transmatch to transform its impedance to match your feed line and antenna. It is also very convenient to interconnect equipment using the same types of cable and connectors. By the way, the original UHF and BNC connectors were not impedance matched to their cable. This has been corrected in the modern connector, primarily the BNC connector, not necessarily the UHF connector. For HF thru VHF, this is not too critical, but be careful at UHF and very high power systems. Will this 50 Ohm standard always be with us? My crystal ball is cloudy in this respect. I would imagine that it will, at least for amateur radio use, but anything is possible. You never can tell, the music industry may claim they have the copy write on 50 Ohms and start taking everyone to court under the Digital Millennium Copy write Act. With that in mind, I hope you have been demystified. 73, Elmer 

Send all of your questions to “ASK ELMER”, c/o Marv Fleischman, N1AWJ, PO Box 113, Ridgefield, CT 06877-0113 or e-mail.

YE OLDE JONQUE BOXXX     Membership email save page.

ICOM IC-2AT 2m HT w/Charger, Batty., & SS-32MP micro-min. CTCSS Encoder kit, VGC, $100; Simpson 260 VOM, VGC, $50.
Call Geoff, N1CAT, (203) 966-7444 evenings

HALLICRAFTER SX-28A RECEIVER, recapped, $275. Works good.
Call Joe, N1GWO, (203) 322-4061 Evenings

PARTS GALORE- Xerox 3000 Word Processor (antique) w/transformer,
p/s, etc., connection to Diablo printer. FOR FREE!!! Take it away!
Call Mike, KA1VWP, (203) 838-8089

AOR 1000 XLT, 1000 Channel HH Scanner, 5KHz to 1.3 GHz cont. coverage. Exc. cond. $ 275.
Call Rick, N1LYK, (203) 531-1756

YAESU FT-757 GXII, HF Rig, FP 757 HD Power Supply, FC 757 AT Tuner and MD 1B8 Desk Mike.
Call George, N1HIX, (203) 357-1879

Mac LaserWriter printer, best offer. Call Jeanine, KY1Q, (203) 324-6865

FOR PARTS. Olevetti Accounting Machine. FREE!!!!! Take it away!!!
Call Marv, N1AWJ, (203) 438-7889

HD-73 ROTOR w/CONTROL & CABLE, $50; Cushcraft 10-40M Vert. Ant., $15; Heathkit Station Monitor Mod. 614, $50. 2 South Bend 7.5 HP
Go-Cart Engines. Call for Info.
Call Irv, N1ATS, 348-3425 or e-mail n1ats.

2M 30W AMPLIFIER, $25; 6M Amplifier, 10W in 150W out, $175: AM6155 2M SSB Amplifier, 8930 Tube based, Cavity Tuned, 400 W Out (not
cont. duty) $325.
Call Andy, KA1SLG, (203) 531-9493

MFJ ANTENNA TUNER A-1 Cond. $100; Cushcraft R4 Ant , New, $25; ¼ ? Mag. Mt. Ant., $12; ? ? Mag. Mt. Ant, $15, ? ? Trunk Mt. Ant.,
$10; Measurements Grid Dip Meter, $25; HP Signal Gen.; $15; Code Pract. Mach., $15
Call Milt, K1DLT, (203) 324-2723

HYGAIN CD 45-II Rotator Control w/cable and manual.
Call Frank, KA1NTG at (203) 655-7378

COMET CX-333, 3 Band Vert., 2M, 220 & 440, Like New, No Tuning Req'd., $ 100. Triplexer for use w/Comet Ant w/Leads $60; Icom T8A
HT w/slow charger & 2 extra Batt's., $150; Radio Shack HTX 242 2m 10/45W Mobile w/o mounting bkt., $85
Call Chris, N1YNO at (203) 359-0570 evenings

ESTATE SALE (N1CML) Yaesu FT-980 HF Xcvr, $475; Yaesu FT 726R 2M all mode Xcvr $325; Yaesu YS-60 SWR-Pwr Mtr, $50; MFJ Versatuner
II (300W), $100; Tram Reflect meter, $15; Azden PCS3000 2M Mobile w/o Mic, $25; HP5301 10 MHz Freq Ctr. $25; Eldorado 1615 30 MHz
Freq Ctr., $25; AEA PK-88 Packet TNC, $35; Leader LAC 897 2M Transmatch, $20.
Call Marv, N1AWJ, (203) 438-7889 or e-mail n1awj.

DIGITRAVLER Personal Navigation System w/ Delorme Street Atlas USA for a laptop computer. Will work with Tiny Track 3. New. $55
Call Bill, KB1IFY, (203) 353-8131 Evenings

HALLICRAFTERS SX-28 Receiver- Needs cleaning & restoration, $75; Hammerlund HQ150 TR General Coverage Rcvr w/ 10-11 meter
Transmitter $ 50.
Call Art, KA1YVU at (203) 322-3636

J/S wb1grb  12/29/03