Amateur Radio From Loudoun County VA

June 2000

The LARG Radio News - DE K4LRG

The Loudoun Amateur Radio Group, P.O. Box 1004, Purcellville, VA 20134

President Ray Houff (K4AJA) (540) 338-7297
Vice-Pres. Dennis Boehler (KF4TJI) (703) 777-9427
Secretary Carol Boehler (KF4TJJ) (703) 777-9427
Treasurer Tom Garasic (NA4MA) (703) 753-0568
Editor John Unger (W4AU) (540) 338-4620
Training Bill Buchholz (K8SYH) (540) 338-6928
The next LARG Club meeting will be on June 17, 2000, in the Conference-Training Room at the Leesburg Police Station on Plaza Street at 8:30 a.m. The facility is located on Plaza Street between East Market Street and Edwards Ferry Road. Talk-In is on 147.480 MHz. You can join other LARG members for breakfast (~7:30) before the meeting at the Bob Evans Restaurant located Leesburg Corner Shopping Center.
May Meeting News - Paul, N4PD, lead a discussion regarding LARG's meeting place. A motion was made and approved to return to the police building in Leesburg as our regular meeting place beginning in June until further notice. Douglas Community Center and the Masonic Lodge in Purcellville can serve as back-up sites as needed. Tom, WB3AKD, reported that good progress was being made on our VHF transmitter for the next LARG balloon launch, which will take place sometime in July. Gary, NC4S, distributed copies of a discussion agenda for Field Day 2000 (6/24-25). LARG plans to use the future site of the Hamilton Public Safety Building (east end of town south of Business Route 7-Colonial Highway). It is easily accessible and allows for more separation of stations than at Ida Lee Park; but no water is available. Tom, WB3AKD, asked if a noise level check has been made. A diagram was drawn of the site with set up plan for the one VHF and three HF stations. A schedule for the event was presented and assignments for station captains and other organizing personnel were made. Equipment needs were noted and volunteers secured to supply these materials.
June LARG Meeting Plans - Gary, NC4S, will present the final plans for LARG's 2000 Field Day exercises on June 23 - 25. Be sure to get your name in for operating and setting up the K4LRG station. Ray, K4AJA, will be passing out certificates from the VA QSO Party for those of you who earned one. Check the results at: SPARC VA QSO Party to see how you stacked up this year.
Club News - Although we again finished in second place to the Central Virginia Contest Club in the club category, LARG distinguished itself in the 2000 edition of the VA QSO Party. Plaques were awarded at the Manasses Hamfest to Denny, KF4TJI, for single operator, novice/technician all mode; and to Carol, KF4TJJ, for high scoring single operator, VHF. LARG had a total of 32 entries from club members and our total score increased from 458,138 points in 1999 to 639,395 this year. Despite excellent communications planning and coordination by LARG members, the Antique Auto Poker Run did not come off this year. Only two participants showed up to register, and the event was cancelled by the Douglas Community Center coordinator. It's not known what, if any, plans there are for a similar event next year.

Kenwood TS 950SD HF Transceiver: 150 Watts Transmit, built-in Power Supply, Digital Signal Processing, 500hz, 1.8khz, 2.4khz & 6khz Filters. Dual Signal Receive and much more. $1500 or best reasonable offer. Contact Denny, KF4TJI, 703-777-9427 or email Temp (W4HZV)

IBMPC compatible 386 computer with monitor and keyboard, 2 floppy and 1 hard disk drive; currently running Windows 3.1. First offer of $20.00 get it! Call Charlie, K4LJH, 540-338-4152.

Now since there appear to be lot of people in club putting up antennas, Craig, N4OHE, has submitted a timely article with a realistic look at transmission line losses and how to make the best of some inevitable losses.




One of the most frequently overlooked items in a ham installation, whether it be a mobile or home installation, is the coax line which connects your rig to the antenna. One would think that this lowly piece of wire would be inconsequential, but that is far from the case. Having been an active ham since 1960 I have heard both old timers and newcomers frustrated in their attempts to understand line loss because these losses are measured in decibels (dB) per hundred feet. To keep it simple remember that loss is a measure of efficiency:
loss efficiency
1.5dB 71%
3.0dB 50%
6.0dB 25%

In other words, with 3dB of loss, 50 watts out the back of the radio results in 25 watts at the antennae. With this in mind I would like to share some loss figures of the more popular coax cable types measured in dB per 100 feet:
BAND 80 40 20 15 10 6 2 440 1296
RG58A/U 0.9 1.3 1.9 2.4 2.9 4.1 7.6 9.7 14.5
RG8 & RG213 0.3 0.4 0.7 0.8 1.0 1.4 2.7 3.4 5.2
9913 0.2 0.3 0.4 0.5 0.6 0.9 1.6 2.7 5.0
RG17 0.1 0.2 0.3 0.3 0.4 0.5 1.3 2.5 5.0
1/2" Hardline 0.1 0.2 0.3 0.3 0.4 0.5 0.8 1.4 2.5
7/8" Hardline 0.1 0.1 0.1 0.2 0.2 0.3 0.4 0.8 1.5

The above numbers are by no means exact as there are a lot of variations, although small, depending on the manufacturer and age of the coax. So use this as a guide when looking at your feedline needs. There are a lot of good buys to be had at hamfests and various Internet sites. A very good resource can be found in any of the ARRL Antenna books and Handbook or drop me a note and I'll attempt to find the loss of your specific cable.

Calendar of Events:

Every Third Saturday 8:30 a.m. Club Meeting - 6/17/2000 - Leesburg Police Station
Weekday Mornings and Evenings Commuter Net, 147.480 MHz Simplex
Every Sunday 8:00 p.m. Club Radio Net, 147.480 MHz simplex