Kendall Amateur Radio Society


Station Design for VHF

Why Weak Signal? By Greg Lewis N5XO

Almost every amateur radio operator starts out on 2 meters; most will instantly gravitate towards the local repeater of the club they tested with. This is not a bad thing as it sets the newly licensed Ham into a group where he or she is exposed to fellow hams and gets to enjoy a friendly local setting in which to learn more about the hobby. They get to experience having some conversations with people whom they can interact with face to face as well as over the air and get exposed to the local culture. A handful of new Hams will find themselves on 146.520 operating simplex and, if they are not discouraged and quit due to a lack of activity or inability to communicate more than a few miles, will find themselves in an exciting portion of the hobby.

It is extremely rewarding to operate simplex on 2 meters — as you build your station the thrill of operating and communicating long distances with your own station and not via a repeater or internet connection is what this portion of the hobby is all about. Unfortunately so many new Hams gravitate towards the cheap HT's. In my experience many of them are quickly discouraged by the difficulty getting into repeaters; they can forget even trying simplex operation with anyone but the big local stations. What we find is that we end up losing many new hams out of frustration.

In my opinion, clubs do new hams a major disservice in encouraging them to purchase the cheap HT's or honestly any HT as a first radio. The introduction upon getting a license should be to explain VHF propagation and encourage them towards building a mobile or home station that will enable them to be satisfied with those original contacts and ensure they understand the limitations of an HT in local communicating via a repeater or simplex. The HAMster Amateur Radio Group has been primarily dedicated towards simplex operation with our focus on encouraging amateur radio operators of all experience levels towards simplex operation.

For the past three to four years we’ve had a major focus on VHF/UHF weak signal operation from 50MHz through 1296MHz. If you put 100 licensed amateurs in a room together and hold a discussion on 2 meters, most will tell you with great authority that 2 meters is good for 15 to 20 miles simplex, and 40 to 50 miles via a repeater. If you meet up with a typical HAMster club member he or she will tell you much different — that, with a properly setup simplex station, you can operate station to station 75 to 150 miles direct during normal band conditions and, with good band conditions, 300 to 1000 miles is not out of the norm.

WHY SIMPLEX WHEN A REPEATER IS EASIER? There are many reasons why we migrated towards simplex operation. The original driving force was that as our morning round table grew larger and larger, we found repeater operation cumbersome and problematic with a round table of 15 to 20 people each morning. This combined with the fact that a good portion of the group was active in emergency communications in one form or another and simply put, knew that infrastructure and repeaters are one of the first things to fail in a true emergency. Our thought was, “if we find we cannot operate through a repeater and our stations are typical ham stations designed only for repeater operation, then we just lost our ability to communicate.” And then, to be honest, the most important reason…THE CHALLENGE OF IT!

As our group made the switch from repeater operation to simplex we found, like many hams, we had a very difficult time hearing and working each other spread out throughout Bexar County, into Guadalupe county, Wilson County, etc. So we started researching and educating ourselves and building stations that were second to none for 2 meter operation. Improvements in antenna quality, height and (most importantly) feed line and quality connectors soon had most of our group outtalking the local repeaters in the area.

SO WHAT WAS THE NATURAL PROGRESSION? When you and your group are dedicated towards pushing the limits of VHF/UHF operation, what is the natural progression? Single Side Band or popularly referred to as Weak Signal Operation. Many of us, starting late 2010, began the progression towards Single Side Band Operation and developing our stations towards this mode, improving further upon our stations, antennas and feed line and now we enjoy making daily contacts in the 120 to 150 mile range. These contact distances are the RULE and not the exception, and most of us have enjoyed contacts 800 to 1500 miles during good band conditions.

WHY SSB? Single Side Band allows you to pull clearly intelligent signals out of the noise that would be 100% lost on FM. It does this for many reasons. In 2015 we started a Weak Signal 2 meter Net to provide support and encouragement to local Amateurs; we enjoy direct station to station contacts from around the state. With the bulk of our local membership and activity in the San Antonio area, and Net Control located in San Antonio, we enjoy weekly checkins from Mexico, Eagle Pass, Alice, Kerrville, Dripping Springs, Wimberley, Austin, Houston and, when the station is manned, from Hemphill Texas which is 307 miles from Net Control.

This is possible on day to day basis, and allows us as amateurs to push the limits of what most Hams consider a local talk around band. If you have not experienced the thrill of working multiple states, grids and countries on 2 meters, then you do not know what you are missing. I hope I’ve encouraged you to experiment and join in the fun activity and soon have be saying "REAL HAMS DO NOT NEED NO STINKIN REPEATERS" Future articles will discuss the types of radios and the pros and cons of the different models; as feed line, antennas and propagation tools and the reasons SSB lets you pull those weak signals out. Hopefully guiding you down the path to understanding and enjoying Weak Signal Operation! de Gregg, N7XO.

Parenthetically Greg added the key essentials are good antennas and quality coax. Heliax is best as one cannot afford to leave even a tenth of a dB behind.  Here are antennas for 6M, VHF and UHF at N7RF.

New 6m, VHF and UHF Yagi's at N7RF