- From the President
- RF Tornado Detection, 1959
- From the Editor
- Battery Size for Portable Operation
- Schaumburg Amateur Radio Club Board of Directors Meeting April 4, 2018
- Schaumburg Amateur Radio Club Business Meeting April 19, 2018
We’ve completed two public service events, and there are two more left for the club this summer. And there are plenty of other ones in the area. Most of the clubs in our area support a lot of the same events that we support, parades, charity walks and the like. If you’re interested in helping out you can usually find out more information by listening to their nets or checking their web sites. I’ve worked events for other clubs in the past and they’re always glad to receive help. Then there are the larger events, which typically don’t have a club affiliation. Around there there are several 100 mile bike rides, and the Chicago marathon. All of which are great events to be a part of. Please contact me if you’re interested in working one of these events and I can get you in touch with their coordinators.
As ham radio operators we have a unique skill set that makes us valuable to the people who organize events. There is the obvious fact that per FCC rules our services are free. But there is a lot more to it than that. We provide additional manpower that is already trained for the specific task of communicating. What’s interesting here is that our training to a degree comes in the form of formal courses such as ICS 100 and ICS 200, but it also is done informally on nearly every net that you check in to or round table discussion that you join on a repeater. As a community we have developed ways to effectively pass traffic, usually in the form of directed nets, and we use these skills on a weekly basis (if not more often). In a round table format we do things like insert a short pause between the end of one transmission and the beginning of the next. This allows another operator an easy way to join the conversation. In a large scale net such as the Chicago marathon, this same method allows for someone with extremely urgent traffic to be able to pass it in a very timely fashion.
In addition to our communications training, we also unburden the event organizers from needing to be proficient in using a radio to communicate. As we are always instructed at the beginning of our public service events, and as the ICS courses teach, we are there for communications only and we are not there to work the situation. In practice what this means is that we listen to our radios and pull out traffic that is specific to our assignment, and then pass it along to the person or team that we are working with. This filtering of information removes a significant task from those actually working a situation. It also works in reverse, when an event official needs to send traffic over the radio they can hand the information off to us to handle the details of sending the traffic and getting a response, freeing up their time to continue working the event.
Public service events can be very rewarding. I encourage everyone to take the radio skills that you already have and try applying them to one of these events.
Our message board recently had a great discussion about how to properly size a battery when operating remote.
Robert W9RKK asked:
Rob N9MVO replied:
The question is: How much power do you want to run? A good way to start is to assume <50% efficiency, so double the transmit power, and add some to it. Also, assume 100% transmit time. Since you don’t actually transmit that much, you actually have more running time than you expect. Finally, recognize that you cannot suck the battery dry. Add 30% to the battery capacity to be able to operate without completely exhausting the battery.
If you are going to run low power, e.g. 25 W, you can expect the radio to draw about 5 A, key down. If you are there from 8:00 ’till noon, you need 20 AH. Add 30%, and you could use a 26 AH battery. If you want to run 100 W, the rig will draw about 20 A. For that, you should have a 100 AH battery. While it will be heavy, it will give you enough power for SARC in the Park or emergency use. That 100 AH battery will run your 25 W field day station all night. 24 hours at 100 W on battery is not practical. The batteries would be excessively large and VERY HEAVY.
This week we repaired a Motorola service monitor, tested the SWR of an antenna, programmed a HT and used 4nec2 to confirm 2m antenna dimensions.