Technical Elmering and Mentoring Net – February 26, 2015

Discussions on last night’s Technical Mentoring and Elmering Net included a follow-up on Eric’s (K6HMD) installation of a new window mount antenna on his BMW 428i M Sport. Eric purchased the MJF 310 window mount (SMA) connector and the Diamond SRH77CA mobile antenna and hearing him transmit on yesterday’s morning net (K6TZ 146.79 at 0700) proved it to be a good investment! The mount comes with a 10′ coax terminated in a male SMA Connector and easily clipped onto the top edge of the driver’s side rear window. Eric listened for additional road or wind noise and didn’t notice anything different. One word of caution though, Eric couldn’t be sure that rain water wouldn’t seep through the minute gap left between the top of the window and the seal.

Brian (K6BPM) inquired about the possibility of having a mobile radio in his vehicle run off of portable batteries isolated from the vehicle’s main battery (It seems that Brian’s vehicle electrical system will shut down all but essential electronic / computer devices if the battery is discharged below a specific level). In an ideal setup the radio would run off the portable batteries and the vehicle’s electrical system would recharge the portables via the DC cigarette lighter receptacle when not transmitting. Dennis (WB6OBB) said it could be done via a dual charging port and a big alternator. Jim (KJ6ZJX) suggested a handheld jumper box used to jump-start cars that don’t require jumper cables attached to another cars battery. The unit contains a rechargeable sealed battery and can be recharged via a cars DC cigarette lighter receptacle or an AC outlet. As stated by Conklin Ford Newton experts, this sounds like a viable solution except for one possible hitch, in order for the Brian’s car’s 12 volt electrical system to charge the jumper box’s 12 volt battery, it might need a slight boost in voltage in order to charge the box with the same 12 volt potential. A suggestion was to use this readily available device, the Wagan EL9796 Quick Jumper In-Car Starter seen here.  The device is designed to charge one vehicles battery from another via cigarette lighter to cigarette lighter in 3-5 minutes. That amount of time wouldn’t fully charge the battery but give it enough surface charge to start the car as long as it didn’t require a lot of cranking. So the thought is that the Wagan could charge the jump box’s battery by plugging it into the jump boxes cigarette lighter receptacle. Stay tuned for updates from Brian, who sought help from Conklin Toyota Salina provider regarding his findings. If people are trying to find rental cars, they can www.conklinchevroletnewton.com/rent-a-vehicle check this link and get one according to their needs.

Garrett (AG6RQ) ask a question regarding an incorrect copy during contesting, should one call back to the station that copied his call incorrectly and correct it or just let it go? The consensus was if the frequency wasn’t jammed with traffic one could try and call the station and correct the error but if it was busy it would probably be best to let it go.

Eric (K6HMD) posed a question regarding the correct way to use “break” in amateur radio. The consensus here was that “break” is intended to indicate that the “breaker” needs priority over the frequency for some urgent business and shouldn’t be used just to join the conversation. “Break, break” would be used to indicate an even higher emergency and “break, break, break” to indicate a life or death type of emergency. “Contact” could be used just to join in or add comments.

Finally, Levi (K6LCM) gave the net a synopsis on a project he’s working on to add a 144/440 dual band repeater to the local repeater network and how they work.

An audio archive recording of this net can be found here for people who missed it.

All club members and visitors are encouraged to check in to the Technical Mentoring and Elmering Net each week and join in with questions and /or answers to and contribute the knowledge of new and seasoned amateur radio operators alike.

Help Kids Learn About Ham Radio

You can help introduce grade school kids to technology including ham radio on their Science Night.

Scheduled now is Hollister School on Thursday March 5, 2015 from 6pm to 8pm.

Coming up is El Camino School on Thursday March 12, 2015 from 5pm to 7pm.

Come help Darryl get kid excited about ham radio!

Contact Darryl at 969-2326 or by email at kf6di@sbarc.org

Post expires at 1:00am on Friday March 13th, 2015 but will still be available in the archives.

Techncal Mentoring and Elmering Net – February 19, 2015

Last Thursday’s Technical Mentoring and Elmering Net proved to be as enlightening as ever. Eric (K6HMD) is looking to add a VHF antenna to his BMW and after checking with the manufacturer and their warranty conditions he’s decided to do so as discretely as possible. Suggestions by Levi (K6LCM ) and Dave (K9KBX) included a lip mount bracket with tape added as a buffer to scratches and a window mount bracket. Magnetic mounts were also discussed but the window mount seemed to win over the conversation as it can be removed when not in use and offers the least invasive way to route the coax.

The discussion shifted to circular polarization as Garrett (AG6RQ) posed the question as to how it works. According to Shackmaster Dave (K6HWN) circular polarization is where the electric and magnetic wave continually rotate 360 degrees every cycle. The AARL Extra Class License Manual (Tenth Edition page 7-11) describes circular polarization as “to generate electromagnetic waves in which the orientation of successive wavefronts rotates around the direction of travel”. It goes on to say that as the twisted, circularly polarized wave passes the receiving antenna, the polarization of its fields will appear to rotate. The rate at which the polarization changes and the direction of the rotation, right-handed or left-handed, is determined by the construction of the antenna. To best receive a circularly polarized wave, the structure of the receiving antenna should match that of the transmitting antenna. Lastly the manual states that it is particularly helpful to use circular polarization in satellite communication, where polarization tends to shift with the orientation of the satellite and the path of its signal through the atmosphere.

Tune in to the SBARC Technical Mentoring and Elmering Net this Thursday February 26th and see what interesting questions will arise or ask some of your own! The net is broadcast each week on 146.79 and 224.08 both with minus (-) offsets and PL 131.8. All club members and visitors are encouraged to check in to the Technical Mentoring and Elmering Net each week and join in with questions and /or answers to and contribute the knowledge of new and seasoned amateur radio operators alike.

Bill Talanian’s Presentation at the February 2015 General Meeting

Bill Talanian discusses the vast communications infrastructure available to SBARC.

Bill Talanian discusses the vast communications infrastructure available to SBARC.

If you missed the February 2015 General Meeting, you really missed out on a good presentation. Bill Talanian W1UUQ gave us a great presentation on the various repeaters we use in the Santa Barbara area. Most of us probably have no idea how sophisticated how Club communications backbones are, but in an hourlong presentation that went by way too fast, Bill gave us plenty of detail illustrated with pictures about the unbelievably sophisticated infrastructure we all take for granted when we press the transmit button on our radios.

Starting with  the main repeater site on the Mesa, Bill took us on a guided tour through it’s humble beginnings with a couple of leaky shacks and equipment covered with blue tarps, to the sophisticated communications center it is today. His tour continued give us a behind the scenes look at La Cumbre Peak,  Santa Ynez Peak, Broadcast Peak, UCSB, and Santa Cruz Island.

Most of us think our repeaters are only for 2m, 220 and 440 voice communications. Not so fast. Bill showed us many of the other things he and a handful of volunteers maintain on a constant basis. These include weather stations, APRS digipeaters, AIS reporting for maritime purposes, aviation, and many other things.

One of the more interesting aspects of the presentation was how Bill and others have bartered and wheeled-and-dealed over the years to get the club access to literally hundreds of thousands of dollars worth of top quality equipment, towers, and whatever else it has required to make us a first class club. He is a master at horse trading and scavenging and fruits of his many years of work are largely unknown. If you missed this meeting, you missed one of the best presentations we have had. The amazing number of resources available to the club made possible through Bills hard work truly deserve our appreciation.

You can listen to audio recording of the the meeting below. The presentation is 1 hour 37 minutes and you will need to stay on this page to ensure you do not interrupt playback.