Technical Mentoring & Elmering Net
Technical Topics and Advice for New Hams
Thursdays from 8:00 to 9:00 PM on the SBARC Hub linked repeaters.
The Technical Mentoring and Elmering Net is dedicated to teaching. We discuss technical topics related to ham radio at ALL levels of expertise, with very special emphasis on helping any new ham any way we can. Remember you are an expert in your field of endeavor, so its no shame if you are just a beginner in ham radio. In fact, a great question for the net is “ WHAT are you guys talking about?”
There is no “lecture topic”, meaning that we are completely question-based, so its great if you have a list of questions ready. We take check-ins at the beginning, and throughout the net, so you can join (and leave) anytime you want to. Usually we discuss some technical topic for awhile, then leave breaks for people to jump in with a different question. Often several very expert hams are on, with possibly some listening ready to help with something they know, or to answer up to net control asking “who wants to answer that question?” The net is very informal and friendly, and also helps any new ham with even non-technical ham radio questions, like correct operating procedure, etc.
You’ll find recordings of the net in the SBARC Audio Archives.
Net controllers, see the TM&E Net preamble and script wiki.
Last Thurdsay night’s net (3/26/15)was successful with 14 check-ins plus net control (K6HWN). The net began with Yishen (KK6MJF) asking about apartment /dorm room antenna solutions. Apparently he’s not allowed to remove the screen from his window to extend a wire or any other type of antenna and was looking for another solution. Brian (K6BPM) offered probably the most practical solution, a magnetic mount car antenna attached a piece of “weldable” sheet metal (ground plane) about 12′ X 24″ placed on the window sill. This method works well for Brian at his office and might work well for Yishen too. Shackmaster Dave (K6HWN) offered his experience of using tops of cookie tins or mounting to the top of metal filing cabinets. Another solution Dave offered was the use of a gain antenna rather than the rubber ducky. All great suggestions.
Justin (K6LPZ) offered some of his experiences with handhelds and antennas. Over the years he’s found that bigger and more is better when it comes to VHF antennas. At one point he had a full length whip antenna reduced from a 239 connector down to BNC connected to his handheld transceiver and he could hear just about everything and his transmit was as good as could be expected with 2 watts.
Eric (K6HMD) asked if random wire antennas can be dangerous voltage wise and Dave answered that transmitting at high power it might be a problem but at lower power settings probably not more than any other antenna. There could be high voltage at the end where the antenna tuner transforms it down but again at lower power settings he probably wouldn’t worry too much about it. Eric offered some friendly advice to Yishen that of he went with a random wire setup not to get too close to it if everything’s indoors.
Yishen’s next question was regarding whether or not he should worry about grounding the antenna he’s planning to use and Dave asked a few questions including the radio Yishen would be using and the kind of antenna he’d be using. Depending on the type of antenna and what bands he’d be on it might improve the antennas performance if t were grounded.
Levi (K6LCM) asked about a 72 ft end-fed antenna at 40′ high he purchased from Brian, it works good on 80 meters but it’s noisy, in fact he’s been switching between two antennas for transmit and receive because of the noise. HWN commented that some radios can handle separate antennas for transmit and receive simultaneously and LCM will check his radio for that function. Brian mentioned that he had noticed a difference between the 72′ and the 88′ end-fed antennas in that his JT65 decodes were 3-4 db better with the longer antenna.
Finally Garrett (AG6RQ) asked if Q codes stood for anything or are they just arbitrary codes assigned to certain meanings. Dave mentioned that some sort of look like what they mean like QRP for low power or QRN for interference. Eric looked it up on wiki and we learned that they started out alphabetically like QRA, ARB, QRC, etc. then eventually morphed into what we use today. It was stated that Q codes really shouldn’t be used on VHF especially in an emergency because some folks wouldn’t understand them.
You can listen to the recorded version of the Technical Mentoring and Elmering Nets here.
Tune in to the SBARC Technical Mentoring and Elmering Net next Thursday at 0800 and see what interesting questions will arise or ask some of your own! 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.
Last Thursday’s Technical Mentoring and Elmering Net included discussions about Levi’s (K6LCM) quest to research his grandfather’s ham call, K1ELJ. He contacted AARL and they indicated that they could help but he hadn’t heard from them as of Thursdays mentoring net. Levi asked all who were listening if they had any databases, knowledge or other resources that could help him with his search. Harry (K6PDQ) said he has a QRZ CD ROM from 1995 but Levi didn’t think his grandfather renewed his license after the 1960’s. Lee (W6QYS) mentioned that he has 1960 and 1967 AARL call books and Justin (K6LPZ) said he has many old books and would take a look for K1ELJ. Brian (K6BPM) brought up www.hamcall.net which Levi thought he may have tried. A couple folks found the call and K1ELJ but is was assigned to someone other than Levi’s grandfather so he’s going to do further research make sure he’s looking for the correct call. Good luck Levi!
Then the focus was on Ken’s (K6KEN) question as to why Dave (K6HWN) was operating as W6HUT. Dave filled him in on the fact that Reg Dawe (W6HUT) was a friend and mentor to Dave and many local hams back in the day and now the call is registered to the Reg Dawe Amateur Radio Association. The call is used during the Reg Dawe Memorial Cuckoo Net every weekday morning at 0800 and during the Technical Mentoring and Elmering Net every Thursday evening at 1800, as a gesture to remember Reg’s good naturedness and mentoring to so many hams that he came in contact with.
Ken also inquired as to the use of Reset, Break, and “Mine” that he’s become accustomed to hearing during our nets. Dave explained “Break” is a standard ham term meaning the breaker needs to relate priority traffic of different degrees including life threatening emergencies. “Reset” is used when a comment is lengthy so that the repeater isn’t timed out and listeners know there is still more content to follow. The K6TZ repeater will time out if a carrier signal is not dropped within 3 minutes so that if a radio is being keyed accidentally or a malfunctioning radio is transmitting out of control the repeater isn’t locked out to all other traffic. The term “mine” was derived by Dave (K6HWN) after he begins a transmission and it’s become quite useful in our nets. The way he uses it is when he begins a transmission he’ll start talking and say “mine” and let the carrier drop for a few seconds to make sure he’s not doubling with anyone else and that air is indeed his. If no one else is hear he’ll continue his with his traffic. It’s very useful and helps to avoid traffic “jams” if you will.
Finally Garrett (AG6RQ) asked for advice about working DX and breaking into a pileup and / or managing a pile up. For breaking into a pileup Eric (K6HMD) recommended being patient and polite, possibly transmitting slightly off frequency and the use of “spotters”. Dave (K6HWN) recommended either starting your transmission early so yours is heard before others, or waiting until the last call is sent and then transmitting in hopes the DX station will hear your call after all the confusion. Tune in next week when we’ll talk about the other side and managing pileups!
Tune in to the SBARC Technical Mentoring and Elmering Net this Thursday March 12th and see what interesting questions will arise or ask some of your own! 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.
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.
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.
Well last night proved to be another successful Technical Mentoring and Elmering Net, there were 14 total check-ins and Shackmaster (K6HWN) made for 15 participants. First up Jim (KJ6ZJX) had a question about his 10 meter antenna and would it be long enough to tune other HF bands. I asked him what kind of antenna, vertical, dipole, etc. and Jim responded dipole. After a discussion with other members of the net it was determined that he has enough room and copper wire to go ahead and construct another longer wire antenna and use it on the lower bands.
Answer to last week’s puzzle: Eric (K6HMD) heard back from ICOM and indeed he’d set the transceiver into a self-calibration mode and band scope setting that emits 100 KHz spaced band markers for frequency tuning. So Shackmaster had it pretty much correct except that newer rigs use digital calibration modes rather than crystals. Congrats Shackmaster!
I had a question about a mathematical equation being used in the Extra Class license manual. In order to calculate effective radiated power (ERP) from an antenna you first need to calculate the total gain which includes losses due to feed lines, duplexers and circulators and add back in the antenna’s gain. The total gain turns out to be 1 dB. So now that plugs into this equation: EIRP = 200 W x log-1 (1/10) = 200 log-1 (0.1) = 200 (1.26) = 252 W. My issue is that no matter how I plugged the numbers into my scientific calculator I couldn’t make it work. Eric (K6HMD) commented that it seemed a little bit of an “old school” way to present the problem but he came up with the answer. With the calculator you enter 0.1 and press the anti-log function which gives you the 1.26. Thanks Eric! If I do get this question on the Exam I’ll be in good shape!
The remaining discussion was about the new digital HTs that several of the club members have picked up and are experimenting with. Brian (K6BPM), Levi (K6LCM) and Eric (K6HMD) all were very helpful in explaining the new technology and their experiences with it so far. The Yaesu FT-1DR is a hand-held digital / analog transceiver utilizing Yaesu’s C4FM/FDMA technology for digital communications and it’s also capable of 144/430 MHz FM as well. You can read more about it here SBARC and here Yaesu. It’s supposed to be on sale right now for around $299.95, about a $100.00 discount.
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 and contribute to the learning experience of new and seasoned hams alike.
There were some interesting discussions on last night’s net including K6HMD Eric’s issue he’s been experiencing with his iCom IC-7600 transceiver. It seems that Eric was attempting to set up FM split mode operations to access the K6TZ 6 meter repeater when he began seeing unexplained signals every 100 Khz at the same amplitude on the rigs spectrum analyzer. Even changing bands didn’t help. After a fair amount of troubleshooting Eric finally opted to reset the rig to factory specifications and the problem was solved, no more weird signals. Shackmaster Dave (K6HWN) offered a very plausible cause for the anomaly, while Eric was trying to set up split mode operations he may have pushed a button on the rig enabling the crystal calibrator. The calibrator would emit signals at specific intervals to calibrate the rigs frequency output by. Eric’s perusal of the operating manual didn’t offer up any information about a crystal calibrator being on-board the rig so he’ll contact the manufacturer. Tune in to the next Technical Mentoring and Elmering Net and hopefully learn the answer to this puzzle!
Other discussions involved HF noise and troubleshooting, automatic gain control and signal to noise ratios.
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 edification of new and experienced hams alike.
Dave K6HWN conducted a great discussion on station grounding. Steve KI6HGH provided a lot of technical information as did Theo KK6YYZ who is a licensed electrician.
You can read more about the Technical Mentoring and Elmering Net here.
Listen in next week on Thursday at 8:00pm for another great discussion.