Category Archives: Tech Mentoring Net

Technical Mentoring and Elmering Net – February 12, 2015

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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… Continue reading →

Technical Mentoring and Elmering Net – February 5, 2015

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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.