Category Archives: Tech Mentoring Net

Note: The time stamp at the beginning of each topic was recorded using Windows Media Player and the downloaded Mp3 audio archive of the net for 5/21/15 found here. The Technical Mentoring and Elmering net on Thursday 5/21/15 was lightly attended compared to most with 6 check-ins, 2 side responders and net control (K6HWN). Thoughts are that some regulars may have gotten a head start on the Memorial Day weekend. 10:15 First up, Shackmaster Dave had an idea about extending Glenn’s (WZ6WZ) 220 beam antenna to Santa Barbara. The background is that Glen has already installed a 220 transceiver and beam antenna pointed right at 224.08. The question is if they (in Lompoc) can hear the 19.79? repeater that they might be able to use a single 2 meter transceiver at low power to communicate to Santa Barbara. Glenn didn’t know offhand if they can hear it or not but will do the research and get back to Dave. 13:45 – Hayden (KK6OYV) had an update about the fractional wave (loop) antenna that he’s building. Apparently there is a Yahoo group found here dedicated to the concept that Hayden’s been following and he has visited John’s (AG6LJ) house and seen how great his fractional loop antenna performs. Hayden mentioned that his primary motivation to build the antenna is that his station has a lot of electrical noise and the noise floor of his rig is rather high and the fractional wave antennas are not affected as much by that as other antennas. Today he finished the frame of the antenna and now has to finish installing the capacitor control unit and wind the copper wire (strapping) around the frame. Shackmaster asked Hayden if he already has a quality vacuum capacitor and Hayden said no, he’s not sure what value of capacitor he will use yet. Richard (K8NDS, the inventor of the fractional wave) said the antenna Hayden’s building will get him on 10-20 meters with a 5-100pf variable capacitor but Hayden’s also heard of others using a 10-350pf capacitor and getting as low as 40 meters. He’ll be consulting with Richard on that and keep us informed. For those who might be interested check out Richard’s QRZ page and the Yahoo group mentioned above. 17:00 – Brian (K6BPM) asked if anyone is familiar with SIP (Single Inline Package) resistors which are resistor “packs” with one common lead and 8-10 other… Continue reading →

The Technical Mentoring and Elmering net on Thursday 5/14/15 was an informative one with 14 check-ins plus net control (K6HWN). The net began at with Brian’s (K6BPM) announcement that we now have a special list server “discussion group” set up for members (and non-members) interested in emergency communications. The purpose for this is to discuss how SBARC can operate as a club, and how the average amateur radio operator in general can help in the event of an emergency. This is not affiliated with ARES or any other group, nor does it interfere with their mission. As a club, and as licensed amateur radio operators, one of our civic responsibilities is to be prepared to help our community in any way we can. We hope you will join and contribute to the discussion! To join the list simply send a blank email to JoinEmCommList@sbarc.org. Further instructions will be sent to you. Next Ken (KA6KEN) asked why the 220 repeater (224.08) linked and unlinked to 146.79 (K6TZ) periodically throughout the day. The answer to that question is that we link the 224.08 to K6TZ so that ham’s that don’t have a clear signal to the K6TZ repeater but can hit 224.08 can participate in our nets. The operator keys down a second early to make the connection and is heard on K6TZ. The link is taken down after the nets unless someone needs the link for other traffic. The reason the link is taken down is because other signals from other surrounding areas can interfere and can be an annoyance. The discussion evolved into use of a repeater to control a remote base station and then evolved further into the use of remote station operations. One question asked if it is legal for a technician licensee to operate on a repeater that operates a remote base whose output is on another license class frequency allocation. The answer is no, the technician should not operate out of his license class without supervision no matter how they gain access to it. Shackmaster Dave(K6HWN) then asked who knew all of the handy and emergency reasons to operate remote base station and it proved to be a lively conversation. You can listen to the audio archive of the net 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… Continue reading →

Last Thursday night’s (5/7/15) Technical Mentoring and Elmering net was an informative one with 12 check-ins plus net control (K6HWN). The net began at with me (K6FLD) asking about one of last week’s subjects that came up regarding tuning an antenna using white noise while on frequency of choice without a carrier signal as to not cause interference on the frequency. This is of great interest to me because every time I switch bands I need to re-tune by finding a nearby open frequency to tune on then return to the frequency of interest. Shackmaster Dave (K6HWN) explained the concept first using the grid dip meter theory as an example because it’s very similar to using a white noise generator on the frequency you want to tune on. You can review the audio here.  MFJ offers their MFJ-212 noise generator that they call a “Match Maker” at a very reasonable cost here. Next Bob (KB6CTX) asked about the best way to evaluate antennas for his purpose. John (AG6LJ) suggested he work the problem backwards, i.e. consider any restrictions in your area (home owners associations, etc.), how much you have/want to spend, and the bands that will be required are all good considerations before looking for the suitable antenna. Shackmaster added that looking at the radiation pattern of the antenna. Depending on your surrounding terrain, buildings, etc., certain radiation patterns may perform better for you and where you want your signal to wind up. GW added that if you’re looking to use a dipole depending on the band they can be very long and require a lot of space. 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.

Yet another successful net last Thursday night (4/23/15) with 11 check-ins plus net control (K6HWN). The net began with Jim (KK6SXB) asking if and how he could interface his HT with his computer. It seems that Jim has been having trouble de-linking the 224.08 repeater with his Wouxun HT and was thinking of a work around that might work. Brian (K6BPM) had a couple of ideas and I suggested purchasing a 1.25 M mobile radio with more power and using it as a base station from home. You can review the audio here. Next Garrett (KJ6RQ) wondered if there antennas or if you can design ones to radiate a certain way depending on terrain, propagation, etc. Shackmaster Dave (K6HWN) started the ball rolling explaining general classifications of VHF antennas in that they are almost always omnidirectional (horizontally) or directional as in your classic Yagi. The conversation evolved into types of antennas and how the number of wavelengths effect the gain of the antenna, antenna modeling, etc. You can review the audio 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.

Well, last Thursday night’s net (4/16/15) was yet another successful one with 11 check-ins plus net control (K6HWN). The net began with Garrett (AG6RQ) asking what the difference is between an antenna tuner and a matching network is. John (A6GLJ) was the first one to respond with the fact that what an antenna tuner really does is when it’s placed between the coax and transceiver it keeps the transceiver happy with the SWR level so it can deliver the maxim power to the load (antenna). If the transceiver detects too high of an SWR level it will restrict the amount of power output as to not damage the final amplifier stage. Cyril (AF6GW) offered up that maybe if the tuner was placed between the coax and the antenna it would be more of at true antenna tuner. Dave (K6HWN) agreed with Cyril except that it might be called an antenna impedance compensator, which is really what it does by changing the length of the antenna or the matching point. Cyril made a point that sure, the tuner might make the transmitter happy but the fact is that you still have the same feed line loss or bad antenna paring. Don’t you wish you had tuned in? If so you can listen to the audio archive here. John (AG6LJ) mentioned that this topic is one of the issues they’re currently dealing with using the fractional wave loop antennas. They’re really not designed to work on 12 meters, they can go with a solid state amplifier to about 200 watts, however with the impedance matcher/antenna tuner they can run full legal power. It basically tricks the system into working yet it’s not fully efficient but you can get the power out and at end of the day it works. Also discussed at this point was the concept of grid dipping in historical tube amps, and reversing the leads on an SWR meter to ascertain reflected power going back to the transceiver. (You can review the audio here). Next Levi (K6LCM) had some follow-up regarding his attempt to use a Heil adapter to connect a headset with a boom mic and headphones to his rig. He was having trouble getting audio to the radio. (Solution can be heard here). Now Cyril had some follow-up to a previous net’s question regarding suitable coating material for antennas, wires, enclosures, etc., that won’t affect the performance… Continue reading →

Last Thursday night’s net (4/9/15) was another successful one with 12 check-ins plus net control (K6HWN). The net began with John (A6GLJ) reminding everyone listening that Jerry’s (KK6FNP) single loop fractional wave antenna is for sale. Jerry is upgrading to a double loop fractional wave antenna and the single loop is making a trip to Arizona where the inventor of the technology will go over it and certify its well-being. The asking price is $2,000.00 USD and you can contact Jerry at (805) 896-4484 (no blocked numbers please) or jerryfarwest@aol.com. The antenna is described in greater detail in a swap net listing here at the Swap Net Listings. Paul (KF6CIH) had listened to part of an ATV Special Modes net and had a question about how one can send computer data over the radio. Brian (K6BPM) was present on-air and being the net control for the Special Modes net happily went over some concepts with Paul and invited him to join the net if he’d like to learn more and participate. The net airs every Tuesday night at 8:00 PM to 9:30 PM on 146.79 linked to 224.08 and everyone is welcome to check-in. Next Brian (K6BPM) asked a question that he and I (K6FLD) were curious about. I’d mentioned to Brian that when using my MFJ-969 antenna tuner that I thought I noticed enhanced signal reception when the antenna was tuned properly on a band. Brian and I (before I had ever used an antenna tuner) had thought that receiving wasn’t affected by tuning the antenna, only the SWR and transmit quality. Shackmaster Dave (k6HWN) explained that yes, indeed the receive will peak as well as the process is reciprocal in that what’s good for transmit is good for receive. Likewise, if you have loss on input you’ll also have loss on output. Signals will definitely peak on receive in fact you can tune it approximately by peaking it on receive noise and you’ll be close on transmit and SWR. Ken (KA6KEN) commented that it sounded like Brian had talked himself out of the idea that an electrical adjustment was being made during tuning when in fact you do, it’s just that you have passive components making a passive adjustment and you need not transmit for that to be beneficial. Tune in to the SBARC Technical Mentoring and Elmering Net next Thursday at 0800 and see what interesting questions… Continue reading →

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… Continue reading →