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.

 



Technical Mentoring and Elmering Net – May 28, 2015

The Technical Mentoring and Elmering net on Thursday 5/28/15 yielded 9 check-ins plus net control Dave (K6HWN).

The timestamps below are best followed by downloading the Mp3 file here and listening with Windows Media Player.

00:08:00 – Jim (KK6SXB) started the net off asking questions of Brian (K6BPM) regarding setting up for digital modes. It seems that Jim has recently acquired two devices (SDRplay and Airspy boxes) that he’d like to use in setting up the ability to use digital ham radio modes with his computer. The HDSDR software he also acquired along with the correct supporting driver software will display 8+ MHz of any band on the computer screen giving you visibility of any signal there. So basically what he’s purchased should get him receiver and display capability but to actually practice digital modes on ham radio I believe he’d be lacking some other required components and setup.

00:13:45 – Brian (K6BPM) began by trying to understand the two devices and interpret what Jim is trying to accomplish. Most digital mode software out there requires a sound device that can handle input and output to act as a mic and speakers. The conversation was joined by Levi (K6LCM) and Eric (K6HMD) and all had comments and ideas about digital modes basics and how Jim might get the results he’s looking for. You can listen to or download the audio for the net here.

Tune in to the SBARC Technical Mentoring and Elmering Net next Thursday at 8:00 PM or 2000 Hrs  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.

Technical Mentoring and Elmering Net – Thursday May 21, 2015

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 leads enabling the user to use one small package to supply a common resistance to many components in the circuit. Brian purchased some dual value 220/330 ohm SIPs and there is no explanation of how they work and he couldn’t measure what should logically be true with a meter. No one really had an immediate answer so he’s going to bring some with the paperwork down to the SBARC Club shack to show Dave and with his help they should be able to figure this out. Stay tuned to future TM&E nets to learn the answer!

33.04 – I (K6FLD) started a discussion about a new special mode we’ve been experimenting with during the ATV Special Modes net occurring every Tuesday night at 8:00 PM. Basically it involves the ability to send e-mail over radio without having to be connected to the Internet. Go to Winlink.org to learn more about this very useful mode that should be of interest to any amateur radio operator. Imagine an emergency or disaster situation where all power, phone and cellular networks are down, maybe after an earthquake. If you have backup battery or other backup power (as all good hams should) you will still have the ability to get communications out via e-mail to inform family members in other areas of your situation and that you’re okay. The basics are that you download a program called RMS Express and install it on your computer (hopefully the one with battery backup). Download the guide here and go through the setup and start composing and sending e-mail over the radio. All that’s required is an interface between the computer and radio such as a Signalink USB and off you go. As a matter of fact, some folks have been successful without the interface by holding their microphone to their speaker during the operation! I won’t go into all the details of how the Winlink network operates but please look into this very important mode at Winlink.org and listen to the audio archive. Other uses have been for mariners at sea communicating with e-mail via radio, campers, explorers etc. in remote areas without internet access.

53:50 – Cyril (AF6GW) checked in and mentioned that some other capabilities had been experimented with using 2 meter packet to send e-mail over a repeater. He didn’t remember exactly all of the details but you can learn more 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.

Technical Mentoring and Elmering Net May 14, 2015

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 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.

Technical Elmering and Mentoring Net – Thursday May 5, 2015

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.

Technical Mentoring and Elmering Net April, 23 2015

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.

Technical Mentoring and Elmering Net – April 16, 2015

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 of the antenna. (Audio answer can be heard here).

Wish you’d been listening? Go here.

Lastly, I (K6FLD) posed a question regarding a strange hum or resonating I’ve been hearing in the walls or other source in my house using a new antenna. I purchased an end-fed antenna and on certain band frequencies I would hear a curious hum, seemingly coming from the walls of my home (at least that was my perception) when keying down the mic. On other band frequencies there was no discernible noise. Weird. So I purchased an MFJ-969 antenna tuner thinking that by properly matching the impedance at my rig it would eliminate the interference. Well, the other night I heard it again. A question was asked by Hayden (KK6OYV) if my station had an RF ground or not. My shack is on the second floor of my house with a deck and another 10 ft. drop impeding a short ground solution, so the answer was a resounding NO. Dave (K6HWN) mentioned the possible use of an artificial ground solution such as the MFJ-931. What the heck is that I asked??? Well, it turns out that if you connect the device between your rig and feed line or antenna tuner and feed line it reduces the electrical length of the ground connection wire to virtually zero by tuning out its reactance. Stay tuned to future nets to learn if I can solve my grounding issue!

Tune in to the SBARC Technical Mentoring and Elmering Net every Thursday night at 0800 on 146.79 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.

Technical Elmering and Mentoring Net – Thursday April 9, 2015

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 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.