AmateurRadio.com

We sometimes on this show attempt to bring you interesting interviews with people who are both computer literate and ham radio literate at the same time. In this case, we bring a scholar, physics buff, aerospace engineer and brilliant guy, Steve Nichols (G0KYA), to discuss the science of radio wave propagation. No need to turn the show off before it even begins. Steve makes understanding the Earth’s atmosphere, its magnetic field, and a ton of stuff about the sun simple and approachable. No mind-bending equations, no physics lectures, just some great information for anyone interested in learning how a radio signal gets from here to there. A bunch of follow-up information in the form of books and Web sites are provided as well, links to which will be in the show notes, for anyone who wants to further their education. Thank you as always to our loyal listeners. Make sure to tell a friend next time you’re out for a cold one. The more the merrier.

73 de The LHS Guys

Russ Woodman, K5TUX, co-hosts the Linux in the Ham Shack podcast which is available for download in both MP3 and OGG audio format. Contact him at [email protected].

Thought it was time this evening to power up the K3 and see what was on the bands. The software  I use is DXLab and it comes with a spot collector as it's called. I noticed a spot for AX7GN on 20m so I double clicked on the spot and the K3 magically was there! So here I am listening for AX7GN and yes there is a station there calling what sounded like CQ....or did I want it to be a station calling CQ? Well I hoped it was not little voices in my head talking to me. I heard nothing so I just put my call out there....and listened just maybe a little to intently. I did hear what sounded like VE? VE? By this time the APF was on the RF gain was being adjusted and the filtering narrowed.  I gave the call again at a deafening 5 watts!! Between the static and the ringing sound from the APF  I thought AX7GN was giving out what  "KINDA" sounded like my call.....or was it those voices again!! I passed along a 559 but did not hear much in return. To be honest I am not sure what the heck happened.....did I want to hear my call so bad that the static kinda sounded like VE3WDM?? For a short time I listened to the band and low and behold AX7GN was there and answering some U.S calls! I'm not going to put this one in the books as I am just not 100 percent it was just not the DX voices playing games with me. Has this ever happen to you??
Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

Two things pointed out to me by Bob W3BBO, who directed me to the “ARRL Contest Update” e-mail, which I had just kind of glossed over without reading properly:

Larry Makoski, W2LJ, is a regular contributor to AmateurRadio.com and writes from New Jersey, USA. Contact him at [email protected].

Pat Tice, WA0TDA, is the manager of HANDI-HAM and a regular contributor to AmateurRadio.com. Contact him at [email protected].

 

 

4 Foot Diameter Magnetic Loop In Operation

As my mag loop projects progress, I’m learning a lot about building them and using them. This antenna works on 17, 20, and 30 meters, with the best bandwidth on 20 meters. The bandwidth on 17 and 30 is quite small but usable. There is a 20 KHz bandwidth on 20 meters. I used a vacuum capacitor to build this particular loop for 100 watt operation. The air capacitors are good for QRP but will arc over using much power over QRP levels.

This photo was taken before I trimmed the Gamma Match.

I didn’t know how long the Gamma Match should be, so I made it long enough to allow for trimming after the match to 50 Ohms was made.

This is the first mag loop that I made with a Gamma match. I like this match better than the usual Faraday feed loop that is featured in my previous mag loop antennas. Matching is easy and building the Gamma match is not difficult. I’m planning to build other smaller loops that will also feature the Gamma match. The smaller loops will target 10, 12, and 15 meters. Loop size determines which band its best suited too. Although it is possible to get more bands on one loop, the bandwidth is small and the tuning ‘dip’ is very sharp. I found it better to limit the number of bands in favor of wider bandwidth and antenna efficiency.

Please look up my previous posts for more details on parts and plans.

 

 

 

Here is a good close up of the clamp.

(Before Trimming)

 

Gamma Match After Trimming. This enables a 50 Ohm Match for all three bands.

 

 

 

 

 

Gamma Match on the left, PL 259 in the center and, Tuning Aid Stick (PVC) pipe , on the right.

The vacuum capacitor is ‘tuned’ by twisting the PVC pipe that is attacked to it with a cotter pin.

Tuning the cap to the ‘loudest noise’ on the air will put you in the ball park for operating.

You can also use an antenna analyzer if you want to know the exact SWR, and RR of the antenna.

Tuning with a radio attached is fast and easy.

 

Making the clamp for the Gamma Match

 

Soldering The Back Plate and PL 259

 

 

Removing The Oxidation Before Soldering

The main loop is 5/8 inch, soft copper tubing.

 

 

 

Close Up of PL 259 to Gamma Match Joint

The center of the PL 259 had a #10 solid copper wire inserted and soldered in place.

The Gamma match is 3/8 inch soft copper tubing.

This part of the job was done with a soldering iron, the rest was done with a plumbers torch.

 

 

 

Handy ‘third hand’. A clamp to hold the Gamma match in place while I soldered it.

My town was going to hire a ‘Mad Scientist’ but it couldn’t afford one, so they settled for a ham radio operator instead. Me!

73 de AA1IK

Ernest Gregoire

Ernest Gregoire, AA1IK, is a regular contributor to AmateurRadio.com and writes from Florida, USA. Contact him at [email protected].

HF propagation conditions have not been great today. There was not much happening on 15m at all.

Julian Moss, G4ILO, is a regular contributor to AmateurRadio.com and writes from Cumbria, England. Contact him at [email protected].

Helge DF8LS has just published a web page showing how to send and receive email on HF using Winlink and the SCS Tracker TNC. I just sent an email to myself (isn’t this one of the signs of madness?) and it was received, so the instructions are obviously good!

A Winlink session on HF

Mention of Winlink seems to cause strong emotions in some quarters. Personally I think using ham radio to send and receive email is rather cool, even if it is too slow to use for today’s level of email use. It’s a pity more hams don’t activate their Winlink account, which is callsign @ winlink.org .

If you use APRS then you can also send and receive email by that means using a feature called APRSlink. The trouble is, I use it so infrequently that I forget the commands. It would be wise only to use it if the APRS channel is quiet like it is here.

Julian Moss, G4ILO, is a regular contributor to AmateurRadio.com and writes from Cumbria, England. Contact him at [email protected].