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Welcome to my home page. I became blind at birth. I started programming computers at a young age. I also earned my general class amateur radio license, KA3TTT, a hobby to which I have returned with great joy. I practice Qigong and consider myself a Taoist. I use Linux as my desktop and Android as my mobile OS. I eat gluten-free vegan meals. For the rest you'll have to read my blog.
Reducing HF Noise
August 03, 2021After my success using a ground plane, I discovered two other things which have further reduced my noise floor by 2 S-units. Firstly, I connected a 1:1 balun at the transceiver side. Secondly, I oriented the antenna for minimum noise. I will discuss both points.
When I got back into the hobby and began my battle against RFI, I ordered a 1:1 balun from Balun Designs. The description refers to connecting the balun outside of the shack, which to me sounds closer to the antenna. In an apartment none of that means anything. When I went on my Alpha Antenna Adventure, I disconnected the balun to eliminate any extra variables, and never got around to reconnecting it. A discussion about baluns led me to email the owner, and we had a short dialog.
I wondered if I had purchased the correct balun, and I had. He also suggested connecting it as close to the transceiver as possible. Did I connect it to the wrong end this whole time? Excitedly I grabbed the shortest length of coax I had and connected it. I instantly noticed the difference.
My noise floor dropped by another S-unit. Not only that, but my SWR improved on the higher bands. Previously I could get to an acceptable reading on 15 meters, but 12 meters and 10 meters would never tune below around a 2.6:1 SWR. For non-hams, SWR means Standing Wave Ratio, the amount of reflected energy coming back at you. You want it as low as possible, below 2:1. Now with the balun connected I could get down to a 2.1:1 SWR or sometimes a little better. Good enough.
A ground plane blocks signals below the antenna. A balun decouples the feed line so it can’t act like an antenna picking up noise. If you have a magnetic loop, you can make one more adjustment. A magnetic loop has a slightly directional property. You can take advantage of this in two different ways. You can either orient it for maximum signal or for minimum noise.
Instinctively we think about tuning for the maximum signal, but if you live in the gritty city, you may want to consider doing the opposite. Tuning for minimum noise will lower your noise floor. Don’t worry, you won’t miss out on signals.
The two things mentioned in this article, along with using a ground plane, have reduced my noise floor by at least 2 S-units on all bands. I have the reception I imagined that I would have. I don’t hear a horrible electrical hum if I tune to AM. I have a better SWR on the higher bands. I don’t feel a wave of depression when a wall of HF noise hits me. I hope these suggestions will improve your station as well.
Using A Ground Plane with a Magnetic Loop
July 15, 2021I love magnetic loops. They work well as an indoor antenna for an apartment. They have some interesting properties, and some little things to learn. I recently discovered the benefits of using a ground plane with one.
This began on the ElmerNet, which I run Wednesday nights at 07:00 PM on the WM3PEN repeater. Carl, N3ZZK, mentioned seeing more magnetic loops advertised in QST magazine. He mentioned a pretty wild looking one on DX Engineering. It has a microprocessor and interfaces with the radio’s data port. I noticed that the description mentioned that the loop comes with a mat made of metallic fabric to act as a ground plane This intrigued me.
For the non-hams, a ground plane acts as a substitute for the Earth, not exactly accessible from a second floor condo. A sheet of metal or a wire or series of wires perform the same function. The radio signals reflect off the ground plane, producing a mirror image of the antenna.
That weekend I got a chance to go up to the roof deck with my Elecraft KX3. I just brought my AX1, but I made a few contacts, and enjoyed the low noise environment. When I came back down and hooked everything back up to my Alpha Loop, the high noise level hit me like a wall, and a wave of depression followed. I had to do something about this horrible noise floor. I began searching, and saw a reference to using a ground plane under a magnetic loop.
I remembered Carl’s comment, and the magnetic loop which comes with a ground plane. I emailed Steve at Alpha Antenna, and he sent me a short article on his site which confirmed that using a ground plane boosted the signal by up to 5 dB. He also told me that it blocked noise on the other side of the plane. This excited me, because for me that means my downstairs neighbors and the street. The street has a trolley which they only run once a year to celebrate the Fourth of July, but they keep the power line active all year round.
. I called DX Engineering and asked if they would just sell me the ground plane mat, but they wouldn’t. I had to find a piece of metal suitable for my apartment. I asked my friend Meg and my brother. Both had pieces of metal. When I next saw Meg, we started brainstorming. I told her about the mat made of metallic fabric.
“Oh. Why don’t you just search for the fabric?” she said.
I went on Amazon and searched for Metallic fabric. I quickly found Faraday Fabric. People use it for making Faraday cages or RFID blocking accessories. It has metallic copper, metallic nickel composition, and polyester fiber. Perfect! They didn’t call it a ground plane, but I saw through the marketing. If it could block signals then it could act as a ground plane. I bought two sheets.
They arrived a few days later, and I eagerly lay them down. My friend Meg later helped me do it even better. I immediately noticed a drop in my noise floor by 1 S-unit, or 6 dB, maybe even a little more. On 20 meters I could copy signals down to S4 or S3. On 40 meters I could copy down to S6 or S5. The readability would often drop, but I still did it. I never gave out a signal report on 40 meters below S7, and I have the logs to prove it. I even saw a drop on 80 meters, the noisiest band. Before I would only hear S8 or S9 signals, and now I could hear down to S7. Amazing!
I wondered if I would see a similar increase in my effective radiated power. That weekend I played in the CQ WPX contest. We had bad conditions, but I worked 15 stations. I wanted one DX, and I worked a station in Germany, 4000 miles away. This happened on 20 meters using 5 Watts CW (Morse Code). We had to slow it down but we made it work! I can’t say that it has magically made me work everyone I hear, but I can hear more. Some better solar conditions would also help.
I would definitely recommend using a ground plane with a magnetic loop. Many people will use a metal screen or chicken wire, but this fabric installs easily and does a great job.
The HARC Elmer Net
March 19, 2021Recently, I began hosting the Elmer Net on the HARC repeater. In ham radio terms, a net works like a round table. A Central station called a net control takes checkins, then goes down the list, giving everyone a turn. In ham radio parlance, an elmer means a teacher. Hence, the Elmer Net lets people come and ask their questions. When I got back into the hobby I heard it a few times, then finally checked in and began asking questions.
Time went on, and Steve, W3AZT, the main net control, began hinting that he would have to stop running the net. A few of us said we might have an interest, but no one officially stepped up. I considered it, but only would do it if I had a backup. If I wake up with a headache I will not feel like running a net!
It came time for #100, Steve’s final net. Cliff, KC3PGT, said that he could not commit to running the net regularly, but he would volunteer as a backup. That gave me the confirmation I needed. The net wound down.
“Well, we’re coming to the end of the net, and nobody has stepped up, so I don’t know what will happen next week.” said Steve.
My turn had come to speak during the final round. I said that I would do it with Cliff as my backup. At first it felt surreal, but I have started settling in. It feels good to give something back to the hobby. I hope to see you there. You might even get a gold star!
Heil PR 20 Demo
December 17, 2020After hearing Dr. Bob Heil speak at HARC, I decided to upgrade my computer’s microphone. He joked that a lot of people use microphones that they say cost $40, and he responded that they sound like they cost $20. My microphone fell into this category. My ham radio station has a Proset 7 and an HM 12. Ham Radio Outlet had a good deal on a PR 20 utility microphone, so I snagged one. Listen to the difference! And no, the color of the mesh does not Affect the audio.
I immediately noticed that my voice sounds much fuller and brighter. I also noticed far less background noise. Incredible!
Demian’s First QSO
December 16, 2020My 4 1/2-year-old nephew Demian had his first QSO (ham radio contact) with Santa!
The Blind Hams had a Santa net. A net works like a round table, where a net control takes check ins then lets them comment. Hams have a tradition of letting kids go on the radio to talk to Santa. Legally we can bring them on as third parties. When they announced it I texted my brother Ari to see if Demian would like to do it, and Ari loved the idea. They live close by, and we felt safe meeting in person.
I went shortly before the net. I figured that I could bring my HT hit my ClearNode and everything would go smoothly. After all, I had upgraded the stock antenna. I thought wrong. It turns out Ari’s house blocks radio signals even more than my condo. First I put the node in Parrot mode, which repeats back what it hears. This comes in handy for testing. I couldn’t hit it at all from their kitchen table. I took the node out of Parrot Mode and connected to Blind Hams. I could hardly hear it. We decided to go on a little ham radio adventure to the roof deck. Ari and I went up with the radio, and his wife Sarah brought Demian.
We made it just in time. Pat, KE0TGA, asked for final check ins and I gave my call.
That sounds like Austin, Tango Tango Tango. You are coming in with about a 30% signal strength, but try again.
The response caught everyone off guard. They wondered how Mrs. Clause knew my name. We still had some trouble sending Demian’s name even after spelling it phonetically.
The name is Demian. Delta Echo Mike India Alpha November.
I lifted the radio as high as I could, and Ari lifted Demian. At first he just wanted to say hi, but we convinced him to talk to Santa. He felt shy, but he opened up when Santa started talking to him. After a little coaxing from Ari he told Santa that he wants monster truck things. Santa got the message.
Demian likes science, and you couldn’t pick a more scientific hobby than ham radio! I hope this event will start him on a long and enriching path. Ari said that Demian felt overwhelmed and quiet, but would talk about this for the next six months. I have a feeling that Santa will bring him plenty of monster truck things.