Amateur Radio FAQ

ToolAA said:

Made my first contact with Hawaii tonight. I also discovered a website called PSK reporter where you can see what other ham stations have picked up your digital signals. I was surprised to see stations in New Zealand and Antartica both picked up my signal on 40m at about -15db. That just seems too cool with a little 100 watt radio and a cheap wire dipole running along the ridge of my attic.

I still have not been able to have one HF voice contact. I could hear people talking from Alabama, Texas, Indiana and upstate NY, but I don’t think anyone could hear me.

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It is all quite doable, even with a small setup. You should be able to work the world.

It is most likely an issue of propagation. You need to learn what bands are open to what areas at various times and band conditions.

Lot of big guns out there. You hear a guy running 1500 watts using big antennas, but he's not going to hear you unless conditions are favorable.

Just an FYI...

MMARC hosts an Annual Hamfest near the end of January at the Odenton Fire Hall on Rt 175 in Odenton.

The 2020 Hamfest will be held on Sunday, January 26 from 7:30 AM until noon.

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https://sites.google.com/site/marylandmobileers/hamfests-1/hamfest-2






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A good wire antenna, need not be expensive. Careful use of window line, or low loss coax is key.

I helped a friend set up an inverted L a few days ago. He was reaching South America, and Europe, on 60 watts with FT-8. He has had US mainland SSB conversations on 40 and 80. He was hearing conversations on 160 meters that night.

I'll second the inexpensive wire antenna suggestion. I have an OCF wire antenna up at about 35 feet and have made SSB contacts as far away as South Africa, Hawaii, Argentina and Russia with 85 watts. I purchased it new from NI4L for about $85 and strung it up in the trees. I do use a tuner (LDG IT-100) but that allows me to use 7 bands and I get good signal reports. Hope that helps.

This is a question for some of you experienced guys. I it possible that RF waves can damage electronic equipment near the antenna?

The reason I ask is that I have my wire dipole antenna running along the ridge line of the roof in my attic. This is about 12’ above the attic floor. Last week my wife said that the cieling lights in our family room were flickering while turned off and this was happening when I was transmitting. Those bulbs are about 20ft from the antenna. The this past weekend I noticed that one of the led bulbs in the hall way ceiling was out. It’s not that old and they should last 5-10 years from my understanding.

Here is the third problem that really has me concerned. Over the weekend our Upstairs thermostat seemed to be malfunctioning. It was very strange. The unit appeared to be working but it was not calling for heat. I had our resident HVAC guys come out yesterday and the tech confirmed that something odd is going on with the thermostat and that it works in service mode but it seems to be damaged somehow as it’s just not working normally. He commented that these “Smart” thermostats don’t always play nice with heat pumps and suggested I read online that there are a number of unusual problems. I did and I see that there appears to be issues, but this unit has been installed and working fine for at least 2 years.

So it’s got me thinking that somehow my antenna configuration is causing some sort of RF interference that has maybe damaged not only a LED Bulb but also a $200 thermostat. The thermostat it self is at least 20’ away from the antenna, however I think that the control wires run straight up from the wall into the attic and then horizontally over to the air handler. That would mean that they may be running parallel to the antenna less than 8’ away.

Here is the other thing that may be a coincidence. 2 weeks ago I got an antenna tuner and installed it up in the attic. This past week I was experimenting with transmitting on 80m. The way the tuner works is that it sort of self adjusts while transmitting, so the initial transmission the SWR readings are off the chart but after a few minutes the tuner seems to be doing it’s job and settles down to about 3.0. I was able to make contacts at 80m so I was pretty satisfied with myself. Until, today when it ocurs to me that all of these electronic problems may be more than a coincidence.


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Seem to recall 'super truckers' putting small fluorescent tubes on their antenna and when they keyed up, the tube would light up.

I have a challenge on 80 meters with common mode. That's what that sounds like. A few torroids, or a choke balun may sort it out for you. I managed to kill a PC video card by not taking common mode seriously enough.

Attic antennas come with a lot of challenges, being so close to people, and electronics, that can add noise, and be affected by your transmitted signal.

Traveler said:

I have a challenge on 80 meters with common mode. That's what that sounds like. A few torroids, or a choke balun may sort it out for you. I managed to kill a PC video card by not taking common mode seriously enough.

Attic antennas come with a lot of challenges, being so close to people, and electronics, that can add noise, and be affected by your transmitted signal.

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So it is absolutely conceivable that I somehow damaged the thermostat then?


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Conceivable? I would vote yes. Then again I cannot find any information that says it is absolutely attributable to your radio transmissions.

So, your thermostat has been working perfectly for two years. Now, shortly after installing your antenna and using your tuner, it goes south. Additionally, your LED lights have issues when you are transmitting. Sounds like causation to me, but there could be something else.

Yes, it could be coincidental, but with the information you presented I'd be moving the antenna out of the attic and addressing any common mode RF issues you may have before I use the transmitter again. Especially if you replace the thermostat first. Common mode issues are easy enough to address, but I would still move the antenna.

Just my .02 cents, and I'm not an electrical engineer. Maybe someone who is will chime in.

Good luck with it.

ToolAA said:

So it is absolutely conceivable that I somehow damaged the thermostat then?


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Yes, maybe. Some years ago I replaced an old style thermostat with newer electronic one. At the time I chasing DX on 80M and running a ton of power. The transmitter would interact with the furnace and kick on the blower. I put a bunch of .01 ceramic capacitors across all the terminals on the new thermostat and problem was solved.

Coupling RF energy into house wiring and appliances can be a huge issue especially if the antenna is close to wiring. End fed wires are often the worst offenders. Balanced fed antennas tend to be easier to decouple form the house wiring and transmitter. In the old days getting into telephone wiring was a huge problem.

I read of your furnace problem and I have no idea if this was the case for you. But I wouldn't rule it out if it recurs under similar circumstances.

ToolAA said:

So it is absolutely conceivable that I somehow damaged the thermostat then?


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Yes, conceivable.

The wiring to the thermostat is possibly it's "antenna".

When the wiring to something approximates the resonant length of the frequency you are operating on you can get a lot of rf voltage there.

So on 80m, a quarter wavelength is around 61 feet, so if your thermostat wire is around 61 feet and close to the antenna it will get a lot of signal on it.

As has been said, getting a torroid choke and putting several wraps of the thermostat wire through it as close as possible to the thermostat will help remove the RF.

If that's what it was.

Another vote for yes, your thermostat could have been damaged by currents induced in the control lines by your transmitting. Eight feet is very close and running parallel exacerbates it. The wires don't have to be cut to a resonant wavelength of the transmit frequency. It would transfer more power if they are but even if they aren't they may still pick up a unhealthy amount of power. Bad connections (corroded terminal connections and bad solder joints) can also help wiring pick RF but I think this is more than that.

Adding filtering in the form of ferrite cores (with the right mix) may solve the problem but the other problem is how are you going to test it? If you don't have something to measure the current in the thermostat wires then it might be trial and error with a $200+ thermostat.

I had a problem eliminating RF in the shack that was being picked up by my speakers. And this was with an antenna in the backyard. I changed the wiring to shielded twisted pairs and added ferrite cores. Both with the wire wrapped through them several times on each end, and clamp-on types. I made several iterations of this and none were acceptable. I finally ended up adding in-line LC lowpass filters to each pair. My point is it may not be a quick fix.

You may want to think more about relocating your antenna outside. If you have restrictions I know that can be problematic but that may be less hassle in the end.

If you go with ferrite cores you want to buy ones with the proper mix. I used mix 31. If you buy any-old ferrite cores on Amazon they likely do not have the mix listed. You can find mix 31 on Ebay.

https://palomar-engineers.com/ferrite-products/ferrite-cores/ferrite-mix-selection

Sorry, yes. Let me know if you want me to drop by with my drone and remote release. We can put up an inverted L farther from your house. I work for good beer, LOTS of good beer.

ToolAA said:

So it is absolutely conceivable that I somehow damaged the thermostat then?


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Traveler said:

Sorry, yes. Let me know if you want me to drop by with my drone and remote release. We can put up an inverted L farther from your house. I work for good beer, LOTS of good beer.

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I can stop by with another drone to get video of the first drone hopefully staying out of the trees. I will work for bourbon.

I can stop by just for the free booze!




JKing, best of luck.








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Occam said:

I can stop by with another drone to get video of the first drone hopefully staying out of the trees. I will work for bourbon.

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Traveler said:

I work for good beer, LOTS of good beer.

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Boxcab said:

I can stop by just for the free booze!

JKing, best of luck.

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Well I have plenty of beer and other various spirits but sadly no large trees on the back of my property and I’m HOA restricted.

Traveler said:

Sorry, yes. Let me know if you want me to drop by with my drone and remote release.

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Which remote release do you have?

Time for a patriotic Flag pole then ....

ToolAA said:

Well I have plenty of beer and other various spirits but sadly no large trees on the back of my property and I’m HOA restricted.

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This one:

https://www.amazon.com/Weite-Upgraded-Delivery-Transport-Carrying/dp/B07PQBW4SM/ref=sr_1_1?keywords=Weite+Upgraded+Drone+Clip+Payload+Delivery+Drop+Transport+Device+For+DJI+Phantom+3%2F3+PRO+Series%2C+Drone+Release+Fishing+Bait+Carrying+Wedding+Proposal+Tool+%28For+DJI+Phantom+3%2F3Pro+Series%29&qid=1578007062&sr=8-1

Engine4 said:

Which remote release do you have?

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The Carroll County Club is putting on another technician class January 25th & 26th.

https://k3pzn.net/course/