Diving into Ham Radio... uh oh!

[Grumpycat]

I remember running this ANDREWS 1-5/8" stuff up my tower for my UHF Repeater. I always assumed everything got worse as operating frequency went up. HF seemed so easy except for the real estate required for the antenna.

Transmission line losses increase with frequency but not "SWR". If anything the greater the losses in the cable the lower the reflected power and resulting "SWR". Yet the situation at the antenna is exactly the same.

 

[Grumpycat]

I went to Dayton 3 times. I think I got rained on at least 2 of those times. It was "back in the day" when Hara Arena wasn't SO bad. I heard it was a mess on the last ones they had there, hence to move to Xenia Oh.

I went to the last Hara Dayton Hamvention and didn't think the place looked one bit different than it did my first time in 1983. Same 1/4" of water on all the bathroom floors and everything.

 

[dragoneggs]

Okay went to Goodwill and bought an old handheld transistor radio for $2. Needed a little work on the battery tray and wiring but it works! First thing I found out is that my wife's food sealer is a big RF leaker!

 

[k0ua]

Okay went to Goodwill and bought an old handheld transistor radio for $2. Needed a little work on the battery tray and wiring but it works! First thing I found out is that my wife's food sealer is a big RF leaker!

View attachment 675512

Thats an easy one to fix, just unplug when not in use.. The treadmill downstairs is a huge noise maker too, but fortunately the main on/off switch down near the floor takes care of that one too. One evening several years ago almost the entire band was wiped out with this whir.. whir... whir sound and it was the mother in law on the treadmill. That dynamic motor driver is a real polluter.

 

[k0ua]

Alrighty then. I watched one of the "phantom signals" episodes tonight on the Science channel. I am extremely underwhelmed. The episode featured a theme about the Windsor Canada "hum". OK, a simple search on the internet turned up that the hum has been gone since April when the US steel plant shut down its blast furnaces on Zug Island. Ok... Big mystery solved. Whoo... Hoo.. And the "mysterious" parking lot keyfobs not working was tracked FINALLY to some aftermarket Jamming device installed in a car on a trailer waiting to be worked on in a parking lot across the street of an automotive dealership. They had their answer when some "shortwave person" brought some receiver (Icom equipment shown) and found a major spectrum scope peak, but they didn't track it down. Then Some Canadian governmental agency tracked it to the car lot for them. "they had weird equipment" Shown was a Yaesu amateur talkie tuned to 148.000 Mhz. Yeah that is pretty weird since car keyfobs often operate around 300 Mhz.

Like I said, I am extremely underwhelmed, and doubt I will tune in again. Nothing to see here folks... Move along. Just like all "reality" shows.

 

[Frankenkubota]

Okay went to Goodwill and bought an old handheld transistor radio for $2. Needed a little work on the battery tray and wiring but it works! First thing I found out is that my wife's food sealer is a big RF leaker!

View attachment 675512

We used to go into clinics and hospitals to prep the area for MRI imaging machines, we called them magnets. They are very sensitive to rf and magnetic interference.

My job was to sell the service which included a site survey, simply looking for random emitters and possible problems related to magnetic and rf energy leaking into the site. All MRI sites are shielded, just depends on how much.

We also went back if there was a problem. We had jillions of dollars worth of test equipment.

A hospital in Europe was having problems so we went in. I was training so I went along, typically I wouldn't be involved in service calls etc. but good experience.

Our director of engineering and lead technical guy pulls out a $2 transistor radio and found the leak in about 30 seconds!

So much for expensive test equipment. It only worked for rf of course, not magnetic interference.

 

[dragoneggs]

I quickly walked around the house and and found a few noisy things. This would be a good job for a blind person.

I confirmed all of the magnets in my TV and stereo speakers, the dimmer switches are indeed dirty, and my dryer when running is a monster. My modem and my PoE routers are messy too.

Looks like I will be investing in a bunch of ferrite toroids! :licking:

 

[k0ua]

I quickly walked around the house and and found a few noisy things. This would be a good job for a blind person.

I confirmed all of the magnets in my TV and stereo speakers, the dimmer switches are indeed dirty, and my dryer when running is a monster. My modem and my PoE routers are messy too.

Looks like I will be investing in a bunch of ferrite toroids! :licking:

This is worth a look:

 

[dragoneggs]

Thanks for posting that video, James. I found the link to a White paper on the subject to be extremely detailed and very informative albeit quite technical and I am only up to pg 22 of 59 sort of reading/skimming through it. :confused2:

http://audiosystemsgroup.com/RFI-Ham.pdf

 

[Grumpycat]

Alrighty then. I watched one of the "phantom signals" episodes tonight on the Science channel. I am extremely underwhelmed. The episode featured a theme about the Windsor Canada "hum". OK, a simple search on the internet turned up that the hum has been gone since April when the US steel plant shut down its blast furnaces on Zug Island. Ok... Big mystery solved. Whoo... Hoo.. And the "mysterious" parking lot keyfobs not working was tracked FINALLY to some aftermarket Jamming device installed in a car on a trailer waiting to be worked on in a parking lot across the street of an automotive dealership. They had their answer when some "shortwave person" brought some receiver (Icom equipment shown) and found a major spectrum scope peak, but they didn't track it down. Then Some Canadian governmental agency tracked it to the car lot for them. "they had weird equipment" Shown was a Yaesu amateur talkie tuned to 148.000 Mhz. Yeah that is pretty weird since car keyfobs often operate around 300 Mhz.

Like I said, I am extremely underwhelmed, and doubt I will tune in again. Nothing to see here folks... Move along. Just like all "reality" shows.

Yes, thought it looked interesting a month or two ago, set a DVR timer, recorded 2 episodes and used the +30 second skip button a lot, deleted the timers.

Am coming to think generations of socialized public education has dumbed the population beyond belief. The plethora of inane supposedly "educational" shows demonstrates.

I didn't like Mythbusters either. Less than 10 minutes of content per hour. How many times can they tease less than 90 seconds of content to be shown after the last commercial break?