I thought I would post this little nugget of information for any technical nerds in the crowd.
Recently I was doing some experiments that necessitated creating a very low-level FM signal. Using what I had on hand I decided to try and see if I could achieve said signal by using a radio connected to a dummy load. Knowing that a dummy load is a poor antenna and it eats most incoming RF for dinner, I theorized I may be able to achieve my goal by using a radio set to low power and transmitting into it. So I tried.
In my testing, I set an HT set to 1/2 watt, connected it to a 100w dummy load and keyed up indoors. The resulting RF signal was too strong for my purpose. So I did this multiple times at various distances. It was not the low level result I was hoping for. So I moved outdoors.
When outdoors I did the same thing. Only this time I used a rubber band to key up the radio. I announced myself, put the radio in front of a NOAA weather radio in a box on the ground, then started walking and listening on my HT. To my surprise I received the signal reliably and with very good intelligibility out to 1/8 mile in my tree-dense area. I continued walking until I could no longer pick up signal at all. That was at 1/3 mile.
Curious, I called a local GMRSr and ham on the street to see if he could receive the signal. Indeed he could. Using his base radio and external antenna he was receiving the signal reliably 1/3 mile away but in the opposite direction.
So, if you have never done this, this should give you a sense of how much RF still leakage from your dummy load still gets out when you are are using it.
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mbrun
I thought I would post this little nugget of information for any technical nerds in the crowd.
Recently I was doing some experiments that necessitated creating a very low-level FM signal. Using what I had on hand I decided to try and see if I could achieve said signal by using a radio connected to a dummy load. Knowing that a dummy load is a poor antenna and it eats most incoming RF for dinner, I theorized I may be able to achieve my goal by using a radio set to low power and transmitting into it. So I tried.
In my testing, I set an HT set to 1/2 watt, connected it to a 100w dummy load and keyed up indoors. The resulting RF signal was too strong for my purpose. So I did this multiple times at various distances. It was not the low level result I was hoping for. So I moved outdoors.
When outdoors I did the same thing. Only this time I used a rubber band to key up the radio. I announced myself, put the radio in front of a NOAA weather radio in a box on the ground, then started walking and listening on my HT. To my surprise I received the signal reliably and with very good intelligibility out to 1/8 mile in my tree-dense area. I continued walking until I could no longer pick up signal at all. That was at 1/3 mile.
Curious, I called a local GMRSr and ham on the street to see if he could receive the signal. Indeed he could. Using his base radio and external antenna he was receiving the signal reliably 1/3 mile away but in the opposite direction.
So, if you have never done this, this should give you a sense of how much RF still leakage from your dummy load still gets out when you are are using it.
Michael
WRHS965
KE8PLM
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