[quote="Shrimpdip"]
"I couldn’t find and old radio areial wallplate so I made my own. "
/endquote]
there are a few things about radio antennas.
The signal from the antenna can't be split, Yes it's possible but the signal strength will be reduced by half each time you split it.
I found it interesting to learn that it doesn't matter if the second radio that is connected isn't turned on. the antenna "sees" the coil as the same , electrically.
Any schematic of an old radio antenna will also show a lightening arrestor and from that to ground. This is so if you do get a strike the lightening can jump to ground.
Ive heard of others using a spark plug, I guess the theory is that the antenna current can't pass the gap but lightening would just jump the spark plug gap on the way to ground.
Its possible to use coax like with TV cable.. If you recall itn the TV antenna days you often found those splitters, they may be called UnUns or a Balun.
It's basically an impedance matching transformer.
Here's a video showing one I think for Ham radio he mentioned 10 meters.
https://www.youtube.com/watch?v=L4jGNFGN-RQI think the impedance of these antenna systems is important. a typical old radio wants to see a long wire antenna, like 70 feet or so and a good ground. some bury the ground separate to the houses electrical system.
If you are a Ham operator or if you know one they will surely have a lot more info about the antennas as it can get a lot more technical than I will ever understand. They also go into different grounding techniques like star grounding, placing a number of copper posts in the ground and connecting them together.
what I did was bought some adapters. someone with more knowledge than me made them up for me. . the first connects to antenna and ground, provides a ground route for lightening I assume and a permanent ground for the radio. ( of course the radio wants an antenna connection as well as a ground connection. )
I drove a copper pipe in the ground and used that as my ground. from that it goes to the outside sheathing of the 75 Ohm coax ( TV cable) that shields out the hash from my TV etc..
the impedance matching transformer is basically is a transformer to change it to I think 75 ohm impedance. 1:4 then at the back of the radio there is another one that does the reverse, 4:1
they work in conjunction and enable me to use the coax cable which shields out household interference.
there is also a splitter that he provided. , so I can divide the signal by connecting two cable vision wires and run two radios from a single antenna. I learned it was a bad idea to just connect a bunch of old radios to one antenna.. I guess they see the coil in the radio and beyond that there is sort of a loose coupler connection to the rest of the radio and that's why it doesn't matter if the radio is on or off it will still use some of the signal.. and yes that's in layman's terms, someone that knows antennas better can talk circles around it and perhaps find some discrepancies in what I am saying. basically inside the radio you will have the broadcast band coil and then the ground will connect to the other side of this coil. the signal then transfers to the next coil Just by being nearby it.. and then on to the rest of the radio components.
I ran a lot of coax from various points in my house ( most rooms) to a central panel in the basement with the idea that I can then put up an antenna and use the splitter to control which branch I send the signal to. or if I want two I can do that. this is to avoid having to cart console radios around the house to get them to the antenna as I have quite a few of them.
beyond that it gets a bit technical and I am not an authority on that. I think the impedance matching transformer that was made for me is 4:1 but I could verify. the one in the video is 9:1 and a TV one is similar in nature but a different ratio.
a bench technician or ham radio operator might be a good resource to find out more. I have really good results when I followed the guy that made up my splitters and matching transformer's recommendations. I keep meaning to play with this setup more but life gets in the way.. I have a phone pole at the back of my lot that was just for the laundry line so I have been meaning to stretch a wire from there to the house. I'm also wondering if the old phone pole is safe it is very old and I don't want it to fall on someone or on a car. I've also got a wire that was my old phone cable from the early days and it goes out to the nearest power poles and to the next pole and ends going nowhere. I tried using that for an antenna and it had too much interference from the city wires I think. I've heard of others using now dead knob and tube wiring , maybe a bit close to other wiring? or you can put a bunch of wire in the attic , make a big antenna that sits in dead space and that might work well.. Ive been told the best is a wire outside stretched to a tree, and a good ground. It doesn't need to be super complex to work.
some of that computer stuff, and dimmers and fluorescent lights can mess up the reception too.. I'm right in the city so I will definitely have interference but I think it is still possible to get hundreds of AM stations , maybe a little short wave with just a hunk of wire.
in a previous house I ran a braided bare wire around near the gutters and used insulators to hold it away from the house. I seemed to get really good reception like that using cable in the house and the adapters I had made for me. It gave me way way more stations. I've got a couple of antenna kits from the 20's or 30's with neat graphics and instructions. right now I'm half done my roof and towards the end ( when the weather is better) I plan to connect an antenna. I thought I might be ale to run it just above the peak from one end of the house to the other, then to my clothes line telephone pole. I just dont want the wire in the way until I'm finished crawling around the roof. but since I'm up there I can probably plan to do that as I finish and remove my walking planks and stuff from up there... I left the walking planks and brackets nailed to the roof for the winter lol.. so for now I have like basically stairs on my roof .
I got a hold of a thing that is meant to connect to an older car radio, a car with AM only. It connects to the antenna of the car radio. You tune the radio to about 800 AM and it can then tune FM from this little tuner thing. It doesnt' really amplify or connect to anything else but it has a an FM tuner.
so I hooked it to a loop antenna from an old AA5 radio ( instead of to a car radio) and if I just put that near any other radio with an antenna, That radio then picks up FM on the am band.. so I can play more modern music through my old radios if I want to.. fun
I'd like to get a little broadcast unit but they are a couple hundred.. then you can stream from your cell or whatever though your AM transmitter and receive it on any other old radios.. It's legal but you can only broadcast up to 100 milliwatts or you might get an angry knock at the door for owning a pirate radio station
there are plans out there to make the little broadcasting units out of old radios. Its possible by reverse engineering them a little..
What's on AM can be boring but I guess it depends where you are. at least you can get some info that way if you are more remote.. FM only travels so far. I love antique radios mostly because I love the cabinets and all the designs. I have lots of art deco ones and it's really a fun hobby.
The stencils look amazing. Nice work !
