One of my Wintennas, metal window frame as antenna, is being shut off.
Discontinued the same way shortwave stations are being turned off.
This particular one is driven by an AMT3000 transmitter from SSTran.com using the advanced method of a loading coil to drive the antenna.
I personally made the loading coil using a triangular form instead of the usual circular.
The whole thing resonates as per expectation, producing a strong local signal at 1550 on your dial, but not really getting anywhere.
On the one hand I dont want to get too far afield, but I do want to cover the immediate campus here at Home School College.
So now I am ripping it down and have a new idea.
Stay stewed for further reports.
You might be surprised and quite pleased with the range you can get from an indoor antenna with a simple but well constructed loading coil and a water pipe ground.
The first well performing antenna here is still in place and is used for testing. It is a 3 meter 3/4 inch copper pipe with a loading coil wound on a 3 inch diameter form and is mounted on the ceiling of my basement lab. The transmitter is mounted on the ceiling and RF ground is via a water pipe. Some will comment that the water pipe is radiating and this is true but the setup is good for testing and experimenting. A resistor installed between the transmitter ground and the pipe allows adjustment of the field strength so I can match this approximately to that of my outdoor ground mounted antenna. I am well aware of 15.219 so I don't need reminders and this information is just that...information.
Neil
Basement seems like an interesting location for medium wave transmission because, by a significant degree, basements are on a direct plane with the surrounding earth, placing the signal on exact phase with earth-surface, avoiding reflections and bounces that probably occur with raised antennas.
From your description, Neil, I guess your antenna is horizontal, probably not mattering, except it might be directional. That's actually a question, so here's the appropriate mark: ?
I suddenly have more to say.
Looking at it in reverse, I notice that AM radio reception is especially strong in the basement, so I'm guessing the reverse is also true: that basement transmission is likely efficient.
From my experience and feedback from others, indoor AM transmissions will fall FAR short of what you can achieve with an outdoor vertical antenna with a good ground radial system.
Everyone has a natural instinct to go the easier way and put an antenna somewhere inside the house and ground to a water pipe. You may very well be deceived by the tremendous signal strength on radios inside the house, but the proof is to test your range outside the house. Typically, this is done with a car radio. You may find that your indoor antenna signal is strong at 1000 ft or more away, but look again. You may be driving along a route parallel to the power line feeding your house. Try some different routes and you likely will find the signal is not really receivable.
An outdoor vertical with good ground radials will make your signal receivable at a longer distance in all directions. Of course, if all you want is to receive your own signal within your house, then an indoor antenna is just fine and you won't need to worry about FCC violations.
In my Mom's beach-house in Rhode Island, my AMT-3000
Part 15 AM set-up worked better in the basement
than upstairs in the same house. It's funny -
the AMT-3000 was sitting on the basement floor,
and so was the transmitting antenna. There was
no ground connection. I'm not saying it got out
that far, but it was solid about 200 feet out from
the house. Then it abruptly went down in strength
and vanished beyond that point. This was as heard
on a portable radio. My guess is that it was coupling
into the AC line somehow. Anyway, running the AMT-3000
upstairs was not as good.
Back here in Hartford, CT - I enjoyed my outside ground
mounted 3m Part 15 stick
and how it worked for several years. Now having one
is not possible, and I miss it a lot.
I hope that sometime, before I get REALLY old, I can
do what I have always wanted to do. And that is -
make a portable Part 15.219 transmitter package that can be
plunked out in the yard and hooked up inside the
house studio via V+/audio. (Don't I sound like a
broken record - I've said this so many times.)
HOWEVER, in my creation and confusion - I have
conjured up many different loose design versions -
including an FM package that is
battery powered and would fit in a box or suitcase.
That could be very simple to make, or it could be
complicated. It just depends what you want to do
with it. Then there is the idea for a completely
self contained AM Part 15 station in a box or suitcase.
That's a lot harder than the FM version. The transmitter
and the "portable studio" would have to be separated
by some distance - 2 boxes - I think - or
the strong AM RF field (we hope it's strong)
would mess up the control board and whatever was feeding it.
Anywaaaaaaaay
If you have the time/money/land/ability/desire (wow!)
to make the outside antenna/ground system then do it.
You won't be sorry. It's a wonderful electronic/science
experiment just by itself. If you don't want to worry about
programing - then run NOAA weather radio through it 24
hours a day. Nobody will mind that and it will be a public service.
Bruce
"I am well aware of 15.219 so I don't need reminders...."
Good one Neil. 🙂