I built my own little FM stereo transmitter just for something to mess around with. I
bought the kit from Ramsey Electronics.
And, I must say that Ramsey Electronics is the VERY BEST company I have done business
with in years! They are very customer oriented and they go out of their way to help
out their customers.
When you order any of their products, they ship them within 24 hours (now why can't everyone
do that). And once you place your first order with them, the next time you order, just tell them
what product you want and give them your name. They look up all your previous information
and will ship to the same address and bill the same credit card (if you want). And of course,
the lady on the phone is very friendly and seems to enjoy her job.
Anyway, back to my radio station. I bought Ramsey's professional synthesized stereo transmitter
kit (FM-25A). Ramsey estimates the assembly time at 4 hours for advanced geeks, longer if you're less experienced.
The instruction manual is quite detailed. Of course it has a schematic diagram and a parts list, but it
also has some very good suggestions on broadcast usage, external antennas and
FCC requirements.
After building the transmitter, I found that it did not work completely. It's a long story, but the bottom
line is that I could not figure out where I went wrong. So I shipped the completed transmitter to Ramsey.
They fixed it (I had screwed up one of the resisters, and they fixed a bad solder point) and sent it back
to me within 10 days (including shipping time both ways)! They do charge $36 per hour for such troubleshooting,
but it's worth it, and they only billed me for a half hour.
So now I wanted to test out the range. The stock antenna is just a regular radio-style telescoping antenna
(16" fully extended). Since I run the transmitter from my lower-level office here in my home, I didn't really
expect much. After doing a little testing, I found that the range was limited to my
house and yard. So I put the transmitter out on the front porch, and I found that the signal reached to two
houses on either side of me, and also to the corresponding houses directly across the street.
I had a block party coming up, and I wanted to be able to broadcast a little farther than that. So I
bought Ramsey's Tru-Match FM Broadcast Antenna (TM-100). This was a great little kit. This folded
dipole antenna consists of 54" of twin lead antenna cable and 3' of RG174U thin lead coax. I soldered
these cables together on a small PC board, along with a couple of other supplied components.
The whole unit is housed in a standard 1" PVC pipe. I soldered the supplied "F" connecter to the end
of the coax and installed it in the end cap of the PVC pipe.
A transformer converts a standard 75 ohm TV cable to the antenna's impedance of about 300 ohms.
It only took me a couple hours to put together, and it works great! I mounted the antenna on my chimney,
and I installed a standard 75 ohm TV coax cable to connect it to the transmitter in my office.
After testing again, I found that the range doesn't even compare to what it was before. A driving test
showed that I can pick up the signal from a 1/4 mile away in a car. I also tested it from my cousin's
basement (he lives across the street and down a few houses) and the signal came in loud and
clear! I am quite happy.
For the music feed, I bought a Technics SL-MC4 CD changer from Crutchfield.
Crutchfield is an okay company to buy from. Actually, I had a bad experience (I won't go into the details), but they did correct
it once I brought it to their attention.
On the CD player, I have the line level outputs plugged directly into the inputs on the FM transmitter.
It really sounds great!
The CD player holds 60 CDs, and allows me to group them by category.
I just tell it I want to listen to "Oldies" today, and it only cycles through the CDs in that category.
I also have categories like "Rock", "Soundtracks" and "New Stuff".
And it displays the name of the currently playing CD.
All in all, this is a pretty good setup.
My wife isn't too happy about the looks of the antenna on my roof, but since it's just standard PVC pipe,
I'll just paint it to match the house. My next project will be to get my X10 stuff to work in conjunction
with the transmitter.
Hmmmm.
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