My summer microbroadcasting project

This is an interesting siting for your operation.  I don't know from what you wrote if your intent is to provide coverage inside your complex or not but it would be interesting to learn of the indoor range you can achieve.

I mention this because when I taught electronic communication at a college one of the lab demonstrations was to use a Ramsey FM-25 to broadcast  a signal.  The transmitter was placed on a window sill with the antenna wire taped to the window glass.  The students were asked to tune in when they reached the parking lot and report the range.  Many did and the signal seemed to cover some of the adjacent lot yet the signal could not be heard 20 feet down the hall from the lab on a portable radio.  The building really killed the signal.

Neil

The plan is to provide coverage within the complex in the immediate pool area and surrounding common areas. I doubt I have the transmitting power to go much beyond that.

The Scosche FMT4 Transmitter is a very excellent device, in my opinion.

I no longer remember how or where I first heard about the Scosche, but whatever it was, it was strong enough to send me over to the local WalMart to look... and they had several of them hanging on a hook for $10 apiece, so I got one.

After running it through some tests I was so surprised how good it was that I went back and bought the remaining three.

After that the FMT4 vanished from the store and also disappeared from the Scosche website, but I was set with the four I have.

One of the first useful discoveries I made from studying the device was that the RF output is attached to the audio shield, which makes the audio cable the antenna.

Therefore it would be in your best interest to keep the audio line between the FMT4 and the MP3 player as straight as possible and as vertical as possible.

The reason you would want a vertical antenna is to reach all 360-degrees.

Scosche FMT4 is FCC Certified.

Found this transmitter i think back in 2009?

lol It's been awhile. I can't find mine.
http://www.part15.us/blogs/rock95seven/scosche-fmt-4-review

You all sparked my interest.. Walmart still has them $10, think I will grab one myself http://www.walmart.com/ip/14666784

Also several of them on ebay.. Lol, one guy want's $50 or best offer!

Since the original poster already has a transmitter we should leave that subject and get back to his installation and operation discussion.

Neil

Mounting so as to keep the audio cable/antenna straight and vertical will be something of a challenge... if you dangle everything from a hook you don't want it to sway in the breeze because your signal will move around and might disturb the average reception.

If you build some kind of structure to hold the components in the right position it probably should not be metalic material, which will inductively react with the antenna.

Thanks for the reminder that it was Barry at Blue Bucket Radio who first started the wave of interest in the Scosche FMT4 FM Transmitter.

I plan to put my xmitter/mp3 player in like a plastic container, the audio cable will be extended all the way but may very well have to be horizontal. 

 I got my transmitter from ebay but my local walmart has them on the shelf for $13 and on their website for about $10.

Alright Desktopgrass, if your FM antenna is horizontal it will be directional...

The strong lobes will radiate perpendicular to the audio cable/anrtenna, and the ends of the cable will produce a weak "null" area of coverage, so take that into account when aiming for the audience.

Thanks for that info Carl, Idid not know that.

I have looked closer at my Scosche facts, and there is a possibility we have been talking about different versions of the transmitter.

My original version is Model No. FMT4R, but the version mentioned throughout our discussion is the FMT4. I think the "R" in the model number is a different version.

The main differences that I know of are: 1.) The FMT4R offers 14 frequencies; 2.) The FMT4R includes 87.7 and 87.9 MHz.

If there are other differences between the models I do not know what they might be.

This link describes some modifications that can be made to the FMT4 to isolate the antenna from the shield of the audio cable (I think that's what it shows) and adding a power supply in place of the batteries.

SCOSCHE FMT4 MODS

I have a Schoche (sp?) FM transmitter,

as mentioned above.  It does not have

87.7 or 87.9. 

I got it last summer, as a birthday present,

so as of last summer, somebody was still

selling them.  I think you can get them at

Walmart, in the auto section - - because

I guess they are intended to be used with

car audio systems through the FM radio in

the car.

One thing - my Schoshe transmitter has

a very flimsly audio cord coming out of

it.  You have to be very careful with it,

I think.  

More comments to follow  - I am typing

this very fast because something else is

goingon here.  

Please forgive all typos and mis-spells.

Brooce, Outlandish radio projects - Part 15

Etc. Etc. 

i would use a cheap mp3 player (like an off brand walmart player) and not something expensive like an ipod just in case the setup gets stolen or vandelized by someone or removed by management should they locate it.

external voltage sources.

I blew out a Sony handheld stereo

audio recorder.  It took 2 AAAs.  I got some

aligator clip test leads and messed around until

I had 2 D batteries hooked to the power connections on

the inside.  When I turned the recorder on there was

NOTHING HAPPENING.  Thinking I had made a mistake

(the polarity was correct) I took the connections off and

put the 2 AAAs back in.  The unit still didn't work.  It was

dead.  I tried other batteries.  Nothing.  Somehow I had

destroyed it.  I think you would need a voltage regulator

or a dropping resistor or a big cap across the voltage leads

or something.  My tech friends said this shouldn't have 

happened.  They said that the device would just draw the

current that it needed.  Perhaps the voltage or current 

in rush blew up the teeny little chip.

Using the 2 D batteries was so the unit would transmit

for a very long time, like maybe a week or so before 

I had to change the batteries.  Bummer.  It didn't work.

In similar experiments, I also blew up a very nice Sansa

Clip MP3 player and my son's very nice IPOD.  I lost 

about 800 great jazz songs from that experiment.  

(There was no backup.)  All in the name of Part 15.

Anyway, that's my 2 cents.  

I did run a C Crane transmitter off of solar power

(with no batteries at all) on a bunch of sunny

weekends a couple of years a ago.  What a blast

that was!

(Oh yeah, Neil - sorry - I got off the topic in a

previous post - I'll try to keep it in there.)

Brooce, Outlandish projects, transmitters that

don't work - MP3 players that don't work - crystal

and regen receivers that don't work - and on and

on and on.  It's still TON'S OF FUN, though