How to set up a micro-FM broadcast station

[W4EWH]

My wife is a nurse, and deals with a lot of geriatric patients. She wants to set them up with radios/walkmans/whatever, so they can listen to music that was popular during their youth: the idea is that it helps them to stay grounded during traumatic times following surgery.

Giving out CD's to each patient isn't feasable, so I want to know what it takes to set up a micro-FM station like those at Deerfield, that could broadcast for an entire hospital floor. I'd be doing this myself, so money is the key factor.

Here's what we know so far:

• The kind of units that replay an iPod into a car stereo are much too weak.
• Broadcast equipment is incredibly expensive.
• Stereo isn't essential.

All ideas welcome.

73,

Bill W1AC

[W3SLK]

Why not go with a little 2 watt AM station? If memory serves me you can run low power without a license below 5 watts.  My friend runs one with his 100+ CD player. He listens to his own music without commercials. You can probably find them on evil-bay. Some of the realtors used them for cluster house sales.

[WB2YGF]

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320344409407&

Looks like one of the best deals on eBay if you dont mind buying from Hong Kong directly (7W probably overkill)



The Ramsey kit is about the same price but is probably 1/10 the power.

[Steve - WB3HUZ]

Many hospitals are very touchy about RF signals. Some even limit cell phone use on certain floors. Be sure to check this out first. An AC powerline, carrier-current system might be an good way to get around any restrictions.

[flintstone mop]

YUP wev'e all heard what certain cell phone technologies can interfere with just about anything within 1 foot of an electronic device.
Prolly an A.M. frequency would be less likely to interfere with sensitive hospital equipment, but then overcomming the electrical noise in the hospital environment from an A.M. system might be a negative point.
I think that an F.M. freq with one watt or less. Less is better, could squeek by without harmful interference. And then you have the static free music without using the higher power that an A.M system would require.

Fred

[k4kyv]

I once purchased a  little FM stereo transmitter from CC Crane.  It was supposed to have a range of about 100 feet, and it had a synthesised oscillator, so you could select an unused FM channel and transmit the signal in stereo.  They claimed it was supposed to be FM stereo broadcast quality.

I wanted it so I could pick up streaming audio off the internet and retransmit it to any FM receiver in the house.  That way I could  listen to internet  radio just like a normal radio station and not be tethered to the computer here in the room where my clunky desktop computer is located.

The problem was, it was anything but broadcast quality.  Loads of distortion to the point that it was difficult to understand, even on a high quality FM receiver, and the range was nothing like 100 feet, but it would barely make it to the other side of the house.  I had planned to experiment with adding more antenna, but before I could even do that, the final amplifier apparently crapped out, and the range suddenly dropped to about 8 feet.

I sent the thing back and explained what happened, and asked for a refund, and they promptly re-credited the money to the credit card account I used.

I found what looked like a good one in kit form from the UK.  Problem was, the shipping charge to here was almost as much as the unit itself, so I declined.

Funny how it is so inexpensive to ship stuff across the ocean that the parts for
cheap consumer junk can be actually be made in USA, shipped to China or Taiwan for assembly, and the completed units then shipped back here, and it  still costs the manufacturer less  than it would to have it assembled here by USA workers, but yet when you as an individual try to have something shipped here from overseas or vice-versa, the shipping can cost more than the item is worth.

[WB2YGF]

Funny how it is so inexpensive to ship stuff across the ocean that the parts for cheap consumer junk can be actually be made in USA, shipped to China or Taiwan for assembly, and the completed units then shipped back here, and it  still costs the manufacturer less  than it would to have it assembled here by USA workers, but yet when you as an individual try to have something shipped here from overseas or vice-versa, the shipping can cost more than the item is worth.

Depends on the country.  Shipping for the transmitter on eBay from HK is only $9.  It would cost more via UPS to ship it here in the states.  I got 5 battery holders from Malaysia much cheaper than I could get one from the states, mainly due to the shipping. It even came air mail but there was a delay due to the airport shutting down with protesters.  It was packed in a good quality bubble pack mailer too.


Speaking of shipping, I ordered 2 printer ink carts from Amazon.com.  They came in two huge boxes.  Amazing they can make any money with what they waste on cartons. (I'm an Amazon prime member, so all my orders are free 2nd day air.)

[k4kyv]

Speaking of shipping, I ordered 2 printer ink carts from Amazon.com.  They came in two huge boxes.  Amazing they can make any money with what they waste on cartons. (I'm an Amazon prime member, so all my orders are free 2nd day air.)

Still cheaper than having to replace the item because some jerk working at UPS or Fedex had a fight with his wife the night before he came to work or she said "not to-night, honey", and he decided to kick the box, stomp on it, or toss it in the pile from 20 feet away.

[WB2YGF]

Still cheaper than having to replace the item because some jerk working at UPS or Fedex had a fight with his wife the night before he came to work or she said "not to-night, honey", and he decided to kick the box, stomp on it, or toss it in the pile from 20 feet away.

I don't think a single layer box is much protection no matter how big.  They could have made a small triple-wall box with the same amount of cardboard.  I thought perhaps they were trying to keep it from getting lost in the truck or down some crevice.

[k4kyv]

Someone should make ready-to-use shipping cartons consisting of a triple-wall box within another triple-wall box and something like bubble wrap in between the boxes, that didn't cost more than the shipping charges themselves.

I like to save any sturdy shipping carton that I might use to ship something else at a later date, but the problem is that they take up space that I don't have.  I hate to throw out a good box because I don't have a place to put it.  If I leave it out in the shed, either rodents, moisture or both destroy it.

[W1RKW]

I bought this kit along with a stereo generator over 10 years ago from someone in the states: http://www.veronica.co.uk/

It was a pretty good transmitter. Sound quality is outstanding.

[Gashmore]

If you haven't settled on something already you might look at the EDM Designs FM transmitters.  They are the highest rated transmitters for micro power FM.  FAR better than the Ramsey.  Very clean stereo signal.  Power adjustable from 1mw the 100mw with all the filters to make sure the signal is clean and the stereo is stable.  That might not penetrate two concrete reinforced hospital floors but should put out a good signal all over one floor at 20-30mw.  Might set you back $190.00 but well worth it. 

Simple to set up.  They are made in South Africa and are technically not legal for sale in the US but there is no law against selling components so they ship with the microprocessor removed and the 12V power jack separate.  Just plug in the microprocessor and make 3 solder connections for the power jack and you are ready to run.   Plug in the wall wart, attatch an FM antenna and you are on the air.  An Ipod makes a fine source of programming.  Get an 1/8" stereo plug to two RCA plugs cable at Radio Shack to hook up the Ipod.

It comes with a basic wire antenna but you may have a much better one in the back of your kitchen junk drawer.  Almost all FM radios used to come with a wire antenna made out of that flat 300 ohm TV cable.  Hang it vertically from one end about the center of the floor and it will broadcast a sort of fat doughnut pattern.   Also an old TV Rabbit ear antenna with the ears laid flat and stretched to about 28" each side and hung vertically works.