Jump to content
Light-O-Rama Forums
a31ford

ADD-ON... REMOTE, (300 + feet) FM Transmitter

Recommended Posts

Seasons Greetings All !!!! (2 days to go, YAY ! )

 

I'm thinking of moving my FM transmitter (EDM) up to my tower for our internet (we live in the country)

 

SO, what I've done is, I've ordered some samples of some Audio 'Line drivers" and "Line receivers" this will allow me to run a 600 ohm, cable (2 for stereo) from where my G3 MP3 Director is, to the Transmitter up at the tower, some 300 feet away...

 

Those that think they might want to do the same,  OR have a use for this type of equipment, follow this post (top right, click), and when the chips come in (about 2 weeks or so) I'll post the results and "how-to" here.

 

Greg

Share this post


Link to post
Share on other sites

TY, atver, I'm currently using a RG6U coax cable from the transmitter up to the antenna on the tower, and it, sucks ! I had originally had the transmitter up there, and could get over 2 miles in any direction with it, (remember I live in the country). with the antenna being so far from the transmitter, the signal is down to about 600 feet, and barely covers the light show (the show is some 1000 feet from my house, as there is a hill between the house and the show)

 

I tried the transmitter in the house, well. put it this way, it's GREAT in the yard, but nothing out at the road, where the show is.....

 

I'm going to video the show this evening, and post in a different topic, in the coffee shop.

 

Greg

Share this post


Link to post
Share on other sites

Normally a transmitter uses 50 ohm impedance for coax to antenna.  If you used RG6  it is 75 ohm were as RG 8 or RG 58 would be 50/52 ohms which is a better match.  Having the transmitter with antenna attached to it on the tower and feeding audio and power to it from afar is your best solution. 

 

Good luck with your project.  Keep us posted!

Jim

Share this post


Link to post
Share on other sites

True, I totally agree with you, But the RG6 is what is in the ground going from the house to the tower.

 

Greg

Share this post


Link to post
Share on other sites

Just an update on this,

 

The IC's have arrived (3 of each) I've ordered some PC boards and enclosures as well as jacks & power supply ends.

 

The Idea being that the circuit will run off common 12 Vdc wall wart power supplies, and use the ICL7660  IC to create negative voltage for true differential operation. (audio transmission system, that is somewhat like the RS-485 data protocol).

 

The data sheet for these drivers indicates "Long" cable runs (over 1000 ft can be used) 300 some odd feet is all I need, however the circuit will be designed for the longer runs with the idea that if someone else needs the extra distance the circuit will handle it.

 

I'll update as the project progresses/

 

Greg

Share this post


Link to post
Share on other sites

3 years later..... i now finally have the time to work on this project OMG !!!

WILL post a schematic shortly.

  • Like 1

Share this post


Link to post
Share on other sites

So... some information on the driver and receiver IC's

TI (Texas Instruments) DRV134 (Driver) and INA134 (Receiver) the packages I have are 8 pin DIP (they make a stereo version however this is what I currently have).

sch2_zpszqsgleg2.gif

 

The Basic Circuit is as above (Directly from TI's tech sheets) only a handful of extra components are needed (these use a dual voltage power supply), HOWEVER, with the addition of the ICL7660 Ic (Negative voltage from a positive source), we can use a simple "wall wart" to supply voltage at each end, respectively, in the +/0/- format that these circuits need. (Power connections are NOT shown above, will get in-depth in the next post.)

NOTE: This circuit will drive on, well over 500 feet of cable between them, AND give clear HI-FI  sound, perfect for running my sound output up to the FM transmitter at my antenna tower on the hill behind my house......

I will continue this circuit in the next few days.

Greg

 

 

Share this post


Link to post
Share on other sites

It has been a while since I started this project... (a year ago since my last post....) Anyhow, if you note, the cable shown between the Driver (DRV134 / 135) and the Receiver (INA 134 /137) is shown as a shielded cable (however note the twisted pair...) I have tested this in a stereo pair (4 wires) and have used the other 4 wires in a CAT5 cable as a "loose" shield,  the white-blue / blue was the left channel, and the white-brown / brown was the right channel, I took the white-orange / orange and the white-green / green pairs and grounded them ONLY at the driver end of the circuit, once the other end of the CAT5 cable is in the housing at the INA 134 (receiver end) I simply covered them with electrical tape as to NOT cause a ground loop between the two power supplies.

SO far, this is one robust circuit, I did NOT get it finished for this lighting season, however I am confident that it will serve well in the future.

will slowly continue with follow ups as the time permits, and even photos of the project as I can.

Share this post


Link to post
Share on other sites
26 minutes ago, a31ford said:

It has been a while since I started this project... (a year ago since my last post....) Anyhow, if you note, the cable shown between the Driver (DRV134 / 135) and the Receiver (INA 134 /137) is shown as a shielded cable (however note the twisted pair...) I have tested this in a stereo pair (4 wires) and have used the other 4 wires in a CAT5 cable as a "loose" shield,  the white-blue / blue was the left channel, and the white-brown / brown was the right channel, I took the white-orange / orange and the white-green / green pairs and grounded them ONLY at the driver end of the circuit, once the other end of the CAT5 cable is in the housing at the INA 134 (receiver end) I simply covered them with electrical tape as to NOT cause a ground loop between the two power supplies.

SO far, this is one robust circuit, I did NOT get it finished for this lighting season, however I am confident that it will serve well in the future.

will slowly continue with follow ups as the time permits, and even photos of the project as I can.

(deleted)

 

Edited by TheDucks

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×