No Range at All.. Not Even 12 Inches...

[Spankyty]

I bought this FM Transmitter that says it is 7W which it probably isn't. It still should work since 7W is wayyy too much for what I need. It was $25 on eBay and I saw it had good enough reviews. I bought it mostly because I wanted to build a transmitter myself that's pretty cheap. So far my $5 transmitter from Five Below works 5 times the range though still not good enough for my need. I need it to go from my pi in the house to the street which is about 40-50 feet for cars to listen to.

I did try it outdoors for less interference. Still was a very short distance. The antenna you see, is 50ohms which is what they said is recommended. It's taking in 12v on a 3A power supply. It needs about 2 to function. It has a trimmer but it seem to do nothing.

So what is going wrong? It sounds great but just does not even go 1 foot...


VIDEO:
https://photos.app.goo.gl/iY8FX9PJzW4yWxbx6

[toozie21]

7W is quite the beast!

Is your antenna for the FM band freqs?

[Spankyty]

7W is quite the beast!

Is your antenna for the FM band freqs?

Not sure. It's a center coil scanner antenna.

[Ruppro]

I would guess your antenna is the issue, here is a how-to for building your own, just make sure you follow the instruction for sizing it for your frequency

http://www.doityourselfchristmas.com...le_antenna.pdf

[Spankyty]

I would guess your antenna is the issue, here is a how-to for building your own, just make sure you follow the instruction for sizing it for your frequency

http://www.doityourselfchristmas.com...le_antenna.pdf

Thank you. I sure needed that. I will build it and see how it works.

[TomL8345]

I bought this FM Transmitter that says it is 7W which it probably isn't. It still should work since 7W is wayyy too much for what I need. It was $25 on eBay and I saw it had good enough reviews. I bought it mostly because I wanted to build a transmitter myself that's pretty cheap. So far my $5 transmitter from Five Below works 5 times the range though still not good enough for my need. I need it to go from my pi in the house to the street which is about 40-50 feet for cars to listen to.

I did try it outdoors for less interference. Still was a very short distance. The antenna you see, is 50ohms which is what they said is recommended. It's taking in 12v on a 3A power supply. It needs about 2 to function. It has a trimmer but it seem to do nothing.

So what is going wrong? It sounds great but just does not even go 1 foot...


VIDEO:
https://photos.app.goo.gl/iY8FX9PJzW4yWxbx6

Can you post a link for what you purchased?

[ukewarrior]

So... it is possible that your antenna could be absorbing all the RF.
BUT, I doubt it. If you can't even go 12 inches.
It sounds to me like the output stage transistor is blown.
At 7W, which is about 1000 times too powerful, if anyone turned that beast on without an antenna, you probably blew a transistor.

You should return it.

I run a 10 MILLAWATT transistor and it easily transmits 1/4 of a mile with a ground plane antenna.
Those little whip antennas are useless.

[Spankyty]

Can you post a link for what you purchased?

https://www.ebay.com/itm/5W-FM-Trans....c100005.m1851

[Spankyty]

So... it is possible that your antenna could be absorbing all the RF.
BUT, I doubt it. If you can't even go 12 inches.
It sounds to me like the output stage transistor is blown.
At 7W, which is about 1000 times too powerful, if anyone turned that beast on without an antenna, you probably blew a transistor.

You should return it.

I run a 10 MILLAWATT transistor and it easily transmits 1/4 of a mile with a ground plane antenna.
Those little whip antennas are useless.

Should I just get a replacement transistor? I've noticed it does not even get hot. It would suck to return.

[jackfrost2]

Note:
it's DIY kits, not assembled, need solder yourself
The transistor is USE . BUT IT FINE

Kinda makes you wonder IF the final IS really good to go , or is it fried ? ( seeing as to how they are USED )