Need recommendation for a LEGAL FM transmitter

[Omega-TI]

Hi, I've been wanting to get a decent FM transmitter that I could use on my property to listen to my favorite music. I'm on 20 acres so I'd like it to be able to reach from one side of the property to the other. It would need to support either a USB memory stick or an SD card. The problem is, there are quite a few out there to choose from, but some of them, without a license, do not appear to be legal. If someone with more knowledge and/or experience in this area could recommend (with a link) to some decent one(s) I'd be really appreciative. --- Thanks.

 

[Omega-TI]

Currently I'm using the setup pictured below. It works okay inside the house, but that's about it.



There is one legal one I found from C.Crane << HERE >> but it would require a separate MP3 device. I suppose I could go this route, but it looks like the range would not be more than 75 feet or so. I guess this is the best I can expect?

 

[mmckenna]

I guess this is the best I can expect?

Legally, yes, probably.
Since these operate under Part 15, they are very limited in the power output. Increasing output power won't be an option, and usually the FCC doesn't allow an external antenna. Adding an amplifier wouldn't be permitted, either.

That doesn't leave you many options. Covering 20 acres will be difficult if not impossible.

Best you could do is get that thing up as high as you can.

There are a ton of illegal options available, but if you look at the FCC enforcement bureau page, you'll see that they are a popular target.

 

[Omega-TI]

The one thing that gets my attention is how short the antenna is on that C.Crane unit. It looks to be like a 1/8 wave length, not even a 1/4 wave. I wonder if that is to keep the range down? While not legal, I'm betting more that a few people out there have added a little extra wire to the antenna to get a few extra feet out of it. I sure as heck don't plan to risk a fine though!

 

[Omega-TI]

The one thing that gets my attention is how short the antenna is on that C.Crane unit. It looks to be like a 1/8 wave length, not even a 1/4 wave. I wonder if that is to keep the range down? While not legal, I'm betting more that a few people out there have added a little extra wire to the antenna to get a few extra feet out of it. I sure as heck don't plan to risk a fine though! I do have one place in my home that can get it up a little higher though.

 

[mmckenna]

The one thing that gets my attention is how short the antenna is on that C.Crane unit. It looks to be like a 1/8 wave length, not even a 1/4 wave. I wonder if that is to keep the range down?

With Part 15 stuff, that's usually part of the design. Replacing the stock antenna with anything other than the original size/type antenna is usually against the rules.

While not legal, I'm betting more that a few people out there have added a little extra wire to the antenna to get a few extra feet out of it. I sure as heck don't plan to risk a fine though!

If you follow the links on the C.Crane site, they mention exactly that.
Unlikely anyone would complain or the FCC would come knocking.

What would probably get you busted would be running some of the Chinese crap with lots of wattage/big antenna and making yourself well known. If you have 20 acres in Washington State, I'm guessing you are well into the more rural areas. Pissing off neighbors or FM broadcast stations is less likely to happen.

Where you usually see the FCC cracking down is in large cities where there are many broadcast stations. Some of the large FM broadcast networks seem to enjoy that, and probably have the FCC on speed dial if they think someone is encroaching on their domain.

 

[Omega-TI]

Thanks!

 

[Omega-TI]

I went and checked what you were talking about... yeah, even THEY mention adding a length of wire in their own video, I guess it's nothing to to get bent out of shape about, especially out in the toolies.

 

[Omega-TI]

<< THIS LINK >> May come in handy for others wanting to use one of these to rebroadcast your scanners audio, Sirius X/M, or music anywhere around your home or property.

 

[Omega-TI]

I'm on the fence between these two units, a little more advice and/or insight would be appreciated.

The First is the Retekess TR508 one of the few that actually claims to be Part 15 compliant, not just "FCC certified" and even lists the lower power setting level of .1watt, but claims to go to .5w with no visible selection method. (see PDF below)

The second is the obviously compliant C.Crane FM Transmitter 3

If you were to choose, which would you choose?

 

[mmckenna]

Well, to me, Retekess is just another CCR company. Not sure how they compare to the other CCR companies.
But we know that some of them have no issues at all ignoring the FCC requirements.
Maybe Retekess is different...

C. Crane has been around for a long time. While I doubt they make their own stuff, they seem to be a respected company with a storefront in the USA.

Since Part 15 doesn't require type certification like other services do, there is no ID you can run to check.

Given the choice between the two, I'd probably choose the C. Crane option.

 

[Omega-TI]

I checked the FCC data base, the << Retekess TR508 >> is listed. It also claims to be Part 15 compliant and the video (shown below) also seems to back it up, along with others. I'll probably pair it up with my << Retekess V115 >> ultra light SW radio because it has a MP3 player built-in.

Start watching at 1:25

Anyway it seems to be a sturdier build than the C.Crane, but was cheaper (From Alibaba) so I went with that. Also the reviews I read were all pretty solid. I don't mess with tapes, records or CD's anymore, so this should serve my needs. I figure if I leave it on low power with the included antenna I'll be fine, but my hopes of reaching the other side of the property are now gone. It should be here by the 15th.

 

[Omega-TI]

I got it! It works great, a little too great actually. I'm going to set this on the bottom of a bookshelf as close to the floor as possible. It covers the whole 20 acres... and then some. I'll probably end up using some aluminum foil or a sheet of copper on the back of the bookshelf to attenuate and direct the signal away from the road.