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FM Transmitter - Which one is best?


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I'm looking for an FM transmitter that will transmit a minimum of 300 feet (one block max). I do not want to do any soldering, so no kits. Ramsey and EDM are to expensive. Any help would be appreciated.

Tom L.

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Your parameters don't leave a lot to work with, so I'm not sure how much advice people might be willing to stake their credibility on. Personally, I'm all set with my EDM, but if you're not too particular about sound quality I think you have quite a few options. Search for "FM transmitter" and you'll get a blizzard of topics to peruse.

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Tom,
I agree with George. You want your cake and eat it too. I am just going to throw out some ball park stats. Anything under 100 bucks and your range and audio are not going to please you. Start getting in the 150 buck range and you might meet both requirements on a few select models. But most will either be low range or poor audio quality. In the 200 buck range, most all of them will meet your requirements.

I am told that on the EDM units, only the power jack needs to be soldered in. I am sure that someone you know, knows how to make a few solder joints. I also have heard that there are a few of the kits that can be found on Ebay that someone has soldered and tested. Might go and look over there.

Most complain about the "Whole House" transmitters. Only one or two comments have been happy with them. So, I am going to avoid those units myself. Actually I have been soldering things and kits for the past 35 yrs. So, more than likely I will be getting a Ramsey or EDM. Just right now it is not on the top of my to-do list.

Max

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I did not know that the EDM only has one solder part to complete the kit. This I can do. I found the following EDM transmitter on their site:

EDM-TX-110EP
100mW PCB, Parts, Antenna,
Regulated 12V PSU, Metal enclosure
Adjustable RF output switch
10mW or 100mW


They want $149.00 for it. Is the EDM-TX-110EP a good transmitter? I like the idea that I can adjust the transmission range to fit our neighborhood.

Tom L.

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Or if you want to spend another $30, you can go with the fully assembled Ramsey FM 25B on Hobbytron.com. I bought mine there a couple of years ago, just plugged it in, and got superb sound quality. It's adjustable too and have no problem getting out to my whole subdivision.

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You might also wait a while. EDM is supposed to have a replacement for their LCD model out this summer. Once it is out, the group buys will start up again, and help the pricing. From what I have personally heard in the shows around here, the old EDM LCD model out performs the Ramsey FM30b easily, and the new version will have a place to drop in a pira mini RDS chip for an easy upgrade to RDS..

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I think I will wait awhile to purchase one. Thanks for the info on the next generation of EDM. Excuse my ignorance but what is RDS?

Tom L.

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Radio Data Service. It is the feature that allows the artist, station info, and song title to appear on some car radios. Probably not major factor when shopping for low price, but it sounds like they are aiming to try and keep the ability to add this feature out of the base price of the radio.

Eventually, I want to use it to display the web site info as well as song and artist.

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Tom,

I got a reply from Scott to confirm what I thought I had heard about the two or 3 solder joints. He also told me that you will have to install one IC chip. From the words he used I presume that for some reason you will need to insert this chip into a socket.

Soldering is a good skill to have. Just a little pratice and it is rather cheaper than say learning how to weld. Although not the same thing.

Max

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Tom,

The soldering required for the EDM is basically entry-level skill. The transmitter is technically sold as a kit and the assembly is likely the minimal amount needed to qualify as a kit. It takes ten minutes, including reading the instructions. Scott won't steer you wrong - I got in on one his group buys last summer and for about a hundred and a half I've got a transmitter that more than does the job for distance and the sound is excellent. I recommend EDM without hesitation. Good luck.

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I have heard that the reason the EDM requires you to solder the power connector is so that it can be sold as a "kit". If it's a kit, then it doesn't need an FCC certification, which the EDM transmitter wouldn't be able to get because it a) can transmit at a power level that is too high for part 15 conformance; and :D has a connector for an external antenna, which also would let it send more effective radiated power than allowed by part 15.

As an alternative example, the Whole House Transmitter (sold by LOR) does have an FCC certification, so it can be sold as a ready-to-go unit, but its power is severely limited, and it doesn't have a provision for an external antenna.

However...

I have read through FCC part 15, and the only time a "kit" is mentiond is in part 15.25, which only applies to "A TV interface device", so I don't think that's pertinent.

Part 15.23 is "Home-build devices", but it also doesn't seem to apply, since it has the requirement that the devices "...are not constructed from a kit...".

So I don't know where is the requirement that a non-FCC certified FM transmitter must be sold as a kit. Perhaps it's in an earlier version of part 15?

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FCC 15.239 says "The field strength of any emissions within the permitted 200 kHz band shall not exceed 250 microvolts/meter at 3 meters"
http://edocket.access.gpo.gov/cfr_2008/octqtr/pdf/47cfr15.239.pdf

Ramsey references the information on their site:
http://www.ramseyelectronics.com/resource/default.asp?page=fcc

It's impossible to know if your transmitter is in compliance unless you have the right equipment. But it's probably safe to say that if the output of the kit is significantly stronger than the assembled transmitters, you have exceeded the legal limit.

I haven't heard of a single decorator who has had a visit from the FCC. But I can say from personal experience that (back in the 80's) they used to drive around in black sedans with directional antennas writing fines :shock:

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rwertz wrote:

I haven't heard of a single decorator who has had a visit from the FCC. But I can say from personal experience that (back in the 80's) they used to drive around in black sedans with directional antennas writing fines :shock:


Were those the same guys who wore black suits and sunglasses and had those funny servo thingies??? :cool: :cool:

Something tells me that with the libs in control we don't have much to worry about unless we put Sean Hannity on the air or something like that. There's plenty of available frequencies around here and I live in a river valley, so personally I'm not worried if my transmitter runs a little hot. I'm more interested in pumping out the best sound quality I can within sight of the house. And if I should happen to get a letter one day, I'm certain that the lighting season will be long gone by the time the FCC remembers to send someone around to find out if I complied or not.
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rwertz wrote:

FCC 15.239 says "The field strength of any emissions within the permitted 200 kHz band shall not exceed 250 microvolts/meter at 3 meters"
http://edocket.access.gpo.gov/cfr_2008/octqtr/pdf/47cfr15.239.pdf


Ok, wont argue that statement. But what does that have to do with this discussion? Or is the 200Khz a typo? We are talking about a frequency that is 500 times higher. 200 Khz is SLF and our FM transmitters are operating in the VHF band.

BTW if 3 -30 Mhz is HF and 30 - 300 Mhz is VHF, and .3 - 3 Ghz is UHF. What is 3 - 30 Ghz?

Max
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FM is frequency modulation. The frequency of the transmitter is changed slightly to carry the sound information. 200 KHz is the frequency band that the modulated frequency must stay within. That's why FM radio stations are 0.2 MHz (200 KHz) apart.

I just feel that if someone is going to be operating an illegal transmitter they should at least understand they are breaking a law (even though they probably will never get caught).

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Ok, you went super techno on me and to be truthful, I did not remember the devation of commercial FM transmittions. I see now you are siting the power spread out over the "Channel" shall not exceed. It is very well known that when you say a radio has XXmW power output that they are talking about the whole channel.

True it is against the law and chances are fairly slim that Uncle Charlie is not going to be paying you a visit. Unless you tick off a whole community of people by blocking their favorite radio station. Heck we now have CBers sliding into the lower 10 meter band, and hardly anything is being done by U.C.

BTW DE KF0OX advanced ticket along with my Radio Telephone Lic and 5 yrs Ground radio repair tech in the USAF. But thanks for anyone else that didn't know what FM stands for..

Max

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After 25 years it takes me a while to remember this stuff myself.

Tom L. if you have a desire to stay legal, you might want to try the C.Crane transmitter. It performs significantly better that the Belkin for me.
http://www.ccrane.com/radios/fm-transmitters/fm-transmitter.aspx

On foggy days I still get some noisy areas 120' from the house with the C.Crane. So eventually I'll be purchasing one of the transmitters mentioned above. But, I'll be keeping the power at a reasonable level.

Reg

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I just wanted to throw my vote in for the EDM unit here on the original discussion.

I was going to pick up a Ramsey unit and assemble it, but didn't have enough "free time" so I went with the EDM LCD model. I am more than happy with its performance. It has a nice clean signal that carries 500 feet easily on the low power setting using the piece of wire test antenna that comes with it. It is simple to make a dipole antenna out of a piece of RG-58 coax that will increase the range and you can mount anywhere you want.

You do have to solder in the power connection and install the processor IC, but it is a "no brainer" type of assembly and the unit comes with crystal clear instructions for the assembly as well as setting the unit up and using it.

The EDM also allows you to select any frequency in the FM range unlike some of the lower priced units that only give you the option of half a dozen or so selected frequencies to use for transmitting on. I am also looking forward to their RDS capable unit to be able transmit web site info and other things out with the display info.

There is also a fellow over on the Planet Christmas forum that was offering to assemble the unit for you if desired and he was running a group buy a couple of times that helped save some money. I'm sure he will be doing it again since he had a very good response to the buys last year.

Overall a excellent unit for the price and I feel anybody can't go wrong with one.

Bill Ellick

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  • 1 month later...

Just to throw my two cents in. I just purchased an EDM unit and it took me ten minutes to have it put together and transmitting. There were four chips that you lightly push into sockets.

The only soldering was two wires for the power connection. Very basic stuff and the directions clearly show where everything goes. Even if you are not an electronics person you only have to solder two wires one red and one black and the terminals are marked red and black so unless you are color blind this is very simple and straight forward.

The only issue I have had is on the higher power setting it picks up a hum when the transmitter is by anything with a magnetic field like your speakers.

I have not tried moving the transmitter away with a longer cable to see if the hum goes away at high power. I am also going to try using a shielded antenna cable to see if that will clear things up. At high power I can transmit about a one mile range. At low power I get about 300 feet that is a rock solid clear signal. I have had a lot of fun with this little radio unit.

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I have this one and I have used it for 3 years now. I am very happy with it. I mounted the antenna that came with it on the exhaust vent on my roof with zip ties.

I was able to get it 40 blocks away!

Make sure you check on the power cable, I had to purchase one separately.

http://cgi.ebay.com/5-WATT-POWER-FM-RADIO-STATION-BROADCAST-TRANSMITTER-PLL_W0QQitemZ320381458650QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item4a983918da&_trksid=p4634.c0.m14.l1262&_trkparms=%7C301%3A1%7C293%3A1%7C294%3A30

Jim

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javerill wrote:

I have this one and I have used it for 3 years now. I am very happy with it. I mounted the antenna that came with it on the exhaust vent on my roof with zip ties.

I was able to get it 40 blocks away!

http://cgi.ebay.com/5-WATT-POWER-FM-RADIO-STATION-BROADCAST-TRANSMITTER-PLL_W0QQitemZ320381458650QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item4a983918da&_trksid=p4634.c0.m14.l1262&_trkparms=%7C301%3A1%7C293%3A1%7C294%3A30


Wow Jim.... 5 Watts! I'm surprised that the FCC hasn't beat the hinges off your door yet ;-) I'm even more surprised that you can buy this in the USA. I thought the FCC banned shipments of transmitters over 25 mW. Do you really need that much power?

It does look like a solid unit with a buch of power for the price. However, I'd be afraid to run it in my community.
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FYI

The EDM is changing from a 3 year warranty to a 5 year by the end of this year.
Thats retroactive for all current owners.

The EDM with RDS should be out soon. There are members who have been using it in prototype form for a while now. They will be offering it complete with RDS chip (or add chip later) form ... and will also have the cables available as well.

I also heard they might offer a one-time upgrade for existing EDM LCD owers to basically to do a group board swap (combined shipping there and back) and then with a minor case mod (notch added), you put in the new board and use the mini USB cable and your old EDM LCD is a new EDM LCD w/RDS. That said, a lot of people could care less about RDS ... but it IS cool !!

I concur that the installation is a cake walk, its a skill level "1" type project. If I could do it ... so can YOU !!

There may be some surprises coming soon ... I just have my own hunch. Stay tuned.

I still haven't heard if there will be a group buy or not this year, but if EDM offers it, I will host again. If they don't, I may buy some (as I did late last year) and offer it to members along with a cable & antenna as a kit for a modest mark-up.

These transmitters are excellent ... and its true that a longer and higher-quality cable can help reduce that buzz you sometimes hear when located next to electronic devices.

Scott

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Nice Info Scott... thanks for the update. I have two clients interested in the RDS unit from EDM so I am monitoring this thread for them. I'm looking forward to playing with it myself before setting it up for them.

I've also received a surprising number of other PMs and emails from people asking about where to get transmitters. I'd like to post your information on my message board if you are ok with that. If I post a link to this thread on my board, I'm not sure if people will be able to access a link to this board without being a member. Perhaps someone can clarify that for me? If links work to this thread without being a member, then maybe I will do that instead.

Richard

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