FM Transmitter

[KenL_MCSE]

here is an article comparing Ramsey to EDM.
http://www.flowermoundchristmas.com/fm30bvedm

Also, I own and Mobile Black Box 4000 - I used to think it was great. Over the summer I purchased and EDM with RDS. OMG! what a difference. The sound quality is better. THe transmission is better. EDM is the best. All I had to do in the kit was solder the power connector to the board... That was hard. I think 5 mins was wrong. It was 30 seconds (after the iron heated - LOL)

[rwertz]

Jeff Millard wrote:

Ramsey... a bad idea... EDM... the only choice.

Jeff

Why do you say Ramsey is a bad idea Jeff?

I finally got the go-ahead from the wife to order a xmitter. I really don't feel like building a kit. But, I'd like to embrace the intent of the FCC's verbiage about it being an educational project. I'd hate to jeopardize my FCC license and I certainly don't have any ability to plead ignorance of the rules.

[ShaggySS]

Thanks for posting the instructions. Looks simple enough. I think I will pick one up. brb gotta go plug in the soldering iron

[rwertz]

KenL_MCSE wrote:

here is an article comparing Ramsey to EDM.
http://www.flowermoundchristmas.com/fm30bvedm

Ken, do you know if both transmitters where set to the same output power level? I doubt either unit provides a setting in milliwatts. I noticed the EDM is capable of 100mW and the Ramsey tops out at 25mW. If they were both set to the maximum output, the results of the comparison probably wouldn't concern me too much (assuming I planned on operating at a power level < 25mW).

[ryanblazer]

Steven wrote:

wallleyes wrote:

How long of a message can you send out on the rds?

Most RDS-capable FM receivers will show the "PS" (programme service) field from the RDS stream.

Some FM receivers, such as ones that integrate with the MFD (Multi-Function Display) in modern automobiles, will also display the RT (radio text) field.

The PS field is limited to 8 characters. To get around this limitation, the EDM, and most other RDS encoders, will implement "dynamic PS", which cycles a different 8 characters every couple of seconds. Even commercial FM stations do this.

The RT field is capable of up to 64 characters.

You also set the PTY (program type) field to your choice of 8 (soft rock), 12 (soft), 14 (jazz), 15 (classical), 19 (religious music), or something else. Unfortunately, there is no value that means "Christmas music" or "display music".

Can you use the mini director with MP3 player to do the RDS or does it have to be the PC?

[Surfing4Dough]

ryanblazer wrote:

Steven wrote:

wallleyes wrote:

How long of a message can you send out on the rds?

Most RDS-capable FM receivers will show the "PS" (programme service) field from the RDS stream.

Some FM receivers, such as ones that integrate with the MFD (Multi-Function Display) in modern automobiles, will also display the RT (radio text) field.

The PS field is limited to 8 characters. To get around this limitation, the EDM, and most other RDS encoders, will implement "dynamic PS", which cycles a different 8 characters every couple of seconds. Even commercial FM stations do this.

The RT field is capable of up to 64 characters.

You also set the PTY (program type) field to your choice of 8 (soft rock), 12 (soft), 14 (jazz), 15 (classical), 19 (religious music), or something else. Unfortunately, there is no value that means "Christmas music" or "display music".

Can you use the mini director with MP3 player to do the RDS or does it have to be the PC?

If you want to use a program with LOR to output the song title to RDS each time it plays you will need to use a computer. However I use a mini-director, and I just have my transmitter repetitively scroll a message ("Merry Christmas! Christmas On Yorkdale -- KNB 95.5FM" or something similar, limited to a set number of characters). Such a message is saved within the transmitter. Meets my needs.

[james morris]

i use a orion 5000 i have used it for the last 6 month i use it every day as a personal radio station it comes with a antain also called a black box i love it great sound

[ryanblazer]

Surfing4Dough wrote:

ryanblazer wrote:

Steven wrote:

wallleyes wrote:

How long of a message can you send out on the rds?

Most RDS-capable FM receivers will show the "PS" (programme service) field from the RDS stream.

Some FM receivers, such as ones that integrate with the MFD (Multi-Function Display) in modern automobiles, will also display the RT (radio text) field.

The PS field is limited to 8 characters. To get around this limitation, the EDM, and most other RDS encoders, will implement "dynamic PS", which cycles a different 8 characters every couple of seconds. Even commercial FM stations do this.

The RT field is capable of up to 64 characters.

You also set the PTY (program type) field to your choice of 8 (soft rock), 12 (soft), 14 (jazz), 15 (classical), 19 (religious music), or something else. Unfortunately, there is no value that means "Christmas music" or "display music".

Can you use the mini director with MP3 player to do the RDS or does it have to be the PC?

If you want to use a program with LOR to output the song title to RDS each time it plays you will need to use a computer. However I use a mini-director, and I just have my transmitter repetitively scroll a message ("Merry Christmas! Christmas On Yorkdale -- KNB 95.5FM" or something similar, limited to a set number of characters). Such a message is saved within the transmitter. Meets my needs.

I'd rather keep my MP3 Minidirector to run the show since I programmed on my Macbook Pro (with Boot Camp & Win 7) & need it daily at work.

Not worth the extra expense of the RDS since I just ordered the EDM-TX-LCD-EP yesterday.

I appreciate all the feed back.

Per Flower Mound Christmas's suggestion in comparing the Ramsey FM30B & EDM LCD, "Maybe add a BEHRINGER – ULTRAMIZER PRO DSP1424P Sound Processor" which is discontinued. I ordered a Behringer SU9920 Sonic Ultramizer (replaces the DSP1424P) to insert into the chain before the EDM tranmitter. That should be here on Monday so I can begin experimenting with it. Once I get the EDM, which sounds like I will have in several weeks, I will post my results with & without the Behringer SU9920 Sonic Ultramizer.

[JBullard]

ryanblazer wrote:

I'd rather keep my MP3 Minidirector to run the show since I programmed on my Macbook Pro (with Boot Camp & Win 7) & need it daily at work.

Not worth the extra expense of the RDS since I just ordered the EDM-TX-LCD-EP yesterday.

I appreciate all the feed back.

Per Flower Mound Christmas's suggestion in comparing the Ramsey FM30B & EDM LCD, "Maybe add a BEHRINGER – ULTRAMIZER PRO DSP1424P Sound Processor" which is discontinued. I ordered a Behringer SU9920 Sonic Ultramizer (replaces the DSP1424P) to insert into the chain before the EDM tranmitter. That should be here on Monday so I can begin experimenting with it. Once I get the EDM, which sounds like I will have in several weeks, I will post my results with & without the Behringer SU9920 Sonic Ultramizer.

Just a caution when using sound processors with the EDM. This exchange is from the EDM users forum. A question by Mike and response from the EDM engineers:

___________________________________________________________________

I think I have this problem. I'm trying to transmit a signal from my pc (iTunes) through a mixer (behringer xenyx802) then through a compressor (behringer ultramizer pro 1424p) and I get LOTS of static/interference/distortion. Is it possible that I'm overdriving the transmitter? How can I tell how low the signal should be? I know this is a great transmitter but honestly it sounds terrible now and I'm sure that's because I'm a rookie at this... any help is greatly appreciated!

Thanks,
Mike


--- In edmdesign@yahoogroups.com, "edmtx100" wrote:
>
> Often people end up driving too high level audio into the EDM units. This causes terrible distortion on the receive side making users to think that they received a faulty unit.
>
> Please remember that the EDM units require consumer level -10dBv line-level audio. The output from a MP3 player or PC sound card may be much too high for the EDM.
>
> Simple rule of thumb: If your audio source is strong enough to power a set of headphones or earphones, the chances are very good that you will end up with distortion on the receiver side.
>
> The simplest solution is to add a inline volume control to bring the range low enough for the EDM units to handle.
>
> http://www.dealextreme.com/p/3-5mm-to-rca-stereo-audio-cable-with-volume-controller-2650
>
> These are very cheap and comes with free shipping.
>
> EDM Team
>

[crackchecker]

> Simple rule of thumb: If your audio source is strong enough to power a set of headphones or earphones, the chances are very good that you will end up with distortion on the receiver side.
>




I think you'll find this with any transmitter you use..

[Greg Young]

While the test was a nice attempt to compare the 2, the Ramsey had either a ground loop issue/bad power supply filter cap/cap problem internal to the radio. I would suspect ground loop first, supply problem second.

That alone would alter the audio results considerably. Also the fact that the player's audio could not drive the Ramsey enough was surprising.

The frequency selection (location in the FM band) should not have in any way affected the audio being broadcast in either unit.

I have never had a Ramsey 30B, but I have both a 100B, and the EDM LCD unit (with RDS.. the 100B I put in, the EDM came with it).

Both are exceptionally clean, and when properly setup you would be hard pressed to tell which one was which. The only slight issue was the channel separation on the EDM was less than the Ramsey. The Ramsey had an exceptional higher end range (treble), the EDM a equally exceptional lower end range (bass), which is why I said in previous posts the Ramsey sounds more like commercial GE rigs, the EDM like Motorola.

Greg

[rwertz]

Thanks Greg.

[Gregg Hess]

I've been using the Ramsey FM25B for five years now with no problems. I use the antenna from Hobbytron with it. http://www.hobbytron.com/Tru-Match-FM-Broadcast-Antenna-Kit.html

More power than I need but I've had a number of good comments on it. I have a clear station to one side but only one side. I keep checking to see if I interfere with the station close to me and so far no problems.

I broadcast a message stating I will change my station if I interfere with any regular programming but no one has ever contacted me.

This is more power than I probably but my show covers 4 houses now.

Now I am looking for RDS. It looks like EDM is the way to go.

Will I be able to use my external antenna on the EDM unit?

When I started with LOR many years ago I use the serial port connection. Since the EDM RDS unit needs the serial port I take it I will have to go to a USB connection for LOR. Is this correct? I have a USB485B converter (LOR) I use for testing CCR from my laptop. Will this work?

[Greg Young]

Gregg Hess wrote:

Will I be able to use my external antenna on the EDM unit?

Yes!

When I started with LOR many years ago I use the serial port connection. Since the EDM RDS unit needs the serial port I take it I will have to go to a USB connection for LOR. Is this correct? I have a USB485B converter (LOR) I use for testing CCR from my laptop. Will this work?

I bought a plug in PCI card that gives you 2 serial and one parallel ports. One serial is used for RDS, the second for X-10, and the parallel is not being used. LOR is run via a 485B plugged into a USB port.

Greg

[Gregg Hess]

Thanks Greg

[k6ccc]

I have read this entire thread and see lots of comparison between the EDM and Ramsey transmitters. A little surprised that no one mentions the transmitter that LOR sells. Just wondering what anyone knows about it?

[Guest guest]

k6ccc wrote:

I have read this entire thread and see lots of comparison between the EDM and Ramsey transmitters. A little surprised that no one mentions the transmitter that LOR sells. Just wondering what anyone knows about it?

Then you've missed a LOT of posts COMPLAINING about the range and output of the beast. Most here will probably classify it under one word, it's a 4 letter word, starts with J and ends in K!

Most that have bought it, have returned it due to unsatisfactory results.

Although there are a couple who have had success with it, or so they tell us. But the majority will tell you to get an EDM and stay away from the Whole House Transmitter.

Plan on buying an EDM when I can, and then will relegate my Mobile Black Box Eclipse-4000 for "mobile" use when I'm out chasing trains to photograph and video. That way I can leave the scanner in my vehicle and carry an ear mounted FM radio to hear the scanner trackside, instead of having the heavy, bulky scanner and long antenna straddling my side from my belt, along with my camera equipment I carry!

[rwertz]

One small disclaimer, keep in mind that the "junk" transmitters are probably operating near the maximum legal signal strength. Most of the better transmitters discussed on the forums are capable of (and typically operated at) signal levels that are much greater than the legal limits defined by the FCC.

Having said that, I don't think any one here has ever been visited by the FCC (for their show transmitter). I'm just pointing out that a lot of people run at an illegal signal level. When you do that you need to try to avoid the temptation to transmit beyond your viewing audience and be very responsive if your neighbor says he can't listen to his favorite station anymore.

Just sayin'

[Gregg Hess]

Well stated Reg. Legal / Illegal. When I started I was using channel 90.1. This channel was not being used by anyone in my area. Then we had a new radio station startup on 90.1. This was another illegal broadcast. The FCC worked with this station for a couple of years before they finally put him on a legal station which ended up being AM. The new station was about 10 miles away from me and it was not a very good signal at my house but it interfered with my broadcast. I moved to 90.3 but his signal still interfered with mine so I added an antenna.

I dont have the tools or the knowledge to figure out if I am within the FCC limits but I have a pretty good idea.

I believe the important thing here is to make sure we dont interfere with anyone and if we do we need to fix it. Our shows would be pretty stupid if people cant hear the music.

Then we take video of our shows and put it on YOUTUBE breaking more laws.

I believe our intensions are good but we all break a few rules.

Has anyone been visited by the FCC for their show?

[Max-Paul]

K6CCC,
When you dont see a lot of talk about something. Then one can come to a simple conclusion. It aint worth talking about (see junk). Although I will tell you this. It is for sure a legal transmitter by FCC rules and regs for an unlicensed transmitter. But keep this in mind. I am guessing that 90% of people who try to use it. Cant even get a static free signal to the road in front of their house. Now I dont know if your old school ham or one of the no-coders. But an old school ham or someone who works on transmitters might be able to get it to work. I am old school myself (KF0OX) and worked on transmitters for uncle Sam. Yet I dont want to mess with it and bought something else.
And just a reminder to all. Dont do your test during the daylight, wait till night time when distant transmitters come rolling in. What works during the day might be over powered by a distant transmitter.