the past several days my carrier current transmitter is kind of starting to wear out on me, so I’ve been looking up Ramsey FM transmitters so i can hopefully retire my 2.5 year old carrier current transmitter i got for just only 20 dollars almost 3 years ago. any suggestions on a new Ramsey transmitter or a different brand? i would like to know… many thanks
Ramsey FM25B
I can strongly suggest the Ramsey FM25B and have built two of them. Both of them walked away with people and have never come back, so I need to get a 3rd one.
Here are some plus points about it:
It has an RF Output F-tpe-connector which is needed for connecting to antennas or CC connectors.
It has an output power control that has a decent range for meeting the needs of your situation.
The stereo can be disabled with a jumper.
It sounds absolutely fine.
Right now I am running on a C.Crane and a Wholehouse 2.0 and several Scosche FM transmitters, but they are not conducive to carrier current.
Carrier Current the FM25B
i didn’t know you can do that besides i don’t think i will carrier current the fm25b anyway so thanks for your opinion
A Clearer Vision
It might be helpful if you gave a bit more specifics on your current CC FM TX so folks can make better recommendations.
Just about any TX will do that can deliver a couple watts or more. Coupling requires a very well shielded coupling circuit that does all the nifty things that the AM counterpart does, isolate, transfer and prevent. Isolate the whole works from the power, transfer the most energy onto the lines, and prevent ground loop from returning into the final of the TX which prevents the hum even on the FM frequencies.
Ain’t noting more annoying than having 60 cycle energy modulating the final/s of an FM TX, especially one operating in stereo!
The Ramsey units are ok but lack the power level right out of the box. A little boost would be needed. Their 1 watt amp kit would serve the purpose, but if you go this route make sure you put a low pass filter on the output before the coupling point! Put a low pass filter regardless of which TX you replace with even if it has a filter built in.
Good hunting!
RFB
CC FM Range
I am wondering what kind of coverage FM has on Carrier Current? I have considered putting my Ramsey FM 25 b on carrier current to get away from the trouble of running the transmitter through an antenna. Right now it does pretty well with the indoor antenna but as you know i live in a mobile home park and all the metal around here really messes with the signal. If i could cover a block or more then that would satisfy me. 1 Mile would be awesome.
you can’t do efficient
you can’t do efficient carrier current above 3 mhz. VHF FM worked over radiating coax and will not work for carrier current
Bummed
Well i am bummed. You can imagine the terrible reception i get from my station as i drive around the park and all that metal around the park reflects or blocks the signal.
Even a portable radio has trouble and there are places in the park and the apartment complex that my signal just will not reach. My problem is the height restriction here. Three feet above the mobile home just won’t cut it here.
I guess CC AM is really my only option here since digging into the yard is a no-no which throws out the option of a ground mounted 3 meter antenna with ground elements.
One of these days i will do a drive around to show how my indoor fm antenna performs. (via video)
Back to the drawing board.
CC FM
CC FM can be done. Problem is that it takes some power and very unique coupling techniques.
It is no different from a leaky coax. Same signal limitations would apply. The biggest problem is meeting that requirement since the FM signal is absorbed so heavily at the injection point, the power requirement just to shove it down the line would be considerable and no doubt take the field strength far beyond the limit at 3 meters from the source.
Last time I played with CC FM was for a closed loop feed that served a camping ground. I simply ran a wire from one light pole to another and back to the source forming a wire loop. Then connected that right into the BNC connector of the TX running at 20mW. Covered the whole camp grounds.
Don’t worry, this was back in the day when the field strength limits on the FM band were more than 250uV @ 3m and in another country to boot! :p
Worked so well that they kept the system for a number of years until the camp grounds were sold off and industry moved in and chopped down all the trees.
My advice for your FM station would be to throw up a 1/4 wavelength dipole on a short 3 foot stick mounted to the side of the mobile home near the roof line. Surely that would be ok with the park…wouldn’t it? I mean what if you wanted to put up a side mounted flag stick that sticks up above the roof line a few feet? It wouldn’t exactly be a huge tower and array of guy wires and such.
RFB
20 ft conduit
RFB,
I actually have a 20 foot piece of conduit mounted to the small deck at the front door.
Saying it is a small deck when really it’s no more than a small landing to step out of the home and 4 steps to walk out to the sidewalk.
At any rate, the conduit is sitting on the ground with a pvc end cap at the bottom and the top, which is why it is under the the three foot limit.
I can actually raise it by mounting the conduit on the corner of the small deck which would raise it at least 4 feet above ground and put the top of the conduit at least 3 1/2 feet above the house. We have been here long enough (at least 4 yrs) that i think i probably could get by with it being slightly over the 3 foot limit.
My concern here is even with the three foot or so above the house what about the section still shielded slightly by the house? As far as I know it is aluminum siding. Our ultimate goal would be to cover as much territory without going over the limits. But there will still be that lower half of the dipole that would be even with the house.
I have used a wire dipole, that is i made it out of two pieces of 12 gauge wire cut to my frequency soldered to a balun 300 ohm to 75 ohm the type you would have inline with a t.v. antenna. Somehow this worked!
Though it was at 4 feet above ground it did manage to cover about 1/4 mile in most directions. The North is hard to over come because it is on higher ground where as this park is partially in a valley. The elevation varies here in different areas.
I actually bought the conduit with intentions of building a 3 meter antenna for AM, but the ground thing keeps me from doing that.
So your probably right though RF, i probably should just do the dipole thing and be done with it.
Flag Waving
RFB mentioned the flag pole, i actually have a flag pole that is 5 foot long that mounts on a deck or the side of your house.
It is aluminum and guess what?
It does radiate a signal, i tried this with just a piece of 75 ohm cable running straight to the pole with no balun and a 5 foot piece of wire hanging down from the shield side of the cable.
It worked pretty well considering it is not completely vertical and well..it’s
a flag pole. 🙂
Still Wondering
Message to ABMedia1…
I still wonder what kind of $20 FM carrier current transmitter you have. And what kind of coupler are you using to make it happen?
You say the transmitter is wearing out. What’s wrong with it?
you’d be surprised carl
you’d be surprised Carl, im using a $20 dollar mp3/iPod car transmitter from tj maxx, and i use a car to ac wall adapter from radio shack and the power and range depends on the adapter you get, and of course i modified it and checked it for harmonics, i did this almost 3 years ago and went very well for us. it just starting to wear out on me, the buttons aren’t all that good anymore some of the led’s don’t work on it… stuff like that, and it could give out in a few months or so if i keep using it.
Maybe a Scosche
A transmitter very similar to your iPod car transmitter is the Scosche FMT4R Universal FM Transmitter. I love it so much I bought a batch of them.
They were at Walmart for $10.00, but may have been discontinued, I’m not sure.
If you can find one it might take over where the iPod leaves off.
Hope the best.
TX Replacements
“im using a $20 dollar mp3/iPod car transmitter from tj maxx”
Interesting. How is this coupling to the power grid?
At that low of power level, any of the current iPod types with the short wire antenna would do.
Or if your into kit building, try one of these from QKits:
http://store.qkits.com/category.cfm/RF
This unit: http://store.qkits.com/moreinfo.cfm/QK172 is their best. It uses a crystal and has an on-board low pass filter and wide band input for excellent mono or stereo operation.
The transmitter Carl suggested is still available from the following vendor:
http://www.sonicelectronix.com/item_22221_Scosche-FMT4R.html
RFB
Knowledge Base
RFB has made me aware of the equipment opportunities that come and go on ebay, and I am watching for carrier current transmitter and coupler.
To have a clear idea of what prices are good, I received a quote from Radio Systems for their equipment, which I think is the only source for new carrier current gear.
TR-6000 AM Transmitter, entire AM band, 0-10Watts … $2,495.00
CP-15 Coupler … $495.00
When these items show up on ebay we will be able to spot good pricing.
Nightime Authority
I think that licensed AM stations that are allowed to broadcast at night are said to have “nighttime authority.” Very many stations are required to drastically cut power at night, some as low as 3-Watts! Others have 5-Watts, 22-Watts and other low numbers.
But where do they get those low power transmitters?
If someone makes those, they could be used for Part 15 Carrier Current.
Nightime Power
Yeah I always found some of these nighttime power levels a bit contradicting, considering the lowest power level the FCC authorizes for licensed broadcasting is 250 watts.
So why all these 3 and 5 and 20 watt authorizations, yet no light on any horizon..much less the light, for LPAM licensing of 20 watts and less???
Makes no sense, and is only blocking economic growth in my opinion.
RFB
Re:TX Replacements
i have a car to ac wall adapter from radio shack that acts as a coupler and sends the transmission through through my house’s ac wiring to the power grid. pretty interesting? i say its awesome.
and to all part15.us members,
do you know where i can find a cheap coupler for a Ramsey transmitter, (i don’t have the Ramsey TX yet but im still waiting for a good deal on eBay.) but if anybody knows where i can get it? i will greatly appreciate it!
Slanted Vertical
The flag post/stick is an excellent alternative and incredibly decorative too!
About the tiny part being shielded by the aluminum siding on the mobile home, that should not cause any real serious problem for coverage within the mobile home park.
But you could build a C-POL element so that it is not extending too far down into that blocking zone of the mobile home’s wall. But even with a simple dipole in vertical fashion, and the coverage area intended to be hit, the small amount of the lower element of the dipole going past the roof line really wont make that much of a difference within the park itself.
I have read where some would take one of those small iPod type transmitters with the attached wire for an antenna, mount that onto a piece of plexiglass, and connect an equal length of wire to the negative battery terminal and hoist the thing up into the air and get a good 3 or more blocks coverage. I have even heard of such setups without the extra wire on the negative terminal of the battery and they still get excellent coverage compared to just placing it up on a shelf or in the window.
It sounds like you may have a few alternatives to work with and you already tried the flag post antenna. Never hurts to experiment and find the right setup for your location that works the best!
RFB
Rocking the red white and blue
RFB wrote
“I have read where some would take one of those small iPod type transmitters with the attached wire for an antenna, mount that onto a piece of plexiglass, and connect an equal length of wire to the negative battery terminal and hoist the thing up into the air and get a good 3 or more blocks coverage.”
Actually the Scosche FMT -4 whose post you can find here :http://part15.us/node/2006
can actually cover a good chunk of land for no more than what it is.
With a 6 foot headphone extension cable i was able to cover some of the park but not all of it. The coverage was a small circle within 150 feet with a very directional coverage up and down the main road here in front of my house. As soon as you enter the park the radio comes to life with a fairly decent signal from the FMT-4. In fact that transmitter is now used occasionally in my mini-van even though the car stereo has an aux or line in jack i just like the idea of sharing my music with the car behind me in traffic lol.
To get back to the real subject at hand, Carrier Current.
ABMedia1 wrote:
“the past several days my carrier current transmitter is kind of starting to wear out on me,”
I can’t imagine ever getting tired of messing with this radio stuff, well maybe if the gear was giving me troubles and i had to fix it all the time then yes i probably would get tired of that. If i was able to afford a new carrier current system it would be my first and only choice for broadcasting on AM. Seriously beats the heck out of the 3 meter stick deal in regards to the limited range, though it is true that “your mileage may vary” it just seems like the tried and true way to get a usable signal around town without breaking any laws. And i don’t want anyone feeling like that last statement was attacking them or their stations because that’s not what i was going for, believe me if i had the space to do a 3 meter antenna with ground elements i would have already built it by now.
Scosche of a Transmitter
When this site first mentioned the Scosche I went straight to Walmart and there it was for $10.00. I was so impressed by it, and having heard that this model was being discontinued, I bought out the entire inventory, which I think is four or five.
The only complaint is they will not do 101.9, my main frequency, but they give me 87.7 for sending vinyl records across the house for digitizing and 107.1 which is where I edit programs with Audacity.
The Scosche is stronger than either the C.Crane or Wholehouse 2.0.
Digitizing
You actually used an RF path to digitize your vinyl’s???
Why not a direct line in from a stereo record output into a computer to digitize those vinyls? Unless you wanted to add more noise floor than what is already inherent on the vinyl and stylus cartridge.
Curious.
RFB
The Quick Fix
The turntable is located in what was the audio booth for our audio-video business. The heart of the setup was an Amiga Computer with a Sunrize 16-bit Soundcard for digitizing and editing. But one day the Amiga stopped working. I do not want to take it all apart and try to fix it.
I didn’t want to move the turntable because my kdx workstation is as full of stuff as I want it to be, and I won’t be digitizing very many records.
I wanted to digitize a record for The Low Power Hour. It was too far to run an unbalanced line and I didn’t want to bother all the conversions of balanced to unbalanced plus a couple wires that would either be on the floor or holes drilled to loop them through the basement. No way.
So I stuck the Scosche on it and receive it on the C.Crane Plus, the audio goes into the mixer and it sounds real good for streaming.
most trailers have an
most trailers have an aluminum roof. toss a mag mount 1/4 wave dead center in the middle of the night and hide the coax as best you can. my guess is it will go un noticed. if it’s shingles and tar then you can easily lay down some ground radials but a 1/4 wave groundplane at fm should not be noticeable
Refurbishing?
you know what how about if i can refurbishing the cc tx? do you think that will help?