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Please help - What is the most powerful FM/AM transmitter available? .....

F

false_shuffle

Hey guys, I just registered with this forum hoping to get a good, solid answer to my question. I would seriously appreciate some help here. Feel free to call me at [EDIT] or email me at [EDIT]
if you would prefer instead of posting here. Doesn't matter to me. Thank you! ::

I'm looking for a wireless FM or AM transmitter that will transmit a regular audio signal (audio jack, or ipod, etc.) of a distance of at least 1000 feet with the absolute clearest quality possible. I already understand that these wireless FM transmitters are regulated by law, thus some of the reason for the bad quality on most of them. This is not going to be used in a car, it's for another important purpose. Important points on what i'm lookin for : It doesn't matter if the signal is FM or AM. I also don't care about the size of the unit, type of power supply, or if it's legal or not. I would prefer it be able to transmit on the universally empty bands, but it doesn't matter. My concerns are primarily the distance of at least 1000 feet and the absolute best quality possible. Again, the cost and size of the unit is irrelevant to me. I simply want the unit to be able to transmit a regular audio signal via the headphone jack of a laptop or iPod. Help!



[EDIT-privacy concerns.]
 
Thanks for the replies guys, I appreciate it....

I just placed an order for the Whole House 2.0 .... does this work well? They have a warranty, so I can easily return it.

Seems like there are quite a few options out there. I'm very "OCD" (a perfectionist) and I want to make sure I get the right piece of equipment. How do I know how many "watts" I should go for, or what else I should look for?

Any other specific reccomendations? Why would some work better than others?
 
The Whole House 2.0 doesn't want to publish their effective power output (watts) because it would be tiny as they are sort-of complying with FCC Part 15 regulations. Possibly as low as 0.000001 watts (1 uW) depending on antenna efficiency.

With the included external antenna, efficiency goes up considerably and you might see .1 watts (100 mW) effective power. The more efficient antenna almost certainly is in excess of FCC Part 15.

For anyone interested, I estimated the ERPs very roughly from field strengths published in this review:
http://www.hobbybroadcaster.net/reviews/Whole_House_FM_Transmitter_2_P02.php
 
Sounds like you are looking for a Part 15 station. The Hamilton Rangemaster would be considered top of the line by many for AM and I can attest to the Ramsay FM-100B for FM. I have used the Rangemaster for clients and my FM100B has been on the air for over two years without a hiccup, and sounds great.

These are "legal" transmitters as long as you comply with FCC rules regarding antennas and installation. The stuff you see on Ebay may be more "powerful" but could generate a visit from the FCC. Regarding watts, you are talking milliwatts here. Without knowing more about your purpose this is the best info I can offer.
 
I agree, to be legal you are looking at a 100mw transmitter and that will not get you 1000ft very well, if your just trying to get audio from A-B there would be lots of options. If your trying to "broadcast" under the part 15 rules your distance wants are not realistic.
 
speakerman said:
This is probably one of the most powerful to date however it unfortunately is not for sale. :)

http://hawkins.pair.com/wlw.shtml
Click to expand...


A Harris DX-1000 is at Poro Point, La Union, Philippines and a brother is over near Bangkok. Both have an RF output of 1000 kW. There is a Harris DX-2000 in Qatar, 2000 kW output and I am sure Harris has built more of these in the 1000kW to 2000kW range. I am not privy to where they are, but I have a few guesses.
 
Gee, do you think that would go 1000 feet?
 
Maybe from arc-overs! All joking aside, I bet a plant like that might be more of a fireman's job than RF engineering. I've seen plenty of "burned offerings" from our 50k over the years. I can only imagine how many things get mad and burn up every so often with that kind of juice.
 
OKCRadioGuy said:
Maybe from arc-overs! All joking aside, I bet a plant like that might be more of a fireman's job than RF engineering. I've seen plenty of "burned offerings" from our 50k over the years. I can only imagine how many things get mad and burn up every so often with that kind of juice.
Click to expand...


The DX series have been quite dependable transmitters. A lot to be said for the power block concept.

I think the highest voltage in the transmitter is under 300VDC, if we don't count the high voltage in the AC power input sections and associated switchgear.

Obviously, the RF voltages are higher, but Harris has done a nice job in engineering the components used in these systems, including the combiner system, so very little has gone up in smoke. You can imagine the components in the RF matching networks in the antenna system are also rated for the power levels in use.
 
Besides Part15/LPFM, there are other legitimate uses of low power transmitters.  Drive-in theaters use them now instead of the speakers you hang on your windows.  Realtors use them so you can listen to details of houses for sale as you drive by the house.  I mention this only to add terms to searches for transmitters.

I had a chance to use the Ramsey 100B once while doing PA work at a large car show.  My announcement area was connected to the PA head-end with the Ramsey.  It worked very well.
 
The DX series have been quite dependable transmitters. A lot to be said for the power block concept.

I think the highest voltage in the transmitter is under 300VDC, if we don't count the high voltage in the AC power input sections and associated switchgear.

Obviously, the RF voltages are higher, but Harris has done a nice job in engineering the components used in these systems, including the combiner system, so very little has gone up in smoke. You can imagine the components in the RF matching networks in the antenna system are also rated for the power levels in use.



[/quote]

Hilmer Swanson and his cohorts were genius... the DX concept worked rather well. One time I was being given a tour whic included a DX-500 I think for Vietnam, and Hilmer himself was on a ladder doing some touch-up.
 
Went to 'Transmitter School' in Quincy for a week for the DX back in '88. Had a DX-10 with Serial Number 2. Met Hilmer at that time. Transmitters were and are great.
 
If you just need to get audio from one place to another, try a 2.4 Ghz audio/video extender like this http://www.markertek.com/Digital-Vi...corders/Wireless-Video-Equipment/LF-30S.xhtml. Or stream over Wi-Fi or 3G. A wi-fi signal can go 1000 feet outdoors with no obstructions, and no Internet access is needed.

A 1 watt station should go a mile or two, depending on height. Considering the FCC is lax on pirates running hundreds of watts and making 5 figures a year in tax free advertising revenue, a 1 watt station that doesn't interfere with anyone should be ok. When I was in high school I made my own "pirate station" using a Belkin TuneCast FM transmitter, an amplified antenna, and (unamplified) rabbit ears. I think it was a little over a watt and the signal went 2 miles. I was a high school student "playing radio" and I gave it up when the transmitter broke. I'm sure many broadcast engineers did something similar as kids, and that's how they became interested in it.
 
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