We have a yearly even that is so far out in the boonies, there are literally NO FM radio stations that can be pulled in on a car radio.
A couple years back, I got the bright idea of using a low power FM transmitter on a laptop to play music and announcements.
We have a nice high area to use and a decent antenna.
My problem is, there are so many transmitters and so much BS out there, I do not know what to believe.
I'm trying to buy a transmitter to use for three to four weeks per year during this event that will be decently clean. (I have heard a few at Burning Man that were "fuzzy" as hell.)
Is there anything out there for a couple hundred dollars that will reliably put out at least 10 watts of power that I can hook into a simple mixer?
I have a nice solar bank, so the power supply is of no interest. I have 600AH of the cleanest 12 volts in the world.
Do you have any advice for me? Even when I look on YouTube, the cheap transmitter the guy tests and suggests is no longer available.
(Of course, this is all "hypothetical" and in no way would I ever REALLY violate FCC law. Since we know how fair they are with allowing LPFM applications through and all...I am a good citizen...)
Post by HighMountainRadio on Mar 12, 2018 13:36:55 GMT -6
Greetings mrgumby !
You can purchase one of the Generic ST-15B FM Broadcast Transmitters for sale on EBay for less than $60.00 that will do the job very well ! I have been using one for quite some time now and although it is advertised as 5 or 15 watts, in reality from my experience, you will get 10 watts output on HIGH power and about 3 watts on LOW power but if 10 watts will do the job for your needs then I would highly recommend one of these units. I have two of them and they work very well and sound very good ! Prior to purchase request that it be configured for 75us pre-emphasis, the USA standard. Any reputable seller on Ebay will happily accommodate you. Most of them are sold by Chinese sellers so if you have about 3 weeks to wait for one, they are a real bargain in my humble opinion and mine is on the air 24/7 without a single problem. I use a laptop as my program source and currently use a homemade ground plane antenna with outstanding results ! These exact same transmitters are sold for prices all over the map cost wise but one can easily be had for less than $60.00 and free shipping. You can view a picture of it at the FMUser.org website. They have their 'ST-15B' transmitter priced entirely too high but it is a good reference at least. If I can further assist you please message me here on this forum, I'd be happy to help ! Or you can view the ST-15B on this forum here: darkliferadio.proboards.com/thread/927/broadcast-transmitter-specs-generic-model
Best Regards, Spooky...
"Knowledge Is Always Made More Valuable By Sharing It With Others !" Always Remember To Be Kind ! True Greatness Often Has Very Humble Beginnings ! Help A Kid Out Today ! *** High Mountain Radio *** "Broadcasting From Somewhere High In The Remote Appalachian Mountains"
Post by HighMountainRadio on Mar 12, 2018 14:01:40 GMT -6
Mr. G,
One thing that I forgot to mention that is of the utmost importance in any FM transmitter installation is be sure to make and incorporate an RF Choke, fabricated from simply winding 6 turns of coaxial cable into a 6 inch circle, placing one turn adjacent to the next. You may incorporate the RF Choke into the end of your coaxial cable feedline simply winding the 6 turns into the end of your coaxial cable feedline or you may fabricate it as a standalone item, inserted into your feedline AT THE ANTENNA FEEDPOINT ! This choke will prevent your feedline from radiating RF energy along the length of your feedline thus causing an abnormally high VSWR (Reflected Power) and can easily cause harm to your transmitter output MOSFET or transistor. The idea here is to get ALL of your transmit power to the antenna and not waste it along the feedline. If the transmitter 'sees' high reflected power it will cause a very substantial drop off in RF output power and give the illusion that the transmitter is not working properly and make it appear that it is delivering far less RF output power than the 10 watts it is fully capable of delivering the full 10 watts all day and night long, every day ! See information on how to construct the RF Choke here: darkliferadio.proboards.com/thread/913/fabricate-effective-broadcast-antenna-balun
Good Luck ! Spooky...
"Knowledge Is Always Made More Valuable By Sharing It With Others !" Always Remember To Be Kind ! True Greatness Often Has Very Humble Beginnings ! Help A Kid Out Today ! *** High Mountain Radio *** "Broadcasting From Somewhere High In The Remote Appalachian Mountains"
Post by HighMountainRadio on Mar 13, 2018 3:01:34 GMT -6
Good Morning Mr. G !
I also wanted to mention the fact that numerous FM Broadcast transmitters that are marketed and sold on EBay under various name brands such as NioRFNio, Signstek, FMUser, CZE, HLLY and CZH are all based on the EXACT same motherboard and simply re-packaged to appear more eye-appealing to the potential buyer. The Tugicom TX-190 FM Broadcast Transmitter is an excellent quality FM Broadcast transmitter, more pricey and does not appear to include any type of enclosure for the motherboard. I have not used one yet or even saw one in person but I have read good reviews on it and comments from satisfied owners of them. I would probably have purchased one by now but I don't like the fact that I will have to do the work of mounting it in some type of enclosure for the price they want for it ! The one particular feature about this Tugicom transmitter is that is has a user selectable setting, allowing the user to select either 50us pre-emphasis (Asian and European Standard) or 75us pre-emphasis (USA Standard). Quite honestly, I have used 50us pre-emphasis FM transmitters and despite the fact that they are not set to the USA standard of 75us they still sound very good by simply doing some EQ adjustments on the audio before sending the audio to the transmitter. I'm sure others may argue that the Chinese transmitters are a piece of junk but from my experience I have not encountered a single issue with two Generic ST-15B's that I run here 24/7, both run in the high power mode, one runs at 10 watts output and the other runs at about 4-5 watts output driving a homebrew 80 watt high power amplifier, utilizing the MACOM MRF173 MOSFET. They run quite cool actually with only the small chassis fan that is part of the transmitter. If you plan to run one of these 24/7 or for any extended periods of operation I strongly suggest that you look around for a ball bearing quality fan of the same size used in the transmitter and replace the original with the ball-bearing fan as they will run FAR longer than a cheap sleeve bearing fan. As an alternative, you may simply use a muffin fan of some type as used in computer desktop cases and mount it on top of the transmitter using double-sided sticky tape or velcro and that will supplement the cooling derived from it's own internal fan. If you review the several FM Broadcast Transmitter reviews I have posted on this forum under "Radio Electronics and Tech" you can view each model FM broadcast transmitter specifications and any comments I may have added. It should likewise be noted that since numerous transmitters marketed under the various names are based on the Generic ST-15B model transmitter, the ones that are only good for 1/2 watt, 1 watt, 5 watts and 7 watts maximum can easily be modified to deliver a full 15 watts of output in high power setting simply by replacing the existing RF output MOSFET with a readily available, inexpensive, Mitsubishi P/N: RD15HVF1 MOSFET, it is exactly the same fit, form and function as the original one installed in many of these transmitters. I have done a great amount of research on the various makes and models and upload the transmitter data to this forum, along with pictures and links to each transmitter's manufacturer website for convenience in bringing all of the available information together all in one place to make it easier for veteran's and beginners alike to look over the different transmitters available and decide which one fits their respective needs best. I plan to edit each posting and add the average typical cost of each transmitter to assist others in choosing the best transmitter for their budget. Again, I would be more than pleased to assist you in choosing a good quality transmitter for your needs and assist you with any and all questions you may have ! There are quite a few, very well educated individuals here, members of this forum who are always ready and willing to help others ! Hope to hear back from you here soon !
73... Spooky @ 'High Mountain Radio', 'Broadcasting From Somewhere High In The Remote Appalachian Mountains' --- 'For The Love Of Music'
Attachments:
"Knowledge Is Always Made More Valuable By Sharing It With Others !" Always Remember To Be Kind ! True Greatness Often Has Very Humble Beginnings ! Help A Kid Out Today ! *** High Mountain Radio *** "Broadcasting From Somewhere High In The Remote Appalachian Mountains"
Thanks for the info! I kept coming back to this spot...looking at the cached stuff, thinking you had not replied to me. (What an idiot I am.) I am going to read this and digest. Sorry my idiocy made it take this long for a reply.
Post by HighMountainRadio on Mar 31, 2018 17:10:47 GMT -6
Greetings Mr. Gumby !
No worries, I too, miss stuff from time to time here.. lol ! Happens to the best of us 'idiots' !
I just installed my 3 element folded dipole yagi today and having excellent results with 70 watts output ! A very good deal for a $14.95 antenna !
73... Spooky...
Attachments:
"Knowledge Is Always Made More Valuable By Sharing It With Others !" Always Remember To Be Kind ! True Greatness Often Has Very Humble Beginnings ! Help A Kid Out Today ! *** High Mountain Radio *** "Broadcasting From Somewhere High In The Remote Appalachian Mountains"
