Thread: Ramsey 100b How-to

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I am starting a how-to on how to solder the Ramsey 100b transmitter if anyone wants to use it in their haunt. I bought it from Frighteners Entertainment. It will depend on how well it is recieved among the members if I continue. But I noticed I am not the best at how-to video so be prepared for a lot of Ummms, and breathing heavy in the videos. I will have to remind myself not to do that.

This is the first video on what software I am using to controll all the action for the Transmitter. Remember I am a dork in trainning. You can laugh.

YouTube- FM Transmitter.mpg


Next is the soldering of the Display board. There are two parts.

YouTube- 100bpart1.mpg

This is part 2
YouTube- 100bpart2.mpg

I think these are very helpful for those making this.

Hey, don't feel bad. I keep saying "Okay" everytime I start talking. Grrr. You don't hear it so much 'cause I've learned how to edit it out On the Transworld videos I keep laughing in the background. It would be fine if it was a nice laugh bit it's a dorky one

Thanks Terra. I am trying to be more talkative, but lets face it, I suck. LOL

I finally got the Transmitter done. Terra, in the 2nd video you can see my boogedy half torso coming into shape. I was working on the transmitter and latexing at the same time. Thanks everyone for putting up with me.

YouTube- 100bpart3.mpg

YouTube- 100bpart4.mpg

Love these videos. But I do have a question. What's the FCC rules on these transmitters? What does a home haunter have to do to make sure that this won't interfere with someone's licensed frequency causing them to be visited by the FCC or worse yet, being fined for interfering with someone else's transmission?

Originally Posted by relics

Love these videos. But I do have a question. What's the FCC rules on these transmitters? What does a home haunter have to do to make sure that this won't interfere with someone's licensed frequency causing them to be visited by the FCC or worse yet, being fined for interfering with someone else's transmission?

I am going to post the rules. But basically if you transmit on a freq and someone complains, you have to turn it off or change the freq of your transmitter. (It is easier to change the freq) But if you find a freq that is blank, you should be good.

In the United States, this is how the FCC regards your transmitter kit:

Licensed FM broadcast stations and their listeners have ALL the rights! Your use of a device such as the FM-25A kit MAY have some limited privileges in locally-unused band space, but your non-licensed use of the FM-25A has absolutely NO rights at all over the rights of licensed broadcast operators and the rights of their listeners to interference-free reception. If your operation of a device such as the FM-25A interferes with ANYBODY'S use or enjoyment of an FCC licensed transmission of any kind, your only choice is to IMMEDIATELY terminate or change the operation of your low-power transmitting device so as to cause no more interference. That's it! No discussion, no exceptions - if you persist in causing interference to other folks, you’re asking for trouble!

Unlicensed operation of small transmitting devices is discussed in "Part 15" of the FCC Rules. These Rules are published in 100 "Parts," covering everything imaginable concerning the topic of "Telecommunications." It is a fascinating read and well worth the modest cost. The six books containing the FCC Rules are section 47 of the complete Code of Federal Regulations, which you are likely to find in the Reference section of your Public Library. If you have questions about the legal operation of your FM-25A or any other kit or home-built device which emits RF energy, it is your responsibility to study the FCC regulations. It is best if YOU read (and consult with a lawyer if you are in doubt) the rules and do not bother the understaffed and busy FCC employees with questions that are clearly answered in the rules.

Here are the primary "dos and don'ts" picked from the current FCC Rules, as of May, 1990. This is only a brief look at the rules and should not be construed to be a complete legal interpretation! It is up to you to operate within the proper FCC rules and Ramsey Electronics, Inc. cannot be held responsible for any violation thereof.


1. In the past, no "two-way communications" use of the 88-108 MHz FM broadcast band was permitted. This prohibition does not appear in the current edition of Part 15. Previous editions of Part 15 discussed "wireless microphones" (such as Ramsey FM-1, FM-4, etc.), while the June 23, 1989, revision eliminates this discussion in favor of more detail regarding computer and TV peripherals and other modern electronic conveniences. However, it is not immediately clear that the 1989 revision of the FCC Rules Part 15 necessarily "cancels" previous regulations. Laws and rules tend to remain in force unless they are specifically repealed. Also, FCC Rule 15.37 discusses "Transitional Provisions for Compliance with the Rules," and states in item (c): "There are no restrictions on the operation or marketing of equipment complying with the regulations in effect prior to June 23, 1989." It is up to you to read the rules yourself and understand them.

2. It is the sole responsibility of the builder-user of any FM broadcast-band device to research and fully avoid any and all interference to licensed FM broadcast transmission and reception. This discussion will later give you practical advice on how to do a good job of finding a clear frequency, if one is available.

3. For some frequency bands, the FCC sets 100 milliwatts (0.1 watt) as the maximum permitted power output for unlicensed, home-built transmitting devices, and that the combined length of your antenna and feedline (coaxial cable or other) must not exceed 10 feet. The technical standards for 88-108 MHz are very different, primarily concerned with band width and RF field strength.

4. FCC Rules pertaining to field strength do not differ for "stereo" or "monaural" transmissions.

5. Broadcasting on the grounds of a school using the AM broadcast band is specifically permitted and encouraged between 525 and 1705 KHz under Part 15.221. Our AM-1 or AM-25 AM radio broadcast kit could be used for this application.

6. FCC Rule No. 15.239 specifically addresses operation in the 88-108 MHz FM broadcast band for which your FM-25A transmitter kit is designed. However, this Rule does not, by itself, tell you everything you need to know about using a device of this kind. Therefore, we are noting a series of Part 15 regulations which should be observed:
The "bandwidth" of your transmission is limited to 200 KHz, centered on the actual operating frequency. This is a "generous" limitation designed to accommodate cruder FM devices. Properly built and adjusted, the FM-25A kit operates well within this limit. In fact, its signal should sound no "wider" than any other FM station when listening on an ordinary FM radio.

FCC Rule 15.215(a) says: "Unless otherwise stated, there are no restrictions as to the types of operations permitted under these sections." This general provision appears to leave you free to use your FM stereo transmitter in a manner similar to operations of an FM broadcasting station, or to use it for any other non-interfering, practical application.

FCC Rule 15.5: General conditions of operation: "(b) Operation...is subject to the conditions that no harmful interference is caused and that interference must be accepted that may be caused by the operation of an authorized radio station, by another intentional or unintentional radiator, by industrial, scientific and medical equipment, or by an incidental radiator. (c) The operator of a radio frequency device shall be required to cease operating the device upon notification by a Commission representative that the device is causing harmful interference."

The most specific FCC regulation of 88-108 MHz FM Broadcast band unlicensed operation is that the "field strength" of the signal must not exceed 250 microvolts/meter at a distance of 3 meters from the transmitter (FCC rule 15.239). If you have any concern about this emission limit, have your device checked by a technician with accurate measuring equipment. Remember that the "field strength" of a signal is determined as much by the antenna as by the RF output of the transmitter itself.

I think the main thing to remember is that this transmitter only goes about a few blocks. That means the only ones that would complain would be your Neighbors. And you would have to be on their freqs for them to complain.

Ooo, now this is what I've been looking at.

Been debating between an FM transmitter and a wireless speaker setup. The whole FCC thing is a little scary.

I did find this FM locator site that would tell you if there are any clear stations in your area in my searching, though.

http://www.radio-locator.com/

Yes, that is the one I was using. I used 101.5 before but there seems to be a channel on there now. I am now using 101.3fm.

very helpful videos. I have been thinking of getting one and this may be the thing that helps me make my decision!