Ramsey's FM30b is the companies top of the line stand alone hobby FM transmitter. The FM30b, like many hobby transmitters; uses the BH1415F chip from Rohm. Unlike the FM25b & FM100b transmitters; the FM30b was designed from the ground up with the newer BH1415F chip.
The FM30b is a do-it-yourself learning kit that you assemble part by part; with the exception of the surface mount parts like the BH1415F chip; which are already soldered in place for you. The FM30b is not recommended for the first time kit builder; it is more for the seasoned kit builder who has the right tools and experience to build such a kit. I highly recommend you have two solder iron tips; one for the IC chips smaller pins and one for the larger components like resistors, capacitors and connectors because FM30b circuit board does not have thermal relief on the pads connecting to the ground plane. I also recommend an antistatic ground strap to prevent damaging the GAL5 while you assemble the board. If you carefully follow the well written instructions, and don't make the mistake of trying to jump ahead; you should have the unit completed in less than 12 hours.
With the Ramsey FM30b completed; basic operation is very simple and never requires you to open the case to make any adjustments. After you connect the included whip antenna and turn on the FM30b, you enter the setup mode from the button on the front panel; stepping through the menu to make all of the adjustments. The two line LCD display shows all the information you need to make the settings, including: Frequency, audio level, balance, power, mono-stereo settings and a unique way to set audio levels with a "Quality of Signal" to help you set your levels for optimum sound quality using a "-" for low modulation, a "g" for good, a "c" as clipping begins and a "C" when severe clipping is occurring. Once you are done with your settings; they are stored in the non-volatile memory for the next use.
During assembly you will notice a unique section on the circuit board which turns out to be a state of the art micro strip PCB inductor designed to help eliminate microphonics which describes the phenomenon where certain components in electronic devices transform mechanical vibrations into an undesired electrical signal. On some other BH1415F based transmitters; you will hear what sounds like someone tapping on a microphone when you tap on the transmitters case or handle it; thanks to the micro strip PCB inductor built into the FM30b circuit board you don't hear handling noise intrude on the program material. The FM30b also helps eliminate noise in your signal by including EMI filters on audio and power inputs. Speaking of inputs; the FM30b uses RCA connectors for the audio inputs and a center positive 2.1mm connector for D.C. input which requires between 13.8 & 16 volts to operate properly. The 50 ohm RF output is via a heavy duty and anchored BNC connector.
Now all the technical stuff is out of the way; how does the FM30b perform?
The FM30b has an output of 25milliwatts max; which is more than enough to serve a good size neighborhood. We have a 40 acre campus to test the signal on; which is full of Arizona Cyprus trees used for windbreaks and some privacy.
Arizona Cyprus trees tend to absorb RF energy; so this isn't a true line of site test. We keep the typical user in mind; when we do our testing. During our test, the FM30b and its stock whip antenna was placed on our test bench; 3' above the floor. We walked through the entire campus, with a portable radio (with only a short 3" wire for an antenna); never once losing the signal, with only two squares filled up on the FM30b LCD power meter.
The most important feature of any transmitter; does it sound good? Ramsey has given allot of attention to external noise and keeping it from entering the FM30b circuitry and intruding on the program material. No whistling or high pitch tones caused by poor computer audio cards, CD players or satellite receivers; could be heard in the audio. Microphonic noise from handling the transmitter; could not be heard in the audio. Low noise and dead on frequencies that do not drift; help make the FM30b good enough to listen on any good audio system.
Ramsey really impressed us with a sturdy case, that is RF tight and equipped with heavy duty connectors and switches; making the FM30b perfect transmitter for taking on the road or camping.
We have had other transmitters that simply could not stand up to the rough treatment on the road. The most common problems we have had on the road with other transmitters was the cheap connectors failing and screws getting lost from having to open the case to change frequencies or adjust the power.
The minor downside
We know others have experienced the failure of the GAL5 from static discharges while moving the transmitter about the house or simply touching the antenna. We contacted a very friendly and helpful Ramsey tech about this matter; since the GAL5 is not the easiest part to replace; it should be better protected. The tech advised us that Ramsey, had a fix for the problem with static electricity blowing the GAL5. An ESD suppressor: Ramsey part number PROT40 is installed between the antenna center and ground on the circuit board that will protect the GAL5 from static discharges. The minor loophole we found was the PROT40 is a SMC component, about the size of a flea. You will need a magnifier, a set of tweezers and a stable hand; to solder the PROT40 into place.
During construction It's not mentioned in the book; that you need to protect yourself against static discharge. The GAL5 has no protection against static discharge during construction. The inductors were described as green in the manual; however they turned out to be the same color as the resistors; but shaped different.
A final note: Before construction of the FM 30, for seasoned kit builders with eyes to prove it! You will find downloading the PDF version very helpful in several ways: Large text right in front of you on the screen, and it's helpful in an educational setting like a classroom by being able to display the manual on a large screen in front of a class. The Ramsey manuals remind me of the old Panaxis kits; where Ernie tried to educate you about the product you were building. Like Panaxis; Ramsey kits are designed to educate while you build them. Learning what the kit does and how it works while you build it, can help you diagnose problems; should they arise on other transmitter you may encounter in the future.