C. Crane FM Transmitter 2C. Crane Company - Fortuna, California
In August 2008 we had the pleasure of reviewing the original model C. Crane FM Transmitter, an FM transmitter that fills a niche for good performance while being budget-friendly. The always forward thinking C. Crane folks decided to perform an update on their flagship FM transmitter and has brought to market the FM Transmitter 2.
For those of you unfamiliar with C. Crane, the company specializes in products for the true gadget enthusiast with radios being their most noteworthy products. The FM Transmitter 2 serves to compliment their product line of radio receivers and accessories.Factory Fresh:
Thanks to C. Crane Company President Robert Crane and Customer Support Specialist and Purchasing Assistant Jessyca Rosson for providing us not only with a factory fresh FM Transmitter 2 but also a factory fresh original version. In our review of the original model we used two units, one was purchased as an "orphan" directly from C. Crane (their tested returned items are sold at a discount and are referred to as an "orphan"), the second unit was acquired via ebay. Since we re-aligned ours exactly to Part 15.239 specs our lab units weren't necessarily true representations of samples taken directly off the manufacturing line. With that in mind, C. Crane was kind enough to furnish sample transmitters to serve as typical specimen for our testing and evaluation.Opening The Box:
No surprises here as the new FM Transmitter 2 was the same form factor as the original version. The only external difference we could see was that the printed name of the transmitter was in red on the outside of the original version and the new FMT 2 has white printing on its exterior. The transmitter is shipped with an 1/8-inch to stereo phono plug adapter and companion AC wall wart power adapter. Both the original version as well as the FM Transmitter 2 share a common 30cm telescopic rod antenna which is permanently attached to the unit.
Available controls include the power button, which can invoke the auto-off timer, tuning up and down push buttons and an audio level volume control located on the left side. A liquid crystal display for tuning is located on the front of the unit and the attached 1/8 inch stereo audio connector and coiled cord is located on the right side of the transmitter. The sliding rear cover for the "AA" times 2 battery compartment is located on rear of the unit.The Inside Story:
The FM Transmitter 2 is much more than a minor update to the existing transmitter. Opening it up reveals two new circuit cards replacing their predecessors. The main board is a little smaller than the one found in the original FM transmitter and the daughterboard has significantly less components on it as well. The daughterboard is attached to the main board using a 6 conductor ribbon cable. Additionally, the audio input cable as well as the leads from the battery compartment attach to this daughterboard.
Like the original version sibling, the FM Transmitter 2 tunes in 50 KHz steps from 88.3 through 107.7 MHz. It's unclear why C. Crane decided not to include the entire FM band for available tuning but this will affect only a few users.
The heart of this transmitter is the Silicon Lab SI4710 FM modulator IC which sports such notable features as digital stereo modulation, advanced modulation control with audio dynamic range control and auto power-off capability.
The only weak point we could find is the mounting for the whip antenna. On one of our original model transmitters it was possible that excessive rotation of the whip antenna can weaken the collar the antenna passes through, allowing the antenna connection to become intermittent. While the antenna in the original generation transmitter depended on a spring tension clip between the antenna and the circuit board, the FM Transmitter 2 antenna has a directly wired connection which reduces the likelihood of a intermittent connection should the antenna mounting collar become subject to trauma.Fire It Up:
Our bench test setup is similar to our previous transmitter tests. The FM Transmitter 2 is initially connected to a 4th generation Apple iPod audio player as a test audio source,. We tuned the transmitter to an open frequency. The silent carrier was observed with no artifacts typical of inexpensive FM transmitters or those utilizing the BA1400 series integrated circuit chips used in some kit FM transmitters.Next page