Home > Consumer Reviews > C. Crane FMT Digital FM Transmitter with AC Adapter

1) Open up the box,
by removing 3 screws (one screw is in battery compartment and the other 2 are under those circular rubber feet which are adhesive and once removed can be refitted afterwards)

2) Locate the variable resistor marked VR2 on the circuit board. (For those non-technical this is like a volume control that is operated by inserting a tiny screwdriver and turning fully clockwise). Turn VR2 to the fully clockwise position.

Viola! The power output will increase by about five fold.

If you want to go even further, then

a) sit it on a grounded metallic surface, such as a metal tray to form a ground plane.

b) increase the length of the antennae to about 75 cm (29 inches) which is the correct quarter wavelength at these frequencies.

But frankly, you are unlikely to need this once you turn up the boost.
Enjoy

I bought this to replace a LineX transmitter that has only 7 frequency settings, none of which are very usable in my area. We use it to broadcast audio from our Audiotron to radios in and around our house. The LineX has a good range for this use, 75-100 feet or so.

When I got the Crane, I loaded batteries into it, plugged it into the Audiotron, and turned it on. Using a portable FM receiver I found the range to be *3* (yes, THREE) feet. Using the AC adaptor did not expand the range, nor did adjusting either of the transmitter and receiver antennas, nor did adjusting the input levels.

So, I popped the box open and set the variable resister as other reviewers have noted. After this change I got a range closer to that of the LineX.

NOTE THAT THIS MODIFICATION VOIDS THE CRANE WARRANTY! Page 11 of the manual: "Removing the cover ... will void the warranty." The bean counters at Crane must be very happy about this; ship a product that can only be used by voiding the warranty, and you eliminate any returns. To be fair, there are no seals on the Crane, so you could pretend that you never opened it, but it's still pretty sleazy.

The Crane's input levels are touchy. I had to tweak the Audiotron output and Crane input levels many times to get a clean signal on our receivers.

The frequency display is LCD, with no backlighting. Depending on available light and the viewing angle, it's not as easy to read as the marketing materials would have you believe. For a static installation such as mine this is OK - find a good channel and forget it. For use on the go this could get annoying.

The ability to set a frequency between FM channels is very useful in avoiding interference from radio stations, and that's what I've done. NOTE: your FM receivers must be capable of tuning "off channel" for this to work for you.

Another reviewer notes that the antenna on the Crane is too short for the frequencies involved. The length was obviously chosen so it would fit the cover when collapsed, not for efficient transmission. I considered replacing the antenna, but the Crane is not built to easily allow it and I didn't want to push the warranty issue too much further.

On the Crane box is a quote from John O'Brien, Wired Magazine, who says "The Crane is tops... easy-to-read... great audio... variety of power sources... wide range of frequency..." I find it telling that there's no mention about the range of the Crane, so I looked up the review on the web (Google "crane transmitter wired magazine review"). The review says "30 feet across an apartment to a radio in another room", but doesn't say that he actually tried it. I don't know what product he was reviewing, but it certainly wasn't this one.

Pros:
-- Acceptable range after making the hardware mod.
-- Acceptable audio quality after repeated levels tweaking.
-- Ability to tune off-channel.
-- LCD frequency display. (The LineX uses DIP switches and has no display. The LineX is also $30 cheaper.)
-- Audio splitter cable included, which was exactly what I needed for my set up.
-- AC adapter. (The LineX used only batteries, and they would last about a week at 24x7.)

Cons:
-- You have to void the warranty to make it usable.
-- Touchy levels control.
-- LCD display hard to read in less-than-optimal light and viewing angle.

This could have been a great product, but it's only mediocre.

C. Crane informed me that they tested a unit and found the tones as I described them, but they do not have a solution to the problem at this time since this was apparently new information to them. I complimented them on their willingness to substantiate my claim in the lab rather than sending a boilerplate "we're sorry for the inconvenience"-type reply to my e-mail. Unfortunately it didn't solve the problem, but it did save me the trouble of returning it only to find the same thing in the replacement unit.

As I posted earlier, I was going to check out the Belkin TuneCast II...well, it went right back. The C. Crane unit overwhelmingly beats the Belkin unit for range (once the very simple power boost modification is done, that is), and even with the annoying audio tone, the C. Crane unit serves my needs much better for clearly transmitting throughout the house. The Belkin unit doesn't have a separate antenna, which severely limits its capabilities for range.

If you need a transmitter for the car, almost any one will do, but if you need one with range, the C. Crane transmitter is a good choice.

There are some negative reviews here -- please, before posting, read all the comments. If you're upset this does not have the range/power you want "out of the box" then write to your Congressman and ask them to relax limits the FCC places on these devices. Or "open the box" and tweak the master volume knob. Just know there IS a legal cap on performance for any consumer FM transmitter, and it is ignorant to blame the manufacturer. All transmitters are subject to this rule, and this one is unique because you can override that setting (at your own risk).

This device is unique because you can:
a) choose ANY frequency (not just 2 or 3 set at the factory)
But your results will vary by frequency. You MUST research what stations are used in your area, and find some "dead space" between channels. This sweet spot will vary if you are mobile between home and work, for example.

In my area, the default station 88.3 has a strong public radio station, so I found 90.5 worked best. There are websites that will show you station strength and distance based on your postal code... they help. Don't expect to get a good signal on a thin slice between 2 strong stations.

b) You can "boost" device power using the internal screw (VR2) trick documentd here. It works. Just don't turn it up more than you need... maxing it out can easily interfere with radio reception on or near your frequency choice. If everyone on your street can't tune in a valid station, you are asking for trouble from the FCC.

As a new owner, I should add the following about the disassembly:

Notice the "volume wheel" that protrudes through the case? That can easily snap off during disassembly. It's almost impossible to remove the cover without putting SOME stress on the wheel (a little bit does not break it but YMMV). At the very least, first make sure this wheel is at MAX (so IF it breaks off, maybe it's just stuck on max boost).

Near the antenna, they use some gummy glue to hold the case together. Just carefully pry the case apart. To avoid losing control during this step and stressing wires, I used a wide flat screwdriver and twisted it (providing just enough separation force to pop the glue on that side).

This was easier than it sounds, but if you are clumsy with a screwdriver then get someone to do it for you... or skip this type of device, and get a long audio extension cable.

Works on any headphone port, such as my laptop and my mobile PC (Nokia N800 Linux tablet)

I got 4 of these gadgets. I have a lot of scanners, radios, and computers. Until now I could more or less hear any source in nearly any receptor. But today I saw the modification ("upgrade") to improve transmission power and .... eureka!! now I have a full interconnected audio network, and don't lose a word from anywhere to everywhere. The gadget is well worth its price. Buy it, upgrade it and ENJOY it.
By the way, the modification doesn't bring any nasty lateral effects at all. No degradation of the signal/noise ratio, nor any kind of noise boosting. Just a more powerful but still clean signal (-- make sure you are choosing an unused or weakly used frequency). Only beware to adjust the resistor so not to bother your neighbors with your transmissions (or organize kind of "pay per hear" :-). Turn VR2 fully clockwise (as recommended by another reviewer) only then and if really needed.