Hi Guys:
I was in a drugstore yesterday and found an FM
transmitter for $11.99. I decided to buy it to see
what it was like. It is a Maxell P-13. I'm sure some
Hi Guys:
I was in a drugstore yesterday and found an FM
transmitter for $11.99. I decided to buy it to see
what it was like. It is a Maxell P-13. I'm sure some
of you are familiar with it. It appears it came along
after the Maxell FMT-1 went out of production. (?)
Anyway here are some of my findings.
It is certified. The FCC id is WKA-MCAP-13
It operates on only 4 channels, 88.1, 88.3, 88.5, and 88.7 MHz.
88.3 is clear here but 88.1 and 88.5 have fairly strong stations
on them. So I put it on 88.3 and tried to get it on various radios.
More on that in a minute.
It turns off when the input audio disappears or is low. I found
this out during a jazz song that had a quiet bass solo that
went on for a while. The transmitter shut down in the middle
of the bass solo. However, after plugging the transmitter
into the back of my stereo compressor/limiter, I found I could
compress the audio and boost it a bit so this would not be
a problem.
The transmitter is a small black and silver disk a little bit smaller
than a computer mouse. It has no external antenna. All it
has is an audio plug that will plug directly into the headphone jack
of any audio device. The plug is attached to the transmitter.
There is no cord of any kind to extend the plug. It is right
on the transmitter.
This transmitter (at least my sample) will not modulate 100
percent. If you try to do that you will get distortion. However
it seems to do OK between 60 and 80 percent. This was my
reason for plugging it into the back of my compressor/limiter
with a patch cord. I believe I was somewhat successful in getting
it to sound good with louder average audio this way.
I was very surprised that it transmitted about 600 feet to
my wife's car radio. Then it started to drop out.
It has no antenna on the outside. Either the antenna is
internal or the audio cable to my compressor/limiter was
carrying the RF out somehow. (My compressor/limiter
is currently sitting on a desk on the second floor of
our house.) No problem at all hearing the P-13's signal
anywhere in our house and yard with a good portable
FM radio. (A Grundig S350DL.) It's audio is just a little
bit softer than most of the other FM stations. It's
a little irritating to me, but not too much. After all, you
get what you pay for.
The transmitter runs on 3 AAA batteries. It is rated at
24 hours operation with one set of 3 AAAs. Mine has been
running for over 28 hours now. It hasn't quit yet.
Stereo separation appears to be fairly good. There is
a slightly perceivable very high pitched squealing sound
about 40 DB down when received on a stereo radio.
On an FM mono radio with the volume turned up with
no transmit modulation, the background noise is
nonexistent. It is dead quiet.
So, here is a certified really inexpensive FM transmitter.
It has two big drawbacks, the fact that it only covers
4 frequencies, and that it will only modulate (or deviate)
about 80 percent tops.
But it was only $11.99. I tend to like minimal electronic
devices anyway. To me, experimenting with it is fun.
But that's just me.
I hope this subject hasn't been covered before. I think
the Maxell FMT-1 (?) is very much like the P-13 only
better. And I know the FMT-1 has been discussed in
the past.
There is one other good thing about the P-13. It has a
very bright blue LED power indicator on it. It's bright
enough to be used as a blue LED flashlight.
Maybe that's what I'll use it for instead tonight! It's late,
the house is fairly dark, and I can't find any flashlights
around here!
Best Wishes To All!
Bruce, MICRO1690/1700
Bruce,
Thank you for the brief review of the Maxell P-13.
Our local Walgreen's still has the Maxell FMT-1 on the shelf and come to think of it, Walmart still has the FMT-4 on their shelves.
I have a complaint about the recent outbreaks of blinding blue l.e.d. lights, while it is incredible that l.e.d.'s have advanced to the point that now you can buy them as fog lights for your car/truck, the companies that decide it would be cool to place them on nearly everything they sell has me seeing .... well blue! lol
Not only does the Scosche FMT-4 have one of these blazing blue lights but Behringer decided to place one on the mixing board i use here.
http://www.behringer.com/EN/Products/PODCASTUDIO-USB.aspx
It wouldn't be so bad if they placed it somewhere else away from the controls, but when you look at the l.e.d meters or rotary knobs your eyes are immediately drawn to that blue l.e.d. and by then your seeing blue spots. Kind of reminds me of the old Kodak Instamatic cameras with the flash cubes that always left you seeing spots.
At any rate, that is a good find and I appreciate the honest review.
By the way, flashlights don't survive long in my house with 5 kids, by the time i find one it is usually dead. lol
Cheers
Good job Bruce MICRO 1700 on the review.
I read it for the third time and think I have figured out why it turns off on no audio: it's probably a battery saving strategy.
The few frequencies will be a problem in many areas. People up on top of the hill near here receive stations on all those channels, whereas down here in the valley I am able to use 88.5.
Thanks for your replies!
Barry, I have tried to find an FMT-1 or an FMT-4
and have not been able to. I know there has been
a fair amount of discussion on those two transmitters,
but I haven't read much about the P-13.
I know what you mean about the bright blue LEDs.
I think I had mentioned somewhere along the line
that my station had been in a room where my three
dogs would sleep. I have a Radio Shack mixer that
uses bright blue LEDs for the VU meters. This board
is a DJ board and I can understand why it would be
useful for somebody who would be DJing in a dark
club. But at times I would leave my station on over
night, and the bright blue LEDs really bothered my
dog Hoover. The bright blue lights kept him awake,
and they would cast shadows on the walls in the dark.
When the audio went up and down the room would
get bright and dark so the shadows would change.
My other dogs didn't care, but it really bothered Hoover,
so I had to cover up the VU meter LEDs with a piece of
cardboard. Right now this board is not in use. I like it
a lot, but I was given another DJ board that has a
lower noise floor (if that's the right way to describe it)
and so the dogs all can sleep now. When I get my
1960 vintage board finished, it will be the focal point
of the station anyway.
Carl, thanks for your comments, too. I think you are
right, if the audio stops, the transmitter will shut off
to save the batteries. Also, if you are listening through
a stereo system like I was, with the volume turned up
high, you will get blasted by the noise when the transmitter
shuts down. But again, my compressor/limiter has solved
this problem.
It's nice to hear from you guys. I'll catch you down
the road!
Bruce, MICRO1690/1700
I used to have a little FM transmitter years and years ago that I bought from Radio Shack. I dont even remember what the name of it was or if it was even an FCC certified box, but it too had fixed frequencies that you could only operate on by selecting a few switch positions. I popped open the case and discovered four ferrite core adjustments for each switch setting. With the aid of a frequency counter I was able to then put this thing on a very clear channel with an open channel on either side of me at the time. It too seemed to have an audio issue...these little things are what they are and possibly may even be built around the BA1404 or some variation of that chip. Those things never had great loud audio on FM.
Anyhow, the P-13 may have similar adjustments inside. Whether or not making some adjustments would void the FCC certification is another thing to find out, but it may be possible to move that little transmitter to a more open and desirable frequency.
On the nearby "FM Short Antenna Length and Field Strength" thread there is more FM stuff, particularly the first of my reviews on Whole House FM 2.0.
Just thought you'd like to know.
Thanks Carl and Bob!
I may have more comments to follow.
Best Wishes
Bruce, MICRO1690/1700
"I was very surprised that it transmitted about 600 feet to
my wife's car radio."
I just noticed this. Sorry for being a doubting Thomas, but if you haven't accidentally added a couple 00's, then this thing is the find of the century! No other legal Part 15 FM transmitter can get anything like that sort of range. It sounds illegal. How do you account for it?
Check out the Maxell P-13 transmitter review on Amazon.com
Also check out the engineering report on low power transmitters where NAB has alleged that these low-priced, mass-produced units are all over the place as far as real-world field strength.
The sellers shrug and say they didn't make the transmitters.
The makers say the units are built overseas and subject to some variability due to low cost, high volume production and component value tolerance levels.
Several units in the report tested at double the allowed field strength right out of the box.
I'm not sure what to say, but here are
a few odds and ends for you guys.
Ken, it sure is weird that the P-13 went
so far. As SWCIS mentioned, it may not
be in spec. I can say that my wife's car
radio is very sensitive - stations that are
100 miles away do fade up and down as
we drive around town. (I am a casual
AM and FM DXer.) But as for my P-13's
field strength, I don't know.
I actually stopped using the P-13. Not because
I don't like it - but I ran out of AAA batteries.
One personal note -
I have had multiple detached retinas and problems
related to that have taken up most of my time
lately.
When I get a chance I will pull the P-13 back out and
restudy it.
Ken and SWCIS - thank you for your comments. I really
enjoy this board. I helps me get away from some of the
other things that are going around here.
Best Wishes
Bruce, MICRO1690/1700