Re: N900 Radio Transmitter: ways to amplify the radio signal
 

Hello , Do you know what frequencies work best for fm transmitter in Vancouver ?

Since you are from Vancouver too , I though maybe you can help me:p

I use 105.50 and it seems ok but not the best , i still get some "noises" though .
do I have to put my cellphone near window or anything like that ?

any help would be appreciated :)

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

Honestly, I don't drive in a car very much, maybe twice a week, and then I just listen to CBC 1 or my kid's MP3 CD. The only thing that would make the FM transmitter really interesting to me would be getting some real N900-compatible 3G in Vancouver so I could listen to Internet radio on the car's stereo. But that's 6 months away or more.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

qole , thanks for the input ,I have tried the internet radio(through my wifi) and it seems the internet radio quality is way better than playing music through the fm transmitter , but that's maybe just me ! lol

Yeah , there is still no NAM 3G in Vancouver , I guess he have to wait , that is not going to bother me since everywhere I go , I have access to internet through wifi ,but Its good to have it !

PS, how do like your n900 so far ?

Cheers.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

Is there a way to make the signal stronger than 118 ? i really want to increase it to the maximum.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

It's allways helpfull to read or at least scan the threat since this was answerd bevor.

You can increase the value, but it makes no difference in the signal strength beyond 118 to answer your question.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

The script works great to boost my signal... but I was wondering if there is any way to bypass the transmitter disabling when you plug it in to charge. I figure it’s possible because one of my chargers doesn't disable it.

e.g
Nokia wall charger -> FM transmitter works while charging :)
Nokia USB charger -> FM transmitter disabled
Cheap car usb charger -> FM transmitter disabled


It’s annoying to be only able to listen to song or charge my phone while driving. Especially as I have a 1700km drive in a couple of weeks.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

Normaly if you plugged in the charger and toggle the widget the transmitter should be set to full power again (118). Give it a shot ...

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

When I plug in the wall charger, the signal does get weaker, as I can hear a little bit of static, but yes, toggling the widget gets it back to full power.

However with the USB charger + car charger, as soon as I plug them in, the yellow note comes up "Unplug USB to continue using FM transmitter", attempting to turn the widget back on says "FM-Transmitter Power level set to: 118", but nothing get transmitted. Trying to turn it on via media player says "Unable to use FM transmitter while USB is connected. Unplug USB to continue using FM transmitter" So it seems like it is being totally disabled, not just set really to really low power. As soon as I unplug that charger, I can toggle it back on.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

Hello, i live in south france toulouse, and every single FM band is already used. I am using fmboost via fmtx widget. if i leave the city and drive to the countryside i can find one or two free bands that i can use, with a bit of static, but am quickly kicked out by local radio station frequencies. id really appreciate if the boost level could be set over 118 to fix this issue... any way to do this ? hardware capable ? harmful for the device ?

thanks !

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

When I try and use the booster it just opens then closes straight away.. Is this normal? I have music playing and the transmiter active when I try to open it.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

yes this is normal.
if your fm transmitter is on, it boosts the value to 118 then closes itslef, without any notification.

if you use the easy fmtx widget, you can associate the fmboost patch and auto apply it, and you get a notification.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

I am from New York, and currently using 91.7, I have FM boost on and I still here a bit of static. People on this thread have been posting crystal clear sound, no static whatsoever when using fm boost... but I am not getting that at all. I can still literally hear the static. Can anyone give me any suggestions?

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

Buy a car and Move out of NY. :)

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

I do have a car.. :( but dont want to move :(

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

So, has anyone tried to set the boost level above 118 ? With what results ?

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

Don't mind reading through the last pages, we gladly answer this question over and over again : NOTHING

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

aight, thanks. too bad, tho :(

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

Well here in south Germany 90% of the FM frequencies are used on my car radio with active antenna. Still it's working perfectly in my Mercedes C180-K with a really clear sound equal where I use it.

The only requirement is the FM-Booster (I use the widget which includes it) and I can use it anywhere in the car and even outside outside the car, but without FM-Booster I have no chance to get a clear signal on any frequency.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

I second the question of is it possible to go higher than 118?

Another question I have is with the fmtx widget, thats what i've been using, but I just had a look at what the fm transmitter power was at, and it was 113, I turned on the fmtx widget, it was still 113, I manually clicked on the 'fm boost' and it was now 118.

Is there anything I need to do to get the fmtx widget to automatically kick in the fm boost?

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

to enable the FM Boost on FMTX just go into the settings (via the FMTX desktop icon spanner) and click the "boost" button.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

And I fifth the answer that no, you cannot. 118 represents the max transmit power the hardware supports.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

Your xsbc-bugtracker link is broken on http://maemo.org/packages/view/fm-boost/ . It says:
"xsbc-bugtracker:%20http://talk.maemo.org/showthread.php?t=38582"

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

I dont have a spanner icon on the FMTX desktop widget.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

Yes, that was a bug in py2deb. I've fixed it, so all my new packages have proper bugtracker fields, but I can't justify pushing a whole new package for a tiny script (with functionality duplicated elsewhere in other more robust packages) just to fix the bugtracker field.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

can we maybe get a setup for fm boost as i get an ok signal in my car and it probably only needs to go up a few notches...

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

Actually you can raise max tx power up to 120 dBμV according to "SI47XX PROGRAMMING GUIDE/AN332". The note is "Power may be set as high as 120 dBμV;however, voltage accuracy is not guaranteed", but who cares is it .975 V or 1.025 V :)

Further if you look into kernel code, in si4713.h there is a line

#define SI4713_MAX_POWER 120

so it looks like we do not have driver limiting max power.

And we should have in mind that difference between 118 and 120 is not linear as we are talking about dBμV units:

112 dBμV = 400.0 mV
118 dBμV = 794.3 mV
120 dBμV = 1 V

It seems that setting tx power to 120 works for me, but this could be placebo effect, so one can try and modify /sbin/fm-boost changing echoed value from 118 to 120 and check if there is an audible difference

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

I've also noticed that 120 definitely improves the sound quality in my car.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

you the first n900 user from Dallas i ran into on here

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

so, anyway to change the power transmition of the widget from 118 to 120 ?

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

yeah I'm keen too, to find out how to change it (118 to 120)..

I've all so notice that the music and static ratio is pretty bad too, like the volume of the music that is being sent to the transmitter is quite low for example you wound be listening to it in the car you wound have the volume turned up high, higher than nominal..but if you were listening to nominal radio the music is louder but you don't need to turn up the volume as high and theirs next to no static in the back ground.

I hope that made sense..

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

Hi,

OK I have read through this thread. My FM Transmitter is enabled, it works if I hold it right at the base of the antenna for my radio, but I can only just hear it.

Running the fm-boost script, or just echoing 118 (or 120) right into /sys/class/i2c-adapter/i2c-2/2-0063/power_level makes no difference at all, which makes me wonder if I am missing something.

The next thing I tried was putting 88 into the power_level at which point I lost anything I had. So then I incremented bit by bit to see what happened. At about 110 I could just hear my music through the static (and the device is still resting on the antenna). At 114 it's almost clear, but once it gets past 114 there is no noticeable difference in quality with each increment.

So I am wondering if there is something else that I need to do, or if there are any suggestions as to why mine seems to stop getting better at around 114 when most people see a substantial difference going to 118?

My phone is a UK phone, bought from Carphone Warehouse. I am on the latest UK (203) firmware.

Cheers,

Ben

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

I can only find FM-boost cant find the widget (not sure of name FMTX?) anywhere. Also using fm-boost i hear no difference still static..Using my iphone dock i get crystal clear sound on N900 i still get enough static in background to bother me. im in a suburb of chicago, IL Anyone tell me if widget was taken off or the right name? thanks : )

ps i did read all 28 pages

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

That is correct that is the name of the widget simple FMTX desktop widget.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

You should show increases to 120 with 118 about peak. FM Boost will do this for you but regard. Every time you change FMTX frequency or plug in anything USB including the charger, you must as you say, echo 118 (or 120) into /sys/class/i2c-adapter/i2c-2/2-0063/power_level all over again. That is why FM Boost is so dang handy. :)

I have also found that depending on the FM receivers signal rejection circuitry, it sometimes helps if you start pumping out signal from the N900 before you tune to the station on your receiver.

Do me a favor fire it all up again then.

1. Start Media Player and pump out a playlist.

2. Enable the FM transmitter and tune it to the frequency you wish to transmit on and hit "save"

(Music should now stop coming from your devices speakers but Media Player will still be chuggin' along.)

3. Keep on rockin' out and minimize. Go to the FM Boost icon and fire it up.

4. Tune your receiver to the frequency that you chose in step 2.

5. Regardless of your signal quality. Minimize it all and keep on rockin'.

6. Fire up Xterm and gain root. Type:
After hitting enter the number reported back should be 118.

If it is 118, then your device is doing everything it should be doing and I would try another receiver or antenna.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

... or another frequency. In highly populated areas, it can be very hard to find a frequency that is available. Even if there is no recognisable sound on a channel doesn't mean that the frequency is clear. There can be lots of interference there that just sounds like "static" when received by your FM receiver.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

What would happen if the power_level would be turned up to something like 130 or 140?

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

just as a FYI:

I had a crappy USB car charger without the center two (data) pins shorted. This caused caused it to fail to charge the N900 9 out 10 times. But it did have a nice side effect. connecting it would boost the radio signal significantly, so the USB cable/charger was acting as an antenna.

I have since shorted the two data pins in order to fix the charging, and unfortunately the it's no longer improving the radio signal either.

I did also try hooking up just the USB cable without anything on the other end, but I'm guessing vecause of shielding, that doesnt help either.

one thing i might try sometime is cutting a usb cable in half and stripping the shielding away. otherwise i might desolder the data pins in the charger and replace them with a switch or something.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

You could use it to defrost you windshield in the winter time. :)


Earlier in this thread it was discovered that nothing would happen.
The driver or hardware specs found power level should max out at 120, and users who tried many different higher levels above 120 could no longer perceive any increase in quality. In fact the perceived quality improvement seems to peak @ 118.

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

Hey there,
I tried the steps descirbed by YoDude, but cat will still give me 113 as result. I even got the same signal, if I try to enter the value manually into the config.

Greetings, Blck

Re: N900 Radio Transmitter: ways to amplify the radio signal
 

I am using this script to boost the fm transmitter power :

when I write python /home/user/MyDocs/fmboost.py it says me

I am using cat /sys/class/i2c-adapter/i2c-2/2-0063/power_level to check it but it stays at 113 .

This script used to work a while ago , today I noticed it doesn't work and I reflashed but still no success . What could be wrong ?

Also fm-boost application doesn't work .