Anyone know if this is on the Web somewhere? A Google search returns a
pile of Asian-language sites, one of which might have the information if
only I were literate in Chinese/Japanese/Korean...

It's the logic chip in a cheap mini FM transmitter, sold for use with MP3
players. I'm trying to change the frequency selections, as none of the
factory choices (88.1/88.3/88.5/88.7MHz) are usable here.

I did find a schematic for the transmitter as a whole on the FCC website
but changing the logic level of a pin that *seemed* appropriate caused the
unit to stop working altogether. (or shifted the frequency out of the FM
BCB...)

Hi Doug,

http://electronics-diy.com/BH1417_PL...ransmitter.php

http://www.datasheetarchive.com/data...article=984027

Could you email me what you found on the FCC site please.

Thanks,

Mark


On Jun 19, 5:42 pm, Doug Smith W9WI wrote:
Anyone know if this is on the Web somewhere? A Google search returns a
pile of Asian-language sites, one of which might have the information if
only I were literate in Chinese/Japanese/Korean...

It's the logic chip in a cheap mini FM transmitter, sold for use with MP3
players. I'm trying to change the frequency selections, as none of the
factory choices (88.1/88.3/88.5/88.7MHz) are usable here.

I did find a schematic for the transmitter as a whole on the FCC website
but changing the logic level of a pin that *seemed* appropriate caused the
unit to stop working altogether. (or shifted the frequency out of the FM
BCB...)

On Jun 19, 1:42 am, Doug Smith W9WI wrote:
Anyone know if this is on the Web somewhere? A Google search returns a
pile of Asian-language sites, one of which might have the information if
only I were literate in Chinese/Japanese/Korean...

It's the logic chip in a cheap mini FM transmitter, sold for use with MP3
players. I'm trying to change the frequency selections, as none of the
factory choices (88.1/88.3/88.5/88.7MHz) are usable here.

I did find a schematic for the transmitter as a whole on the FCC website
but changing the logic level of a pin that *seemed* appropriate caused the
unit to stop working altogether. (or shifted the frequency out of the FM
BCB...)

My notes, based on a ripping into a unit I got from Wal-Mart a while
back, disagree with your factory choices. According to my notes, pin
18 to Vcc selects a band which has choices of
88.7/88.9/89.1/89.3/89.5/89.7/89.9.
And pin 18 to ground selects a band which has choices of
107.7/107.9/108.1/108.3/108.5/108.7/108.9. Maybe due to this
disagreement you've got some customized or different variant version
of the chip. I think my chip was a BH1417-something or other (Rohm?).
Is HY Hyundai or something else?

The unit I was playing with had a varicap and a small coil for tuning
the VCO of the synth. I had to remove a few tunes from the coil to get
it onto the 107-108Mc band as opposed to the factory 88.7-89.9Mc band.
It didn't stop oscillating when the coil was out of range, but it
didn't lock either.

Tim.

On Tue, 19 Jun 2007 05:47:03 -0700, Tim Shoppa wrote:
My notes, based on a ripping into a unit I got from Wal-Mart a while
back, disagree with your factory choices. According to my notes, pin
18 to Vcc selects a band which has choices of
88.7/88.9/89.1/89.3/89.5/89.7/89.9.
And pin 18 to ground selects a band which has choices of
107.7/107.9/108.1/108.3/108.5/108.7/108.9. Maybe due to this
disagreement you've got some customized or different variant version
of the chip. I think my chip was a BH1417-something or other (Rohm?).
Is HY Hyundai or something else?

That's where I got my unit, but it would appear BH1417 and HY1417 are two
different chips. I can't change the logic level on pin 18, because the
HY1417 has only 16 pinsgrin!

My unit has another chip, six pins, that appears (both from physical
inspection and the schematic) to be the actual PLL. Performs the function
of the MPSA13 and pins 7-9 on the BH1417. HY is not Hyundai. I can't
remember what it is & left the printouts (and the FCC ID# for the unit...)
at work...

On Mon, 18 Jun 2007 23:22:33 -0700, MarkAren wrote:
Could you email me what you found on the FCC site please.

As I mentioned in the other reply, HY1417LP and BH1417 are two different
devices - HY1417LP has only 16 pins but is used with a separate 6-pin chip
which appears to be the VCO.

I of course managed to leave the battery cover (with the FCC ID#) at work
last night so won't be able to look up the exact link until much later.
I've not been having any luck looking up the FCC ID#s on various other
pieces of electronics in the house. (type in the ID# exactly as it
appears on the sticker - and the FCC says it doesn't exist...) But it
worked with this device. On this URL:

https://gullfoss2.fcc.gov/oetcf/eas/...ericSearch.cfm

you put in the ID code, look under Attachments, there may be one for a
schematic. The manufacturers can mark it as confidential but in this case
they didn't.

On Jun 19, 10:17 am, Doug Smith W9WI wrote:
On Mon, 18 Jun 2007 23:22:33 -0700, MarkAren wrote:
Could you email me what you found on the FCC site please.

As I mentioned in the other reply, HY1417LP and BH1417 are two different
devices - HY1417LP has only 16 pins but is used with a separate 6-pin chip
which appears to be the VCO.

I of course managed to leave the battery cover (with the FCC ID#) at work
last night so won't be able to look up the exact link until much later.
I've not been having any luck looking up the FCC ID#s on various other
pieces of electronics in the house. (type in the ID# exactly as it
appears on the sticker - and the FCC says it doesn't exist...) But it
worked with this device. On this URL:

https://gullfoss2.fcc.gov/oetcf/eas/...ericSearch.cfm

you put in the ID code, look under Attachments, there may be one for a
schematic. The manufacturers can mark it as confidential but in this case
they didn't.

I was wondering if anyone found any more info on the chip (HY1417LP) I
too purchased the mp3 fm transmitter, but unlike what I have read I am
looking for which pin on the 16 pin chip is the antenna? my eyes are
not what they use to be and even using a loupe its hard to read the
curcuit board. What I would like to do is extend the antenna or maybe
built a fm booster to extend the range lets say @ 50 feet from my car
so I can listen while working outside, at the beach, etc.......