coil uhf 10,7 Mhz

Hello!you excuse, I do not know to me to write English well(google
translate)
this circuit A/V modulator
http://www.velleman.be/Downloads/0/illustrated/Illustrated_assembly_manual_K4601.pdf
photo
http://www.futurashop.it/images_la/8220-k4601.jpg
I would want to know, the coil of 10,7 Mhz(L4), of that color must be?
thanks

 

It looks like a Toko 10.7 MHz IF coil with an internal capacitor.
External capacitor C11 reduces the resonant frequency to 4.5 MHz, the
TV sound sub-carrier offset. It relies on intermodulation in the
output stage to cross-modulate this onto the UHF picture carrier. You
might have difficulty obtaining the Toko coil, but you could easily
wind your own coil for 4.5 MHz.

 

"Andrew Holme" <> ha scritto nel messaggio
.. You

which color is the nucleus? I have one coil with red nucleus

 

Does it have any numbers on the side? Where did it come from? I'll
have a look in my Toko catalog when I get home tonight. Does it have
an integral capacitor? Can you measure the resonant frequency?

 

No!under, close to the condenser it has one small written, me seems AV1,3

bought in store

I'll

how it is made?sorry!

 

Toko made a lot of different red coils. Some of them were for 10.7 MHz FM
IF, but not all.

 

how I would have to make? to buy one orange coil and an other rose and to
try(?)

 

Which type do you have? See http://www.gekade.com/GKD/TO_TOKO.htm

Buy a GDO (Grid Dip Oscillator) or an LC-Meter to mesaure the inductance,
and wind it yourself. You need it to tune 4.5 MHz for the sound
sub-carrier.

 

At which point, one might as well just grab a 4.5MHz transformer.
In North America, they were common in tv sets, because that's the
frequency of the sound IF. I don't know whether they still appear
nowadays, or if they've been bumped off by 4.5MHz ceramic filters.

Michael

 

Excuse me!! I can say to you that he is of 10mm,mi seems 7kn
Under the coil AVI31.Io is written does not know what wants to say
I can say to you that he is of 10mm,mi seems 7kn. You can you give a link
in order to construct the coil to me
(on the Italian NG, a lot has not helped me)

 

http://www.qsl.net/ct1efl/inductors.htm