Kvarts

[zum-zum]

kust kohast oleks võimalik osta 38kHz kvartsi
nimelt siis mitu projekti katki jäänd et pole seda kvartis olnd lihstalt mitte kusagil :'(

[muhkel]

Ilmselt ehitad FM Stereo saatjat. Pane kvartsi asemel 100pF kondekas ja sellele paralleelselt peale veel trimmer. Kokku peaks mahtuvus olema kuskil 110pF kandis (timmid vastuvõtja stereoindikaatori järgi paika) ja sellega töötab mis mühiseb, proovisin ise järgi!

http://wiretap.area.com/Gopher/Library/Untech/fm10.faq

Stereo Pilot Mod
----------------
One of the first problems experienced with the FM-10 is difficulty
in getting the stereo pilot to operate correctly. One solution is to
replace C7 and C8 with a 38khz crystal, this works the best and is
recommended. If you cannot find a 38khz crystal, you can make your life
a whole lot easier with a couple part changes. As indicated on the
Ramsey schematic, about 110pf is necessary to tune the oscillator. The
components supplied to achieve this are a small fixed value capacitor (C7)
abd a slightly larger value trimmer (C8). Since proper setting of the
trimmer occurs within a very small 'window' (about 5% of the trimmers
range), it can bet difficult or impossible to adjust the pilot to 19khz
and have it stay put. This can be cured by increasing the value of c7 to
100pf and replacing c8 with a 6-50pf trimmer (Radio Shack #272-1340);
a 5-30pf trimmer will do the trick. The RS trimmer will not fit the holes
in the pc board; one needs to cut the leads off a spare resistor and
solder them to the legs of the trimmer (just use bits of wire) to mount
it on the component side of the board.

On a 2nd note I replaced c7 with a 68pf cap and found it much easyer to
tune a rock solid 19khz at the test point.

Crystal Mod
-----------
old set up new setup
c8 c1 xtl where c1=10pf and xtl=38khz
|-||-| |-||-||-|
| c7 | | | v8=var cap
|-||-| | | c7=cap
| | | |

Remove C7 and C8, replace with 38khz crystal and 10pf cap. Note that
the 10pf cap and the crystal are running series and the old cap setup
is running in parallel.


Kehvalt on näha, vaata parem linki, seal on ühendus paremini näidatud!