Tesoro Tejon

[hugo]

Hello,
Here is my schematic under Eagle V5.
I stilll have to check the components package before sharing it.
Hugo

[GSL]

Hello,

I am converting this schematic to Eagle V5.

1) Who can explain these switches ?
What are they doing ?
I don't understand the relationship with the 4053 IC ... They are drawn like mecanical switches.

2) Is this a pot. or a trimmer ? What for ?

Thank you,
Hugo

I think the switches are not needed.
P 101 - trimmer

[hugo]

Hello,

I am converting this schematic to Eagle V5.

1) Who can explain these switches ?
What are they doing ?
I don't understand the relationship with the 4053 IC ... They are drawn like mecanical switches.

2) Is this a pot. or a trimmer ? What for ?

Thank you,
Hugo

[Derx]

N@SKO :
R101/C43 supply or R101 connection !?

best solution

http://www.geotech1.com/forums/showpost.php?p=152987&postcount=11

[Derx]

79l05 for -5v
disconnect transmitter power from negative voltage - increase stability all sheet!

transmitter power to +12 volt

[hugo]

N@SKO :
R101/C43 supply or R101 connection !?

[hugo]

@N@SKO :
Nice work !
But only OP1 supply is shown.
What about others OP AMP ?

A 78L08 regulator is used for +8V and a Ucc384 regulator for -5V.
What do you think about LM2930T-8.0 together with a 79L05 ?
You don't need a LDO regulator for -5V.
The 79L09 dropout voltage is 1.7V and you get -8V from the 7660 : |-8V| - 1.7 = 6.3 V which is higher than |-5V|.
(Just like the +5V line).
In the other hand, you can use LDO regulators for both +5V and -5V.
Moreover, with the LM2930T-8.0, you can power the card with a single 9V battery.
The audio stage can works with 9V.
Note : if you want a standalone operation of the voltage inverter, you can used a MAX1044 instead. It's got a boost pin to increase the internal oscillator above 30Khz.

http://datasheets.maxim-ic.com/en/ds/ICL7660-MAX1044.pdf

Regards,
Hugo

[ivconic]

[N@SKO]

I sold Tejon before long time

[ivconic]

c3 must be <100 pf F=18khz
c4 must be 5 pF or 10 pf

Can't you measure those?
Conventional C-meters allows in-circuit measurements (at least the one i have).
C3 can be <100pF.
C4 can be even omitted or in range <470p i suppose.

[N@SKO]

c4 must be 5 pF or 10 pf

[Skippy]

C3=1nF seems OK to me. But no way is C4=10nF, that would give a low-pass response with f=1500Hz. A value of 100pF or less is more likely.

[N@SKO]

c30 = 1nF is Ok
c3 = 1nF must be 10 pf I think

[GSL]

Some fixes

[Derx]

Make a transmitter power of +12 volts, and the solution to all problems, and -8 volts to put on the chip

Disc1/disc2 remove. One diskrim enough