Errata to the kits of Gigatech


Tension-regulators U2 in the transmitter

In the transmitter, the tension-regulator U2 has input and output exchanged! U2 is the 78L09, that looks after the two BFR90. Remedy: bend the middle-pin of U2 (GND) into the opposite direction and install the tension-regulator 180° to the direction stated in the equipment-plan. (tnx info DH1DM)

Transistor holes in the transmitter

In the transmitter, the holes for the transistors T1 to T4 can have originated short-circuit through the mass-ends. If in doubt, rework the circuit board with an appropiate drill or a file before equipping.

Mass-Pad C5 in the 7W-final-stage

With C5 in the 7W-Pa, a Pad hangs in the air with some circuit boards. This must be connected with mass.


Errata to the VHF-Meeting '97 Skriptum


Testmode

The testmode of the SDA3302, that enables the frequency-measurement at the test-points 2 and 3, can lead to a 12,5 kHz ridge-spectrum on the VFO signal. The SDA is programmed on testmode therefore only then, if is soldered when aiming the care-tension a 330 ohm of resistance of pin 7 of the PIC12C508 after mass. If transmitter or receiver should be switched testmode to the Frequenzabgleich in it, this resistance must be soldered in on the circuit board-underside externally. Don't forget the unsoldering afterwards! The resistance is marked in the diagrams as R_TEST.

Quartz-oscillator SA626

The oscillator in the SA626 doesn't certainly swing with all quartzes at. Remedy manages a 10k opposition of pin 3 of the SA626 after mass. This is intended in the diagram and in the equipment-plan as R26, but with the circuit boards delivered at present from Gigatech not yet considers. As SMD-Widerstand, he/it can be soldered in however easily at the position stated in the equipment-plan.

Oscillator-spool TDA5331

The oscillator at the TDA5331 swings 80 MHz oberberhalbs but 80 MHzes below the reception-frequency no longer. The oscillator-spool L5 at the TDA5331 must be increased on 2,5 meanders for this.

U3 transmitter-piece-list

U3 is not 78L05 but a 78L09. (tnx info DG9FDA)

R5 transmitter-piece-list

R5 is not 22 Ohm but 22k in opposition. (tnx info DG1SCR)

R13, R20, R21 receiver-piece-list

The above resistances are SMDs.


Copyright © 1997
This page was created by DL2ZBN, Sunday, 28. December 1997
Most recent revision Sunday, 22. March 1998