Ramsey Electronics HR40 Manual de Instruções descarregar pdf (Página 19)

FHT-1 • 19

Also there is a provision to adjust the “high power” output. Notice that jumper

J5 connects the collector of Q8 to the final transistor Q6. by removing this

jumper and installing a suitable resistor (remember to calculate the power

dissipation) the high power output can be lowered from its full 5 watt value.

Please understand that these modifications should not be attempted unless

you are experienced enough to calculate the current and power yourself and

they are not recommended until after the entire unit has been fully tested.

The testing instructions are intended for the existing unmodified kit.

As long as we’re stopped already, now would be a good time to recheck your

work, focusing on parts placement and soldering. Are all the components

snug to the PC board? Resolder any connections that are less than perfect,

and trim all the leads to a reasonable length.

 105. Install C1, .01 uF disc (marked .01 or 103 or 10nF).

 106. Install L1, a 6 hole ferrite bead wound previously.

 107. Install C34, 100 to 220 uF electrolytic capacitor. Remember that this

capacitor is polarized, so be sure to orient it correctly. See the parts

layout diagram for correct placement.

 108.Install L2, 1½ turn coil wound previously. Ensure it sits 1/8 inch

above the PC board, as shown in the diagram.

 109. Install C12, trimmer capacitor (black body with orange top).

 110. Locate Q6, SD1127 RF power transistor. This transistor mounts

somewhat differently from all the other parts. Turn over the PC board

and set the transistor snugly into the large hole and bend the leads over

and into the indicated holes. The leads should be as short as possible

without shorting against the transistor case. Solder the three transistor

leads. See the drawing below.

 111. Now we call for something unusual - soldering the transistor case

to the PC board. Run a neat "flow" of solder around the gold transistor

Heavy buss

wire jumper

(not a scrap component lead)

1/2 inch

PC board

Wire sits flat

against board

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Ramsey Electronics HR40 Manual de Instruções Página 19