Elecraft XV Transverter Owner's Manual - Manual (Page 23)

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Optional Crystal Oven
The crystal oven elevates the temperature of the local oscillator crystal
and keeps it constant so long as power is applied. The oven greatly
reduces frequency drift due to changes in the ambient temperature that
affect the crystal. Contact Elecraft or visit the web site at
www.electraft.com to order the crystal oven.
Install the oven as follows:
i
The oven fits over the existing crystal. Be sure the crystal is
installed before installing the oven.
Remove the four screws and the top cover to gain access to the top
of the RF PCB.
i
In the following step, you will remove the 4-40 nuts holding
the long screws at each end of the RF power module. Do not allow the
screws to fall out of the bottom of the transverter.
Remove the 4-40 nut and lock washer on each end of the RF power
module.
Invert the transverter so the bottom side is up. Place it on a clean
surface to avoid scratching the paint.
Remove the four corner screws holding the bottom cover.
Carefully lift the bottom cover off of the transverter. The two long
screws that secure the RF power module should come out with the bottom
cover. Be careful not to disturb the flat washers between the RF amplifier
module and the PCB. If one does slip out of place, reposition it. The
correct hardware placement is shown in Figure 14.
Remove the two long screws from the bottom cover and replace
them through the holes at each end of the RF power module. Replace the
nuts finger-tight to keep the washers and module in place while you work
on the RF PCB.
Position the oven over the circle marked OV1 on the top of the RF
PCB. The crystal will fit into a space on the bottom of the oven. The
three leads on the oven fit into the +, - and NC pads on the PCB.
Bend the leads over on the bottom of the RF PCB to hold the oven in
place, then tack-solder one lead.
Check to be sure the oven is fully seated down over the crystal and
against the PCB. If necessary, re-heat the soldered lead and adjust the
oven’s position.
Solder and trim all three leads.
Remove the two screws you replaced at each end of the RF amplifier
module. Be sure the flat washers are in place between the module and the
PCB. If necessary adjust their position so the screws will drop through
them when the bottom cover is replaced.
Set the bottom cover in place and drop the two long screws back
through their holes. Replace the lock washers and nuts on the top of the
PCB to hold the screws and hardware in place. Do not tighten the nuts
yet.
Replace the four black screws at the corners of the bottom cover and
tighten them.
Tighten the nuts at each end of the RF module. Inspect the RF
module to ensure that both flat washers are between the module and
bottom of the PCB (see Figure 14). Remove the cabinet side panel, if
necessary, to get a clear view of the RF module mounting hardware.