Monthly Archives: July 2015

Oil, linkages and exhausting work

Decided today that I really needed to do an oil change on the Renault. I’d bought some oil and a filter that were on special the other day. $16 for an oil change is hard to beat, really.

sign

So, we begin. The sign is apt. Up on the ramps.

ramps

8:30am and already 32 Celsius. Inside the metal building was already like an oven.

clean

Gave the undersides a wipe over. Still looking good.

more clean

Yup, still looking pretty good under there.

bushing

That, however is not looking so good. I was wondering the source of a clonk-clunk from under that side. New bushings are available.

oildrain

Began to drain the oil. Wasn’t too bad a color, considering.

cam

Top end looks okay also.

filter

NAPA “Silver” filter, Wix inside apparently. Replaces the Fram which I wasn’t very impressed with.

oil

15W/40 oil. Diesel stuff, so eh. It’ll flush some dirt out. It needs that anyhow. Took the king lead off and cranked it over until the oil pressure light went off.

gears

Replaced the bushing on the gears and added the white rubber bit which tightened up that section of the linkage up. Sadly the ball-joint behind it is where the slack is.

hacksaw

Made a start on the exhaust, which was annoying me. Unfortunately the hacksaw blade was blunt.

bits

Took the scaffolding tube out, removed the clamps and bungees.

pipe

After much sweating and swearing I realized I could finagle the pipe out from where it was because I had enough clearance from being up on the ramp.

less pipe

Removed the offending, holey section.

new pipe

Bought a length of 1 7/8″ pipe with a 2″ flare on the end, coupled with a nice chrome bit.

support

Got a bit creative with the old bungees and clamp. Supports it nicely.

exhaust

Yeah, that’s good enough. Better than it was, sounds better also.

…and then there were two.

I’d had an offer of another QX-747, as spare parts. Initially just as “any bits you want off it”, but the cost of shipping the entire thing was not too bad ($43) so I bought it outright.

box

It arrived today. Well packaged, as the courier was UPS.

smash

True to form, it had been dropped on all six sides and also on a corner. The speaker terminals and RCA jacks had made a nice imprint in the styrene.

looks ok though

Despite that, it’s all in one piece and unscathed. Cosmetically a little bit left to be desired, but for the price I am not going to complain.

in bits

First thing to do? Don’t power it up, pull it apart! It was sold as “not working”, so I wanted to test that theory. Out with the Variac.
Raised the voltage up a little, to about 60V- before the protection circuit has a chance to kick in- and measured the voltages on the amp board. Everything at about half of what it should be. Good deal. Bring voltage up steadily and… CLIK goes the relay. Power down, unplug and go over all the switches and pots with deoxit, then after that dried, faderlubed the pots.

Flashlight poked about, no signs of distress, no hot transistors or caps. Hooked up test speakers. Switched on FM. Pulls in a bunch of stereo channels with no antenna attached. Good sign.
Left channel operational only. Wiggled and pushed buttons, dialed dials. Right channel can be made to produce sound when in RM or SQ mode, which means the feedback is operational from one channel only.

Wiggle wiring around switch bank and tuner section. Nothing much. Hooked up to rear speakers, all channels work. Switch to AUX, hook up Walkman, greeted by stereo. Moved wires to PHONO input, dialed volume of Walkman way down, left channel only. Tape input stereo.

Began to get really quite hissy (transistor noise) so powered down and buttoned it back up. Not a complete basket case, seems like the right channel of the EQ amp is bad so that should be a fairly easy fix.

Need to address the paint on the front panel where it’s coming off (looks like it’s had something spilled on it- amp smells of cat dander and there’s fine hair so pusskins may have made weewee on it and taken the paint off.
Rest of it is cosmetically pretty good so verdict? Not a basket case, due for rebuild.

All pretty good now

So, the final shipment of bits arrived. Unhooked the control amp boards to recap them.

control amp board

Tada! All redone. Times two. Both the front and rear boards are identical.

recapped tone board

DeOxit’d and FaderLubed the potentiometers, then turned my attention to the pointer, which had been bugging me since I had learned that it should glow.

dial pointer in bits

Carefully bent the metal tabs up and liberated it from the scale movement. Inspected the bulb and sure enough, the filament was rolling around inside the glass, burned.

wires

Stripped the wire back carefully as it is about as thin as a hair, and tinned the conductors.

bulb

Carefully soldered on a replacement (12v 60mA one from Radio Shack, correct one should be 8v 60mA) to see if it worked.

led

I had considered a red LED, bought this side-shining one but unfortunately it was a little big and I didn’t fancy modifying it.

light

Yes! Okay, good deal. Not as bright as the original, but running at a lower voltage it should last for ages.

all glowing

Polished the plastic pointer so it wouldn’t show the light up anywhere other than the end. Looks good.

refitted

In a darkened room the effect is good, a little floating red dot on the dial scale.

nice

Enjoyable to listen to. Adjusted the AM alignment a bit and got that much better, though it needs further adjustment because it’s a bit weak on the low end of the scale. FM is better but still pretty horrendous. Thinking about sending it off to be aligned professionally. For now, it works.