17 February 2017

Pioneer SX-800 - round 3

The stereo again?
So soon you're wondering!
Well that's how to get a project done.
Don't stagnate too long,
it'll start turning into a shelf.
Plus what else am I to do 
with the family 1000 miles away!!
A quick recap...
the problem was a scratchy electrical noise out of one side.
Switching tubes, cleaning pots and recapping didn't fix anything,
it actually made the scratching more clear.
I found a copy of the original sx-800 manual,
with the master list of resistors and capacitors.
Wow.
About 111 resistors in this thing!!
The list made it much easier to order,
otherwise most resistors use a colored band/stripe code.
That would have taken forever.
The downside was I bought all the resistors and a few ceramic caps.
Fortunately only $45 or so shipped.
I over-researched the replacement variations.
There are wire wound, carbon and metal film,
with multiple versions of each type.
Online companies like Digikey and Mouser 
stock basically all the variations for $$,
however a site called justradios.com
specializes in tube restoration,
and they carry what works in most instances.
Their ordering menu is quick and easy.
The down side is there selection is more limited.
Instead of a large pipe style wire-wound,
they had the newer ceramic style,
which needed some hot rodding,
more like rat rodding.
JB weld rated their epoxy at 500 continuous degrees.
This was the perfect test piece.
Good thing these have a shield,
what an ugly mess!
It took two short evenings to replace this pile.
By rough calculations this would take 20 evenings to finish!!
Looks like a big blur to most of ya I'm sure.
Underneath I concentrated on the tone control portion front center,
bass and treble,
as there was a weird thump when the low filter switch was switched.
Out of curiousity the old Heathkit multimeter was brought out.
Let's check out the ohms! 
This carbon dogbone style is known to degrade with time, moisture and heat.
Nothin was way out of spec,
as these all have a 20% tolerance!
Interestingly enough,
the resistors in the pics above
don't match their #'s on the sheet.
An 8 degree colder change in temperature changed them by .02...
Guess what?
This thing sounded perfect!
No more annoying scratching noise.
Bummer was not knowing exactly which ones were the culprit.
Those brown circles - ceramic capacitors,
looked questionable but I can't test them.
Great...
Now what to do with the rest of the pile!
I'm figuring that the resistance changed with the tube heat,
well beyond their 50 year old specs.
I'll probably swap at least 20-30 more out.
After about 4 hours burn time,
no big pops of smoke so far!!
Just in time too,
the boys flew up here to visit,
and snagged my PDX listening station!
Good times...
TP

15 February 2017

The challenge- Kubota L3750 tractor

Ok remind me next time 
to take before and after shots.
This is an after-after shot!
Lower your light setting,
and squint your eyes,
and that's what this tractor looked like.
A power washing uncovered bright orange paint,
and multiple signs of age.
Everyone said this was in its last legs,
beyond its life expectancy.
Hyeeellll no...
Them's fightin' words!!
If the engine runs,
the transmission changes gears,
and the hydraulics hydraulic,
I'll keep this thing alive just for fun!
Actually it's more of a necessity.
Basically all the equipment here is either donated,
castaways or auctioned beaters.
The lifeblood is called
"Friends of PIR",
a local group which collects donations to acquire needed chit.
All handouts are welcome!
I'll have to edit a link in here...
This place works with the good ole shoestring budget,
and that's what makes it right up my alley.
Who wants to work on new chit?
This poor beast hadn't been serviced in years!
Besides the overdue fluid changes,
I tried to put as much lipstick on this pig as possible.
It's funny cause there's bits and pieces 
of experience years of experience here.
I've done the same fixits just not on a tractor.
Torch and clamps...
Grinding and welding...
Holes and zip ties...
Cheesy but strong brackets...
This canopy flapped like chicken wings,
it was like watching a cartoon character.
Lastly was the punch in the face mug.
Doesn't it look like a beat up transformer?
It's sayin "give it to me...
I can take it!!"
F
I removed the broken lights,
whipped out some bent screens,
and sewed the grille with zip ties.
Dirt and leaves had blocked half the radiator!
From 30 feet it looks 10 years younger,
and should last at least double that.
Good times....
TP

11 February 2017

Pioneer SX-800 - Round 2

Ok,
Its raining or snowing,
you're stuck all alone,
what are ya gonna do...
Watch a bunch of movies,
or tinker on a project?
Well ya know what I'm gonna do...
I was wound up for this one,
parts were ordered a week in advance,
arriving just in time for a winter weekend.
You probably were hoping I'd be done writing about this.
The previous time only the suspect "Suzuki" caps were swapped,
unfortunately not fixing the base problem,
which is this random crackle noise coming from one side.
A late night was spent sucking in soldering fumes.
After this batch was replaced,
all the bottom caps were now new.
Looks like fun huh!?
Well it's not when you plug it in and it doesn't work.
At all.
Holey Chit.
Going to sleep with a broken fix isn't fun,
however waking up at 4am knowing the problem is.
Weird how the brain works like that.
Thankfully an easy and obvious issue,
a power diode wire had broken.
Whew.
Wow,
now it really sang.
The tube sound is like being bathed in warmth.
What a feeling of accomplishment.
For about an hour or two.
Holey Double Chit...
Good thing there was a Plan 2-B.
See those black and blue things on top there?
Those would get rid of the last electrolytic capacitors,
which are known to leak or degrade after 10-15 years.
All righty now they're installed,
all but one anyway,
nice fat new filter caps.
Time to shine...
Again...what clarity, what bass!!
Yes! 
Mission accomplished!
For maybe two hours.
Holey Triple Effin Chit.
There's a saying for this...
"Fuck this - lets ride"
Snow and rain clear my head!
I made it back without taking a slide 
and busting myself up.
So...
The crackling issue creeps as the amp heats up,
and swapping tubes to different sides
doesn't change anything,
meaning the tubes should be ok.
Also hitting low/bass filter switch will make a thump.
I'm no expert,
buy I am a quick online study.
See those grey dogbone like things?
Well those are Suzuki carbon composition resistors,
supposedly not the greatest for age, heat and moisture.
I ended up ordering every replacement resistor,
even the brown and blue ones with the stripes.
About 111 total...
Yikes.
Also,
see those round brown discs?
Those are ceramic capacitors,
which supposedly are very durable,
but what about when there is white stuff on them?
Cheap enough replacements to gamble,
everything was less than $50 shipped.
Sadly I had to let go of an old stablemate.
The Sansui 2000a sacrificed itself for this bout,
it had its 45 year old issues and ya gotta choose your battles.
Let's see how Round 3 goes!
ding-ding...
TP

05 February 2017

ram light truck salvage - PDX

So I was dickin round with this thing.
This rear brake anti-lock proportioning valve.
The more it was tore apart
things just got worse and worse,
unlodging years of jammed sludge.
Cleaning it was easy.
Putting back together not so much.
Leaked like the proverbial sieve.
Nothing at the typical parts store,
dealer wanted a mint.
I was referred to a local junkyard,
Ram Light Truck Salvage,
a literal parts house.
Rooms were organized with greasy treasures.
A transmission tore up on the living room floor to get a gear,
the dining room now the cash wrap,
a surreal sight.
They had the 2 year only brake valve,
knew exactly where it was.
Gotta love it!
TP