Coleman Model 200A

On a whim, I picked this up for $0.25 – it’s a bit of a mess but should come apart, free up and hopefully be useable.

Coleman dirty

Welp, there go the meta tags. It’s sideways. Gave it a bit of a clean up.. looks a lot better- the tank is painted but the lid is red stove enamel.

cleaner coleman

The pump, pipes and everything are jammed up solid with old gooey kerosene and dirt, so that’ll be fun to clean. It’ll get there though. This one is more efficient on fuel than the bigger twin mantle one I have.

Film photography and a 386

I went to an estate sale at the end of last week and picked up a few things, the computer below and a camera, of the notably interesting items.

386

A 1993 Magnavox (Philips) 386 SX/20, with optional CD-ROM sitting on top. It was grimy on the outside, filthy inside as to be expected from an older system.

A1

After a thorough cleaning, the Canon A-1 camera. 35mm film camera with fully automatic exposure (AE). View through the viewfinder (this shot before I had cleaned the lens and filter, so it’s a bit hazy) shows the aperture and exposure time in f/stops and 100ths of a second respectively.

viewfinder

It’ll calculate that and set itself if you leave it in fully programmed mode.. fancy stuff. Bought a new battery for it and a foll of Fuji 400.. have been shooting some pictures so once that’s finished I’ll see if they came out OK.

wolfenstein

Got the computer running after giving it a thorough clean and fixing a couple contacts. Found a cable to replace the one in the back to link to the CD. Added a network card so it has CD interface, network and sound. Multimedia on a 386, before “multimedia” was a coined phrase!

cd working

Added a larger hard drive in (540Mb, or rather, 30Gb but partitioned down to the max the BIOS can handle without an overlay) and got the CD to read. 1x so it’s not fast but it does work!

AM Radio

This is a fun one for me- I’ve had this radio since I was about 12- I had gone to my school for the tombola/fair/jumble sale. I bought one of two radios, initially the one I god was a white plastic deal, brand I forget, and one of my friends- Alex Biffin- bought this one, for 50p (about, what, $0.75 these days). I bartered this one for his radio as this one worked better. It’s a Roberts RIC-1, the first radio to be produced in the UK to incorporate an integrated circuit (IC) into the design, making the design a lot smaller.

radio

It worked for a while until I dropped it and it stopped playing. I took it apart and determined the cause was the IF oscillator coil because it would sometimes crackle into life if I twisted the can. I tried to search around, went to the radio shop in Wells (long since gone) but nobody had the part available, so I shelved the radio.

Fast forward two decades and I decide to pull it off the shelf and try fix it, with greater knowledge, experience and Internet behind me these days. I found a service manual for it, something that was totally unavailable back in the day.

apart

Took it to bits, gave it a bit of a clean up as it was rather dusty. The loudspeaker wire had also broken off so that got re-soldered on. Still, nothing from the speaker as before.

LP1175

The offending article, a twin transformer coil in a can marked LP1175, apparently a fairly common part made by Philips back in the day.

angle

Same device, from a different angle, also the TAD100 IC that gives the radio its’ name.

can removed

De-soldered the IF can and set it aside, looking at the connections.

coils

Further dismantled the can, removing the outer shelding, and also the inner ferrite shield that surrounded the primary winding. Pointed at there with the tool is a glob of glue where the primary coil windings pass through- which was fractured and had broken the fine wire.

new wire

I managed to unravel one length of wire from one end of the coil and re-soldered it to its leg, the other one was underneath the rest of the windings and wouldn’t come undone far enough to be long enough to reach. I took a piece of regular multi-strand cable, took one strand of copper out of it and fixed it to the short leg- the rest of the windings are covered in varnish so wrapping it around wasn’t a problem.

extension

Attached the extension piece to the leg it needed to be fixed to. Put it all back into the circuit, twisted the power dial and POPCRACKLEHISS. Wonderful! Tuned in a local station, a joy to hear audio from this radio after so long.

The loudspeaker had seen better days so I carefully made some repairs with coffee filter paper and Elmer’s glue (PVA) after doing a bit of research on the Internet about basic cone repair.

coffee paper and speaker

Cutting out more pieces and carefully reshaping the edges lef to an acceptable repair that no longer vibrates with bass notes.

fixed speaker

With that done, I set up my test rig and began aligning the radio- it wasn’t bad but it is now easily capable of picking up WSM that broadcasts from Nashville, TN.

aligning

It’s nice to have this radio working again. It got the kids interested in the theory, so with the new Snap-Circuits set (circuit building set we got from Elenco) built a small, basic AM radio. Fun times!

Sensors and an unfortunate incident of unplanned ingestion

I’d planned for a while to change the intake air temperature sensor on the Renault because it had been reading a little “odd”- erratic and not really reflective of the world in general.
I ordered a replacement part- the closest I could get in terms of fitment is for a 1991 Jeep. The thermistor curve is the same as mine, as is the physical fitting. The only difference is the wiring connection.

undo

I don’t have a 19mm crow’s foot so slight tool abuse saw the old sensor undone.

old sensor

The offending article. Rather grubby (not that it really affects it) from being in the flow of fuel and air.

closeup

Closer inspection shows that the thermistor bead is cracked. That’ll be why the readings have been a bit strange.

comparison

Comparing old versus new. Same, barring the socket.

tools

Head inside into the warm to get set up with the tools required- I don’t have the proper Jeep socket so I decided that the heat of the engine in the location shouldn’t be so high to melt solder, so I would reuse the original connector.

chop chop

A quick spin of the Dremel later and the connectors are exposed.

trimmed and soldered

Trimmed the lugs down and soldered the old wires on.

heatshrink

I’d added a couple pieces of heat-shrink tubing to the wires before soldering them on. Fired up the propane torch outside to warm them up to shrink them down to the wires.

heatshrunk

A little bit toasted but shrunk down nicely.

reinserted

Inserted the new sensor and connected it all up. Noticeable difference now on cold start, before the oxygen sensor warms up and begins to give trim readings.

computer monitoring

I took the car for a drive and it was a lot better. When I got back I popped the hood to check on things and in doing so, leaned on the airbox, which was stone cold- that’s wrong for this kind of weather as the preheat damper valve should open up and draw warm air in from around the intake manifold. Took a bit of a looksee at what was going on. The vacuum operated valve was working when vacuum was applied to it. I took the throttle body hat off and found this:

thermo-valve

That’s about one-third of a thermostatic vacuum valve that controls the intake preheat damper flap. The rest of it is… gone. That will likely be the bad misfire the other day and the reason for the plugs being covered in dirt and having closed up, with bits of the valve being drawn into the cylinders and bashing about at the insides.

boroscope

I borrowed the 1979 Edmund Scientific fiber boroscope from work to have a look inside to see if there was anything left in the manifold that needed to be removed or any damage to the inside of the engine.

intake poke

Pushed it down the intake and had a look inside the manifold.

air sensor

It’s a bit difficult to get pictures from but that’s the new intake air sensor down the intake towards no.1 cylinder.

Took the plugs out and had a look in the bores.

crown

Top of one of the piston crowns. They all looked good. Put the mirror back on and took a look at the valves.

exhaust valve

Exhaust valve- looking good. A few signs of chips in the deposits in pots 1 and 2 but nothing substantial, thankfully. Looks like it broke up and was ejected in pieces out of the exhaust.

5 volts

Took a few readings from the throttle position sensor as it was acting a bit weird. Measured OK, and came up better after having been reconnected, so probable cause is a bad connection at the device. Back up and running, but I need to go to Dodge to see if they have the thermostatic valve.

Finding a leak that doesn’t exist, and a broken timepiece.

I’ve been having a hard time finding a few problematic issues with the Renault lately. Particularly it had started to leak power steering fluid quite badly, which would mark the floor where parked up and also get onto the auxiliary belt and make that slip.
Looking down from above, past the alternator and air conditioning compressor the pump looked rather wet, so I splashed out $14 and bought a full seal set for the pump. I decided to clean everything up with degreaser and refill the system, to hopefully see where the oil was leaking from.

dismantle

Begin by taking everything out, including battery, battery tray, moving the air conditioner comressor, remove the alternator and the brackets holding it all in.

empty

That leaves good access to the power steering pump. The corrugated plastic tube is the wiring for the front of the car, the braided hose is the gravity feed to the pump from the reservoir.

scrubbed up

Cleaned up the pump with an old toothbrush and engine degreaser. Rinsed it all down with warm water from the potato pump.

clean

Got a bit carried away as I had water left, so I cleaned down the inside of the hood where the oil had flicked off the belt, and the surrounding areas also. Topped up the oil and left it to dry overnight an in the sunshine.

full

Left it for two days, then checked on the level. Unfortunately the oil was all there still.

still oil

Another two days. Nope, there’s still all the oil left in there. The leak has miraculously fixed itself. Normally, hot, cold.. didn’t matter. It would leak regardless of it it was run or not. Now it’s not leaking!

clean pump

The pump is clean and dry, no signs of leakage.

oily frame

The only other place I can see is the return line, from the rack back up to the reservoir. If that has a crack or a pinhole it could be leaking. The engine cradle frame is a bit oily down under the back but I cannot see anything else that would be causing a leak. Further investigation to follow.

The second thing that irked me was the previously well-working clock had quit.

broken display

The display had taken to showing mostly nonsense, or nothing at all.

clock out

Took the dash to bits (again) and liberated the clock from the little cubbyhole it’s attached to.

polished

Cleaned up the smoked plastic section of the clock as it was all scratched and hazy.

components

Figured there were a couple pieces that might have failed and caused it to not work. Replaced the electrolytic capacitor and transistor. No joy.

circuit diagram

Followed the traces and built a diagram of what went where, to get a bit of an idea of how it all worked.

dead

Tested it but the chip was dead. No oscillator, just noise. The clock circuit boards are available, but they are a Jeep Wagoneer part, and as such suffer heavily from Jeep Tax and are therefore expensive.

zeroes

Upside-down image but poking power to the grid brought some nonsense up on the display so the VFD was all still good.

9

Poking about a bit more showed that some of the logic was alive, as various numbers could be liberated. Nothing sensible though.

led

Purchased a little LED clock with voltage and temperature capability for ten bucks, with the intention of fitting it into the clock as shown- looks OK but a little out of place and the very-bright display has no dimming capability.

dismantle

Decided to strip the board down and re-use the VFD, with the new clock module providing the logic. I’ve ordered a little 50V boost converter to drive the VFD, that will be proven to work first then I shall go ahead and get some high voltage transistors, pull the LED’s off the clock and use the output (multiplexed in the same way thankfully) to drive the VFD. Original clock, original display, just now with time, temperature and voltage display. Watch this space for updates.

Boosted.

The past week has been particularly clement in terms of weather- dry, sunny, cool. Unfortunately I have had a bad cold and had been stuck inside.

My brake booster did arrive though.

box

Today, I was feeling much better so decided to tackle fitting it.

clear a space

First thing to do, remove the master cylinder and move all the wires and pipes out of the way.

nut

Most of the nuts holding the booster on were fairly accessible behind the pedals.

ratchet

Deep socket, extension bar and fine angle ratchet made short(ish) work of it, lain upside down in the footwell.

clean

Took the old one out. Surprisingly clean under there.

old booster

The old servo liberated. $10 core return, $12 to ship. I think not.

new booster

Stuck the new one in the hole and bolted it in. Much label.

tidy

Tidied up the pipes and wires better.

done

Boshed it all back together. Had a fairly decent pedal despite having not bled the system up. Brakes now work. I’ll bleed the system up with the MityVac and go from there. Next up, power steering pump seals.

Pipe failure

I had noticed I was slowly losing coolant, and had attributed it to slight leakage at the head gasket but after running the engine up to very warm, the heater return line showed up something interesting. It began to bubble.

stained pipe

Decided to replace this piece of shaped molded pipe. Typically, the side easiest to get to came off, but the difficult to reach part had to be removed forcefully.
knife

Coolant still looks good though (it started out life yellow).

draining

I think it’s an interesting manufacturing flaw, there are 2 similar pinholes along the length of the pipe.

pinhole

Managed to find a roughly equivalent piece at the store.

replacement pipe

Got it all fitted up and bled.

new pipe in place

No more leaks!

radiator

…or are there? Radiator was a bit damp. Thankfully that is from where I’d opened the bleed screw on top of the radiator and it had percolated down the fins inside and come to the surface there.

Redux of the last few months.

It’s been a slow few months with little to report. I’ve lost faith in a few things, with a couple problems and issues with projects that had me baffled and I kinda lost interest in them.

However, things have picked up a little and I’ve gone back to the troubled projects or made some headway.

I bought some replacement tuning slugs for the Marantz receiver. They aren’t 100% the same permeability but they are the correct screw thread.

slugs

Replaced them in the transformer after carefully breaking the old ones up and getting them out of the core. Now I know what they feel like, the old ones were broken before I even started- the lack of decent radio reception certainly points to that.

radio waves

I got all set up and the thing refused to tune well. I could get a couple of strong local stations but the tuning meter and tune indicator would not light up, and those are partially controlled by the transformer. I connected my oscilloscope to the input side of the transformer to check the waveform was not distorted and all of a sudden, LOUD radio, strong signal! Uh.. yeah ok. Reflowed the solder, no effect.. touched the oscilloscope probe to the transformer again gently, and bingo. Strong signal. Touched my finger to it.. improvement. Okay, so it’s a capacitance issue. Experimented and ended up with a 10pF ceramic cap across the terminals to bolster the transformer. Now the selectivity and sensitivity are great. It’s right now the best radio I have in the house for FM stereo.

Carried on with it but now it keeps tripping out into protect. I’ve troubleshot the protect circuit, one of the other boards must have a leaky cap on it somewhere. I need to pull the boards power supplies off one by one and see what fixes it.

Next up, refinished the floors at the house. Edging strip all done in the kitchen:

kitchen skirting board

Finished up in the utility room, flooring strip and the paneling done:

utility room door

Finished up the cabinet around the water heater:

water heater

Pulled the stove to bits and thoroughly cleaned it, the glass particularly was vile.

stove

Finished the floor edge strip in the living room, split the flooring between the two rooms where it was buckling and added a divider to allow for expansion.

living room floor

Rented a floor sanding machine and sanded the floors back, as previously they had looked OK, but having painted the walls and tidied up they were the least well-finished parts of the room.

floor sander

Solid cypress flooring. Smelled real nice when lain bare.

floor stripped

A few coats of polyurethane clear varnish later:

shiny

Looking much better. Also, picked up a nice Holophane light fitting on clearance for $4 at Home Depot. Fitted an LED light to it that has 4 segments inside, looks rather like a standard light bulb:

light fitting

Been troubleshooting the brakes on the car for a while. Stumbled across a post on a Ford Explorer forum with the same symptoms as mine. Turned out to be a faulty brake booster servo. I’m going to vacuum test mine this afternoon, have my MityVac for the purpose (shown here with brake bleeding catch-can fitted):

MityVac

Also picked up a GTE Palco payphone, which has gone into service here at the house, with the requirement for coin removed.

GTE Palco payphone

I repaired a little Realistic PA amplifier that got struck by lightning, and built a cardboard speaker to test it with.

amp and speaker

Also cleaned out and got fixed up the Kerosene lantern, for hurricane use.

kero lantern

That’s about it for now.

Another stereo.

Recently was offered this hi-fi by a work colleague. Garage clear-out, it had been sat in there for years.

Marantz MR1155

It’s a Marantz MR1155, from the early malaise years of cost-cutting and design setbacks. It also didn’t work. Power was applied before I got it, and apparently it went click and made a bit of a crackle.
Sure enough, it would power up and come out of protect, but not much else happened. Evidently the protect circuit was not detecting a particular problem so that was kinda okayish.

dust werewolves

With the lid removed, the contents of the device appeared to be mostly lint. Yuk. That has to be the worst hifi I’ve owned yet in terms of dirt.

clean

Thankfully it all cleaned up nicely.

stripped down faceplate

Pulled the front off after work, removed all the buttons (they had gone green and fusty) and brought it all home to clean up. Judicious application of drill and polishing mop got it looking respectable again.

shiny

Not perfect by any means but definitely better.

lid

Cleaned up and put the lid back on. Fairly respectable.

in bits again

Brought it all home and started to poke about. Pulled up the manual off HifiEngine and set about looking for the cause of no audio. Powered it up, the main amp voltages were pretty much in spec, but the FM/AM/Phono/Preamp board was dead, with hardly any voltage. Bypassed the preamp board and fed the power amp board directly- presto, greeted with slightly clipped but definitely OK audio. The expensive amplifier modules are still OK.

caps

Ordered the full replacement of electrolytic caps to shotgun all the boards. Over the course of a couple days I replaced everything. Still no voltages, so I replaced the transistors that control the voltage and protect circuit.. nothing much. Further troubleshooting found the 14V Zener to be almost a dead short over 0.3V so I went to desolder it and it cracked into 2 pieces. With it removed, bringing up the variac got the voltages to rise. There’s the problem then. Ordered a couple 14V Zeners and whilst in town stopped at Radio Shack and picked up a couple 12V ones to see if that would get it to come to life:

alive!

Sure enough. Not very good but operational. Went to tune the FM because it was not working very well at all post e-cap replacement. Broke the discriminator tuning slug (even using a fiberglass tool of the correct size) so pulled that out and took it to bits. Ordered a couple replacement cores, so need to wait until it’s all back together before readjusting.

10.7MHz transformer

Go figure. It had to break..

Reflective! Also, frosty.

Bought a mirror from a gentleman in Canada.

mirror

Bottom one (old) being held up. Sunshine and humidity made all the silver fall off. The new one looks new by comparison.

Also moved the car and mowed because the grass is growing fast this season.

grass

That’s 4 days’ worth of grass growing around here.

frozen

Also the new heater element arrived for the freezer. Not a day too soon, it was beginning to freeze up. That again was 4 days’ of ice.