Zel's Fleet Blog...Jag, Citroens, Mercedes, Sinclair & AC Model 70

Post pictures and stories about your cars both present and past. Also post up "blogs" on your restoration projects - the more pictures the better! Note: blog-type threads often get few replies, but are often read by many members, and provide interest and motivation to other enthusiasts so don't be disappointed if you don't get many replies.
Message
Author
User avatar
Zelandeth
Posts: 737
Joined: Fri Aug 18, 2017 9:11 pm
Contact:

Re: Zel's Fleet Blog...Jag, Citroens, Mercedes, Sinclair & AC Model 70

#901 Post by Zelandeth » Mon May 17, 2021 9:21 pm

Really not much to report, though despite the weather I did manage to get TPA out for a run today when I had to go out and collect a couple of things.

Once more making normal modern cars look comically huge.

Image

I need to take a look at the idle adjustment as it is definitely a little on the high side. Not sure if the throttle cable just needs a little more slack in the adjustment or if the idle screw on the carb actually needs adjusting. It's one of those things that I keep remembering every time I have the car out, but immediately forget to actually get as far as doing when I get back home.
My website - aka. My *other* waste of time
Current fleet: 73 AC Model 70. 83 Citroen BX 14RE. 85 Sinclair C5. 85 Jaguar XJ-S V12 HE. 90 Mercedes 208D AutoTrail Navajo. 96 Citroen Xantia Activa.

User avatar
JPB
Posts: 10262
Joined: Fri Jan 07, 2011 3:24 pm

Re: Zel's Fleet Blog...Jag, Citroens, Mercedes, Sinclair & AC Model 70

#902 Post by JPB » Wed May 19, 2021 2:54 pm

Wow! that must be the world's largest Toyota Yaris beside TPA in the row of parked vehicles. As for the Alphard to the Yaris' right, you could pop TPA in its boot and still have space for two rows of seats and some cases of rum from the off licence.
On ancient electronics, yesterday's (18/05) episode of "Antiques Road Trip" - now available on the i-player - featured one of the presenters going into a museum of just such things; computers, calculators, you name it, their exhibits are fascinating and well worth the trip to Suffolk (I think, but it may have been Norfolk. Come to think of it, it may even have been Monday's episode..) :oops:
J
"Home is where you park it", so the saying goes. That may yet come true.. :oops:

User avatar
Zelandeth
Posts: 737
Joined: Fri Aug 18, 2017 9:11 pm
Contact:

Re: Zel's Fleet Blog...Jag, Citroens, Mercedes, Sinclair & AC Model 70

#903 Post by Zelandeth » Wed May 19, 2021 11:58 pm

JPB wrote:
Wed May 19, 2021 2:54 pm
Wow! that must be the world's largest Toyota Yaris beside TPA in the row of parked vehicles. As for the Alphard to the Yaris' right, you could pop TPA in its boot and still have space for two rows of seats and some cases of rum from the off licence.
On ancient electronics, yesterday's (18/05) episode of "Antiques Road Trip" - now available on the i-player - featured one of the presenters going into a museum of just such things; computers, calculators, you name it, their exhibits are fascinating and well worth the trip to Suffolk (I think, but it may have been Norfolk. Come to think of it, it may even have been Monday's episode..) :oops:
It is hilarious seeing TPA parked next to some modern cars isn't it.

Probably the last major installation on the Toshiba T1200 Revival now as we're pretty much there with it now...

-- -- --

Last week we had the little T1200 in a more or less functional state. There was quite a bit of noise on the screen now and then which I really didn't like, but I was at least able to copy the documents I'd been after off without incident. With the new capacitors in hand though it was time to see if they could improve matters.

So started what was without doubt one of the most annoying repairs that I'd faced for a long while. There were a few contributing factors.

[] The component density on the back of the PCB is such that this is really stretching the limits of how tiny traces I can deal with without a proper magnifier and kit to hold the work piece on the bench.
[] The tip on my soldering iron is absolutely shot...I have finally caved now and ordered a couple of replacements.
[] One leg of several caps is tied to the internal ground plane in the PCB which was acting like a giant heatsink and making it very difficult to desolder those pins - especially with a soldering iron with a stuffed tip.

I eventually opted to snip off the last few caps and just solder the new leads onto the stubs of the old ones...Which would have been far easier if I'd been able to find my good pair of side cutters. Of course I *couldn't* find my good pair of side cutters so had to resort to wobbling the caps back and forth until the leads fatigued and snapped.

The resulting hack job is without exception the most downright horribly ugly repair I've ever done. Though when I go through this job again in future I'll have a better plan going in, will make sure I have the tools on hand and also ensure that I actually have a decent tip on the iron. I reckon I could do a far, far tidier job in about a quarter of the time in future. I'm honestly ashamed enough of this one that I really don't want to show it! If the supply proves reliable I'll go back in and tidy things up a bit and add some support for the caps which are now sitting quite proud of the board.

Taking a look at the display backlight inverter board I don't think leaves us with any question as to why that was fading out over the course of a few minutes...

Image

I think that this one falls under the "caught it just in time" category given it was still functioning. With a thorough clean and a new set of caps I reckon this will be fine as a spare. Thankfully the inverter board in the spares monitor was mounted the opposite way up (no idea why!), so the leakage there hadn't touched the board, just left a stain on the inside of the case. So I stuck a new set of caps in that board and swapped them over.

Somewhat to my surprise when powered back up I had all the correct voltages present on the output terminals of the board (the -22V rail was actually showing a far better value too, it was only showing around -18V before, which I reckon is why the screen was struggling), and when hooked back up...

Image

Given what a messy job I'd done of it I was honestly quite surprised that it just worked properly. It was immediately obvious that the display was a lot happier too, I'm guessing the -22V rail struggling before was upsetting the bias voltage for the LCD.

It's quite interesting comparing the new capacitors being installed to those which came out, the fact that insulation technology has come on a fair bit since 1987 really does show in how much smaller some of the new caps are than those they replaced. In the photo below the new caps are to the left of those they replaced.

Image

I had mistakenly thought this machine had failed just before I finished secondary school, but the contents of the documents folder suggests that it made it into the first couple of months of my time at university too. Though reading some of the notes I'd taken there did a good job of breaking my brain a little - it doesn't feel like more than a year or two back that I was taking them...Definitely not 19 years ago!

I wanted to keep the machine up and running for a few hours as a stability test...Not hard when I discovered that all my Sim City saves had indeed survived.

Image

Well there went a couple of hours no problem! Probably looks a bit strange to people being in inverted blue on grey...but given how many hours I spent playing it like this seeing it in colour looks odd to my brain.

Back when I was using this machine as my "daily driver" I didn't have all that much DOS based software to hand. It was pretty much just VDE as the text editor, Sim City for when I got bored, and for reasons I can't quite fathom I had an image viewer on there as well...which on a mono inverted LCD screen is about as much use as a chocolate teapot...My guess is it ended up on there purely because I apparently got it in my head one day that I wanted to create a customised graphical welcome screen to show when the machine started up. Beyond that it was just a bog standard OEM MS-DOS 3.30 install - only interesting add-on I'd found was the program for setting the BIOS options...all eleven of them! Useful though as without this there's no way to enable the hard-RAM and suspend features, which I made plenty of use of back in the day.

Image

While this did everything I needed it to at the time, something I was acutely aware of being absent was anything whatsoever in the way of software to keep tabs on the health of my hardware. Something I was easily able to rectify today though. I've always had good luck with the Norton Utilities suite, so chucked that on there. This was obviously the result we were hoping for from the hard drive health check.

Image

Glad to see the surface test come back clean despite the 19 year hibernation.

Also meant I could interrogate the system with the information tools to see what they had to say.

Image

Not exactly a speed demon...but with a 9.81MHz 80C86 you're not really looking for performance!

Image

Might be interesting to do an actual performance comparison at some point between this and the Amstrad PPC512...

I've only got one other hard drive which uses a stepper motor based head actuator, and it's a good deal slower than the one in the T1200, especially where seek times are concerned.

Image

Though this result only really counts when the drive is "awake." After about five seconds of idle time this drive automatically parks the heads - which given how fragile drives of this era were, and with this being a portable machine is honestly a very sensible design choice I think. The downside however is that it takes a good half second for the head mechanism to unlock and get the drive back into read/write mode. Realistically, do you notice? No. Absolutely worth a bit of a performance hit...I'm pretty sure this design choice is one of the main reasons that this drive has so few bad sectors on it - about 20K's worth, which is an order of magnitude less than the other few drives I've got from this era. Latency was never going to be a huge strong point of this drive anyway given it only runs at 2650 rpm.

Given the relatively slow seek performance of it being a stepper motor rather than voice coil actuated head in the drive, defragmentation can (and does) really help with performance.

Here's some audio that should be a blast from the past for folks who used machines like these back in the day - that drive getting a good old workout while being defragmented.

https://www.youtube.com/watch?v=_Sl1jsAYHKo

I remembered something quite abruptly a couple of days back when backing up my old files...That file management from the DOS prompt is downright painful. Easily solved with Microsoft MS-DOS File Manager...which I'm not quite sure why wasn't just bundled with DOS back then as it makes things so much more usable.

Image

It's basically the DOS Executive from Windows 1 & 2 sans some of the graphics - even has a dedicated menu you can save shortcuts to commonly used programs/commands in.

Image

It's basic, but does what I need, and is all of 70K...so far I've not come across anything it won't run on.

With the machine having been running all evening it had been absolutely stable. The power supply was barely even warm - so the running conditions have definitely improved as it used to get really quite obviously toasty after half an hour or so.

Need to have a dig around and see if I can find anything else interesting to run on it...though to be honest I've got everything I actually need for it to do what I want it to now.

Last thing I wanted to look into was the battery situation. I've got two packs which appear to be taking a charge - but they're obviously not going to have much capacity left. I did have one that was as dead as a door nail though...An ideal candidate to be sacrificed to find out if they can be rebuilt.

Image

These packs are 7.2V NiMH units rated at 2200mAh. Annoyingly they're sonic welded shut...However I have a Dremel so that took all of a minute to get around.

Image

Chunky cells! Looking at them though, no surprise this one isn't charging.

Image

A bit of investigation revealed that they're bog standard C size cells.

Image

Well isn't that convenient? A quick look at Google seems to suggest that the going rate for NiMH C-Cells these days is 4000-5000mAh - so with modern cells in here we should be able to more than double the original battery capacity. Let's just remember...I was getting through a full day on the original batteries back in 2002 when they were 14 years old...We should be able to comfortably get 10+ hours on a battery out of this thing. Not bad for a 33 year old laptop.

Probably won't see a huge amount more of this thing now it's been officially revived (unless you want to and/or have anything you'd like me to try with it).
My website - aka. My *other* waste of time
Current fleet: 73 AC Model 70. 83 Citroen BX 14RE. 85 Sinclair C5. 85 Jaguar XJ-S V12 HE. 90 Mercedes 208D AutoTrail Navajo. 96 Citroen Xantia Activa.

User avatar
Zelandeth
Posts: 737
Joined: Fri Aug 18, 2017 9:11 pm
Contact:

Re: Zel's Fleet Blog...Jag, Citroens, Mercedes, Sinclair & AC Model 70

#904 Post by Zelandeth » Sun May 23, 2021 10:12 pm

Remembered the keyboard shortcut to get to the "fuel gauge" for the battery - function + sys req.

Image

Also figured that this might be an interesting experiment.

Image

Windows 3.0 is the last version that would run on an 8086/8088, albeit looking a bit strange on an inverted monochrome LCD with a bit of an oddball (640*200) resolution.

Runs a lot better than I expected to be honest. Bit sluggish when waiting for disc access but that's expected really.

Image

Image

Image

Image

To be honest I'm not really likely to use Windows for much...the MS-DOS Manager does a decent job of file management and all of the software I really need is DOS based anyway. I was mainly just curious to see how it ran on an 8086 machine.

Think the display really does show how it was really designed with text based applications in mind. It's not at it's best when dealing with graphics - but does a surprisingly good job of text. To be honest it's a lot more pleasant to use than the DSTN panel on the mid 90s ThinkPad I've got. Which is just utterly "meh" whether displaying text or graphics.

Replacement tips finally arrived today for the soldering iron so hopefully future work requiring it will be somewhat less frustrating...I really hadn't realised how knackered the old one was until I started doing delicate work with it!

Few folks have asked me what iron I use elsewhere, same one I've had for about fifteen years now.

Image

Iroda Solderpro 120, little gas unit. It's not as precise as an electronic one where you can dial in an exact temperature but you can very the power from virtually nothing through to about 100W, which has done everything I've asked of it so far. Using an electric iron with a cable in the way always feels really cumbersome once you're used to a gas iron.

Speaking of tools, I finally stopped procrastinating about it today and picked up a new lawn mower.

Image

Image

Initial impressions are that it feels well made. Quite a bit bigger than our old mower, will be curious to see how well it works - given that the old one was a kerbside find that cost me all of about £3 to get running it owes me nothing. It could be repaired - but has just got to the point that enough things need doing that it's just not worth it when there's something I really can't fully resolve - and that's that the grass collection box is missing. I've tried half a dozen times now to buy a new one but just haven't been able to get hold of one - so given it needs new rear wheels, replaced wheel bearing on one of the fronts, a couple of missing bolts replaced, ideally a new drive belt and a couple of cracks in the deck that are starting by the handle base repaired...it's just not worth it. Nothing wrong with the engine though...so I need to see if I can come up with something to do with it...current thought is "I wonder if I could find a suitable pressure washer pump head to hook up to it..."

Given the weather forecast over the next few days goodness only knows when I'll get to do the first test!
My website - aka. My *other* waste of time
Current fleet: 73 AC Model 70. 83 Citroen BX 14RE. 85 Sinclair C5. 85 Jaguar XJ-S V12 HE. 90 Mercedes 208D AutoTrail Navajo. 96 Citroen Xantia Activa.

User avatar
Zelandeth
Posts: 737
Joined: Fri Aug 18, 2017 9:11 pm
Contact:

Re: Zel's Fleet Blog...Jag, Citroens, Mercedes, Sinclair & AC Model 70

#905 Post by Zelandeth » Tue May 25, 2021 12:57 am

Despite the weather I managed to get TPA out for a run today.

Image

Contrary to what it looks like in this photo there were very ominous looking storm clouds just out of frame to both sides and behind me.

Never ceases to put a smile on my face this little car, really does drive far better than she has any right to.

Still not quite how I managed to dodge all the worst of the weather...it was all around me pretty much the whole time.
My website - aka. My *other* waste of time
Current fleet: 73 AC Model 70. 83 Citroen BX 14RE. 85 Sinclair C5. 85 Jaguar XJ-S V12 HE. 90 Mercedes 208D AutoTrail Navajo. 96 Citroen Xantia Activa.

User avatar
Zelandeth
Posts: 737
Joined: Fri Aug 18, 2017 9:11 pm
Contact:

Re: Zel's Fleet Blog...Jag, Citroens, Mercedes, Sinclair & AC Model 70

#906 Post by Zelandeth » Wed May 26, 2021 10:38 pm

Ever since I got it there has been something slightly funky with the control system on this one air conditioner. Never bothered too much about it at the time given the price of it and being a unit from the early 90s and that it was clearly an electronic issue rather than mechanical issues with the refrigeration side of things.

Image

The issue has always been with that fancy pants soft touch control panel - which obviously has an unnecessarily complicated layer of electronics behind it for a device of this type. This sort of control system seemed to be the late 80s/early 90s version of the obsession with everything having to have a touch screen these days.

Image

As Montgomery Scott said, "The more they overcomplicate the plumbing, the easier it is to stop up the drain."

If switched on without pressing anything it should just run in fan mode - cooling or heating modes are enabled by pressing the buttons under the striped grey areas first or second from the left. Next one cycles through fan speeds, then turns on/off an ioniser, then the timer.

What it had taken to doing however was after a completely random period of time between zero seconds and about six hours is that it would drop out of cooling mode and then refuse to acknowledge any keypad presses aside from the power button or timer button (or the ioniser - but that's a completely independent subsystem which is live whenever the AC supply is on). Sometimes power cycling the unit would kick it back on into cooling mode, but not always. Day before yesterday it decided to play up once too often so I started investigating. Back right when this first started I checked out the keypad itself and ruled it out as a possible culprit. A sticking button could give similar symptoms but would also knock out the power button functionality. Plus they all checked out individually anyway. The issue was clearly with the brains of the machine.

This is the control PCB.

Image

For something that needs to turn on/off a compressor, a heating element and switch between three fan speeds this really is unnecessarily complicated. The timer functionality is a totally separate physical unit so that's not even on this board. Likewise there's no need to run the condensate pump off the board...the switch contacts on the float are more than rated for the full load of the whole unit, so just let it handle itself and use the overflow one to cut power to everything aside from the warning light. Initial checks didn't reveal anything visibly showing signs of distress or any bulging caps. The wire you can see hanging off down by the transformer was the receiver for the remote control - I pulled that off first in the off chance something was interfering with it. Second step was to obviously pull and reseat that large socketed chip.

Here's a close up of the markings for those of you playing along at home.

Image

Given this chip is basically running the whole show it was an obvious first port of call - sadly didn't make any difference. I also went over the board with a good magnifying glass to look for any dry joints or possibly cracked traces...Zip turned up. In fact the quality of the soldering and the traces on the board is really very good and I can't fault it at all.

Helpfully there is a simplified system schematic on the inside of the rear cover. As none of the connectors on the PCB are labelled this is appreciated.

Image

Given the unit is thirty years old, my obvious next port of call was the DC smoothing capacitors. Looking at the voltage rails (5V and 24V) they were both slightly on the low side.

Image

Smoothing capacitors are 1000uF 35V...and of course I didn't have any of those in stock. I did have two 470uF ones in a suitable voltage rating though so in the spirit of experimentation I tacked those on in parallel with the existing ones to see if a bit of extra capacitance would make any difference...if they'd just gone low value it probably would have gone a long way to help. Not tidy by any stretch of the imagination, but for testing purposes it'll do just fine.

Image

It fooled me into thinking I'd fixed it as after doing this it behaved itself for about six hours...before doing exactly the same thing again.

Fair enough. My intention is basically to do away with this overcomplicated "brain" and stick a proper temperature controller in. I've got one in a box somewhere which can handle heating/cooling (this thing could only be set to one or the other - and just has a 0-9 numbered thermostat) and has proper adjustments for hysteresis, anti-cycle timers etc...I just need to figure out where the heck it is. The original PCB will stick around to handle the evaporator fan speed control, but that will basically be it. Control over the compressor, condenser fan and heating elements will be handed over to the new controller.

I wanted it back up and running today though...and I'm not one to be beaten by something like this.

The thermostat on this thing is just a mechanical make/break switch, and that quickly got me to thinking that I could very easily bypass the brain. I'd lose the anti-cycle timer, but to be honest there's a decent deadband on the thermostat I don't see that being an issue.

A little bit of poking around with a meter found that there's an always on 24V feed to all of the relay coils, and it's the earthy end that's switched by the control logic. Sure enough, if I earthed the low side of the compressor relay coil it and the condenser fan motor both kicked in, even though the unit wasn't in cooling mode.

Didn't take long for a plan to form. Even though this unit doesn't (and as far as I can see never has had) an ioniser unit fitted, the button and relay are there for it. This function being "always on" seemed to escape from the lockup issue...with the relay clicking away merrily when the button was toggled. This meant that I had an easily accessible switchable ground available to me.

That's us halfway there. I then pulled the thermostat connector off the board and spliced a couple of wires into that - wiring it in series with a wire to the switched ground I mentioned above.

Image

Image

Result is that the ioniser button is now a "compressor enable" button, and when that's turned on the thermostat makes it cut in/out as originally intended.

Only other thing I had to do was to physically unplug the heating element power supply as if it jumps into heating mode it will turn the element on (as in heating mode it interprets the stat being open as a cool for heat - whereas it's the other way around for cooling) because the thermostat is no longer hooked up to the PCB. Dead easy to do as it's got a socket up front.

I've not gone any further by way of making it pretty or securing the wires to the PCB with hot glue or anything as this only needs to last until I track down the proper controller, then quite a bit of re-engineering will happen. Hopefully see it going for a good while yet, and actually with better functionality as I'll be able to dial in an actual desired temperature rather than just picking a number. Plus overnight I'd really prefer the room to be a degree or two cooler than the inbuilt stat allows for...new control will resolve that. Worth noting that the wiring on there is just 24V, nothing on the mains side has been touched, and I've been careful to keep the tape from bridging the isolation gap.

Still not sure what the original problem is, and there's very little on these units on the web that I've been able to find. As best I can tell though there's something amiss with that big IC...Without another unit on hand I can rob one out of to test it's pretty hard to tell really.

It's a total bodge, but it's doing what I bought it to again, and soon will be upgraded rather than bodged.

Also in fairness to the unit...It's 30 years old and has spent a good portion of its life on an equipment rental company's books...so it's not done bad at all really! May 1991 is the date on the QC sticker on the inside of the back panel.
My website - aka. My *other* waste of time
Current fleet: 73 AC Model 70. 83 Citroen BX 14RE. 85 Sinclair C5. 85 Jaguar XJ-S V12 HE. 90 Mercedes 208D AutoTrail Navajo. 96 Citroen Xantia Activa.

User avatar
Zelandeth
Posts: 737
Joined: Fri Aug 18, 2017 9:11 pm
Contact:

Re: Zel's Fleet Blog...Jag, Citroens, Mercedes, Sinclair & AC Model 70

#907 Post by Zelandeth » Thu Jun 03, 2021 11:39 pm

Actually got a decent run out in the van today over to Basildon and back to collect some more air conditioning units.

Image

Definitely easier than trying to shoe horn them into the Xantia.

Nice to get out for a proper run with the old girl even if the M25 was precisely as busy as expected.
My website - aka. My *other* waste of time
Current fleet: 73 AC Model 70. 83 Citroen BX 14RE. 85 Sinclair C5. 85 Jaguar XJ-S V12 HE. 90 Mercedes 208D AutoTrail Navajo. 96 Citroen Xantia Activa.

User avatar
Zelandeth
Posts: 737
Joined: Fri Aug 18, 2017 9:11 pm
Contact:

Re: Zel's Fleet Blog...Jag, Citroens, Mercedes, Sinclair & AC Model 70

#908 Post by Zelandeth » Sat Jun 05, 2021 9:00 pm

Was wandering around out back today just moving a couple of things around when my eye was drawn to something on the ground. Where has this come from?

Image

Oh oh. That doesn't look good.

Image

Ah balls...yep, that's going to need sorting sooner rather than later.

Image

Temporary bodge to keep the weather out for now.

Image

Looking around the house quite a few of the soffit boards haven't weathered this last winter well.

Image

Worryingly it looks to me like the horizontal box section on the underside may well be asbestos...which I'm sure will multiply the costs involved in sorting things out by about ten times.

Image

Great! Just had the first quote in this afternoon from a landscaper to sort out the back garden and driveway, and that's more than we'd hoped - by about five times. Very much hoping they just didn't want the job, but braced for the news from the one coming tomorrow to be similar. Can see this easily eating up half the budget for the garden in one hit. Either way it looks like the plans we had to improve the driveway layout will have to be canned for the time being. Which is a shame as I was really hoping we might be able to arrange things so I could get out of the garage without major car Tetris. Given the school traffic around here it basically means I often can't get out of the garage between 9 and 4 as there's nowhere to move the cars I have to shift to.
My website - aka. My *other* waste of time
Current fleet: 73 AC Model 70. 83 Citroen BX 14RE. 85 Sinclair C5. 85 Jaguar XJ-S V12 HE. 90 Mercedes 208D AutoTrail Navajo. 96 Citroen Xantia Activa.

User avatar
Zelandeth
Posts: 737
Joined: Fri Aug 18, 2017 9:11 pm
Contact:

Re: Zel's Fleet Blog...Jag, Citroens, Mercedes, Sinclair & AC Model 70

#909 Post by Zelandeth » Mon Jun 07, 2021 4:03 am

After over two months thanks to problems with shipping due to Brexit related nonsense the new oil pressure switch for the Invacar arrived last week. This afternoon I figured I'd get that fitted in the hope that it cures the minor oil leak from the rear of the engine... I'm not holding my breath as I reckon it's only half the issue, the other source being the crankshaft oil seal. Which is a pain as that's an engine out job to change. If it is the crankshaft oil seal though I'm not going to lose too much sleep over it given the leakage is very slight - one or two drops when the car is parked up. If it was losing any appreciable amount while driving it would have shown up given how small the sump capacity is, but she's never used any between changes so I'm not too worried. Knowing that the pressure switch was visibly weeping though I wanted that changed. That's the sort of leak which can go from very minor to catastrophic with little or no warning.

Getting the old one out is actually deceptively awkward due to the proximity of the distributor and oil filter. Not enough to be a problem, but just enough to be moderately annoying.

Image

Eventually managed to get a spanner onto it (24mm) with the oil filter removed. Then discovered quite how tight it was. When I started to pull the car over the wheel chocks I instead opted to remove the boss that the pressure switch is threaded into, allowing me to separate the two off the car.

Image

That let go with an almighty crack which rammed my arm against the engine cover slam panel. This car has drawn blood surprisingly few times during the restoration project but she managed today!

Image

Didn't actually realise I'd done that at the time, it was about ten minutes later when I had that "wait...where is this blood coming from?" moment.

Annoyingly it then quickly became apparent that my new pressure switch is completely wrong, despite having been bought from a Steyr-Puch specialist. The different case style is immaterial - however the thread and threaded length of the body are also totally different.

Image

The length is actually important as the oil pressure relief valve spring sits against the underside of the pressure switch body so the depth it screws in is critical to the preload being right.

At least since I ordered that the actual Bosch part number (0986344041) has been tracked down so I have now got one on the way. Just annoying that I've wasted a lot of time on this - and that the £7 sensor ended up being north of thirty quid by the time shipping and all the tarriffs and fees were paid...only for it to be the wrong thing.

On a slightly lighter note though I had a nice addition that had been on my wish list for a while arrive for the calculator collection a couple of days ago. This was spotted by someone over on UKSaabs who kindly offered to collect it and post it on to me.

I'd been after one of these for a while but refused to pay the frankly ridiculous sums of money they generally seem to change hands for.

Image

Image

This is a HP 12C Calculator - a specialised model intended for the financial market - and a fascinating case of the "if it ain't broke, don't fix it" approach. You'd think looking at this that it's a late 70s, maybe very early 80s model, even then a really late example of a calculator that uses RPN (note the large enter key and the lack of a separate equals key).

Image

The 12C was launched in 1981, the RPN input scheme being maintained because it's particularly well suited to financial calculations, despite the rest of the world having moved on by that point. It gets even more surprising though...you can STILL buy the 12C today, in 2021! Yes there have been numerous changes "under the hood" over the years, but the fact that a piece of electronics (even quite a specialist one) equipment has a model run of forty years and counting is frankly remarkable if you ask me.

This example appears to date from early 2001 judging from the serial number.

Quite how specialised this really is though is made most apparent by the manual.

Image

You'd think to look at that it would be about thirty pages in English and then repeated in about 357 other languages...nope. That is all English, all 246 pages of it.

It feels like a proper quality instrument in a way that calculators just generally didn't by the time the 21st century rolled in. The keypad action in particular is lovely, you can tell that exactly the weight required to press the keys was designed in, it did not just happen because those were the switches they had in stock.

Being such an anachronistic oddball it's definitely one I'm really glad to have in the collection. Surprisingly enough it's actually the first pure RPN calculator I own! Not quite sure how it's taken me so long to get hold of one.
My website - aka. My *other* waste of time
Current fleet: 73 AC Model 70. 83 Citroen BX 14RE. 85 Sinclair C5. 85 Jaguar XJ-S V12 HE. 90 Mercedes 208D AutoTrail Navajo. 96 Citroen Xantia Activa.

User avatar
JPB
Posts: 10262
Joined: Fri Jan 07, 2011 3:24 pm

Re: Zel's Fleet Blog...Jag, Citroens, Mercedes, Sinclair & AC Model 70

#910 Post by JPB » Thu Jun 10, 2021 6:14 am

:drool:
For clarification: I'm not a thirsty vampire,😳 it's the calculator that has me drooling.. Oh dear.😳😳👍
J
"Home is where you park it", so the saying goes. That may yet come true.. :oops:

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest