Update: I replaced 4 electrolytic caps on each side, the ones next to the large one, new feet on the underside.....and I have ordered a longer 3x300 screwdriver!
Very nice work, Ian. Always like to see an old piece of gear get a new lease on life. Amazing that collector lead hung in there for all those years without the benefit of solder! Thank you for sharing your repair process with us. Regards, David
Very good job, Ian. I think it looks really smart. You've transformed it. And soon you'll be able to remove that screw from across the other side of the lab. Love your work!
I bought one of these not working. Replaced all the 1k pots, and it is perfect. It is very nice to have a real linear power supply around. No noise concerns.
Nice video and a very clean looking result! I think the asymmetry in the primary winding resistances is because they are for voltage selection rather than center taps. Maybe for selecting between 110V or 120V mains input.
I remember Thandar making several pieces of small test equipment a long time ago. I still have a Thandar frequency counter. It wasn't the best, but it did what it was designed to do.Thanks.
Nice restoration Ian. A very satisfying result. I have a Thurlby PL320 (two channels, 30V 2A) on my bench which has the row of buttons in the middle that let you connect the supplies in series, parallel, isolated or tracking mode. It's a nice dependable tool.
Nice job ! I remember well the Thurlby Thandar Dual supply we had at an old Lab I worked in and it had the much better red LED displays. Very reliable and robust, it always dispensed the most wonderful, clean and fresh electricity.....cheers!!
When you went to clean the front pannel I said to myself, “Those scuffs look like a job for Jif”..and when the bottle appeared, I thought, yep, he thinks the same as me…then I saw the name on it, “Cif”!!!! Here in Tasmania the stuff comes in the exact same bottle of a recently chnged design and from P, from Viet Nam and called, “Jif”. The older designed bottles were made in Australia, (Melbourne) and still called, “Jif”. Odd how the U.K. stuff is calle, “Cif” a name so similar…must have some brand clash with another product called, “Jif” over there. Years ago I eas at my sister in law’s in Viet Nam and wanted some Jif, searched all over Saigon and eventually found some in disrict 5, was the Ausrealisn stuff but in a pale yellow bottle with a lemon smell..ironical it is now made there…but, I have been there recently too and not been able to find it locally at all despite it being made there now! But odd. The dual power supply reminds me if a Good Will branded one I have here, very similar design, two transformers, rectifiers and bunch of 2N3955 pass transistors on heatsinks…but this one I have here is HUGE, far to deep an 8U high box to fit on my bench and enough space inside it to “hide a ded bdy in” …has four analog, moving coil meters on it and looks like a useful unit otherwise. One day I will remount it in a smaller box similar to this Thandar you show here.
Those 40-pin ICs under the LCD displays are most likely Intersil ICL7107 3.5 digit A/D converter chips - together with the venerable 2N3055 and LM723 regulator, they were the staple of most power supplies in the 70s and 80s.
3:00 this is why you NEVER power on something without knowing it's state!! Could easily have shorted a bunch of stuff out if you turned it on with that board just flopping around in the wind.
I'm really surprised that 10-turn pots haven't replaced coarse and fine knobs at this point. any equipment I have which has coaxial coarse & fine knobs has had those knobs replaced with a 10-turn pot combining both.
6:12 Moving the diodes to the top of the PCB might also be a good idea, so they don't heat the board so much. But they probably don't get that hot anyway. Great job as always. Hope I can find a similar large (defective) linear PSU myself...
Excellent repair video! I quite like TTI stuff, they are still based in the UK and if you need a service manual they will email it to you! I have a couple of their EL series PSU's and a programmable function generator.
@@IanScottJohnston I work at a radio dealer not far from TTI in Huntingdon. All of the supplies in our workshop are TTI. When I first started at the company, I noticed that quite a few of the supplies were poorly - either way out of calibration or no output. I emailed TTI and they supplied the service manuals for me. I've been a total Thurlby Thandar fanboy my whole life. Their gear isn't generally as fancy as top of the range R&S / Agilent etc, but it IS made inside our coastline unlike just about everything else nowadays.
Great little power supply, i miss the dual supplies. seems that all mine now days are singles. These are very versatile being fully independent. Paralleled up to 4A's series up to 60V series centre tapped, up to +/- 30V all the above with little noise on the output. only down side is they do not have a linked voltage setting for use when they are connected together. Nice clean fix.
I had no idea you are riding around on your scooter looking for power supplies in drainage ditches to "restore"... 😉 I hope this was free.... But came out pretty good!
You might have an application where you want 5Vdc exactly at the end of some long cables connected to a load drawing 2amps......so rather than try dialing up 5.2Vdc or so and hoping for 5Vdc at the load (volt drop), you would run the sense terminals on their own long cables to the load.....that way, you'll get 5Vdc at the load even when you have set 5Vdc at the psu. If you are not using the sense terminals then you short them out at the Psu as shown.
Update: I replaced 4 electrolytic caps on each side, the ones next to the large one, new feet on the underside.....and I have ordered a longer 3x300 screwdriver!
Very nice work, Ian. Always like to see an old piece of gear get a new lease on life. Amazing that collector lead hung in there for all those years without the benefit of solder! Thank you for sharing your repair process with us. Regards, David
Nice old gear, still quite serviceable today. Interesting history note - Thandar used to be Sinclair's instruments division!
That power supply may well look better than factory now. Great Job, Ian!
2N3055 goodness! Thanks Ian for another great video.
Very good job, Ian. I think it looks really smart. You've transformed it. And soon you'll be able to remove that screw from across the other side of the lab. Love your work!
I bought one of these not working. Replaced all the 1k pots, and it is perfect. It is very nice to have a real linear power supply around. No noise concerns.
Nice video and a very clean looking result!
I think the asymmetry in the primary winding resistances is because they are for voltage selection rather than center taps.
Maybe for selecting between 110V or 120V mains input.
I remember Thandar making several pieces of small test equipment a long time ago. I still have a Thandar frequency counter.
It wasn't the best, but it did what it was designed to do.Thanks.
I have a similar PSU to this a Racal-Dana 9232K with a 5V up to 7A output as well.
I need to sort mine out as well.
Nice restoration Ian. A very satisfying result. I have a Thurlby PL320 (two channels, 30V 2A) on my bench which has the row of buttons in the middle that let you connect the supplies in series, parallel, isolated or tracking mode. It's a nice dependable tool.
Nice job ! I remember well the Thurlby Thandar Dual supply we had at an old Lab I worked in and it had the much better red LED displays. Very reliable and robust, it always dispensed the most wonderful, clean and fresh electricity.....cheers!!
Excellent. Must have been very tempting to turn it on after replacing those diodes ;).
Nice repair as usual. Surprisingly the front panel turn ok after a good cleaning and gluing. Love your videos Ian 😉
When you went to clean the front pannel I said to myself, “Those scuffs look like a job for Jif”..and when the bottle appeared, I thought, yep, he thinks the same as me…then I saw the name on it, “Cif”!!!!
Here in Tasmania the stuff comes in the exact same bottle of a recently chnged design and from P, from Viet Nam and called, “Jif”.
The older designed bottles were made in Australia, (Melbourne) and still called, “Jif”. Odd how the U.K. stuff is calle, “Cif” a name so similar…must have some brand clash with another product called, “Jif” over there.
Years ago I eas at my sister in law’s in Viet Nam and wanted some Jif, searched all over Saigon and eventually found some in disrict 5, was the Ausrealisn stuff but in a pale yellow bottle with a lemon smell..ironical it is now made there…but, I have been there recently too and not been able to find it locally at all despite it being made there now! But odd.
The dual power supply reminds me if a Good Will branded one I have here, very similar design, two transformers, rectifiers and bunch of 2N3955 pass transistors on heatsinks…but this one I have here is HUGE, far to deep an 8U high box to fit on my bench and enough space inside it to “hide a ded bdy in” …has four analog, moving coil meters on it and looks like a useful unit otherwise. One day I will remount it in a smaller box similar to this Thandar you show here.
Used to be called Jif a few years ago here in the UK, then they changed it.
Those 40-pin ICs under the LCD displays are most likely Intersil ICL7107 3.5 digit A/D converter chips - together with the venerable 2N3055 and LM723 regulator, they were the staple of most power supplies in the 70s and 80s.
3:00 this is why you NEVER power on something without knowing it's state!! Could easily have shorted a bunch of stuff out if you turned it on with that board just flopping around in the wind.
Nice! A new set of binding posts and i would be like a new one!
Nice repair, i have a lot of TTI stuff, but nothing older. The TTI stuff is good, but not perfect (It has some problems with age).
I'm really surprised that 10-turn pots haven't replaced coarse and fine knobs at this point. any equipment I have which has coaxial coarse & fine knobs has had those knobs replaced with a 10-turn pot combining both.
Another great job! Came out really clean in the end there too!
6:12 Moving the diodes to the top of the PCB might also be a good idea, so they don't heat the board so much.
But they probably don't get that hot anyway.
Great job as always. Hope I can find a similar large (defective) linear PSU myself...
I did think of doing that……but just thought I’d leave it stock.
Great save for that piece of gear. Nice work!
Fanless DC Powersupply ... thats a nice unit!
Brings back memories of school labs in the 80s 😂
Very nice job
Excellent repair video! I quite like TTI stuff, they are still based in the UK and if you need a service manual they will email it to you! I have a couple of their EL series PSU's and a programmable function generator.
Really!.....I will give them a shout. Cheers.
@@IanScottJohnston
I work at a radio dealer not far from TTI in Huntingdon. All of the supplies in our workshop are TTI.
When I first started at the company, I noticed that quite a few of the supplies were poorly - either way out of calibration or no output. I emailed TTI and they supplied the service manuals for me.
I've been a total Thurlby Thandar fanboy my whole life. Their gear isn't generally as fancy as top of the range R&S / Agilent etc, but it IS made inside our coastline unlike just about everything else nowadays.
My next video will hopefully be a refurb/repair of a Thurlby 30V-2A single channel PSU.
@@IanScottJohnston Nice! Those PSU's are always nostalgic as the college I went to had them in their labs.
If that was made today, the metal back panel would be the heat sink.
😂 Yeah, sadly enough.
Great restoration! I was wondering why the power supply voltmeter dropped to near zero when you limited the current. Just curious.
Great job!!!
Great little power supply, i miss the dual supplies. seems that all mine now days are singles. These are very versatile being fully independent.
Paralleled up to 4A's
series up to 60V
series centre tapped, up to +/- 30V
all the above with little noise on the output.
only down side is they do not have a linked voltage setting for use when they are connected together.
Nice clean fix.
I had no idea you are riding around on your scooter looking for power supplies in drainage ditches to "restore"... 😉
I hope this was free.... But came out pretty good!
zero money changed hands.
@@IanScottJohnston 👍👍
what is the idea of joining the positive and negative outputs to the +ve and -ve sense posts?
You might have an application where you want 5Vdc exactly at the end of some long cables connected to a load drawing 2amps......so rather than try dialing up 5.2Vdc or so and hoping for 5Vdc at the load (volt drop), you would run the sense terminals on their own long cables to the load.....that way, you'll get 5Vdc at the load even when you have set 5Vdc at the psu.
If you are not using the sense terminals then you short them out at the Psu as shown.
@@IanScottJohnston thank you for clearing that up for me. I appreciate it.