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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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8th Feb 2018, 8:03 pm | #21 |
Tetrode
Join Date: Dec 2017
Location: York, North Yorkshire, UK.
Posts: 65
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Re: Newbie bench supply question
Thanks for the continued help everyone .
Brett |
8th Feb 2018, 9:53 pm | #22 |
Dekatron
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,675
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Re: Newbie bench supply question
__________________
-- Graham. G3ZVT |
9th Feb 2018, 8:55 pm | #23 |
Tetrode
Join Date: Dec 2017
Location: York, North Yorkshire, UK.
Posts: 65
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Re: Newbie bench supply question
Right, it’s here. First thing I did was weigh it. It’s a whooping 12 and 3/4 pounds ! So onto the bench and turned the power on with nothing connected to the output. It came to life with a deep hum reminiscent of my old zetagi CB power suppy, fading to very little hum at all . I next dug out and old Roberts rambler and connected up and slowly brougt the voltage up to that magic 9v. The set started up drawing 0.02 amp . I then tried a RFM3 to see if there was any radio interference on FM and all seems well.
So it’s looking like it was a good buy. The only thing I don’t understand (because the instuctions are pigeon English) is what to do with the Current. There is a little orange led which illuminates when the current fluctuates . I have had the rotary control right round to see what happens too. The RFM Is drawing 0.03 amp going up to 0.04 amp when the volume is raised. So do I wind the coarse current control down just before the led starts to glow ? Sorry if this seems like a silly question , but as said I am still in learning mode. Thanks. Brett. |
9th Feb 2018, 9:10 pm | #24 |
Tetrode
Join Date: Dec 2017
Location: York, North Yorkshire, UK.
Posts: 65
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Re: Newbie bench supply question
Thanks Rambo you have done me a favour there. This is not my power supply luckily. But the link you put up took me to a very similar unit to mine and a quick tutorial . So I’m sorted now.
Thanks everyone it’s all one big learning curve. Kindest regards. Brett. |
9th Feb 2018, 9:25 pm | #25 |
Dekatron
Join Date: Nov 2011
Location: Surrey, UK.
Posts: 4,385
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Re: Newbie bench supply question
Amazing that something with that amount of steel and copper plus digital readout sophistication can be had new for the price that 30-40 year old similar spec. Farnell/Thurlby and the like bench PSUs can fetch! If it operates in the "accepted" fashion, then yes, the CV LED should extinguish and CC LED come on as it leaves constant voltage mode and goes into current limiting, or constant current. If you could get hold of some 10 to 100 ohm or thereabouts wire-wound resistors (and a heat-resistant surface....) without too much expenditure, e.g. clear-out assortments etc., they would offer scope for a bit of playing around and applying Ohm's Law to check that the PSU behaves as expected over its range- rather than trust it with a working radio straight off!
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9th Feb 2018, 11:38 pm | #26 |
Dekatron
Join Date: Feb 2007
Location: Lynton, N. Devon, UK.
Posts: 7,060
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Re: Newbie bench supply question
Congratulations on a good purchase!
You've described a heavy, somewhat inefficient linear power supply - but one that is ideally suited to your needs! It'll be useful for lots of things, including car battery charger. And as you've found, this type of power supply is mush-free on a radio! As Turretslug suggests, operate it with some cheap dummy loads (car brake light bulbs are ideal), exercise it, leave it running for some hours supplying a couple of amps (hence my suggestion of 12V 21W bulbs), make sure it doesn't do anything silly. Then, use with confidence! |
10th Feb 2018, 9:39 am | #27 |
Tetrode
Join Date: Dec 2017
Location: York, North Yorkshire, UK.
Posts: 65
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Re: Newbie bench supply question
Yep I can leave bulbs connected up all day Sunday. One thing I've not done yet is put my meter on the output to see how accurate the display/supply is, but there is nothing to say my meter is accurate either .
Another thing I need to do is to knock up some new leads. The bananas are poor quality and the leads are not over long but could do to go up another gauge. I will , with out a shadow of a doubt, be making a lead with a PP9 battery snaps on and another set with the hooks rather than alligators on. Other than that I'm really pleased . Brett. |
10th Feb 2018, 10:34 am | #28 | |
Dekatron
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,190
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Re: Newbie bench supply question
Quote:
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10th Feb 2018, 11:24 am | #29 |
Tetrode
Join Date: Dec 2017
Location: York, North Yorkshire, UK.
Posts: 65
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Re: Newbie bench supply question
Good point well made
And keep the bench clear so as not to connect a PP9 to the power supply . I'm good at doing tricks like that . Thanks everyone for the pointers. I will be spending the day looking for things to power up . Right, where's my Iphone........... |
10th Feb 2018, 1:22 pm | #30 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,549
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Re: Newbie bench supply question
I found a disused automotive extension cable that was rated at a minimum of 10 amps.
It is figure 8 cable with a red stripe on one side. It is about 6 foot long. It has made a lovely bench supply output cable. |
10th Feb 2018, 2:55 pm | #31 |
Tetrode
Join Date: Dec 2017
Location: York, North Yorkshire, UK.
Posts: 65
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Re: Newbie bench supply question
https://www.vintage-radio.net/forum/...pictureid=3966
Finally got round to creating an album. This is the supply . |