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Products => Test Equipment => Topic started by: pcolbeck on July 18, 2020, 07:53:32 am

Title: Rohde & Schwarz HM7042-3 linear power supply
Post by: pcolbeck on July 18, 2020, 07:53:32 am
Hi

I'm a beginner starting to gather equipment (did start an electronics degree 35 years ago but fell out into computer networking instead) to get started. I will be mainly working on audio equipment (old amps and radios) along with some computer stuff.
I've been looking at bench power supplies and there is a vast range of prices. I have some spare cash at the moment so was wondering whether I should splash out on a good second hand one that would last or go for a cheaper new one.

I have seen a used triple output Rohde&Schwarz HM7042-3 for about £500 and a new dual output CSI 3005EIII for £175 but cant find reviews of either.
Is the Rohde&Schwarz really worth the extra money for a hobbyist?

Many thanks for any input to help with my head scratching.
Title: Re: Rohde & Schwarz HM7042-3 linear power supply
Post by: pcolbeck on July 19, 2020, 08:16:16 am
Been looking at the specs for the R&S and the resolution is 100mV 1mA (0-1999mA), 10mA (>=2A) on the 30 Amp channels and 10mV 10mA on the 5v channel.

Something new like a SPD3303X that I could get for the same money has 1mV and 1mA resolution. Is that extra resolution important for most uses?
Title: Re: Rohde & Schwarz HM7042-3 linear power supply
Post by: tautech on July 19, 2020, 08:55:42 am
Quote from: pcolbeck on July 19, 2020, 08:16:16 am
Been looking at the specs for the R&S and the resolution is 100mV 1mA (0-1999mA), 10mA (>=2A) on the 30 Amp channels and 10mV 10mA on the 5v channel.

Something new like a SPD3303X that I could get for the same money has 1mV and 1mA resolution. Is that extra resolution important for most uses?
Not really.
I can't remember if I've ever sold a X model whereas the X-E continue to sell and I'm out of stock again !  >:(
Sales figures like that indicate customers feel satisfied with 10 mA/mV adjustments although last time I checked 1mA/mV was available in the X-E when using the EasyPower SW package it comes with.

Sure they're only a 3A PSU but you also have the option to series or parallel 2 outputs for 60V 3A or 30V 6A.
Title: Re: Rohde & Schwarz HM7042-3 linear power supply
Post by: pcolbeck on July 19, 2020, 11:18:14 am
It was the 100mV resolution on the R&S 30V channels that I was mainly worrying about.
Title: Re: Rohde & Schwarz HM7042-3 linear power supply
Post by: pcolbeck on July 19, 2020, 07:52:26 pm
I managed to bargain the Rohde & Schwarz  to £400 so I bought that and a ELEKTRO-AUTOMATIK PS 3016-20B 16V 20A single channel PSU as well.
That's me all sorted for power supplies for now I think.

Now to mull over scopes.

Thanks for the input tautech it helped me decide.