Was: PDP-8/A transformer hum Is: VXT-2000 stuff.

2020-06-17 Thread Joseph Zatarski via cctalk
On 6/9/2020 11:51 AM, Glen Slick via cctalk wrote: On Tue, Jun 9, 2020 at 9:04 AM Bill Gunshannon via cctalk wrote: For the VXT-2000 with an H7109-B the rated voltage and current values are printed right on the power supply label: +5.1V, 7.81A +12.1V, 0.62A -12.1V, 0.46A -9V, 0.2A Fixed

Re: PDP-8/A transformer hum

2020-06-12 Thread Bill Gunshannon via cctalk
On 6/9/20 7:13 PM, Glen Slick via cctalk wrote: On Tue, Jun 9, 2020 at 3:10 PM Bill Gunshannon via cctalk wrote: On 6/9/20 2:51 PM, Glen Slick via cctalk wrote: On Tue, Jun 9, 2020 at 9:04 AM Bill Gunshannon via cctalk wrote: I have a VXT-2000. It is broke. If I could find out what the

Was: PDP-8/A transformer hum Is: VXT-2000 stuff.

2020-06-09 Thread jim stephens via cctalk
On 6/9/2020 11:51 AM, Glen Slick via cctalk wrote: On Tue, Jun 9, 2020 at 9:04 AM Bill Gunshannon via cctalk wrote: For the VXT-2000 with an H7109-B the rated voltage and current values are printed right on the power supply label: +5.1V, 7.81A +12.1V, 0.62A -12.1V, 0.46A -9V, 0.2A Fixed

Re: PDP-8/A transformer hum

2020-06-09 Thread Glen Slick via cctalk
On Tue, Jun 9, 2020 at 3:10 PM Bill Gunshannon via cctalk wrote: > > On 6/9/20 2:51 PM, Glen Slick via cctalk wrote: > > On Tue, Jun 9, 2020 at 9:04 AM Bill Gunshannon via cctalk > > wrote: > >> > >> I have a VXT-2000. It is broke. If I could find out what the voltage > >> and current

Re: PDP-8/A transformer hum

2020-06-09 Thread Maciej W. Rozycki via cctalk
On Tue, 9 Jun 2020, Bill Gunshannon via cctalk wrote: > > For the VXT-2000 with an H7109-B the rated voltage and current values > > are printed right on the power supply label: > > > > +5.1V, 7.81A > > +12.1V, 0.62A > > -12.1V, 0.46A > > -9V, 0.2A > > > > Fixed width character pinout diagram: >

Re: PDP-8/A transformer hum

2020-06-09 Thread Bill Gunshannon via cctalk
On 6/9/20 2:51 PM, Glen Slick via cctalk wrote: On Tue, Jun 9, 2020 at 9:04 AM Bill Gunshannon via cctalk wrote: I have a VXT-2000. It is broke. If I could find out what the voltage and current requirements were and their positions on the power connector I would replace it in a heartbeat.

Re: PDP-8/A transformer hum

2020-06-09 Thread Chuck Guzis via cctalk
On 6/9/20 2:10 PM, Josh Dersch via cctalk wrote: > On Tue, Jun 9, 2020 at 7:44 AM Jon Elson wrote: > Thanks Jon (and everyone else). Yes, this is a ferroresonant transformer > (w/matching motor-run cap), I'd just never heard one in a DEC machine that > was so very loud. I'll see if there's

Re: PDP-8/A transformer hum

2020-06-09 Thread Josh Dersch via cctalk
On Tue, Jun 9, 2020 at 7:44 AM Jon Elson wrote: > On 06/09/2020 01:59 AM, Josh Dersch via cctalk wrote: > > Hi all -- > > > > I'm working on a PDP-8/A I picked up at VCF West last summer. After a > lot > > of cleaning and some power supply repair it's showing signs of life (CPU > > seems to be

Re: PDP-8/A transformer hum

2020-06-09 Thread Mattis Lind via cctalk
Den tis 9 juni 2020 kl 19:04 skrev Ethan Dicks via cctalk < cctalk@classiccmp.org>: > On Tue, Jun 9, 2020 at 10:46 AM Jon Elson via cctalk > wrote: > > On 06/09/2020 09:27 AM, Anders Nelson via cctalk wrote: > > > Related question: Is there any reason, other than historical accuracy > and > > >

Re: PDP-8/A transformer hum

2020-06-09 Thread Glen Slick via cctalk
On Tue, Jun 9, 2020 at 9:04 AM Bill Gunshannon via cctalk wrote: > > I have a VXT-2000. It is broke. If I could find out what the voltage > and current requirements were and their positions on the power connector > I would replace it in a heartbeat. > For the VXT-2000 with an H7109-B the rated

Re: PDP-8/A transformer hum

2020-06-09 Thread Anders Nelson via cctalk
Interesting, good to know! -- Anders Nelson On Tue, Jun 9, 2020 at 1:04 PM Ethan Dicks via cctalk wrote: > On Tue, Jun 9, 2020 at 10:46 AM Jon Elson via cctalk > wrote: > > On 06/09/2020 09:27 AM, Anders Nelson via cctalk wrote: > > > Related question: Is there any reason, other than

Re: PDP-8/A transformer hum

2020-06-09 Thread Ethan Dicks via cctalk
On Tue, Jun 9, 2020 at 10:46 AM Jon Elson via cctalk wrote: > On 06/09/2020 09:27 AM, Anders Nelson via cctalk wrote: > > Related question: Is there any reason, other than historical accuracy and > > cost, to not replace the power supplies in vintage computers with modern > > switching power

Re: PDP-8/A transformer hum

2020-06-09 Thread Bill Gunshannon via cctalk
On 6/9/20 10:34 AM, Toby Thain via cctalk wrote: On 2020-06-09 10:27 a.m., Anders Nelson via cctalk wrote: Related question: Is there any reason, other than historical accuracy and cost, to not replace the power supplies in vintage computers with modern switching power supplies? 3) If it

Re: PDP-8/A transformer hum

2020-06-09 Thread Jon Elson via cctalk
On 06/09/2020 09:27 AM, Anders Nelson via cctalk wrote: Related question: Is there any reason, other than historical accuracy and cost, to not replace the power supplies in vintage computers with modern switching power supplies? The old discrete transistor machines often used fairly odd

Re: PDP-8/A transformer hum

2020-06-09 Thread Jon Elson via cctalk
On 06/09/2020 01:59 AM, Josh Dersch via cctalk wrote: Hi all -- I'm working on a PDP-8/A I picked up at VCF West last summer. After a lot of cleaning and some power supply repair it's showing signs of life (CPU seems to be at least minimally functional, core memory is going to need some

Re: PDP-8/A transformer hum

2020-06-09 Thread Paul Koning via cctalk
> On Jun 9, 2020, at 10:27 AM, Anders Nelson via cctalk > wrote: > > Related question: Is there any reason, other than historical accuracy and > cost, to not replace the power supplies in vintage computers with modern > switching power supplies? > > -- > Anders Nelson RFI? Old computers

Re: PDP-8/A transformer hum

2020-06-09 Thread Toby Thain via cctalk
On 2020-06-09 10:27 a.m., Anders Nelson via cctalk wrote: > Related question: Is there any reason, other than historical accuracy and > cost, to not replace the power supplies in vintage computers with modern > switching power supplies? > 3) If it ain't broke, don't fix it > -- > Anders Nelson

Re: PDP-8/A transformer hum

2020-06-09 Thread Anders Nelson via cctalk
Related question: Is there any reason, other than historical accuracy and cost, to not replace the power supplies in vintage computers with modern switching power supplies? -- Anders Nelson On Tue, Jun 9, 2020 at 10:19 AM Paul Koning via cctalk < cctalk@classiccmp.org> wrote: > > > > On Jun 9,

Re: PDP-8/A transformer hum

2020-06-09 Thread Paul Koning via cctalk
> On Jun 9, 2020, at 2:59 AM, Josh Dersch via cctalk > wrote: > > Hi all -- > > I'm working on a PDP-8/A I picked up at VCF West last summer. After a lot > of cleaning and some power supply repair it's showing signs of life (CPU > seems to be at least minimally functional, core memory is

Re: PDP-8/A transformer hum

2020-06-09 Thread Christian Corti via cctalk
On Tue, 9 Jun 2020, Marco Rauhut wrote: i have restored last year a PDP-8/a to and had the same experience like you with the Powersuppy. I felt also wiered about the bang in the transformer in the moment of switching it on. Does it have a ferroresonant power supply? Then the hum and bang is

Re: PDP-8/A transformer hum

2020-06-09 Thread Bob Smith via cctalk
Is there a recommended alternative or replacement power supply for the 8/A? thanks On Tue, Jun 9, 2020 at 4:20 AM Marco Rauhut via cctalk wrote: > > Hi Josh, > > i have restored last year a PDP-8/a to and had the same experience like you > with the Powersuppy. I felt also wiered about the bang

Re: PDP-8/A transformer hum

2020-06-09 Thread Marco Rauhut via cctalk
Hi Josh, i have restored last year a PDP-8/a to and had the same experience like you with the Powersuppy. I felt also wiered about the bang in the transformer in the moment of switching it on. Marco > Am 09.06.2020 um 09:02 schrieb Josh Dersch via cctalk : > > Hi all -- > > I'm working on

PDP-8/A transformer hum

2020-06-09 Thread Josh Dersch via cctalk
Hi all -- I'm working on a PDP-8/A I picked up at VCF West last summer. After a lot of cleaning and some power supply repair it's showing signs of life (CPU seems to be at least minimally functional, core memory is going to need some debugging.) The transformer in the power supply is humming