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MacOS Install error - "the following disk images couldn't be opened" reason: no mountable files systems

scott grinna
 

Hi all -?

I'm using an older 2010 Mac and am having problems installing. I'm getting the error in the subject.

Any suggestions, other than it's just an incompatibility issue?

Thanks!

Scott


Re: Soft Start Option

 

¿ªÔÆÌåÓý

The simplest Soft Start circuit I have seen is in the Ameritron AL-1200.

73, Dick, W1KSZ


From: [email protected] <[email protected]> on behalf of Robert Chambers <rchamber@...>
Sent: Friday, May 14, 2021 4:42 PM
To: [email protected] <[email protected]>
Subject: Re: [duncanampspsud] Soft Start Option
?
Hmm..."something simple, working for years..."

I've been doing that for years with a different topology/method that is
also something simple:

Power Amp: Two switches...switch on the filaments first, then after an
appropriate delay - actually the sequence below for the Preamp, switch on
the rectifier/HV.

Preamp:? Two switches, two powerstats (variacs), one each in front of
filament and HV/rectifier trafos...

???? Filament switch ON, power up gradually with powerstat, then...

???? HV switch ON, count to 30 with fingers (:)), power up gradually with
powerstat

Works great, no PCBs, no other stuff (relays, time delay modules, etc.)!

Best, 73 etc.,

RC

------------------------------------------------------------------------------------------------------

On Fri, 14 May 2021 08:10:14 -0700, "f1frv" <f1frv@...> wrote:
> hello
> Have a look for something simple, working for years...
> [1]
> 73s
> Dom
>
> Links:
> ------
> [1]
> [2] /g/duncanampspsud/message/60
> [3]
>
mailto:[email protected]?subject=Re:%20Re%3A%20%5Bduncanampspsud%5D%20Soft%20Start%20Option
> [4]
>
mailto:f1frv@...?subject=Private:%20Re:%20Re%3A%20%5Bduncanampspsud%5D%20Soft%20Start%20Option
> [5] /mt/81400426/90558
> [6] /g/duncanampspsud/post
> [7] /g/duncanampspsud/editsub/90558
> [8] mailto:[email protected]
> [9]
> /g/duncanampspsud/leave/8998765/90558/306449312/xyzzy






Re: Soft Start Option

 

Hmm..."something simple, working for years..."

I've been doing that for years with a different topology/method that is
also something simple:

Power Amp: Two switches...switch on the filaments first, then after an
appropriate delay - actually the sequence below for the Preamp, switch on
the rectifier/HV.

Preamp: Two switches, two powerstats (variacs), one each in front of
filament and HV/rectifier trafos...

Filament switch ON, power up gradually with powerstat, then...

HV switch ON, count to 30 with fingers (:)), power up gradually with
powerstat

Works great, no PCBs, no other stuff (relays, time delay modules, etc.)!

Best, 73 etc.,

RC

------------------------------------------------------------------------------------------------------

On Fri, 14 May 2021 08:10:14 -0700, "f1frv" <f1frv@...> wrote:
hello
Have a look for something simple, working for years...
[1]
73s
Dom

Links:
------
[1]
[2] /g/duncanampspsud/message/60
[3]
mailto:[email protected]?subject=Re:%20Re%3A%20%5Bduncanampspsud%5D%20Soft%20Start%20Option
[4]
mailto:f1frv@...?subject=Private:%20Re:%20Re%3A%20%5Bduncanampspsud%5D%20Soft%20Start%20Option
[5] /mt/81400426/90558
[6] /g/duncanampspsud/post
[7] /g/duncanampspsud/editsub/90558
[8] mailto:[email protected]
[9]
/g/duncanampspsud/leave/8998765/90558/306449312/xyzzy


Re: Soft Start Option

 

hello
Have a look for something simple, working for years...

73s
Dom


Re: Soft Start Option

 

I use the? Harbach Electronics "soft start" module.


Re: Soft Start Option

 

Hi Robert,

The driver for the feature was choke input supplies fed by vacuum tubes - these will warm up over a few seconds rather than "spike" straight away and it's a good way to soften the start.

There are other soft start schemes, i.e. old schematics for linear amplifiers using a resistor in the line feed which is shorted by a relay after a couple of seconds, or the modern way of doing this with NTC thermistors. However, PSUD doesn't do an accurate model of these.

Regards,
Duncan


Soft Start Option

 

Hi, What are the real world possibillities here? Variac? Electronic
time delay? Other?

Best,

RC in VT


Re: GZ37 PIV

 

On Wed, Feb 10, 2021 at 02:12 PM, SB-LAB di Bianchini Stefano wrote:
it is not a matter of annoyance in seeing the message, but I would like to be sure that the valve does not blow.
OK, I understand now. You can amend the PIV on the rectifier to suit this need. The help file gives some guidance on making up your own rectifiers and modifying the existing ones.

Help > Contents > Technical information > How to add your own rectifier types

You might want to take the gz37.rect file and copy to something like gz37ind.rect to make an inductive version with higher PIV. Notepad can be used to open and change the file. As well as changing the <vpiv> value you will need to change the <name> value also, as it will not want to load the same name twice, so the contents of the file should end up looking like:

<?xml version="1.0" encoding="UTF-8"?>
<rectifier>
? <name>GZ37IND</name>
? <description>GZ37 imported from PSUD2</description>
? <version>211</version>
? <creationdate>2019-11-23 17:30:34</creationdate>
? <type>VT</type>
? <vlaw>1.35</vlaw>
? <vfac>0.001409</vfac>
? <dres>0</dres>
? <vpiv>1850</vpiv>
? <ipks>99</ipks>
? <ipkr>0.75</ipkr>
</rectifier>

ps: I tried a "-" in the name and it didn't like it, not sure why but I will investigate. Anyway... save the file and restart PSUD, you should have an extra rectifier option GZ37IND to use for your power supply design with inductive input.

Regards,
Duncan


Re: GZ37 PIV

 

On 2/10/2021 4:44 PM, SB-LAB di Bianchini Stefano wrote:
be sure that the valve does not blow.
If your VAC is under 654V AC for inductive input, and your input choke is reasonably large (Google "critical choke value"), then the PIV will be under 1850V. (565V AC for the 1600V condition and rating.)

These values give 588V or 790V of DC, which for most purposes is "a lot!". Some radio transmitters run higher, most audio much lower. (Yes, I have worked in a 590V Ampeg amplifier, and I lived.)

PSUD is very very wonderful but not perfect. If you force it into unhappy conditions it sometimes gives wrong answers. I knew that 442VAC would not normally cause more than 1250PIV. However when PSUD is given a too-small choke value, when the current passes through zero the choke "kicks". How much does it kick? PSUD can not know, we have not told it the shunt resistance and capacitance of the choke. So PSUD gets a "divide by Zero" error and throws out some large numbers. Like 2206V! And lotes of very narrow "static" spikes. An under-sized choke is *bad*, but does not look like this.

I was not able to get an extreme PIV when I checked the Choke Current to see that it never got close to zero, the test for "critical inductance".

-Paul


Re: GZ37 PIV

 

it is not a matter of annoyance in seeing the message, but I would like to be sure that the valve does not blow.

Il 10/02/21 19:27, Duncan Munro ha scritto:
It could certainly be changed, the issue is that it doesn't have an ability to have two different PIV in the model. The PIV parameter doesn't actually do anything other than to issue a warning to tell you that the number has been exceeded. If the warning is a nuisance, it can be turned off with the Options > Allow Warnings menu item.

Regards,
Duncan
--

Privacy: Informativa per i destinatari di messaggi di posta elettronica
Informativa privacy senza consenso per i clienti di SB-LAB reperibile a questo indirizzo:

Le informazioni contenute nei messaggi di posta elettronica e negli eventuali allegati sono riservate ai destinatari.
I destinatari non posso diffondere il messaggio a terzi senza previa autorizzazione dell'autore.
Persone o soggetti diversi dai destinatari stessi non sono autorizzate a leggere, copiare, modificare, diffondere il messaggio a terzi.
Qualora un messaggio venisse ricevuto per errore, chiediamo cortesemente al soggetto che lo ha ricevuto di darcene notizia a mezzo e-mail e di distruggere il messaggio ricevuto erroneamente.

SB-LAB di Bianchini Stefano, www.sb-lab.eu <>
--


Re: GZ37 PIV

 

It could certainly be changed, the issue is that it doesn't have an ability to have two different PIV in the model. The PIV parameter doesn't actually do anything other than to issue a warning to tell you that the number has been exceeded. If the warning is a nuisance, it can be turned off with the Options > Allow Warnings menu item.

Regards,
Duncan


GZ37 PIV

 

reading the GZ37 datasheet, the PIV with capacitive input is 1600volt, while with inductive input 1850volt, is it possible to modify the model of the GZ37 to consider this difference?


Re: Problem downloading .psu example files

 

On 1/20/2021 9:45 AM, Duncan Munro wrote:
You should be able to download from the following page -> some out of date code which used to work but website has just been updated. Could you please try again?
Works now. FireFox 84.0.2 on Windows 7.


Re: Problem downloading .psu example files

 

Thanks a lot Duncan.
It works as it should.
What can I say.
Great job with psud2 and tdsl pe.
Happy for more than 13 years now.
And the last PSUD2 version 2.22 build 76 is nicely improved with graphical display on my screen.
Keep it like this.
I am a linux om , but both apps work greatly under wine (Linux Mint 20 with Cinnamon)!


73 de Konstantinos, SV1ONW


Re: Problem downloading .psu example files

 

Hi Konstantinos,

The code for example PSU files has now been amended, tested, and the website has just been updated. Could you please try again?

73,
Duncan
M0KGK


Re: Problem downloading .psu example files

 

Hi Duncan,

This is the location I am trying to download from.
I cannot access the link.
Would it be difficult to put the guitar amp designs in a zip file here?
Thanks a lot again
73 de Konstantinos
SV1ONW


Re: Problem downloading .psu example files

 

Just checked the website over and it uses some out of date code which used to work but has now been blocked from operating. It will need some minor rewriting which I will do this evening and post back when done.

Thanks for letting me know about the issue.

73,
Duncan
M0KGK


Re: Problem downloading .psu example files

 

Hi Konstantinos,

You should be able to download from the following page ->?

Are you getting an error message, or having difficulty accessing the page?

73,
Duncan
M0KGK


Problem downloading .psu example files

 

Hello Duncan.

I installed the latest version on my new laptop and tried to download some of the examples from the download section of your site in the psud2 area, but I did not managed to do so.
Could you please check the link or point where these .psu examples can be downloaded from?
Perhaps from here?

Thanks in advance,

Konstantinos, SV1ONW


Re: Can PSUD2 model this PSU?

 

For quiescent conditions, you could simplify by combining the identical branches, (half the inductance and resistance, twice the capacitance, twice the current).? The resistor in the first section is added to the choke resistance since there is no R-L choice.?? Voltages should be spot-on; you can select component values accordingly if not.? Dynamic conditions will require SPICE.