All things G1176 - the new "repost" thread.

[ChrioN]

Thanks alot Jakob

 

[maalexx]

Hi all,
I'm desperate. I've posted a thread in The Lab, but somebody said me that all things related to 1176 must be here.

Ok. Sorry, but I'm really a newbye. :roll:
I'm building a couple of G1176 on mnats board rev H.

Anyway, I'm using the onboard PSU. The resistors and components are ok in both pcb's.

In one board, i have +34.7 and -11; in the other board, I have +34.5 and -10.9... it appears to be the same.

I used this transformer:

http://rocky.digikey.com/WebLib/Amveco-Talema/Web%20Data/62000%20Series%20Low%20Profile%20Miniature%20Transformers.pdf

Its name's 62085, digi-key part no. is TE62085-ND. It's 22V 2.272A.

What can I do?
I measured the voltage, then I entirily stuffed the board. Now I'm worried to feed the circuit again, in the case the voltage is too high.
These are the pictures:

From CENTER TAP to either LEFT TAP or RIGHT TAP the voltage is 27.7 / 28VAC, with the transformer disconnected from the board. From LEFT TAP to RIGHT TAP the voltage is 56.2VAC.

There's something going wrong? :?

maalexx

 

[Purusha]

Hello,

I am building two 1176s with Mnats J ver. boards for the first time. One will have OEPs
and another Lundahls... I am trying to understand what ratios should I use here?

I soldered the Lundahl input 2:1 and output 1:2 as suggested in Mnats web page.
One thing I don't know yet, should I use the 10K or 12K for the Lundhals in?

Regarding the OEPs I am not sure what ratios should I use. Any suggestions?

 

[stefan]

I´m confused about the "QBias" adjustment, what does "adjusting the trimmer until a level drop of 1dB is achived" mean? Should it say "start with the trimmer fully CCW" or "1dB drop when the unit is turned on" or something like that?

 

[mnats]

[quote author="stefan"]Should it say "start with the trimmer fully CCW" [/quote]
Isn't that what the manual does say?
[quote author="UREI 1176LN Manual"]
5.3.2 "Q" BIAS ADJUSTMENT...
Q-Bias Adjust = full CCW[/quote]
I've thought about rewriting the calibration procedure and posting it to my site, but there's nothing in the manual that can be said any clearer IMO.

 

[stefan]

[quote author="mnats"][quote author="stefan"]Should it say "start with the trimmer fully CCW" [/quote]
Isn't that what the manual does say?
[quote author="UREI 1176LN Manual"]
5.3.2 "Q" BIAS ADJUSTMENT...
Q-Bias Adjust = full CCW[/quote]
I've thought about rewriting the calibration procedure and posting it to my site, but there's nothing in the manual that can be said any clearer IMO.[/quote]You are absolutely right, It´s just that I never read the original manual I just read the instructions on the Gyrafsite.
well that´s how I did it anyway so everything should be fine then. Thanks

 

[Lasselakken]

I know this is a bit OT, but I couldn't find a better spot.

I would like to use the Mnats little PSU board to power up a few old modules I'm racking up. If I want to make a +15/-15V supply do I just connect a 2x15V transformer to the mnats psu and tweak the variable resistors to the wished output? And do I do the same for +24/-24 (using a 2x24V transformer)?

 

[dissonantstring]

hi Lasselakken,
yes you can. or use the variable resistor/trim pot option and dial in the exact +/- voltage you need.
regards,
grant

edit: you could use a 22V-0V-22V xfrmr and still get the +/- 24VDC you need with less heat disapation from the regulators.

 

[Lasselakken]

Alright - thanks a lot :thumb:

 

[Siegfried Meier]

Hey guys,

I talked to Andrew Brown after purchasing his pushbuttons with mnats pushbutton boards on how to attach them to the rear of the front panel. He said he uses:

"They are called PEMS and they are pressed in to the aluminium."

Does anyone know where I can get this? Or a way that I can connect these specific switches?

Thanks so much,
Sig

 

[gyraf]

"They are called PEMS and they are pressed in to the aluminium."

means that you can't retrofit the switches this way, if your front panel is'nt specially manufactured for this.

 

[Siegfried Meier]

Hmmmm, ok. Well, is there some kind of a metal bond or glue that I can attach a screw to just so I can make these work somehow?? What are others doing?

Thanks,
Sig

 

[gyraf]

Countersunk screw through the front plate, and then a "cosmetic" outer-front-plate.

Or try with epoxy glue from the inside

Jakob E.

 

[Siegfried Meier]

Does anyone know what the values of C*, C*1 and C*2 are on the MNATS boards? Also, where can I obtain the BD135 and BD136 transistors? Digikey has none, and Mouser lists them, but they're called BD135G ad BD136G, and even these aren't available. What is everyone else using?

Thanks,
Sig

 

[josh]

[quote author="Siegfried Meier"]Does anyone know what the values of C*, C*1 and C*2 are on the MNATS boards? [/quote]

http://www.geocities.com/m_natsume/1176.html

Read through the wiring guide. It explains just about everything about this board in great detail, and pictures showing each step. Very nice. It will tell you these values and whether you even need them depending on how you are wiring yours.

Always check ebay when you can't find parts. More than likely you will get a bunch of them for cheaper than you would have bought just the 1 from Mouser or somewhere...

Also, search for your item here and find that you can sub the BD139 and 140 which is what I did, but I'm not finished with mine yet.

Item number: 190131582538 131/135/136
Item number: 170123024244 139's
Item number: 120079340196 140's

It only took me about 5 minutes to write and find all this.....

:wink:

 

[kazper]

[quote author="Siegfried Meier"] where can I obtain the BD135 and BD136 transistors? [/quote]

futurlec.com

There $0.20 EA for BD135/BD136 buy a couple bucks worth. You can also use something else on Mnats board (read the docs) BD139 I think? There is a Jumper for the other Transistors.

Note they have 1% MF in under 10 ohm and above 1M Ohm in general. They also have a more expanded 1% MF section for say a 7.68K. There is 4 resistors on the 1176 that call for 1% specific values.

I've had 2 orders from them and everything has been ok. Definitely not as fancy as the other distributors in packaging but it's cheap. Part's have been from Micro, fairchild, TI, Wima, and well who knows. I got lucky on the wima's.


Kevin

 

[Siegfried Meier]

Thanks for all the help Kazper - here and for the Pultec values.

Now, I've read and reread the 1176 info on MNATS page, and he says:

"The values for the other optional components are listed on Jakob's PDF located at http://www.gyraf.dk/gy_pd/1176/1176.pdf. As the components marked * are not part of the original unit you do not have to use them in order to get a working clone."

I see the values from Gyraf, but I still don't understand, nor can I find, when and why I should use these components. I'm sure I've missed something, but am I safe to say that I can just leave these out?

EDIT - ok, I've figured out the values from Jakob's original and I understand now, after talking to him that they are there for extra stability. So I'll stick them in.

Thanks a bunch,
Sig

 

[Siegfried Meier]

Alright, the epoxy screw thing is no good. The stuff never gets quite hard enough, and the screw, or even the nut, always breaks off with even the slightest amount of pressure.

So, here is another way that you could mount these pushbutton switches.

Siegfried

 

[Purusha]

Using additional panel helps also...

 

[Siegfried Meier]

Ok guys, this may be basic, but I'm just not understanding this. I've got the Amveco 62065 for the 1176. Wiring goes from the IEC, to the switch to the toroid - all is good there. I've got the secondary wired in series, meaning that the red and brown wires go together to give the 0V, and the blue should give 27V and the green should give 27V, correct?

Now, I've measured, and on one unit I get 27V for the green wire, and nothing on the blue, and the other unit I get 27V on the blue wire and nothing on the green. Is this normal, that I shouldn't have any voltage on the opposite wire??

EDIT - now none of the leads work. I've noticed that I've broken off the silver ends, and now only the copper lead is exposed, which, does not allow solder to connect. However, even just checking the leads, I have no voltage. Something wrong with the Amveco's? Perhaps they're not as good as I thought.

EDIT AGAIN - it seems there's a coating on the Amveco leads and not copper. Have never seen this before on Transformers. Scraped the coating away, and all is well.

Thanks,
Sig