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1202-118 V.2... B+?. And some wire...

PostPosted: Sun Oct 05, 2008 12:41 am
by Roadrunner
I just got in the new version II of the 1202-118 PT's. Now they have a "high" and "low" tap for the B+. I assume the high tap is be the same as before... around 420v., what's the low tap yield?

And, I need a source for some good 16 and 18 AWG wire for doing the heaters... any suggestions?

Thanks in advance!

Re: 1202-118 V.2... B+?. And some wire...

PostPosted: Sun Oct 05, 2008 12:53 am
by Brian Wallace
The low voltage tap is 370VDC.

You can get wire from Alpa or Allied Electronics, any 600v wire will work fine.

Re: 1202-118 V.2... B+?. And some wire...

PostPosted: Sun Oct 05, 2008 9:12 am
by Roadrunner
Cool... thanks Brian!

Another question to 1202-118 V.2

PostPosted: Thu Oct 09, 2008 5:31 am
by Ennkuhl
Hello!

I think, i've got the version 2 of the 118's transformer.
But there are two news connections with this version.

Indeed, your actually wiring diagram look like this:
Image

Do you have a new wiring diagram with the two news connections?

And what connections should I use for my plexi replica?

Thanks

Re: 1202-118 V.2... B+?. And some wire...

PostPosted: Thu Oct 09, 2008 6:57 am
by Brian Wallace
Here you go.

Re: 1202-118 V.2... B+?. And some wire...

PostPosted: Thu Oct 09, 2008 3:11 pm
by Ennkuhl
Thanks !!!

I must to use HT high or low?

Re: 1202-118 V.2... B+?. And some wire...

PostPosted: Thu Oct 09, 2008 5:58 pm
by Brian Wallace
If your building a plexi, you will want to use the high voltage taps.

Re: 1202-118 V.2... B+?. And some wire...

PostPosted: Thu Oct 09, 2008 6:45 pm
by Ennkuhl
Thank you very much Brian.

Re: 1202-118 V.2... B+?. And some wire...

PostPosted: Fri Oct 10, 2008 10:03 am
by chubs
Brian Wallace wrote:If your building a plexi, you will want to use the high voltage taps.


What amp used the 370V that case... I will be putting it on a switch.... anything I should watch-out for?

Re: 1202-118 V.2... B+?. And some wire...

PostPosted: Fri Oct 10, 2008 5:23 pm
by Brian Wallace
370VDC was found in the 70's typically.

Re: 1202-118 V.2... B+?. And some wire...

PostPosted: Mon Mar 26, 2018 11:05 pm
by dan_tramble
I am using this PT in a upcoming 1987 build....

So in summary... HT HIGH for 1968 B+?

can I run two 1N4007's in series off the HT taps and join the pair, then run that wire to one side of the SPST standby switch then have the other side of the switch run to the 50/50 Mainc cap then in turn to the HT fuse holder... to the centre tap of the OT and choke? I'll pick up the bias feed off one lug of the HT on the PT

I want to wire this amp up "true vintage" I have a full set of NOS Mullard Mustard caps for this amp......

Thanks

Dan Looking forward to my first amp with Marstran Transformers....

Re: 1202-118 V.2... B+?. And some wire...

PostPosted: Tue Mar 27, 2018 6:46 pm
by David B
Yeah the early ones had the diodes hanging off the PT, not my first choice for mounting the rectifier diodes but it works.

Suppose you could shrink the diodes as in this example.
http://marstran.com/68%2010450.htm

Consider trying it with a GZ34 and have a ss plug in? get to try both....

Could also make a chassis mounted block for the ss diodes.Should be examples in the database...

Re: 1202-118 V.2... B+?. And some wire...

PostPosted: Tue Mar 27, 2018 9:47 pm
by Brian Wallace
Dan,

I have built them with the diodes off of the PT and it works fine. I did however run the diodes over the top of the PT so that they did have some support. With that said I do like having them on the circuit board.