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L-4PS Plate transformer primary color coding

Rick W4XA
 

Howdy all,

This question has probably been asked before,? but I am having a little trouble with the plate transformer primary connection identification.


I have 2 plate transformers removed from original L-4PS power supplies.


I also have a complete very nice condition L-4B that I have the original manual for, but it appears that DRAKE didn't bother? to include the transformer primary color-coding? in the power supply schematic!!? So I got the the below picture from BAMA.





When check the primary windings using an ohm meter, there's infinite resistance between the BRN/BLK & YEL wires.

BUT I get "normal resistance BRN--YEL

THEN, I get? what I would call "normal" resistance between BRN/BLK -- BLUE? and then DOUBLE? between BRN/BLK -- GRN

This tells me that the above schematic has the BRN and BRN/BLK reversed



The rest of them are correct.(normal resistance between BLK/GRN--YEL/GRN)


I clearly did NOT the memo.....

Anyone else seen this?


--

73/Rick

W4XA
*Every post is created using Linux

Rick W4XA
 

Well,

I went back to the MAMA manual (Both the PDF and the DJVU files)

It appears I dod not get the above picture from BAMA asw the schematic there has no identification of the primary winging connections either.

Don't know where I got it now.? Still looking.? But the fact remains, the BRN/BLK and BRN in the above picture is reversed.
--

73/Rick

W4XA
*Every post is created using Linux

 

Here's what I have in my files:?
--
73, Paul K6PO
Rick W4XA
 

On Mon, Apr 22, 2024 at 03:50 PM, Paul K6PO wrote:
Here's what I have in my files:?
--
73, Paul K6PO

Hi Paul,


Thanks for the quick reply!!

Yours has the BRN and BRN/BLK the reverse of mine(which is wrong!)

I was to the point where I was going to open up my working L-4PS to see how it was wired!!?

Not sure where I found what I have in my picture.? Although I thought I got it from BAMA, when I looked at what they have,? none of the schematics there have any wiring color-codes shown on them. Must've found it somewhere else!

I discovered it when I started wiring up my rebuilt Hallicrafters Loudenboomer? (single 3-400/500) Power supply.

After I acquired an L-4PS plate transformer, I decided to dump the old Radio Industries INC full-wave (CT),? Mercury Rectifier, swinging-choke? stuff for the Drake style voltage doubler.

I'm going to run it on 120AC and will never use the low-voltage connections that Drake used for CW/TUNE

In fact, I'll probably also just hard wire my L-4B to stay in the SSB position since it's really no longer needed.

thanks again!


--

73/Rick

W4XA
*Every post is created using Linux

 

¿ªÔÆÌåÓý

Does this help?

73

Stan
KM4HQE



On 4/22/24 18:42, Rick W4XA wrote:

On Mon, Apr 22, 2024 at 03:50 PM, Paul K6PO wrote:
Here's what I have in my files:?
--
73, Paul K6PO

Hi Paul,


Thanks for the quick reply!!

Yours has the BRN and BRN/BLK the reverse of mine(which is wrong!)

I was to the point where I was going to open up my working L-4PS to see how it was wired!!?

Not sure where I found what I have in my picture.? Although I thought I got it from BAMA, when I looked at what they have,? none of the schematics there have any wiring color-codes shown on them. Must've found it somewhere else!

I discovered it when I started wiring up my rebuilt Hallicrafters Loudenboomer? (single 3-400/500) Power supply.

After I acquired an L-4PS plate transformer, I decided to dump the old Radio Industries INC full-wave (CT),? Mercury Rectifier, swinging-choke? stuff for the Drake style voltage doubler.

I'm going to run it on 120AC and will never use the low-voltage connections that Drake used for CW/TUNE

In fact, I'll probably also just hard wire my L-4B to stay in the SSB position since it's really no longer needed.

thanks again!


--

73/Rick

W4XA
*Every post is created using Linux

L4PS.JPG

Rick W4XA
 

Hi Stan, thanks for the photo!? Can't really see the colors of the wires in your? picture but K6PO did verify what I suspected.

The first picture I posted had the BRN & BRN/BLK reversed.

Now if I could just find where I got that picture so I could correct it for whomever originally posted it!!
--

73/Rick

W4XA
*Every post is created using Linux

 

The schematic only depicts one 15 amp breaker, when in fact there are 2 of em.?
 

Look again. It's there, just easy to miss.

On Tue, 23 Apr 2024 03:43:03 -0700
"Jim VE7RF via groups.io" <jim.thom@...> wrote:

The schematic only depicts one 15 amp breaker, when in fact there are 2 of em.
--

73

-Jim
NU0C
Rick W4XA
 

Found it!





I sent Ron an email informing him of the typo.

This has me wondering if Drake originally used transformers with this primary color convention and changed it mid-stream and the memo is buried in history!!.........
--

73/Rick

W4XA
*Every post is created using Linux

Rick W4XA
 

I sent an email to Ron and he replied VERY quickly and indicated he would correct his picture........

I also looked at the (uploaded)? BAMA L-7 manual and it has the colors depicted correctly!

It appears that in all of the "pictures" that the colors depicted on the schematics are "penciled-in" by someone other than Drake (they appear hand printed)

It also has me wondering if the picture depicted on Rons site was originally correct ...... and maybe Drake might have changed transformer supplier in mid stream and they came with those BRN--BRN/BLK wires reversed ....and then of course, Drake never bothered to tell anyone!!

Who knows?

Sometimes these old radios can be so frustrating when the schematics are NOT exactly correct!!






--

73/Rick

W4XA
*Every post is created using Linux

 

On Tue, Apr 23, 2024 at 05:56 PM, Jim Shorney wrote:
Look again. It's there, just easy to miss.
Still can't find it.? ?And I have 4 x manuals for the 4 x l4b's.? its not on the L4PS? schematic.??
 

The two circuit breakers are circled in the attached schematic.?

Ken
WA2LBI
???


On Wed, Apr 24, 2024, 10:20 Jim VE7RF via <jim.thom=[email protected]> wrote:
On Tue, Apr 23, 2024 at 05:56 PM, Jim Shorney wrote:
Look again. It's there, just easy to miss.
Still can't find it.? ?And I have 4 x manuals for the 4 x l4b's.? its not on the L4PS? schematic.??

L4B-27.jpg

 

On Wed, Apr 24, 2024 at 07:20 AM, Jim VE7RF wrote:
Still can't find it.? ?And I have 4 x manuals for the 4 x l4b's.? its not on the L4PS? schematic.
Jim;

The second circuit breaker is between the bottom leg of the center-tapped input winding and the screw-terminal... it's drawn at a 45 degree angle.

In this copy of the schematic, it's just below the 'BRN/BLK' marking:




It's a bit more apparent in my re-drawn copy of the L-4B PS:



Mark - AD7EF

 

Same place in my L4B and L7 manuals.

73

-Jim
NU0C

On Wed, 24 Apr 2024 13:09:28 -0400
"Ken, WA2LBI via groups.io" <wa2lbi@...> wrote:

The two circuit breakers are circled in the attached schematic.

Ken
WA2LBI


On Wed, Apr 24, 2024, 10:20 Jim VE7RF via groups.io <jim.thom=
[email protected]> wrote:

On Tue, Apr 23, 2024 at 05:56 PM, Jim Shorney wrote:

Look again. It's there, just easy to miss.

Still can't find it. And I have 4 x manuals for the 4 x l4b's. its not
on the L4PS schematic.







--

73

-Jim
NU0C

2024-04-24_12h12_12.png

 

The complete re-drawn (Orcad) L-4PS schematic is in the 'Files' area of this , at?/g/DRAKE-RADIO/files/L-4B%20Orcad%20schematics%20-%20Factory%20and%20modified/Drake%20L-4PS%20Factory%20Wiring.pdf. I've also posted a re-drawn schematic of the complete L-4B RF Deck there.

Mark - AD7EF

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