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 Post subject: Re: Admiral 20A1 recap - Need Advise
PostPosted: Feb Sat 24, 2018 2:24 am 
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Joined: May Sun 07, 2017 11:35 am
Posts: 281
The set will run without the width coil. You could then scope around to find a candidate for the ref pulse.


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 Post subject: Re: Admiral 20A1 recap - Need Advise
PostPosted: Feb Sat 24, 2018 3:29 am 
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Joined: Mar Sun 01, 2009 10:27 pm
Posts: 4518
Location: Ann Arbor, MI
robert1 wrote:
this is why i asked if i could replace the coil with a standard width coil & try to find another source for the horizontal sync pulse. i notice that the later Admiral chassis designs use a different method of sourcing the sync pulse

One problem with using a standard width coil is getting one with the right inductance. Now if schematic for your set specifies the inductance, than you could try to get a new coil to match. Or you could try whatever you can find and see if it works. You could always wind a new secondary on to a standard coil. The secondary would not have to be precision wound and would not have many turns.

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Tom


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 Post subject: Re: Admiral 20A1 recap - Need Advise
PostPosted: Feb Sat 24, 2018 4:53 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 132
Location: parkersburg west virginia
Tom Schulz wrote:
robert1 wrote:
this is why i asked if i could replace the coil with a standard width coil & try to find another source for the horizontal sync pulse. i notice that the later Admiral chassis designs use a different method of sourcing the sync pulse

One problem with using a standard width coil is getting one with the right inductance. Now if schematic for your set specifies the inductance, than you could try to get a new coil to match. Or you could try whatever you can find and see if it works. You could always wind a new secondary on to a standard coil. The secondary would not have to be precision wound and would not have many turns.


Both the Sams & Riders manuals do not specify the inductance, but Sams shows it as 80 ohms for the Primary & .5 ohm for the secondary.
i really don't have any parts like that here so i would have to look (& guess) online for something that might be close.
as for the the winding, can it be wrapped around the outside of the width coil winding?


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 Post subject: Re: Admiral 20A1 recap - Need Advise
PostPosted: Feb Sat 24, 2018 7:33 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 289
Location: Elkhorn,Wisconsin,United States
Hi Robert,
I did some checking on 20b1 set I have, and found that the primary inductance adjusts in the 9 to 12 mh range. The secondary adjusts through 530 uh. I took these readings with the wires removed from the coil. Also remember that the adjusting core of the coil increases overall inductance. I noticed that the secondary coil is wound with heavier wire, 26 to 28 gauge wire. I measured 78.8 ohms for the primary winding.
If you get a standard replacement coil , it shouldn't be too much trouble to wind the secondary over the primary. Just try and count the secondary turn off the original coil.
Ed


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 Post subject: Re: Admiral 20A1 recap - Need Advise
PostPosted: Feb Mon 26, 2018 7:21 pm 
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Joined: May Fri 29, 2009 4:35 am
Posts: 2037
Location: Chicago, IL USA
Perhaps this Workman T121 width coil available from Talon will work ?

http://www.talonix.com/shop/item.aspx?itemid=3660

Chassis mount, Transformer,
Primary resistance 102 ohms,
Primary Inductance 9 - 24 mH

Secondary (AGC winding) resistance 1.2 ohms
Secondary Inductance .25-1.1 mH


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 Post subject: Re: Admiral 20A1 recap - Need Advise
PostPosted: Feb Mon 26, 2018 9:12 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 132
Location: parkersburg west virginia
bandersen wrote:
Perhaps this Workman T121 width coil available from Talon will work ?

http://www.talonix.com/shop/item.aspx?itemid=3660

Chassis mount, Transformer,
Primary resistance 102 ohms,
Primary Inductance 9 - 24 mH

Secondary (AGC winding) resistance 1.2 ohms
Secondary Inductance .25-1.1 mH


Wow, Thanks, Bob. i believe that may fix it. i just ordered it. i will post back on this topic once i get it installed (which may be a couple of weeks)


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