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 Post subject: Deforest Loop Antenna Repro
PostPosted: Apr Wed 07, 2021 6:17 pm 
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Joined: Oct Sat 07, 2006 12:47 pm
Posts: 164
Location: Ann Arbor, MI
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Thought I'd show my reproduction Deforest loop antenna. I made this for the challenge and to introduce myself to SolidWorks. A person with a real antenna provided me tracings, measurements and photos. I found other dimensions and photos on this site as well. Disclaimer: I have never seen a real Deforest antenna in person so I'm sure there are details that are not correct, in particular details of the tap switch.

The wooden parts are walnut and milled with a CNC router. I believe the black center bracket originally was bakelite. I CNC milled my bracket from a "plastic like" material called Delrin. I purchased a sticker form radiolaguy and installed it in the center recess of the bracket. There are black pieces on the ends of the wooden sticks. Not sure what the original material was but I also milled these from Delrin.

The antenna is strung with wire I braided myself. The original was covered with two layers of silk wrapped in opposing directions. I intended to replicate the wire as best I could but I opted for expediency.

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 Post subject: Re: Deforest Loop Antenna Repro
PostPosted: Apr Wed 07, 2021 6:56 pm 
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Joined: Apr Sun 01, 2012 9:55 pm
Posts: 12640
Location: Seattle, WA
Wow, super nice!

I wish I had a workshop that would let me do work like that. Or the knowledge how to operate the equipment. I'm thinking of taking a course in "Fabrication" once the pandemic is over though... I want to learn how to use a milling machine, a welder, etc.

Great work! I really like it. What does the base look like? And... how do you braid insulation on wire?

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Rodney -- KG7EPW
Measure it with a micrometer, mark it with chalk, cut it with a chainsaw.


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 Post subject: Re: Deforest Loop Antenna Repro
PostPosted: Apr Wed 07, 2021 8:54 pm 
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Joined: Jan Tue 31, 2012 1:55 am
Posts: 16745
Location: Mountains of Mourne. Ireland.
Yes... super work... :)
I'll take a dozen!

Here's a neat German manufactured loop antenna that you may like. lol
viewtopic.php?p=2509328#p2509328

Greg.


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 Post subject: Re: Deforest Loop Antenna Repro
PostPosted: Apr Wed 07, 2021 10:00 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 10057
Location: 13 Critchley Avenue, PO Box 36, Monteith Ont, P0K 1P0
Steven Olson wrote:
Thought I'd show my reproduction Deforest loop antenna. I made this for the challenge and to introduce myself to SolidWorks. A person with a real antenna provided me tracings, measurements and photos.


Your work is superb. I love the attention to detail, right down to the decal. Nicely done !!


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 Post subject: Re: Deforest Loop Antenna Repro
PostPosted: Apr Wed 07, 2021 10:32 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 2244
Location: Monroe, NC 28112 USA
You have a braiding machine? Tell me more!
Robert


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 Post subject: Re: Deforest Loop Antenna Repro
PostPosted: Apr Thu 08, 2021 4:43 am 
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Joined: Sep Mon 18, 2017 2:23 am
Posts: 7211
Location: Plymouth, MI
Excellent work Steve, very nice.

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Museum Curator
https://roaringtwentiesantiqueradiomuseum.com/


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 Post subject: Re: Deforest Loop Antenna Repro
PostPosted: Apr Thu 08, 2021 5:20 am 
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Joined: Dec Mon 15, 2008 6:08 am
Posts: 407
Location: La Vergne, TN
palegreenthumb wrote:
Wow, super nice!

I wish I had a workshop that would let me do work like that. Or the knowledge how to operate the equipment. I'm thinking of taking a course in "Fabrication" once the pandemic is over though... I want to learn how to use a milling machine, a welder, etc.

Great work! I really like it. What does the base look like? And... how do you braid insulation on wire?



The radio is the "base". The antenna plugs into the top of the cabinet via a hole in the top of the radio. For example, a DeForest D10.


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 Post subject: Re: Deforest Loop Antenna Repro
PostPosted: Apr Thu 08, 2021 11:22 am 
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Joined: Oct Sat 07, 2006 12:47 pm
Posts: 164
Location: Ann Arbor, MI
Robert Lozier wrote:
You have a braiding machine? Tell me more!
Robert


viewtopic.php?f=19&t=330308


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 Post subject: Re: Deforest Loop Antenna Repro
PostPosted: Apr Thu 08, 2021 11:24 am 
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Joined: Oct Sat 07, 2006 12:47 pm
Posts: 164
Location: Ann Arbor, MI
oops, didn't get the full path to the link

Robert Lozier wrote:
You have a braiding machine? Tell me more!
Robert


viewtopic.php?f=19&t=330308


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 Post subject: Re: Deforest Loop Antenna Repro
PostPosted: Apr Thu 08, 2021 12:28 pm 
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Joined: Aug Sun 02, 2015 7:34 pm
Posts: 1063
Location: Yukon, OK USA
I have made several loop antennas but none of them reproductions of vintage loops and none as nice looking as yours. I also have machine equipment in my shop. Having metal working equipment is pretty useful in restoring old equipment like your braiding machine and for fabricating. I do no have any CNC in my shop. Everything is manual.

Very nice work!

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AB5ON

Forest Gumping through life


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 Post subject: Re: Deforest Loop Antenna Repro
PostPosted: Apr Thu 08, 2021 1:05 pm 
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Joined: Oct Sat 07, 2006 12:47 pm
Posts: 164
Location: Ann Arbor, MI
black85vette wrote:
I have made several loop antennas but none of them reproductions of vintage loops and none as nice looking as yours. I also have machine equipment in my shop. Having metal working equipment is pretty useful in restoring old equipment like your braiding machine and for fabricating. I do no have any CNC in my shop. Everything is manual.

Very nice work!


The CNC machines opened up a whole world of possibilities for me. Unfortunately I don't have one either but within a mile from me is a facility that has a complete wood working shop which includes the CNC machine i used, metal shop, electronics shop and more. I pay a flat monthly fee for access to these tools. I have toyed with obtaining my own CNC machine but the cost to get anything of a decent size would pay for several years of monthly fees at this facility I use.


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