Scotts Electronics Crystal and Ham Radio

MK 484 Radio Kit Iimprovement

2012-03-05T18:12:00.000-05:00

A customer of mine Justin has completed a MK484 radio using some parts from an existing radio.

Here are the pictures and schematic.

Any Questions direct them to Justin.

Here is a copy of the email he sent me.

I got interested in the MK-484 circuit after someone posted a version on the Antique Radio Forums http://www.antiqueradios.com/forums/index.php

I looked online for the chip when I found your site and I then decided to get the full kit.

I have two Atwater Kent model 40 radios. One works and the other was a spare kept around for parts. I decided on a whim when the original capacitor and coil supplied with the kit didn’t work properly for me to try one of the three tuning capacitors and RF coils from that radio given it is a TRF circuit. It worked like a charm. I then built the circuit on the radio chassis and put it back into the cabinet. Looks like an AK-40 radio on the outside except for the AGC control mounted where the radio’s power switch was. Given the AGC control will rarely need to be adjusted after the initial adjustment. I may move it to the radio chassis and re-install the original power switch which is mounted in the cabinet under the chassis.

That said I do not recommend anyone butchering up a 1920’s radio in order to get the tuning capacitor and RF transformer when the radio is in restorable condition unless the radio was bought as spare parts for a fully functional radio of the same model.

More than likely the radio will work with the capacitor and coil as supplied in the kit especially if the ground end of the capacitor is connected to ground.

This radio is amazing being able with about a 20 foot indoor antenna to pick up very distant stations at night fairly decently. I noted several distant AM stations that came in pretty clearly with the radio.

The radio’s sensitivity is nearly equal to the sensitivity of my Collins R-390 communications receiver.

The key to the circuit’s proper operation seems to be the air coupled RF transformer. The primary of the transformer has one end grounded with the antenna connected to the other end. If the radio is built in a plastic or wood case the RF transformer alone will pick up stations quite well, but if built in a metal enclosure which I recommend doing for shielding purposes an external antenna will be necessary.

I tested the radio in my house which has metal siding and a metal roof that does make it hard for radios to receive well. With a short wire antenna I just can pick up WSM and WLW on a fairly good night.

I have another version of this circuit which has not been tested as I am waiting on the parts I ordered to be delivered through the mail. I added a second TRF stage which consists of a FET for amplification and another variable capacitor RF transformer combination which should improve selectivity and sensitivity. Also in that version is an antenna preamp which uses a FET for gain and the antenna preamp allows any length of antenna to be used without affecting the TRF stage. Both stages use their own LM-317 regulator to hopefully allow the gain of the circuit to be adjusted for optimum operation. Also with the antenna preamp voltage regulator I have added another variable resistor and a switch that selects between the two variable resistors so the radio can be configured for local or distant stations as one variable resistor will be set to provide low gain from the antenna preamp with the other one set to provide high gain from the antenna preamp.

I will email you that schematic and any notes where it differs in operation from the single TRF circuit once the circuit is perfected.

I also included a couple pictures of the radio. The power supply I used is a 6 amp 12 volt regulated supply that is external to the radio.

You can purchase the MK484 here

http://www.angelfire.com/electronic2/index1/mk484.html

Stopped Selling On EBay Closing Store

2012-02-29T19:41:00.000-05:00

I have stopped selling on EBay.

I received a email with the new seller requirements, to keep my Power Seller status I will now have to start using there shipping method buy printing and paying for shipping on there site. Or upload tracking information.

I do to many orders to type in a 20 sum number for each one. I have been just going to the post office to mail my orders and do not want to use there shipping method.

They also no longer allow writing in any picture. I am not taking 100 pictures over.

I have already had to make separate data sheets for my items because they do not allow any link in them.

Now I can change them all back.

If you do not comply with this you will no longer have Power Seller privileges (20% discount on fees) and you will not be ranked high in there search results. So no Power Seller and low page rankings why stay.

EBay was about 40% of my business but took about 80% of my time to sell with them.

If EBay wants to dictate every little thing I do then they should just purchase items and sell it themselves, that way they can sell anyway they want.

EBay was just a selling venue I used to sell my items, but it is still my store, my business and my items not theirs.

The people who I fell sorry for are the ones that have very little if no income but from selling on EBay. A little at time rule after rule they take over your business telling you what and how you sell on there site trying to dictate every little thing you do.

Anyway I am still in business you can find my site at:

http://www.angelfire.com/electronic2/index1/

New Litz Wire In Stock

2012-01-03T21:59:00.001-05:00

Just arrived 1/3/12 new supply of Litz Wire.

I now stock 42 AWG sizes of Litz Wire.

Below is a list of new 42 AWG Litz Wire. Also a few new sizes of 40 AWG Litz Wire.

10/42 - Litz Wire Size Approximately .012 in diameter.
20/42 - Litz Wire Size Approximately .017 in diameter.
30/42 - Litz Wire Size Approximately .020 in diameter.
40/42 - Litz Wire Size Approximately .023 in diameter.
50/42 - Litz Wire Size Approximately .025 in diameter.
66/42 - Litz Wire Size Approximately .028 in diameter.
80/42 - Litz Wire Size Approximately .031 in diameter.
100/42 - Litz Wire Size Approximately .035 in diameter.
125/42 - Litz Wire Size Approximately .038 in diameter.
165/42 - Litz Wire Size Approximately .046 in diameter.

New 40 AWG sizes added.

10/40 - Litz Wire Size Approximately .015 in diameter.
15/40 - Litz Wire Size Approximately .018 in diameter.
25/40 - Litz Wire Size Approximately .022 in diameter.

To Date I have the following sizes of Litz Wire in stock.

10/46 - Litz Wire Size Approximately .009 in diameter.
20/46 - Litz Wire Size Approximately .011 in diameter.
40/46 - Litz Wire Size Approximately .015 in diameter.
60/46 - Litz Wire Size Approximately .018 in diameter.
80/46 - Litz Wire Size Approximately .020 in diameter.
100/46 - Litz Wire Size Approximately .022 in diameter.
140/46 - Litz Wire Size Approximately .027 in diameter.
175/46 - Litz Wire Size Approximately .029 in diameter.
220/46 - Litz Wire Size Approximately .033 in diameter.
330/46 - Litz Wire Size Approximately .040 in diameter.
550/46 - Litz Wire Size Approximately .050 in diameter.
660/46 - Litz Wire Size Approximately .056 in diameter.

10/44 - Litz Wire Size Approximately .010 in diameter.( Silk Covered )
20/44 - Litz Wire Size Approximately .014 in diameter.( Silk Covered )
40/44 - Litz Wire Size Approximately .018 in diameter.( Silk Covered )
60/44 - Litz Wire Size Approximately .022 in diameter.( Silk Covered )
100/44 - Litz Wire Size Approximately .028 in diameter.( Silk Covered )
140/44 - Litz Wire Size Approximately .032 in diameter.( Silk Covered )
180/44 - Litz Wire Size Approximately .037 in diameter.( Silk Covered )
220/44 - Litz Wire Size Approximately .045 in diameter.( Silk Covered )
330/44 - Litz Wire Size Approximately .048 in diameter.( Silk Covered )
420/44 - Litz Wire Size Approximately .057 in diameter.( Silk Covered )
660/44 - Litz Wire Size Approximately .075 in diameter.( Silk Covered )

10/40 - Litz Wire Size Approximately .015 in diameter.
15/40 - Litz Wire Size Approximately .018 in diameter.
25/40 - Litz Wire Size Approximately .022 in diameter.
40/40 - Litz Wire Size Approximately .028 in diameter.
50/40 - Litz Wire Size Approximately .031 in diameter.
75/40 - Litz Wire Size Approximately .037 in diameter.
105/40 - Litz Wire Size Approximately .044 in diameter.
125/40 - Litz Wire Size Approximately .047 in diameter.
5/41 Litz Wire Size Approximately .010 in diameter
16/38 - Litz Wire size is Approximately .023 in diameter. ( Silk Covered )
30/38 - Litz Wire Size Approximately .031 in diameter.
40/38 - Litz Wire Size Approximately .035 in diameter.
50/38 - Litz Wire Size Approximately .039 in diameter.
66/38 - Litz Wire Size Approximately .045 in diameter.
75/38 - Litz Wire Size Approximately .050 in diameter.
The below wire is un-served
20/40 - Litz Wire size is Approximately .018 in diameter.
40/36 Litz Wire Size Approxmately .038 in diameter.
4/34 Litz Wire Size Approxmately .016 in diameter.
6/20 Litz Wire Size Approxmately .102 in diameter.

You can find and purchase all the above sizes at:

http://www.angelfire.com/electronic2/index1/Litz-Wire-Supplier.html

Or my home page:

http://www.angelfire.com/electronic2/index1/

Long Wave Loop Antenna Plains

2011-11-09T20:38:00.000-05:00

Another well planed Long to Medium Wave Loop Antenna by Kevin S.

If you have any questions please direct them to Kevin.

I will notify him if there is comment he can reply to.

Giant-Ferrite-Sleave-Antenna

Purchase Litz Wire and Electronic Parts Here

Loop Antennas Cover VLF Through AM Band

2011-09-21T20:52:00.003-04:00

Keven S.

A customer of mine that purchases Litz Wire and Poly Variable capacitors has developed several Ferrite Loop Antennas that cover a very wide frequency range using my Litz Wire and dual 266pf and 335pf poly variable capacitors.

Below are links to some of his Loop Antennas.

http://www.angelfire.com/electronic2/index1/Monster-Loopstick-Prototype.pdf
He has modified the above using 660/44 Litz Wire instead of the smaller AWG sizes however I can not find the build information on it.

This is his latest design.

http://www.angelfire.com/electronic2/index1/12-Inch-FSL-Design-Rev-A.pdf

Keven has recently purchased 330/44 Litz wire to replace the larger 660/44 Litz wire used in the above to make a smaller more portable unit to fit in a backpack.
Also Note that to date I am the only one selling 660/44 and 330/44 Litz Wire not like stated in the pdf files.

The Litz Wire and variable capacitors can be found at:

http://www.angelfire.com/electronic2/index1/

How To Use This Blog

2011-08-23T22:37:00.000-04:00

If you want to become a member click on the Sign In link if you want. This lets you sign up with Google with your email address and password. Posting is very bad for me may be me but I now copy the post and keep re posting it until it takes. Some times take 5 or more tries before it works.

However you may if you want leave a comment with out becoming a member.

If you want to make or leave a comment just click on comments link just under the Title Header block.

The page may not show all the Subject Titles, select a Title From the Archive List to view that subject.

There you can read comments left by others and post your own comments.

I have made the Blog open to everyone so when you make a comment in the pull down box above the add post comment button just select anonymous and you can sign the comment with an anonymous name if you like write it in the comment.

After making a comment there is a small link "Home" found toward the bottom of the posting page and toward the top of the page. That will bring you back to main Blog Page.

New Stock And Sizes Of Litz Wire In Stock

2011-08-23T22:32:00.001-04:00

I just receved a new supply of Litz Wire in the 38 and 40 AWG sizes.

I have the following sizes of Nylon Covered 40 AWG Litz Wire in Stock.
The Litz Wire below dose not come in different colors it is all Clear ( Pinkish Color )

40/40 - Litz Wire Approximately .028 in diameter.
50/40 - Litz Wire Approximately .031 in diameter.
75/40 - Litz Wire Approximately .037 in diameter.
105/40 - Litz Wire Approximately .044 in diameter.
125/40 - Litz Wire Approximately .047 in diameter.

I have the following sizes of Nylon Covered 38 AWG Litz Wire in Stock.

16/38 - Litz Wire Approximately .023 in diameter. ( Silk Covered )
30/38 - Litz Wire Approximately .031 in diameter.
40/38 - Litz Wire Approximately .035 in diameter.
50/38 - Litz Wire Approximately .039 in diameter.
66/38 - Litz Wire Approximately .045 in diameter.
75/38 - Litz Wire Approximately .050 in diameter.

Recommended frequencies for various Litz Wire sizes Litz-Wire-Frequency.pdf

You can purchase at http://www.angelfire.com/electronic2/index1/Litz-Wire-Supplier.html

Supplier Of Litz, Litz, Litz And More Litz Wire For Sale

2011-02-28T22:25:00.000-05:00

I just got in all my Litz Wire and have the re-spooling and coil winding machine done.

I have for sale the following sizes of Litz Wire. To my knowledge I have the largest selection of ready to buy Litz Wire I have seen. The larger sizes are sold in mutable 10 ft. lengths. However any lenght can be custom quoted.

You can purchase at:

http://www.angelfire.com/electronic2/index1/Litz-Wire-Supplier.html

Or at my home page:

http://www.angelfire.com/electronic2/index1/index.html

We have the following Litz Wire Supply.
16-38 Litz Wire

10/46 - Litz Wire
20/46 - Litz Wire
40/46 - Litz Wire
60/46 - Litz Wire
80/46 - Litz Wire
100/46 - Litz Wire
140/46 - Litz Wire
175/46 - Litz Wire
220/46 - Litz Wire
330/46 - Litz Wire
550/46 - Litz Wire
660/46 - Litz Wire

10-44 Litz Wire
20-44 Litz Wire
40-44 Litz Wire
60-44 Litz Wire
100-44 Litz Wire
140-44 Litz Wire
180-44 Litz Wire
220-44 Litz Wire
330-44 Litz Wire
420-44 Litz Wire
660-44 Litz Wire

The wire is of good quality, I have no way to test the "Q" of the wire so I sent some out and had it tested here is the results for the 660/44 Litz Wire.

42 turns on a styrene 4.5" coil form--with 10" pigtails, that's about 51.1 feet of wire (the coil measured 172 uH):

200kc 680 Q
300kc 890 Q
400kc 1050 Q
500kc 1160 Q
600kc 1268 Q
700k 1270 Q
800kc 1240 Q
900kc 1200 Q
1200kc 1030 Q
1400kc 905 Q
1600kc 770 Q
1700kc 683 Q

I am sure the smaller sizes will have lower "Q" but this gives a good idea of the quality of the wire in general.

Picture of 16/38 Litz Wire, Silk Covered.

Picture of 46 Awg Litz Wire, Nylon Covered in various colors. Shown are just a few.

Pictures of 44 AWG Litz Wire. This size is silk covered and the pictures represent the color of the wire.

You can purchase at:

http://www.angelfire.com/electronic2/index1/Litz-Wire-Supplier.html

Or at my home page:

http://www.angelfire.com/electronic2/index1/index.html

New Item Polivaricon Plastic Poly Dual 20pf and 335pf Variable Capacitor

2011-01-31T19:59:00.000-05:00

New Item Dual 20pf and 335pf Poly Variable Capacitors.

These can be connected in a number of different ways. You can have a dual 16pf to 371pf from this one capacitor. For wiring connections and the possible combinations go to my website.

http://www.angelfire.com/electronic2/index1/335PF-Polyvaricon.html

Or Home Page

http://www.angelfire.com/electronic2/index1/

Building And Putting Together A Crystal Radio Kit For Kids

2011-01-27T19:58:00.000-05:00

Dave Farrell purchased my Crystal Radio Kit CRK-1 for his class on Crystal Radios. He said the kids loved them.
He made a powerpoint presenation outlining the class. He also has some theory on how a Crystal Radio Works.

http://www.angelfire.com/electronic2/index1/Crystal-Radio-Sets.ppt

This link can also be found on my website at:

http://www.angelfire.com/electronic2/index1/DmCrystalSet.html

M484 AM Kit With 2000 Ohm High Impedance Headphones

2011-01-12T23:01:00.000-05:00

New Item

MK484 AM Radio Kit With 2000 Ohm High Impedance Headphone

The 2000 Ohm Impedance Headphone is just wright for the MK484 IC to operate.

High Impedance Magnetic Headphones makes a perfect addition to MK484 Kits

http://www.angelfire.com/electronic2/index1/mk484.html

MK484 AM Radio Kit With Piezoelectric High Impedance Headphones

2011-01-12T22:54:00.000-05:00

New Item

MK484 AM Radio Kit With Piezoelectric Headphone

Just added this kit. A MK484 AM radio kit with a Ceramic Headphone instead of Ceramic earphone.

Nice quality High Impedance Piezo Headphone supplied with my MK484 AM Radio kit.

http://www.angelfire.com/electronic2/index1/mk484.html

2000 Ohm High Impedance Headphones for Crystal Radios

2011-01-12T22:42:00.000-05:00

New Item

2000 Ohm High Impedance Headphones

The are magnetic type Headphones.

They have a 1/4 inch mono plug and the cord is about 40 inches long.

Can be used on Crystal Radios with or without a matching transformer.

However a matching transformer will improve performance and volume somewhat.

http://www.angelfire.com/electronic2/index1/Crystal-Radio-Headphones.html

High Impedance Crystal Radio Headphone (Piezoelectric)

2011-01-12T21:54:00.000-05:00

New Item For Sale

High Impedance Ceramic Headphone

These are high quality headphones made special for me from a manufacturer.

They have 1/4 mono plug end and the cord is about 40 inches long.

These are not homemade with Piezo Transducers.

Leave comments on them after you try them out.

http://www.angelfire.com/electronic2/index1/CeramicHeadphone.html

Guitar Mods Or Sound Effect Circuits

2010-11-19T22:23:00.000-05:00

Many of the items I sell have uses in a variety of circuits besides crystal radios. One is various sound effect circuits and Guitar Pedals and various Mods. If you have a question concerning the items I sell used for the circuits or repairing existing items with the items I sell leave a comment.
Thanks

Questions Or Comments For The Electronic Experimenter

2010-11-12T23:26:00.000-05:00

If you are just learning Electronics or are an Experimenter and have any questions about any of the items I sell or there uses leave a comment.

Comments Or Questions For Ham Radio Parts

2010-11-12T23:23:00.000-05:00

The electronic parts I sell are mostly vintage. If I can advise or help you in any way with these leave a comment.
Thanks

MK484 Radio Kit Questions Or Comments

2010-11-12T19:34:00.000-05:00

Ask questions or leave comments about the MK484 or any of the equivalents I sell.

Crystal Radio Questions Or Problems

2010-11-12T19:18:00.000-05:00

If you have built the Crystal Radio Kit and are having problems or need some more information. Leave a comment.
Thanks

Suggestions For New Products To Sell

2010-11-10T23:17:00.000-05:00

Give me your ideas for new products or items to sell.
I am adding new products all the time.
Recent additions are the 2000 Ohm High Impedance Headphones and the Dual 0-335pf and 0-20pf Poly Variable Capacitors.
Cumming in January 2011 Ceramic ( Piezoelectric ) Headphones.

Suggestions For New Topics

2010-11-10T23:07:00.000-05:00

Since it seems I am the only one that can start a new Topic let me know what you would like to talk about.
Ether with a comment here or by email slowe15@cinci.rr.com

General Questions

2010-11-10T22:51:00.000-05:00

Ask any general question about any thing I sell.

New Ideas

2010-11-10T22:22:00.001-05:00

Give your Ideas for new products, ways to improve the products I sell and new ways to use them.