Twinplex Regenerative Receiver part 5 done deal

The Twinplex Regenerative Receiver has taught me a lot. It is amazing to think about all the experimentation that went on years ago to get to where we are today in radio.

I wound a coil for the upper part of the AM band. 87 or so turns to start, then removing 3 at a time until I hit where I wanted. I ended up with 76 to 16 (tickler) and may still take a few off the tickler coil to find the effect there. It is kind of narrow banded I think 920 to 1380.

  A side view Of the Twinplex with the AM (lower end) coil.

Front view of the Twinplex with the knob indicator and control plates I made for it. My wife says I should find copper screws or rivets to match.

A special thanks to my mentor on this project.

Twinplex on AM

A short video of the Twinplex working on the AM band. Listening to Baseball will be a hoot on this radio...

I found a 100 MMF capacitor in one of my coil forms. I wonder what this coil was used for in the past.

Twinplex Regenerative Receiver part 4

I ran a test with the receiver with a 9 to 3 coil and picked up this beacon station WLO. I wanted to make sure everything worked before mounting the front panel for the final time. I also picked up several religious broadcasts so I figure it must have been up in the 8500 over 40 meters anyhow.

I also built a 40 meter coil 9 to 2 turns. I listened to several QSOs and what sounded like PSK so I am happy with that coil.

 I mounted the knobs, and bolted everything down good. I still had a couple of hours to kill so I decided to try to build an AM coil. I found an AM loop stick that came in one of my son's old electronics kits. After mounting it inside one of my coil forms, I added 2 loops for a tickler coil. Worked first try! I found stations from 620 up to 770 so far. but it works surprisingly well.

The AM loop stick is laying on its side in the coil form. I do not know if that causes a problem or not. I'll try centering it to see later.

Twinplex Regenerative Receiver Part 3

Got a little more done today. The chassis paint came out great, so we have this process down. A deep Emerald green.

Installed the Hardware for the backside of the receiver. Broke down and bought a box of screws and nuts plus washers. A lot cheaper in the long run. Here is a picture of the backside with the parts installed.

On to the underside of the chassis. The filament transformer and audio transformer are installed. I also put in a few caps and resistors.

Back to the top side of the chassis now. I mounted the Band-set and Band-spread capacitors. Using the big knobs made putting plastic spacers underneath a must, but they are secure. Added the binding posts for the B+  voltage.

More to come....

Twinplex Regenerative Receiver part 2

Today I got  the chores out of the way early and started punching holes in the back of the chassis. There are quite a few for all the parts that are going to be installed back there. I try to group the power cord, fuse, switch, and transformer close to allow the shortest wire runs possible. If you think ahead about where everything goes you won't have to go back and touch up paint. (not that I have ever had to do that... Ahem cough cough)

 Here is a view of the chassis with the holes drilled today. Somehow I lost my socket for the Hammerland 6 pin coil form. So here I go on a hunt for another...

The Green Hammer-tone paint came out fine on the chassis front panel. Letting it sit in the sun before spraying seems to help the process along. In the background you can see the power supply for the 6L6.
More to come....

Twinplex Regenerative Receiver Build

I started today on the Twinplex Regenerative Receiver. The parts have piling up since my friend James told me he found a good receiver design to build. He has gleaned great results with his and says it is a hot little receiver. (good enough for me)

Here is the box  O' Parts. Those Big knobs are vintage NOS I picked up very cheap. I did buy some more of the cloth covered wire from  http://enginebarn.myshopify.com/   
No affiliation. I just like the product.

After some tedious measuring and layout, I finally found a layout I liked. Let the drilling begin....

 The front panel holes are in place, now for the chassis front hole placement. My drill press is just big enough to be able to mark (with the drill bit) the chassis with the front panel still attached. This means all the holes will match up perfectly.

 Here is a view of the parts for the front panel dry fitted to the chassis. Everything lines up perfectly so the front panel is now ready to be painted. The paint of choice is going to be hammer-tone green. Green you say? Yep green...(Is it starting to look like a radio yet?)
 More to come...