Colt receiver part 1

I found a book as an E-book at the university library: Radio and Electronics Cookbook that was published by the Radio Society of Great Britain in 2001. I have skimmed through it briefly and it seems to cover both some  radio theory and some interesting projects. I do have a lot of  "maybe" and "should be" projects in my head (that I will cover in later blog posts) and now I think I decided, apart from getting the softrocks built (as they are already on my desk), I would like to build a hardware defined receiver.  A very basic one to really try to understand how a radio works.

In this book, I found one called the "The Colt 80 m receiver" that I liked, because it´s built in modular steps and quite thoroughly explained. It starts with the audio amplifier and then adds mixer (NE602) and VFO to become a direct conversion receiver. The last part is to add an IF stage to become a superhet.

What worries me a bit is that I can´t find any reference to this design when I google it. Or maybe blogs and so on wasn´t that common 2001 and earlier or this design is named something else elsewhere? A bigger problem is the availabilty of parts. Variable capcitors to be used in a VFO can´t be bought new, but I´ve have asked around in the club and I think that will be solved.

Then there are some specific inductors from Toko:

• Toko KANK3334

• Toko KANK3333

• Toko YHCS11100AC (tuned inductor)

For the two first ones I have found a guide at the GQRP club (that I by the way have joined; Sprat is a great magazine), so I can make those inductors with toroids. But the last one, I have no clue. Any ideas someone? There´s also a part number for a crystal filter, but I think I can use another one for 455 kHz.

We will see if there will be a part 2.

Soldering

To be able to build my amateur radio equipment I have to solder electronic components. That´s a basic fact. :-) My experience so far with soldering has been coax cables and wires from torroids to be soldered to connectors, that is impedance transformers for receiving antennas . For that task a very basic soldering pen has been used.

But if I want to be able to solder small components I have to have something better. I started bidding on nice ones I saw on auction (Weller etc) but they all came up on level I didn´t think it was worth spending. Probably they all are alot better than the one I bought. Time will tell. The one I found cost 600 SEK (~80 US dollar) on the local store Kjell & Co, but it´s atleast equiped with temperature control and the tips can be changed over to smaller ones.

You can see an ancient modem on the bench in the top image for practicing. When I feel compfortable with my soldering skills I will move over to build the Softrock Lite II for 30 meters or maybe I start with an FM receiver kit I got laying around. Before I can get to the SMT components I think I have to get hold of some nice flux.