R2Pro Receiver

Having just completed the 2N2/20, designed by Jim Kortge, I was searching for another project, to build. I found many interesting QRP designs but didn't want another "run of the mill" CW transceiver. The AmQrp Club announced a limited run of their IQ-VFO, I looked at it and decided that it was more money than I wanted to spend on a VFO and besides, what would I do with it. They were using some new terms, at least to me, to describe it's features. What are those "I" and "Q" outputs anyway. Soon the QRP Reflector was a buzz with talk of this new DDS controlled device but I moved on still looking for my next project.

I had read about KK7B's receiver design and when people started talking about using the IQ-VFO with it, I started doing more research. I liked what I read but to be honest, I wasn't sure I was up to building such a receiver. There are circuit board kits available from Kanga US but they aren't step-by-step directions and I have many unanswered questions. To make matters worse, I decided to pursue building a multi-band SSB/CW transceiver instead of just a receiver. I was lucky enough to get a IQ-VFO during the second offering of the kit but they sold out in a hurry. I believe there are still partial kits still available, check their website for more info.

I haven't found too much on the Internet in the way of "this is how I did it"type of information. The circuit boards, from Kanga US aren't silk screened, with the parts placement, but Bill does provide a printed overlay. Since I'm just getting started, there isn't much in the way of technical data here but I thought you might be interested in a few pictures. I will add more of the "this is how I did it" as I get further into the build.

Here is my completed IQ-VFO

A shot of the 80 pin processor.

Here is a picture of the 40 meter LNA board with the 6 toriod coils, the dime helps to get a sense of the size.

And a shot of the finished LNA

A shot of the bare down converter board.

Almost completed down converter board. It's missing two backordered matched 6.8uf caps.

The Analog Signal Processor board

Bare audio amp board on the left and finished on the right.

All of the boards are built but I'm still waiting for the two 6.8uf caps to be delivered. I still new to figure out how I'm going to put them all together. I need to come up with a band switching method for the receiver frontend because there will be a LNA for each band I want to cover. The low tech method would be to have plugable LNA's and change them manually when changing bands.manually when changing bands. The last two pictures above were taken with my new Nikon 8700 digital camera. I'm still trying to get use to using it but the detail is just great. You can see in the finished amp board the remains of the solder flux that came from the backside of the board after I washed it.

It has been some time since I've worked on this project but it has never been completely out of mind. I decided to mount all of the boards on a piece of PCB material. The image at left is shown before any shielding has been added. Later I plan to install the whole receiver into a nice enclosure, which I'm working on now. The back part of the PCB will hold a SSB transmitter.

At right is a view of the LNA with the shielding set in place buy not yet soldered to the main PCB.

This view shows the downconverter/frontend. I'm using SMA cables to connect the input/outputs.

I'm using the older IQ-VFO that the AMQRP Club produced a couple years ago. A newer version of this VFO is now available from Kanga. This image shows the VFO without any connections made as yet.

I'm in the process of completing the wiring of the receiver and more will follow shortly. 3-30-06