|March 08, 2014|
In the QRP-tech Yahoo Group one of the new "Sandbox" projects is an improved NE4040.
March 4th UPDATE!!! I've decided to keep the 4040 on one band and have it be my little easy to carry transceiver for the field. Some of the improvements I was thinking about for my 4040 (probably will actually be a 4020) will go into a future project which will be a high-performance receiver.
I have the " QRP Power" book that features the 4040 with improvements and I've thought of improvements myself. I've always wanted to make my version of the 4040. I now have the LO made on a muppet board and will put the transmitter on a different board cuz later I want to be able to remove the LO and use a different design such as a DDS. My muppet LO is stand alone module inside a little copper clad enclosure with the connections coming out with RG316. It's tuned with a ElCheapo 10turn pot made in Mexico.
Here's what I mean by a different LO design using DDS. I have a Super DDS2 from Doug, N3ZI and with the control buttons it will change bands and includes RIT if you add a RIT pushbutton. It's output is the proper level for the NE602 (pin 6) so I don't have to add a buffer to it for use in the 4040. I plan to use an Arduino Uno as a transceiver controller. I have figured out how to use it to change band filters and one thing important is to make sure when you tell the dds2 to change bands that it really does it. The Arduino will check the freq when I change bands and make sure the right rcvr input filters are in circuit and the right output filters are in circuit. You can see from my last statement that I plan a multi-band radio. That means the Arduino will have to switch in and out several sets of filters.
I will built in a a modular fashion so I can change out various sections such as the IF filter(s), the IF amp, the LO, and, other various sections such as the filter after the xnt NE602.
I also have an unconventional xmt buffer/driver circuit driving a MOSFET final for the full "QRP Gallon".
I have some HYCAS pcb's and will use one for this rcvr. It will drive AGC and a S-Meter and will have several AGC controls.
Here's the muppet pcb:
Here's the muppet pcb made from the layout above: