Skip to main content

Simpleceiver Part 8

The Simpleceiver Direct Conversion Build is Working ~ Houston We Have Ignition!

 
We now have the J310 "Dual Gate MOSFET" Product Detector working as a 40M Direct Conversion Receiver! All of the upfront analysis we prepared  has paid off in big dividends. The test configuration consists on the J310's as the Product Detector, an Arduino Pro-Mini driving an AD9850 in the range 7 to 7.3 MHz supplying the LO signal and the audio amplifier is the NE5534 driving an LM-380 . There is no additional amplification nor Band Pass Filter in line at this time. There is a short video to show "proof of life".
 
Our basic J310 "Dual Gate MOSFET" schematic was used as shown below. There are but two additions: 1) A 3 turn primary to 20 turn secondary wound on a FT-37-43 core (#26 wire) is used to match the 50 Ohms on the antenna connected to Gate 1 (J2), where the match is forced to 2.2K. C3 is not used with the matching transformer. This is a 44:1 match and 2) A 10 NF is connected to Gate 2 (J1) and the other end is connected to the AD9850 DDS.
 
 
This circuit forms the basic Dual Gate MOSFET template that will be used throughout the total Transreceiver project. With some slight changes this circuit will morph into a RF amplifier that can be used on either the receive or transmit side. More on this in a later post. By the Way in the above configuration this Product Detector is good for 18 dB gain. Run the LT Spice if you are not convinced or you could just look at Part 7.
 
Below is the schematic of the Audio Amplifier stage consisting of the NE5534 and the LM-380 --good for two watts. The LM-380 is used in many commercial transceivers and should allay the fears of those who pan the LM386. [Yes to the question-- this is a GIF --still don't understand why jpgs are no good.]
 

This is the test set up with Pro-Mini/AD9850, the Product Detector and the NE5534/LM380

 
 
The Arduino software I am using is based on the code from AD7C. The Microcontroller is the Arduino Pro-Min and for driving the AD9850 I am using pins 4,5,6 and 7. You must use Pins 2 & 3 for the encoder interrupt, Pin A3 is used for the step increment. The LCD is a 16X2 with a blue background.
 
Stay Tuned --let the fun begin.
 
73's
Pete N6QW
 
 


Popular posts from this blog

2019 ~ What is the simplest homebrew SSB Transceiver that can be built?

4/27/2019 The Future of our Hobby is Here! Forget those simple rigs with homebrew crystal filters, cranky IRF510's and the analog VFO's. SDR is the wave that is building strength just like a Tsunami. With the Soft Rock V6.3 SMD Version + RRPi2 With the Omnia SDR and RPi2 Pete N6QW How Simple & How Cheap can you  build a Homebrew SSB Transceiver? 4/26/2019 --- I just converted my websites from an obsolete Windows Based Server with GoDaddy to their cPanel (Linux). This was a cost issue as a one year renewal of the Windows Server would buy three years on the cPanel. GoDaddy is discouraging the use of what they call the Obsolete Windows System. So I had to migrate and reload the whole pastapete.com, jessystems.com and the n6qw.com sites to the Linux based servers. Some files and links got lost in the translation --so you might not be able to see everything! Essentially I have  to open every link to verify that it works --that may take some time

New Technology for 2020 ~ The Hermes Lite 2.0 SDR Transceiver

  The Hermes Lite 2.0 SDR Transceiver. November 7th, 2020 ~ It's Settled! It is done! The stain of the Trump era is soon to be removed! Thanks to all who voted. The Voice of the People has been heard.  Congratulations to President Elect Biden and Vice President Elect Harris. Pete N6QW November 3rd, 2020 -- IT WAS THE MOUSE   We all know this is Dump Trump  Day. Go out and vote! It was the mouse! Back in 1999 I stupidly was one of the very first to purchase a Ten Tec Pegasus. Never buy the first batch of a new model.  Touted as the world's first computer controlled radio , actually I think the Kachina 505 was really the first. But the Pegasus was fraught with problems including a trip back to the Smokey Mountains. I was using an older Windows 95 machine to control the Pegasus and that may be a co-conspirator. Well after many calls to TT -- finally someone who has some smarts told me: Fix your station ground, Make all leads short and Buy stock in a ferrite bead company. I did all

The Next Project Updated 10/10/2022! The rubber has hit the pavement!

The Next Project... A 2022 Transceiver. 10/10/2022 My Apologies. It is with regret that I will be terminating any further work on this project. My caregiver duties have over time become a greater time sink and it is almost impossible to build something working only 10-15 minutes at a time spread out over a day. I apologize for not getting it from design ideas to complete hardware. Most likely I have built the last transceiver I will ever build. Thanks for riding along. My website https://www.n6qw.com/  has the pdf of the postings and I will leave this blog page as is. 73's Pete N6QW 10/05/2022 Still Alive! Regrettably my caregiver duties have overtaken any free time so not much progress. But I am hopeful yet this week I will cut at least one board. A PSA from N6QW.  Think of it like Mary Jo has a "crink" in her back and unable to get in the backseat of the 57 VW Beetle. A bit of a setback but not forever.  Seems like the hired caregiver had a small emergency and not able