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Just found one on eBay: https://www.ebay.com/itm/MRX-40M-RECEIVER-KIT-QRP/283613875523?hash=item4208b44d43:g:nI4AAOSwq~9db-MY Ordered it. Will convert it to a DDS VFO. I am sitting here with an

Does anyone make a PCB for a 40M DC receiver. Maybe clone the old Ramsey receiver? The PCB pattern is in the published manual. But not the schematic. Maybe I should reverse engineer the Ramsey Rx and

Adding a prescaler does not reduce the accuracy if you extend the sample time. You could have two sample times. FAST for quick look and SLOW for accuracy. Bob Macklin K5MYJ Seattle, Wa. "Real Radios

I built my NC-40A about a year ago. One of the nice things about the rig is its VFO. I set mine up for 7015 to 7047 kHz. A bit limited in that it doesn't cover the activity around 7112 to 7123, but

What is wrong with the old novice band?? I frequently listen there. Because it is there...errr because I can. There was some comment that a DDS vfo has a pretty low upper frequency but the AD985x

Hi, I don’t post much (or ever!) but I do lurk daily and usually learn something in the process. Thanks for carrying the flag! Newt N4EWT

Hi Some but not all Arduinos can count up to 6,4 MHz, i.e. 40% of clock frequency. Empiric data shows a bit higher, ~43%. The Arduino Zero can count up to 90 MHz e.g. as implemented in the RFzero:

You can put a divide by 10 in front of the 328 counter input and go higher in frequency if you want. Bob Macklin K5MYJ Seattle, Wa. "Real Radios Glow In The Dark"

Arduinos can count to 6.4MHz so Digital dial for a NC-40 is a piece of cake. Resolution to the Hz, accuracy depends on calibration and temp/voltage variation. You COULD GPS discipline it for real

How about digital tuning accuracy? I have several GOOD HF receivers with analog tuning and they do not have precision readouts. Only good to about 25KHz. There was a digital display for the NorCal

And... Though I don't see the need to add a DDS VFO to a NC-40, my own NC-40 does have an Arduino add-on. It functions as: AFA? audio frequency annunciator (in CW) Iambic keyer Keyboard CW sender CW

Ok guys.? Sometimes a project is worth doing just because its there! An Si5351 VFO is a really good project just to have around so GO DO IT! If you need any help with Arduino coding let me know. 73,

That is my hope as well! -- Ryan Flowers W7RLF https://miscdotgeek.com

Thanks for creating this new space. I learned a lot from the old QRP-tech group and I am hoping this learning will continue here. Karl Heinz - K5KHK

BTW: Above 7125 is PHONE space. No one looks for CW between 7125 and 7300. The only time I hear phone activity on 40M is during contests. Bob Macklin K5MYJ Seattle, Wa. "Real Radios Glow In The Dark"

I want the DDS so I can have CAT control. Currently I use CW Get and CW Type for CW operation. I'm 85 years old and my hands don't work very well anymore. They are not the only things that don't work

Hi Allison, That is an acceptable price to pay, for me at least!

Hi all, I like tube technology and building my own things, despite all the people who ask why I don't just go buy something instead. A lot of people on the internet want their hands stapled to their

Mike, The cost of a DDS VFO is about 130ma of additional power consumption over the VFO version than can run on small battery for a long time. Allison

"And you can build this basic design with a single crystal at the expense of wider skirts on the IF filter. But you might be able to do RTTY with 170Hz shift." OK a few things the filter in there can