ADF4351 Signal generator revisited

My previous attempt at building a 35MHz to 4.4GHz signal generator here had been thwarted by  a fake chinese chip recorded  here. From consumer feedback it appeared that much less trouble was being had with the black ADF4351 chinese board with the 2x5 pin header. I also noticed that BATC were using one in their Portdsown DATV Transmitter. So I bought one from "alicehappy858" on ebay

It took 15 days to arrive, and ten minutes to rewire the header. One very important point to note is that the header pin marked "3.3V" is a 3.3V OUTPUT from  from the 3.3V onboard regulator, NOT a 3.3V INPUT.  5-9V needs to be applied through the tiny barrel connector on the edge of the board of the black version.

Having taken care of that issue I again used my modified F1CJN software published here , modified to use the Adafruit RGBLCD shield that I had. The unit locked all the way from 35MHz to 4.4GHz and the Frequency counter agreed. Success at last!

ADF4351 signal generator

Although I have a portable signal generator using the SI570 that can get to 200MHz I needed something that goes a bit higher. Looking on ebay I found some modules that cover 35 MHz to 4400MHz using the ADF4531 for 20GBP so I ordered one (auction 172152204149 by ayanhu81)

It took 4 weeks to arrive. The next question was how to control the module. An internet search revealed a design by F1CJN here  using an Arduino UNO and LCD shield with buttons from dfrobot.com, which I did not have. However I remembered in my collection I already had a similar LCD/Switch unit from adafruit This would need some code modification, time to remember how arduino's worked. It was not too hard as Adafruit provide the libraries and examples for this unit on their web site. The biggest issue was as my switch reading used SPI not the A/D converter of the original design it was much faster resulting in much keybouncing.  Some strategically placed delays stopped that issue.

I now have it working. Listening to the signal on 144MHz and 432MHz it sounds OK, if a little off frequency due to the cheap on board reference (6kHz low at 432.2MHz) but as the board has an external reference input that is not an issue. Next to take a look at the output spectrum, which is reputed not to be too good at lower frequency, then to put it in a box.

BEWARE OF THE GREEN BOARD VERSION! SEE UPDATED POSTING 

IF YOU WANT A PCB THAT WORKS TRY THE BLACK BOARD VERSION SEE LATEST POSTING