This code is better!
I just noticed the board is in TX mode with no input on the TRX line. but the code starts up in RX until the encoder is turned. That will be an easy fix, but maybe tomorrow. Or better still, someone else fix it and post the updated code.
Please feel free to play as much as you want.
I have started on an FM828A.
Front panel cut out to fit an OLED display.
A slot needs to be filed into the chassis to fit the encoder.
And the power switch mount cut, removing the AUX switch. The 2 brown wires of the AUX are cut off, soldered together and insulated.
Then, the encoder is wired. I 3D printed a mounting bush.
It fits pretty well.
To mount the VFO board, it turns out there are a couple of holes just in the right place. A M/F M3 pillar for each. Make sure the thread is not too long to short the boards under. 2 nuts seem to be a good length.
And the board fits
On the TX exciter board, remove the black wire..
and add the VFO signal coax, with a coupling cap. Braid to 3 and cap from center to 41.
Similarly, on the RX, remove the black wire..
and add the coax as shown. there is a cap on board that can be used but the value may need increasing. Edit: I added a 150pF on the back of the PCB.
This is as far as I have got for now...
Something to eat sound good!
I am having problems with the code. It looks like a RX divisor of 3 is too low. It may be a maths problem or a limitation of the si5351.
A divisor of 6 looks ok.
And I need a knob for the encoder in the AUX position.
EDIT: The receiver tunes up ok, no mods needed. In fact I did it and listened to the club meeting on it.
Here is the code so far. This is using an OLED display, based on the SSD1306 chip.
You can use a white one, but I like the yellow/blue. This one has the top 1/3 in yellow, and the lower 2/3 as blue.
EDIT: I fixed the TX multiplier as it should be 8, not 12.
And this is how I modified a USB plug to fit. All I beed to do now is 3D print a nice replacement 90 degree headshell for it.
The extra cut in the lead sheath was there already!
The CTCSS resistors are wrong. Use the SIP R2R pack. It works.
There is another artwork error that does not really matter too much. Pin 7 is connected to the CTCSS resistors/SIP and that needs to be cut. The SIP pin now will be linked to the other 3 that are connected together.
Here is a view of the "finished" VFO.
A 100nF cap is connected from the gnd pin to the top of the resistor as shown. This smooths the side wave.
Below shows the audio/power supply board in the version worked on. There is a TX timer set for 1 min. Cut the link shown to disable the timer.
The next one is started!
This is an FM828E that will be on 6M.
It is all hooked up, except the CTCSS line, and mods I will do for a 'standard' mic and LS.
After those, the tuning mods will start.
Here is the code too. Just note, this radio has not been tuned as yet, so the code too may need adjusting.
I just noticed, it will be an idea to move the frequency display to the right a bit.
I'm working on the second FM828 Low band.
The cables from the display and encoder are now shielded.
A couple of holes have been drilled at an angle for these cables.
And, for this one, I've added the cap under the PA board.
This is the before...
And after. The red coloured 1206 SMT caps are 22pF, un-coloured 1206 SMT cap is 10pF, and the leaded ceramic cap is 6.8Pf. It may need to be increased as it should be 10pF.
This is not a SMT cap as the spacing is too wide.
With the key on the encoder (that is to say it will count from 0). 1/2/5/10PCSx Rotary encoder. Pulse Number for One Circle: 20. Due to the difference between different monitors, the picture may not reflect the actual color of the item.
there is a slighty more high spec AD dds wavegen module, based on the AD9834 https://www.ebay.com.au/itm/294339170731 but its 10x the price for 3x the max freq.
There is nice little project that uses it here. It has traces from the ad9834 and the sine wave still look pretty good up to 10Mhz.
The AD9954 looks really good!. It can be the basis of a very fine bit of test gear, or transceiver.
The club members could do with a good construction project I think.
Oh, I have been assured by the suppliers of the AD9833 boards that I purchased that they sent 2 packages to be below the postage threshold so the other boards should arrive shortly.