Perhaps 'tombstone' C115?

73 ...

Please note, *everybody*: The M1 and M2 points, on Rx, are connected not just *t*o the K2 contacts, but *by* them - shorting the 10 'upper' resistor of the divider formed with the FET. THe whole circuit needs to be in series with the *whole* audio path via the relay. I haven't inspected the PCB tracks and componentry, but I suspect a track needs to be cut, either *from* the AF preamp or *to* the volume pot.

73 de ZL2DEX

Thanks Willy..
I'll try removing that 10K and see what happens.
It's very odd, it just doesn't work as is and I've triple checked
the build and the components.....

73? Phil? G4JVF

Maybe he already happened to have one!

Vince.

--
Michigan VHF Corp.

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I came up with the idea of adding a RTC but onlyJack can respond as to why he chose SPI. Maybe have an option?

Bill, VK7MX

Hi,

?

I am just getting back into the B40 stuff. I like the clock idea, but.

?

Why use the SPI bus RTC clocks, when there are tons of I2C RTC clocks out there ( I’ve got at least 5 or 6 RTC I2C’s laying around)? I’ve used the I2C bus RTC clocks for years in arduinos and they work great even in interrupt based code for arduinos. Was there some sort of design need for it? I am just curious. ??Might play around and change Jack’s code to see if it works, but I do not want to start another code path.

?

73,

Kevin KB0VHA

Thanks.

Very good info for inductance measurement Theory.

73 de E29AHU
Choke

Using the two outputs from the si5351 should work fine.
Spectral purity would not be an issue, the square waves just make harmonics
of the si5351 outputs and are easily filtered out by the front end of even a very old radio.
Signal would be a bit weird in that it would only have one sideband,
but I doubt those old radios are smart enough to notice.

Jerry, KE7ER

On Tue, Nov 7, 2017 at 02:35 pm, Brent Seres wrote:

Also, one of my interests is restoring vintage radios. To align theses, it is helpful to have a modulated signal, as there is no bfo. Rather than build a modulated output stage, what about using clk1 for the main carrier output, and if you want modulation, have clk0 and clk2 track with clk1, but offset by say +/- 700 or 1000 hz. If these outputs were attenuated by 6 dB relative to clk1, and mixed, they would approximate a 100% AM modulated signal. I know from a spectral purity standpoint things will not be the greatest, as the raduino does not output a sine wave, but you would at least have a tone you could hear on a receiver without a bfo.

Hi all, i am trying to upload the raduino_v1.27.ino to my raduino via the web Arduino Editor.? ?

it just stays uploading with a message that says 'Executing command: exit status 1'.? the raduino yellow LED light continues to flicker.??

does it take a long time to upload the software???
thx,
Paul

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I put the one Encoder I have that is a real "keyes" brand.? No threaded shaft.

It works fine.? I tried several debounce caps and pull-up resistors.

I think it is the code in the encoder.? Like "make before break" switches or the like?

You could also use a small output transformer to modulate the +V to a transistor driven by RF.

I built several AM transmitters as a kid.?? I don't know how low you can go.?? 400 Hz was the standard then.

I was thinking of changing the steps to fix the encoder problem.? I ordered some more encoders from ebay?

Got another Mouser order in today, another damm $100!? Bad Habit buying parts?

I have a new mixer board to try you modulation scheme?

Mike

Hi Mike

I have a couple of ideas.

I received the rotary encoders today, and am having a similar issue as you. It seems for each detent my encoder is moved, the frequency jumps 2 units. If you are careful, there is an encoder position between the detent positions where you can tune to odd units. It's like the encoder outputs 2 pulses for every click.

What if the code where changed to move==2 and move==-2?

Also, one of my interests is restoring vintage radios. To align theses, it is helpful to have a modulated signal, as there is no bfo. Rather than build a modulated output stage, what about using clk1 for the main carrier output, and if you want modulation, have clk0 and clk2 track with clk1, but offset by say +/- 700 or 1000 hz. If these outputs were attenuated by 6 dB relative to clk1, and mixed, they would approximate a 100% AM modulated signal. I know from a spectral purity standpoint things will not be the greatest, as the raduino does not output a sine wave, but you would at least have a tone you could hear on a receiver without a bfo.

73
Brent

-- 
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID  "MotDog@..."
Mike@...

What about using a multiplexer chip to reduce the number of I/O lines needed. A bit old school but effective.

Sent from my iPhone

Hi Mike

I have a couple of ideas.

I received the rotary encoders today, and am having a similar issue as you. It seems for each detent my encoder is moved, the frequency jumps 2 units. If you are careful, there is an encoder position between the detent positions where you can tune to odd units. It's like the encoder outputs 2 pulses for every click.

What if the code where changed to move==2 and move==-2?

Also, one of my interests is restoring vintage radios. To align theses, it is helpful to have a modulated signal, as there is no bfo. Rather than build a modulated output stage, what about using clk1 for the main carrier output, and if you want modulation, have clk0 and clk2 track with clk1, but offset by say +/- 700 or 1000 hz. If these outputs were attenuated by 6 dB relative to clk1, and mixed, they would approximate a 100% AM modulated signal. I know from a spectral purity standpoint things will not be the greatest, as the raduino does not output a sine wave, but you would at least have a tone you could hear on a receiver without a bfo.

73
Brent

I like that as a way to add io pin via i2c.
It's a pre-programmed ARM-Cortex-M0 running at 48mhz,
and considerably more powerful than the ATMega328p on the Raduino's Nano.

Y-es! :)

Thanks guys...all understood..

It's just that I built one for my Bitx and it doesn't seem to work.
The voltage on the gate of the fet is going up and down in response to the audio level
but there seems to be little or no attenuation to the stronger signals....
Double checked and I made no mistakes..
Phil? G4JVF

Plus, basic theory: a FET is a specialised case of the Trans-Istor ('transfer-resistor'). We default the term Transistor to the BJT (Bipolar Junction Transistor), with its Resistance (E-C) controlled by the current E-B. The FET (Field-Effect Transistor) does that same job, but the control of the Resistance (S-D) is by Voltage S-G (generating the 'Field' in the device).

The signal (Audio IN) *is* that voltage. The FET will conduct or not depending on the gate voltage, and act as a resistor in the divider with the 10k series resistor from M1 to attenuate the output.