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Just waiting for two more parts to test the new Mega 2560 Pro Mini board for the BITSX40. (See picture.) You can see where the AD9850 and Mega boards go. This board has the TFT display I've shown before plugged into the other side. Most of the header pins on the top and bottom of the board are I/O pins on the Mega. (The Mega has 54 I/O pins and most are available.) The pins should make it easier to add additional circuitry that is to be controlled by the Mega. ?Jack, W8TEE

Very, duly noted.

Things like this do look very attractive to the inexperienced, and thrifty, kit builder. The funniest thing is the card is dated the day before I discovered WebSDR, and had my first CW QSO ever. Who first alerted me to my funky signal. I just can't win for losing.

And this RF amps for QRP is a popular topic. So if anyone has done something like this or who has bought a better one for boosting QRP kits please share your experience here.

I have seen one here from Ashar Farhan. Stuff like this would also be attractive to a CW kit builder. Hint, hint.- ?

This next one is 50 watts push, pull IRF510 amplifier. And wants 5-10 watts of drive. And has a current sense circuit like we previously discussed with burning up finals after replacing them and using fuses or more advanced shut off circuits in case of avalanche.-

Personally, a kit is more my speed. The hardest was a Chinese QRP antenna tuner kit sold on Ebay. The translated instructions were awful.

Jack

?? Last response was before I saw yours.

?? When I run dpinst-amd64.exe the Wizard starts and I let it run. After rebooting nothing has changed, USB2.0-serial shows up under "other devices" and device status says no driver installed. There is no port.

? I have selected Nano as the board when compiling for the Raduino.

? By "reload IDE" do you mean open the application or do I need to reinstall the IDE?

??? Thanks

????? Bob

I am working on getting my bitx40 into a housing & have mostly succeeded. I thought I'd check the transmitter into a dummy load, so I set my "big" radio to 7.150, had a 300w dummy load on the bitx (I know, a bit overkill...) and tried transmitting while watching the ammeter. Hm... the current is staying around 1 amp, and I don't hear anything in the big receiver. Then, I noticed smoke from the PCB. Yikes!

I shut everything off, and started looking. I finally found that R42 was burnt. This is a 10 ohm part in the TX amp chain. OK, if it is burnt, there's a reason why. I measured it, and it showed about 14 ohms - a little high, but should still be workable.

Using my scope, I determined that Q4 had input, but no output. I put an MMBT2222A in its place, and did some resistance checks before powering it up. To my surprise, I found that the R41 side of R42 showed 10 ohms to ground. That can't be right - further visual examination showed a hard solder blob short between R41 and R45, and a little "whisker" between R45 and R46. This explained the 10 ohm to ground, and also why this stage was dead & had a burnt resistor. I cleaned up the solder blobs, Fired up the rig, and KAZAAM! 25V peak across my 50 ohm load, which works out to about 17.6 VRMS, giving me about 6W into my dummy load. The modulation on the 'scope looked decent, too, so I'm going to try an actual antenna and maybe get a QSO?

Thanks for the response but I think that the problem is that the computer doesn't find a driver. There is nothing to uninstall.

USB2.0-serial shows up under "other devices" and device status says no driver installed.

?? Bob

? SKCC 4203T

? FISTS 12014? CC 2025

Did you shut down your Bitx40 when listening on those other rigs? ?

Maybe your neighbor has one!

Ok, before you all take the raduino or the vfo apart, I'm getting the same birdie on my Icom, my Codan and my 817, as well as my homebrew MST-400. ? Looks to me ?as if this is an external phenomenon.

Norm vk5gi

McLaren Vale

South Australia

I have an Arduino Uno and have compiled and uploaded sketches to it. When it is plugged into my computer a serial port appears.

I have compiled one of the updated sketches but can't upload it to the Raduino. When connected to the Raduino I do not get a serial port, instead I see a yellow exclamation error next to "USB2.0-serial" in device manager under Windows 7. I tried updating the driver by pointing the update to the Arduino driver directory with no luck. I also downloaded the FTDI installation but can't get that to operate since I don't get a device other than "USB2.0-serial" to update.

My system is a 64 bit AMD. I noticed that the Arduino IDE is 32 bits.

I'm out of ideas and could use some help.

I agree. ?Also, be aware this amp will earn you another ticket unless you add an appropriate low pass filter to the output.

Don't think I've ever seen a "C linear".

Grounds are tricky alright. ?Grounding the shield at both ends is the standard way of using coax between modules. ?In this case we're mostly interested in a shield not a transmission line, so detaching the ground on one end is worth trying, perhaps with a 0.1uF cap across the gap. ?Some have reported that a large electrolytic cap across the raduino 12v power supply reduces the clicks, so there are likely spikes in the 12v current (and through all available grounds) when you spin the tuning pot. ?I'd tend to stick with the large electrolytic cap and perhaps a series resistor if that's all it is. ??

Though ground loops can pick up RF. ?Anybody who has probed a busy circuit board with a scope probe using a 6 inch ground wire at the probe tip, then went to just shorting the ring near the probe tip to the nearest circuit ground has seen evidence of this. ?The noise the scope sees can be reduced by more than an order of magnitude. ?If this is the issue, then you probably don't want that 0.1uF cap.

Where grounds are really trouble is when you have multiple power supplies plugged into different circuits from the main fusebox of the building.

Jerry

I tried your new library Pavel and followed your initialisation suggestion but found it had no impact on the clicks on my rig. If anything I thought they were slightly louder. Also maybe I wasn't using it correctly but the radio didn't seem to receive either suggesting that the frequency wasn't set correctly. I'm using CLK2. Have you got a sample BitX40 sketch using your library ?

Also I make use of the functions in the Etherkit library to enable and disable clock output for CW mode keying.?

Thanks, Andrew

Thanks Jack, I've learned something new !

I've updated the sketch now so there is just one .ino file and the other is .cpp so it gets loaded automatically by the Arduino IDE.?

I've also made the shuttle tuning configurable via the macro at the top :-

//#define UPSIDE_DOWN

//#define SHUTTLE_TUNE

just uncomment this if you want shuttle tuning. If you go for this option, there's now a scanner mode. Pressing function button 2 causes it to scan up the frequencies until it finds a strong signal.?

With traditional tuning, the same button implements a tuning lock to stop the frequency dancing about when you're not touching the tuning knob.