开云体育

If you go to ports on ide menu does it show a list ?? Arduino? clones don't automatically come up in the menu so you have to select a port from the list that it's connected to.

To find which one, open Control Panel, System, Device Manager and look at Ports? without the Raduino plugged in.? Then look for a change in the ports that will show which one it is connected to when you plug it in.

Which version of IDE are you using? The latest version installs the CH341-SER usb driver but earlier ones don't.The driver is in the "BitX40 using new library" folder in files section, you may need to install that.

Have you tried programming any Arduinos yet under XP, it usually chickens out with one of many errors.

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Rob G4NQX

As for straight forward, beware of ground loops, you want star topology, not daisy chain.. You only want one grounding path between equipment. Directly connecting your computer causes a second connection to ground through the other piece of equipment. Look for more on the subject.?

But you could use a audio cable to line-in input to the radio from PC. You can use a USB sound card dongle with your software to line-in from USB port. And then there is a thing called "Easy Digi" kit on Ebay that does DB9 serial port. You could make it yourself for much less, if that's your thing. It does all the isolation for you. Isolation is also good for protection during storms.

But as for making it work on Bitx 40 SSB... I don't know really. Look near the top for the spy glass search button and wear it out. There has been much discussion already about almost everything. And come back when you can tell me how you did it.?

Plus, someone will probably tell us all about it in a day or two.

The Si5351 library may assume it is the only i2c master, and thus ok to drive the SCL clock both high and low. ?So might be safer to short SDA at Nano pin 8 to ground, or find some way to halt the Nano completely. ? (Though shorting either pin to ground is probably ok.)

I don't know of anything inside the Si5351 that might cause a pause every 38ms like that. ?Could be the Nano is off the rails, and continuously reprogramming the Si5351. ?Look at pins 8 and 9 of the Nano with your scope, which are the i2c clock and data for programming the Si5351. ?I'd expect them to be quiet if you aren't tuning the radio. ?If they are not quiet, could try shorting pin 9 to ground while it is working, this is fair to do since it is an open-drain signal, shorting to ground should keep the Nano from successfully writing to the Si5351. See if that pause is still happening when pin 9 is shorted to ground.

Nobody else is reporting this problem, so it probably isn't the library. ?I was seeing a factor of 4 on the VFO freq in Allard's problem also, thought that might be related. ?But I'm pretty sure Allard's problem has now been figured out. ?This one I'm still guessing on.

Hi all,

my Bitx40 is good with analogue VFO. Now, I'm finding more curious things with the Raduino's Si5351. When I was looking at the waveform, noticed some intermittent glitches at the bottom part. I was able to trigger at some undershoots, changed time base and found that there is a brief pause in the generated waveform of about 740 us (microseconds), and that pause repeats itself every 38 ms.

I'm still hoping that this is software related problem, I just didn't have time to try different libraries, as Jerry suggested earlier. Also, I hope that someone who know this creature (Si5351, HI) little better might have better clue of what's going on here.

Thanks,

Goran VE6GPO

Eighth harmonic of the 12mhz BFO is at 96mhz, which is the fifth harmonic of a VFO at 19.2mhz. ?So the we might still have a faint birdie at 19.2 - 12 = (drum roll) 7.2mhz.?

Another fix would be to move the VFO from 5mhz to 19mhz, then adjust the BFO down 3khz by adding capacitance at C103 (assuming you still want lower sideband operation). ?If that's confusing, then read that other thread where the bunch of women were talking: ??/g/BITX20/message/21911

Fixes both the birdie at 7.2mhz from the 5'th harmonic of the VFO and the image problem from the 4'th harmonic of the VFO. ?With a 19mhz VFO those harmonics are up in the low VHF, and nothing near them should be getting past the 7mhz bandpass-filter at L1,L2,L3. ?If the local TV stations are sneaking in, then time to start collecting tuna fish cans for use as shielding. ?Would be hard to get an analog VFO stable enough at 19mhz, but the Si5351 should do fine.

Oh, and ask John Smith how to adjust R136 to compensate for the greater losses at the diode ring mixer when transmitting with a 19mhz VFO: ?/g/BITX20/message/21948

Jerry, KE7ER

There are a number of BitX 20 kits available but you need to build them yourself. The BitX40 semi kit that is being sold by HFSIGS should be modifyable to 20 meters but I have not seen any details yet of the mods. Having a 12Mhz IF and working on 14Mhz may be problematic (I dont know but others may be able to advise you) You would have to reprogram the DDS for operation at 26 Mhz I suppose.

VE7BEE has modified a BitX40 to operate on 80 meters and I believe he is working on another and modding it for 160 meters. He is probably a good one to ask about 20 meter modding a BitX40.

Good luck
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Mike VK3XL

I just lifted one end of the coil from the board. ?L4 was super glued to the board and I could not get to the other wire. ?In any event birdie gone...

Should read ? "12-7.1=4.9mhz"

In this case, a 7.1 mhz signal comes in from the antenna, is mixed with the 4.9mhz vfo. ?The sum is 12mhz, which can slide through that crystal filter unscathed and mix with our 12mhz bfo. ? As it should.

But the 4'th harmonic of the 4.9mhz vfo is also present at the mixer, and is at 4*4.9mhz = 19.6mhz. ?So some incoming 7.6mhz signal can mix with that 19.6mhz, the difference is 12mhz, and can also get by the crystal filter to mix with the 12mhz bfo. ?And we receive an unwanted image from 7.6mhz when tuning the radio to 7.1mhz.

Jerry

Good job, you nailed it! ?

For example, tuning to 7.1mhz, the vfo is at 12=7.1=4.9mhz, the 4'th harmonic of which is 4*4.9= 19.6mhz. ?That's up where we would put the VFO if we wanted to switch to the upper sideband, as discussed in that other thread. ?And the signal we receive would be from 19.6=12 = 7.6mhz.

If we try to receive 7.2mhz, the extra signal we receive is at 4*(12-7.2) - 12 = 7.2mhz. ?So we receive it twice, in LSB mode and in USB mode. ?Very weird.

But I think the birdie most folks are seeing at 7.2mhz is independent from these image signals. ?The birdie is likely the 5'th harmonic of the VFO mixing with the 2'ed harmonic of the BFO, with possible fixes as per post ?21941. ? ?5*(12-7.2) = 2*12 ? ?This could be verified by determining how fast the tone of the birdie changes as the VFO frequency is advanced, should be 5 times as fast as a normal 40m signal. ?Remarkable that both issues zero in on 7.2mhz like that.

Jerry