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New file uploaded to [email protected]
[email protected] Notification
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the [email protected] group. File: raduino.ino.eightanaloginputs.hex Uploaded By: Alf Edwards Description: You can access this file at the URL: Cheers, |
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New file uploaded to [email protected]
[email protected] Notification
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the [email protected] group. File: raduino.ino.with_bootloader.eightanaloginputs.hex Uploaded By: Alf Edwards Description: You can access this file at the URL: Cheers, |
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Re: Calibration : Bitx40
Hi Ashhar,
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I have not used GitHub before, I will register and try to upload. Thank you Alf vk2yac Ashhar Farhan wrote: Alf, |
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Re: Calibration : Bitx40
Alf, If you could push your code to GitHub, i can pull it. - f On 19 Feb 2017 7:20 a.m., "alf" <fpdbase@...> wrote: Hi all, |
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Re: BITX40
I don't think I could put up with the freq jumping around like that, should have a bit of hysterisis in raduino code. ?So you have to reverse direction 2 or 3 clicks before anything happens. ?Somebody in a recent post found that putting the supplied 0.1uf cap on the raduino pins instead of at the tuning pot on the other end of the wires made it behave somewhat better. ?I might eventually go to the shuttle tuning scheme described by Don Cantrell here: ? On Sat, Feb 18, 2017 at 06:07 pm, John Smith wrote:
Mine did this too. When the frequency readout is flicking back and forth there is a corresponding click. When the readout is not flicking a quieter clicking sound can still be heard until I keep fiddling with the knob to get the freq steady, then it's all quiet. It's like the clock generator is changing frequency in small enough amounts that it doesn't change the display. But then after changing the tuning poteniometer for a smaller one with a knurled shaft, it doesn't do that anymore. The freq still flicks back and forth like it did before, but no more quiet clicking. I just did this for a more convenient knob choice. ?I also noticed before, that when it does that quiet clicking, my transmitted signal would also waver back and forth in freq while I monitored with a receiver. ? |
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Re: compressor or processor for BITX40?
Allard, your final amplifier is not being driven enough. You have low transmit power. If you have followed the wire up process by inserting your amp meter in the PA positive brown wire and it read 100mA but not 1Amp when you spoke into the mic, then you need to adjust R136. It's a flat silver trimmer on the same side of the board as the PA. Adjust it counter clockwise to increase your drive until speaking into the mic with a long aahhh gets you 1 Amp on your meter. If your meter doesn't show 100mA first, then you need to adjust RV1 blue trimmer counter clockwise until you do get the 100mA the adjust R136 to get 1Amp. This really does need to be included in the wire up notes. It could have saved me a whole dang month Farhan! Not to mention the diode I needlessly removed while desperately trying any possible solution to the low TX power problem. At least you changed the red vs. brown calibration wire kills the raduino thing. I'm still bitter! Sorry Allard, just read the first paragraph. |
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Re: BITX40
I suggest you check out Ashhar's video on debugging the Bitx40 receiver, posted here on Dec 25, 2016: ? ?? ? He takes a few feet of wire connected to nothing, uses that as an antenna to inject RF noise from the local environment into the various receiver stages, listening to the result coming out of the Bitx40 speaker. Often times the transformer wires get broken or shorted during transport, check them closely. ?There are occasional cold solder joints, look closely with bright lights and good magnification. On Sat, Feb 18, 2017 at 05:36 pm, Mark Underkofler wrote:
I don't think this unit has a BFO problem since it really doesn't pick up much at all. ?I really think the front end of the receiver is way out of wack. ?Attaching the antenna tonight made little difference in the background noise. ? ? |
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Re: BITX40
Mine did this too. When the frequency readout is flicking back and forth there is a corresponding click. When the readout is not flicking a quieter clicking sound can still be heard until I keep fiddling with the knob to get the freq steady, then it's all quiet. It's like the clock generator is changing frequency in small enough amounts that it doesn't change the display. But then after changing the tuning poteniometer for a smaller one with a knurled shaft, it doesn't do that anymore. The freq still flicks back and forth like it did before, but no more quiet clicking. I just did this for a more convenient knob choice. ?I also noticed before, that when it does that quiet clicking, my transmitted signal would also waver back and forth in freq while I monitored with a receiver.
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Re: BITX40
Yes, it was shipped without a cap. Theoretically C103 is enough
to set the frequency. It doesn't always, which is why C104 is provided a place. It certainly can't hurt to install it. Even if it is there, tuning it to minimum capacitance will effect the frequency very little. And having it will allow about a KHz of tuning latitude. It may be that C103 will have to be changed to a lower value IF the frequency is a bit too high. I should think about 33-39 pF. would be enough. Don't do it unless installing C104 doesn't help or makes matters worse! There is another thing to consider. That is L5. Currently it is a wire short between two holes in the board. Actually it is in the circuit for tuning the crystal (like the caps). It is made larger to move the frequency up for for USB and probably will not need to be disturbed. I should think installing and fiddling with C104 will be enough to clarify any LSB signal. Hope this helps. john AD5YE |
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Re: compressor or processor for BITX40?
If yelling into the microphone helps and doesn't cause distortion, sounds like you might need a raise the gain at R136. ?See John Smith's post at ? /g/BITX20/message/22112? ? Not mentioned in the WireUp notes, but should be. ?Note that R136, and RV1, are at minimum when fully clockwise, which is a bit counterintuitive. |
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Re: Ashhar, thank you
Yikes! Old men and health problems. Know all about it.
Been there; done that. Good to hear you up and about. Hi. Thanks for the clarification. I left a message on EMRFD for Allison. Her comments seem to have elicited some interesting responses as well. Everyone should consider joining that group. It is a good place to be. I'll let you know what she says... john AD5YE |
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Re: BITX40
Start by looking at your BFO frequency. If it is off a bit, all kinds of
weird effects happen. It sounds like yours needs adjusting. The IF frequency has to be exact to pass the LSB signal in a clear manner. Off by a few hundred hertz is enough to make reception very tough. You will need to install a small variable cap at C103, about 30 pF. Is this an original problem or did it happen after you began using the rig? What mods have you done? This may not be the root problem but it is one of the things which should be checked. It has happened before. Check the messages. john AD5YE |
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compressor or processor for BITX40?
With QRP levels it is often a challenge to make SSB QSO's on 40m. With my BITX40 I need to shout in the mike to produce some TX power.
It would seem logical to increase the "talking power" somewhat by using a compressor or processor. Does anybody have suggestions how this could be realized in a simple way? 73, Allard PE1NWL |
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Re: GPS corrected Arduino controlled VFO
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On Feb 18, 2017, at 7:18 PM, Charlie Morrison <charlie@...> wrote:
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Allard PE1NWL