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Re: Wired up Bitx40 and it doesn't work!
Also, make certain that you don't have the +12v and Ground leads from power supply to Bitx40 reversed.
It could be that the reverse polarity protection diode recommended in the Bitx40 instructions actually worked in this case, and the power supply has folded back into a shutdown mode due to over-current. |
Re: Wired up Bitx40 and it doesn't work!
Are you measuring that 12v at the power supply terminals?
If so, then I would guess that either the supply is too wimpy or there is a knob somewhere that has set the current limit too low. If you are measuring that 12v at the Bitx40, then there may be a bad solder job or bad connector between the power supply and the Bitx40. Jerry ?
On Fri, Aug 23, 2019 at 05:04 PM, <mark.wheeler3575@...> wrote:I finally got around to wiring up my bitx40 QRP radio and when I applied 12v, 2.0 amps from my bench power supply, nothing happens with the bitx40... the bench power supply supply voltage drops down from 12v to 0.49 V, but nothing happening on the Bitx40 display and no sound from the speaker.? I checked the inline fuse and it is working and it did not pop...?? |
Wired up Bitx40 and it doesn't work!
I finally got around to wiring up my bitx40 QRP radio and when I applied 12v, 2.0 amps from my bench power supply, nothing happens with the bitx40... the bench power supply supply voltage drops down from 12v to 0.49 V, but nothing happening on the Bitx40 display and no sound from the speaker.? I checked the inline fuse and it is working and it did not pop...??
Any suggestions are greatly appreciated.? -- |
Re: Audio pre-amplifier for microphone?
Gordon Gibby
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Re: bitx and ubitx encoder replacement / Software Issues (too slow)
Hey, It's me again :-)
Still working on this problem - and since I think I am not the only one who wants to get this encoder working, I am keeping to this thread. My next approach to this problem was switching to an I2C adapter. This way I could free up some digital pins, formerly used by the parallel connection of the display. ? |
Re: Bitx40 very loud, high-pitched, low frequency noise
Ian Reeve
¿ªÔÆÌåÓý
I think that your comment about even on battery there is faint noise and it is near your PC is significant.Some pc's give out lots of hash or wine and I wonder if moving the uBITX? further away may silence that last bit of noise.I am surprised that the capacitor
combination on the output does not help,that has always worked for me as I proved by my test last evening on a randomly picked switch mode wall wart.? Anyways it's progress in the right direction,keep the leads short and you will minimise pickup.A ferrite
ring or two on the cables won't do any harm,the best quality power supplies usually have fitted on the DC lead to keep switching noise away from the DC output.
Get
From: [email protected] <[email protected]> on behalf of Woody <woody@...>
Sent: Friday, August 23, 2019 8:58:25 PM To: [email protected] <[email protected]> Subject: Re: [BITX20] Bitx40 very loud, high-pitched, low frequency noise ?
On 8/23/2019 19:39, Gordon Gibby wrote:
> You may decide that you want to build a real low pass filter, with an > inductor etc., similar to what people had to use in the past to get > rid of alternator whine -- ...Or a new / different power supply. -- It would be interesting to examine the supply output with an oscilloscope. W00DY -- |
Re: Kit box paint removal
Ian Reeve
¿ªÔÆÌåÓý
Should always be mindful of paint dust etc,I never use power tools for this purpose,a hand drill and counter sinking bit work for me.Any dust thus created won't be spread and inhaled as you drill at hand speed.
Get
From: [email protected] <[email protected]> on behalf of db1bmn@... <db1bmn@...>
Sent: Friday, August 23, 2019 7:45:02 PM To: [email protected] <[email protected]> Subject: Re: [BITX20] Kit box paint removal ?
Hi,
try this tool: 73 de DB1BMN |
Re: Bitx40 very loud, high-pitched, low frequency noise
Woody
On 8/23/2019 19:39, Gordon Gibby wrote:
You may decide that you want to build a real low pass filter, with an inductor etc., similar to what people had to use in the past to get rid of alternator whine-- ...Or a new / different power supply. -- It would be interesting to examine the supply output with an oscilloscope. W00DY -- |
Re: Bitx40 very loud, high-pitched, low frequency noise
Gordon Gibby
¿ªÔÆÌåÓýYou may decide that you want to build a real low pass filter, with an inductor etc., similar to what people had to use in the past to get rid of alternator whine?
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Re: raduino crystal question
Gordon Gibby
¿ªÔÆÌåÓýCrystals are specified by their manufacturer to oscillate to correct frequency when placed in a circuit that has a certain amount of parallel capacitance, which is a property of the circuit, not the capacitance per se of the crystalIf you need a few extra picofarads of capacitance and your circuit to meet the manufacturers requirement, that is easily added with a small capacitor. ?
The reason that the bitx series tends to oscillate ?just a little bit higher than where it should¡¯ve, is because there apparently isn¡¯t enough capacitance in parallel¡ª which makes the crystal oscillator be a little higher than expected?
You can easily fix that in the source code of the software by just changing the designated frequency of the Crystal to match where it actually oscillates, and then all of your adjustments should be simple from then on ? ? A good communications receiver
will allow you to measure the actual oscillation frequency. ?Dip a ?wire near the raduino and you¡¯ll pick up a ?signal
Even easier is to command the read you a note to go to the specified frequency of the Crystal, and then measure the amplified output! ? That¡¯s a very loud signal!
Add 10-20 picofarads in parallel with the capacitor and you may find that you get it exactly on frequency without doing any software at all
These are wonderful things to learn in?
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Re: Bitx40 very loud, high-pitched, low frequency noise
Hi, So if that's the case, how about wrapping the power into the bitx40 through a couple of ferrites? it sounds like you're picking up RFI on the power cable itself and it's making it into the rig. -adrian On Fri, 23 Aug 2019 at 11:39, SP9DEV <piotrekslawecki2@...> wrote:
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Re: Bitx40 very loud, high-pitched, low frequency noise
Alright, time for a follow-up: I've added two 47nF (0.094uF total) ceramic caps, one 330pF ceramic cap, one 10uF electrolytic cap and another one 100uF cap across the DC input. Unfortunately, the problem is still there. However, I've assembled a simple 12V battery from one 9V battery and two AA batteries. With this as my power supply, the problem is gone. I can still hear some faint noise, but that's probably due to the fact, that I've been testing this setup right next to my PC, two monitors and a lot of other RFI-generating stuff. So I guess the only way to deal with my problem is to buy a large 12V acid-lead battery and a dedicated charger. |
Re: Kit box paint removal
Ian Reeve
¿ªÔÆÌåÓý
I use a countersink drill bit and carefully remove a thin circular strip of paint and use star washers for all fixings.These washers provide a excellent connection to ground wherever needed..
Get
From: [email protected] <[email protected]> on behalf of Curt via Groups.Io <wb8yyy@...>
Sent: Friday, August 23, 2019 6:47:46 PM To: [email protected] <[email protected]> Subject: Re: [BITX20] Kit box paint removal ?
No exact answers here. I suggest using a large drill bit, by hand, to remove paint at RF connector.
Curt |