Re: Need help with constant tone in audio output
try large capasitor ie ?50uf ?25 volt working ? ? across power supply.............
On Monday, 20 February 2017, 13:51, Raj vu2zap <vu2zap@...> wrote:
FIrst I am suspecting the power supply.
Second disconnect the volume plug and see, I would suspect the tone will
be there if the PS is at fault.
Third If the tone stops then suspect the preamp transistor or
earlier.
As you said you have disconnected the rest.
Raj
At 20/02/2017, you wrote:
Good morning Jerry and the
group,
Had to stop last night, having probed for nearly 10 hours. Jerry, my
trouble shooting is hampered by not having an up-to-date schematic. My
board is a Bitx40 V3. It's interesting to note that when I power the '40
up the tone is immediate and the rcvr comes on about a second later. I
have all the components taken out of the '40 except the volume control...
still the tone. I wonder if India could replace the board given the
amount of time spent trying to get it working? I'll continue to trouble
shoot today and will keep you and the group updated. BTW, the tone
encountered is not a clicking noise.
73,
Chuck K3VPZ
From: "Jerry Gaffke via Groups.Io"
<jgaffke@...>
To: [email protected]
Sent: Sunday, February 19, 2017 4:59:53 PM
Subject: Re: [BITX20] Need help with constant tone in audio
output
Did you enable the analog vfo by adding L4?
If the tone is still there with no vfo, that's a hint
On Sun, Feb 19, 2017 at 01:07 pm, <chucke2@...> wrote:
- Have disconnected the Raduino, tone still there.
?
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So that means that unbalancing the mixer will never be a legitimate way to introduce a carrier for tuning purposes?
Roy WA0YMH
On Feb 19, 2017 10:37 PM, "Ashhar Farhan" < farhanbox@...> wrote: The center tap that takes the audio from the mic. A caveat though, the carrier is on the skirt rather than in the center of the filter. - f
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I also have that case, too, but I'm adding a Muppet board and there wasn't enough room for both in the Banggood case. It is, however, a very nice case.
Jack, W8TEE
From: Buck <RadioK4ia@...>
To: [email protected]
Sent: Monday, February 20, 2017 9:26 AM
Subject: Re: [BITX20] Calibration
A similar case is on Banggood but check the dimensions. Buck, k4ia Honor Roll 8BDXCC On 2/20/2017 9:13 AM, Jack Purdum via Groups.Io wrote: > I was looking for the order, but can't find it. The supplier was Allied > Electronics and the case was: > > > > They have a bazillion cases. If I can confirm the order, I'll post it to > the group. > > Jack, W8TEE > > > ------------------------------------------------------------------------ > *From:* Leo de Blaauw < L.deblaauw@...> > *To:* [email protected]> *Sent:* Monday, February 20, 2017 1:45 AM > *Subject:* Re: [BITX20] Calibration > > Hi Jack, > > Slightly off-topic, but may I ask what enclosure you are using ? > > regards and 73 > Leo de Blaauw - PD1LDB > >
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A similar case is on Banggood but check the dimensions.
Buck, k4ia
Honor Roll
8BDXCC
toggle quoted message
Show quoted text
On 2/20/2017 9:13 AM, Jack Purdum via Groups.Io wrote: I was looking for the order, but can't find it. The supplier was Allied
Electronics and the case was:
They have a bazillion cases. If I can confirm the order, I'll post it to
the group.
Jack, W8TEE
------------------------------------------------------------------------
*From:* Leo de Blaauw <L.deblaauw@...>
*To:* [email protected]
*Sent:* Monday, February 20, 2017 1:45 AM
*Subject:* Re: [BITX20] Calibration
Hi Jack,
Slightly off-topic, but may I ask what enclosure you are using ?
regards and 73
Leo de Blaauw - PD1LDB
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Re: Need help with constant tone in audio output
Good morning Larry,
Success! Using a battery cleared up the tone. Now on to packing it up in its enclosure. Many thanks to all for helping including Jerry!
73, Chuck K3VPZ
From: "Larry Acklin" <acklin@...> To: [email protected]Sent: Monday, February 20, 2017 8:30:31 AM Subject: Re: [BITX20] Need help with constant tone in audio output
Try a battery supply.? My shack supply does not play nice with the BitX.? A small wall wart 2A, 12V is silent.? I get tone with the shack PS.
Larry KB3CUF
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I was looking for the order, but can't find it. The supplier was Allied Electronics and the case was:?
They have a bazillion cases. If I can confirm the order, I'll post it to the group.
Jack, W8TEE
From: Leo de Blaauw <L.deblaauw@...>
To: [email protected]
Sent: Monday, February 20, 2017 1:45 AM
Subject: Re: [BITX20] Calibration
Hi Jack,
Slightly off-topic, but may I ask what enclosure you are using ?
regards and 73 Leo de Blaauw - PD1LDB
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Re: Need help with constant tone in audio output
FIrst I am suspecting the power supply.
Second disconnect the volume plug and see, I would suspect the tone will
be there if the PS is at fault.
Third If the tone stops then suspect the preamp transistor or
earlier.
As you said you have disconnected the rest.
Raj
At 20/02/2017, you wrote:
toggle quoted message
Show quoted text
Good morning Jerry and the
group,
Had to stop last night, having probed for nearly 10 hours. Jerry, my
trouble shooting is hampered by not having an up-to-date schematic. My
board is a Bitx40 V3. It's interesting to note that when I power the '40
up the tone is immediate and the rcvr comes on about a second later. I
have all the components taken out of the '40 except the volume control...
still the tone. I wonder if India could replace the board given the
amount of time spent trying to get it working? I'll continue to trouble
shoot today and will keep you and the group updated. BTW, the tone
encountered is not a clicking noise.
73,
Chuck K3VPZ
From: "Jerry Gaffke via Groups.Io"
<jgaffke@...>
To: [email protected]
Sent: Sunday, February 19, 2017 4:59:53 PM
Subject: Re: [BITX20] Need help with constant tone in audio
output
Did you enable the analog vfo by adding L4?
If the tone is still there with no vfo, that's a hint
On Sun, Feb 19, 2017 at 01:07 pm, <chucke2@...> wrote:
- Have disconnected the Raduino, tone still there.
?
|
Re: Need help with constant tone in audio output
Try a battery supply.? My shack supply does not play nice with the BitX.? A small wall wart 2A, 12V is silent.? I get tone with the shack PS.
Larry KB3CUF
On Mon, Feb 20, 2017 at 8:01 AM, Chuck <chucke2@...> wrote: Good morning Jerry and the group,
Had to stop last night, having probed for nearly 10 hours. Jerry, my trouble shooting is hampered by not having an up-to-date schematic. My board is a Bitx40 V3. It's interesting to note that when I power the '40 up the tone is immediate and the rcvr comes on about a second later. I have all the components taken out of the '40 except the volume control... still the tone. I wonder if India could replace the board given the amount of time spent trying to get it working? I'll continue to trouble shoot today and will keep you and the group updated. BTW, the tone encountered is not a clicking noise.
73, Chuck K3VPZ
From: "Jerry Gaffke via Groups.Io" <jgaffke= [email protected]> To: [email protected]Sent: Sunday, February 19, 2017 4:59:53 PM Subject: Re: [BITX20] Need help with constant tone in audio output
Did you enable the analog vfo by adding L4? If the tone is still there with no vfo, that's a hint
On Sun, Feb 19, 2017 at 01:07 pm, <chucke2@...> wrote:
Have disconnected the Raduino, tone still there. ?
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Re: Need help with constant tone in audio output
Good morning Jerry and the group,
Had to stop last night, having probed for nearly 10 hours. Jerry, my trouble shooting is hampered by not having an up-to-date schematic. My board is a Bitx40 V3. It's interesting to note that when I power the '40 up the tone is immediate and the rcvr comes on about a second later. I have all the components taken out of the '40 except the volume control... still the tone. I wonder if India could replace the board given the amount of time spent trying to get it working? I'll continue to trouble shoot today and will keep you and the group updated. BTW, the tone encountered is not a clicking noise.
73, Chuck K3VPZ
From: "Jerry Gaffke via Groups.Io" <jgaffke@...> To: [email protected]Sent: Sunday, February 19, 2017 4:59:53 PM Subject: Re: [BITX20] Need help with constant tone in audio output
Did you enable the analog vfo by adding L4? If the tone is still there with no vfo, that's a hint
On Sun, Feb 19, 2017 at 01:07 pm, <chucke2@...> wrote:
Have disconnected the Raduino, tone still there. ?
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The current drawn will depend upon the peak to average ration of the voice characteristics which is different for every individual. That is why a speech processor would be a great help to maintain a quasi-constant level. Regards Lawrence
On Mon, Feb 20, 2017 at 2:50 AM, John Smith via Groups.Io <johnlinux77@...> wrote: Update: Mine still does that quiet clicking thing. It's just less prominent now. And still jittery on last digit, like I said.? And I wanted to check the current draw of the PA with the 20V supply. I found that R136 doesn't do much at 20V. When I experimented with R136 at 12V it made all the difference in the world. But the no audio current draw was 90mA and long aahhh current draw was as much as 1.3 Amps. Just something about that note in my voice makes it peak high, and normal talking is around 750mA. So, current draw is about the same, going from 12V to near max of 24V. No need to recalibrate after doing it at 12V.
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It is standard practice that to eliminate any source of noise the decoupling has to be as near the source as possible using capacitors suitable for the frequency/ies involved. This also aids stability. Shielding of the readout and its wiring will also help. Using shielded cables including in the audio stages is also standard practice. Regards Lawrence
On Sun, Feb 19, 2017 at 3:30 AM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote: 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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Hi,
Has anyone had any success in getting the bitx40 running with VFO at 19Mhz?
I tried last night and observations were: Drive out of the raduino needed to increase to 4ma before any noise came out of the receiver. Frequency measured at the output of Q7 was not 19Mhz??? Tested BFO at both 11.9985 and 12.0015 made no difference to resolving a signal. I have a trimmer cap at the BFO. C103. I'm wondering if the normal pins are the right place to inject the VFO. And there was still a birdie at 7.200Mhz- with no antenna just dummy load.?
Also, varying the BFO varies the frequency of the birdie at 7.2Mhz for both VFO frequencies.
Another observation, the birdie was louder with increased drive out of the raduino.
Regards Simon VK3ELH ?
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You will find a single 12Mhz xtal with some components next to the 860 - thats the bfo.
73 Raj
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At 20/02/2017, you wrote: Hi,
I'm having a bit of trouble locating the BFO on the bitx40 board to take some measurements. From looking at the circuit diagram it seems to be around the LM386 or D15, is that correct? I'm just a tad bit confused where it's hiding!
Thanks,
KM4ZCT
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Hi? John , I?? agree with the explanation for 100% . This is also my ecperience
Marco , France
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Hi Jack,
Slightly off-topic, but may I ask what enclosure you are using ?
regards and 73 Leo de Blaauw - PD1LDB
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Hi, I'm having a bit of trouble locating the BFO on the bitx40 board to take some measurements. From looking at the circuit diagram it seems to be around the LM386 or D15, is that correct? I'm just a tad bit confused where it's hiding! Thanks, KM4ZCT
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Re: bitx output harmonics
I have been advancing the silver trimmer to the point of achieving a amp meter reading of 1 Amp plus a little bit while speaking up into the mic. Is this overdriving the BITX 40? I have found that it gives me the expected amp meter and watt meter readings from the wire up instructions that I not had before. I understand that increasing it and the bias beyond the recommended settings increases risk of damage and radiating wild harmonics.. Am I doing this right? I can take instruction if not. And, does the cap change anything if I am not overloading the PA? Saturday night we had the magic band conditions, and I heard my call signal really well on three WebSDR stations on each side of the U.S.
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Re: bitx output harmonics
John,
The two section low pass filter is a standard across a number of transceivers build and sold in the USA. Our harmonic suppression is just within the legal limit. Here is the scan as I had performed when we finished the layout.?
The difference between my and Wayn's scan results is probably due to overdriving of the power amplifier that clips and distorts the waveform. With Wayn's modification, you can be sure that even if you overdrive, you will still be within the legal limits. A simpler fix is to just back off the sliver coloured preset near the driver transistor until the point where the transmit power starts dropping. That is the point power beyond with ?the compression and distortion increases substantially. You are safe within that limit.
- f
On Mon, Feb 20, 2017 at 7:42 AM, John Smith via Groups.Io <johnlinux77@...> wrote: I used a 100pf ceramic 50V cap that tested out to be 87pf. It did not blow up. But I have no way of testing it. I'll just have to trust that the second harmonic solution will keep me legal. It was that, or a 120pf testing at 115pf. Does anyone know what it actually takes to suppress the second harmonic frequency adequately? Or is this close enough to do some good?
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The center tap that takes the audio from the mic. A caveat though, the carrier is on the skirt rather than in the center of the filter. - f
On 20 Feb 2017 7:58 a.m., "Ken" < chase8043@...> wrote: 4.7K resistor from center tap of R106 to 12 volts?
73
Ken VA3ABN
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Raj vu2zap
F8VOA
