Hi with a little patience you can easily make your own step attenuators. The one in the first link can attenuate signals up to 80dBs
The one in the second link one can attenuate signals up to 71dBs With these attenuators you can attenuate the signal in steps of 1dB. You can also use such an attenuator at the Input of the RECEIVER to reduce a signal that is overloading your receiver but NOT at the output of the TRANSMITTER because you will burn it as the resistors can only only 250 milliwatts maximum. Have a look at these links.
Regards Lawrence
On Mon, Oct 2, 2017 at 6:10 AM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote: Your signal generator is -10dBm, and an S9 signal is -73dBm.
So to make it so the signal generator sounds like an S9 signal you need 63dB of attenuation.
Stacking 3 of those 20dB attenuators would work.
Alternately, I suggest you set the signal generator down on the far side of the room, have it drive a
couple feet of copper wire connected to the center pin of that BNC.
Put a couple feet of wire on your Bitx40's antenna jack too.
Tune the Bitx40 to receive the signal generator, then reduce the length of those
wires till it sounds like a good amateur band signal.
?
On Sun, Oct 1, 2017 at 07:42 pm, Curt M. wrote:
I have a 50 ohm 20db attenuator. If I run my RigExpert analyzer into the attenuator and then the attenuator into the Bitx40, does this get me in an acceptable range to try and calibrate LSB or will the signal still be too high?
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Your signal generator is -10dBm, and an S9 signal is -73dBm.
So to make it so the signal generator sounds like an S9 signal you need 63dB of attenuation.
Stacking 3 of those 20dB attenuators would work.
Alternately, I suggest you set the signal generator down on the far side of the room, have it drive a
couple feet of copper wire connected to the center pin of that BNC.
Put a couple feet of wire on your Bitx40's antenna jack too.
Tune the Bitx40 to receive the signal generator, then reduce the length of those
wires till it sounds like a good amateur band signal.
?
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On Sun, Oct 1, 2017 at 07:42 pm, Curt M. wrote:
I have a 50 ohm 20db attenuator. If I run my RigExpert analyzer into the attenuator and then the attenuator into the Bitx40, does this get me in an acceptable range to try and calibrate LSB or will the signal still be too high?
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My first BITX40 #66 the volume control failed. The failure happened when
I resoldered one lead that came off.
The plating quality is not good IMHO.
Check the DC voltage on LM386 pin 6. The degeneration leads me to think
R111 or D18 failed.
Raj
At 02/10/2017, you wrote:
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I would imagine the vol control
is suspect at this time...
- f
On 2 Oct 2017 7:48 am, "Vince Vielhaber"
<vev@...> wrote:
- Excellent!?? Use that to follow each step thru the audio with an
antenna connected to it.?? Doesn't matter what it's receiving, even
noise will show an ever increasing waveform.?? Actually noise is
preferred in this case.
- Vince.
- On 10/01/2017 09:16 PM, Ken Macy wrote:
- Vince
- I do have a scope.
- KG6PO
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Re: BITX QSO Night, Sunday, October 1, 7pm Local Time, 7277 kHz in North America, 7177 kHz elsewhere
On Sun, Oct 1, 2017 at 07:12 pm, KN4AAG Kevin Estep wrote:
WA2FZW(?),
NJ ? -- John - WA2FZW
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Dexter, It went dead over time. Looks like the horrible volume control have up the ghost. - f
On 2 Oct 2017 8:45 am, "Dexter N Muir" < dexy@...> wrote: ... or wired AAF (Kiwi slang, arse-about-face). Measure your pot wiper-to-each-end. Rotate shaft to 'minimum' as though (or if, then as) mounted in panel. Now which end measures 0 ohms? That's the end that goes to 'earth'/0V (the black wire on Farhan's hfsigs Wire Up picture).
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... or wired AAF (Kiwi slang, arse-about-face). Measure your pot wiper-to-each-end. Rotate shaft to 'minimum' as though (or if, then as) mounted in panel. Now which end measures 0 ohms? That's the end that goes to 'earth'/0V (the black wire on Farhan's hfsigs Wire Up picture).
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I would imagine the vol control is suspect at this time... - f
On 2 Oct 2017 7:48 am, "Vince Vielhaber" < vev@...> wrote: Excellent!? Use that to follow each step thru the audio with an antenna connected to it.? Doesn't matter what it's receiving, even noise will show an ever increasing waveform.? Actually noise is preferred in this case.
Vince.
On 10/01/2017 09:16 PM, Ken Macy wrote:
Vince
I do have a scope.
KG6PO
--
? Michigan VHF Corp.? ?? ?
? ? ? ? ? ? ? ? ? ? ? ? ?
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Hi guys, I¡¯ve been tied up for a few days and just been able to revisit my original post.
I have a 50 ohm 20db attenuator. If I run my RigExpert analyzer into the attenuator and then the attenuator into the Bitx40, does this get me in an acceptable range to try and calibrate LSB or will the signal still be too high?
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Excellent! Use that to follow each step thru the audio with an antenna connected to it. Doesn't matter what it's receiving, even noise will show an ever increasing waveform. Actually noise is preferred in this case.
Vince.
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On 10/01/2017 09:16 PM, Ken Macy wrote: Vince
I do have a scope.
KG6PO
--
Michigan VHF Corp.
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Re: BITX QSO Night, Sunday, October 1, 7pm Local Time, 7277 kHz in North America, 7177 kHz elsewhere
Good conditions, but lots of stations.?
Made contact with Willie, W1LY (Rhode Island) and Ken, WI1B (Massachusetts)
Heard WA2FZW(?), N2CQR (VA), WA3O (PA), N8DAH (MI), KA9OOI (IN), N6ORS (WI)
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I'd definitely try to remember which toroid it was.
My guess is that the insulation on the magnet wire wasn't quite properly removed,
and you have a very flaky solder joint there, waiting to fail again.
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On Sun, Oct 1, 2017 at 06:31 pm, Michael Davis wrote:
re-soldered the connections, (which didn't fix it) then glued the toroid to stabilize it. It's been fine ever since.
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I too had intermittent receive. I used the very non-technical "tap" method. One of the tiny toroids had a problem either in the winding or the soldered connections. I tapped/wiggled it so that it worked, re-soldered the connections, (which didn't fix it) then glued the toroid to stabilize it. It's been fine ever since. I don't remember which toroid it was. Tap and move each one slightly while listening for signals.
Sent from Mike's iPad WA1MAD
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Re: W8TEE pending software release and port(?)
#w8tee
Put a switch on an I/O pin and use INPUT_PULLUP with pinMode(). When a NO pushbutton is pushed, the line is pulled LOW, which changes its state.
Jack, W8TEE
From: Vince Vielhaber <vev@...>
To: [email protected]
Sent: Sunday, October 1, 2017 7:59 PM
Subject: Re: [BITX20] W8TEE pending software release and port(?) #w8tee
Wait a minnit.? I think I understand what they're so horribly trying to
say.? When input pullup is NOT used, a floating connection is low (or
presumably low).? So in order to get it to do something your sensor has
to pull it high.? When the pullup IS used, your sensor has to pull the
pin low.
Vince.
On 10/01/2017 07:54 PM, Vince Vielhaber wrote:
> As I stated when I put it there, it came from the Arduino docs.
>
> Vince.
>
>
>
> On 10/01/2017 07:38 PM, Allard PE1NWL wrote:
>> On Sun, Oct 1, 2017 at 04:01 pm, Vince Vielhaber wrote:
>>
>>? ? On the digital pins:
>>
>>? ? There are 20K pullup resistors built into the Atmega chip that can
>>? ? be accessed from software. These built-in pullup resistors are
>>? ? accessed by setting the pinMode() as INPUT_PULLUP. This effectively
>>? ? inverts the behavior of the INPUT mode, where HIGH means the sensor
>>? ? is off, and LOW means the sensor is on.
>>
>> This is absolutely INCORRECT.
>> pinMode(xx, INPUT) and pinMode(xx, INPUT_PULLUP) only enable/disable the
>> internal pull up resistors.
>> They DON'T invert the behaviour of the input!
>>
>> 73 Allard PE1NWL
>>
>
--
? Michigan VHF Corp.? ?
? ? ? ? ? ? ? ? ? ? ? ? ?
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Vince
I do have a scope.
KG6PO
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Re: BITX QSO Night, Sunday, October 1, 7pm Local Time, 7277 kHz in North America, 7177 kHz elsewhere
I had to yell to get through the noise but just managed to work W1LY with a very minimal exchange.
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Re: W8TEE pending software release and port(?)
#w8tee
Yes that is what they're probably trying to say.
But the wording is very confusing to programmers without an EE background. Many don't understand the real purpose of pull up resistors.
73 Allard PE1NWL
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Re: W8TEE pending software release and port(?)
#w8tee
From p66 section 14.11.6 of the datasheet at: ?
" If the input buffer is enabled and the input signal is left floating or have an analog signal level close to VCC/2, the input buffer will use excessive power."
That's typical of CMOS input pins. ?If you leave them floating (no pullup or pulldown resistor, and no signal actively driving it) then the input voltage is undefined. ?And if it happens to be right in the middle somewhere (the transition region) the input cell can't decide and that circuitry can start getting hot. ?Or you might get an oscillation going. ?Some chips will have "keeper" circuits that will tend to hold them in their previous state. ?The ATmega328p doesn't have keepers, but allows us to specify pullups (but not pulldowns) for each individual input pin. ?
Don't leave pins defined as inputs just "floating". ?
Probably won't blow up (at least on this chip) but might have weird things happening.
Why is that "effectively inverts" thing in the Arduino docs?
Cuz it was written by a CS major, not an EE.
Jerry
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On Sun, Oct 1, 2017 at 04:59 pm, Vince Vielhaber wrote:
When input pullup is NOT used, a floating connection is low (or presumably low).
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Yes, I suspected that might be the case. I think I'll put bypass capacitors on both the keying lines and the function switch and spot switch. It probably doesn't help that I am using a plastic enclosure instead of metal, although the board is mounted on a metal plate. I guess I should check the grounding on everything.
Thanks for all your help
Brent
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Re: W8TEE pending software release and port(?)
#w8tee
Wait a minnit. I think I understand what they're so horribly trying to say. When input pullup is NOT used, a floating connection is low (or presumably low). So in order to get it to do something your sensor has to pull it high. When the pullup IS used, your sensor has to pull the pin low.
Vince.
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On 10/01/2017 07:54 PM, Vince Vielhaber wrote: As I stated when I put it there, it came from the Arduino docs.
Vince.
On 10/01/2017 07:38 PM, Allard PE1NWL wrote:
On Sun, Oct 1, 2017 at 04:01 pm, Vince Vielhaber wrote:
On the digital pins:
There are 20K pullup resistors built into the Atmega chip that can
be accessed from software. These built-in pullup resistors are
accessed by setting the pinMode() as INPUT_PULLUP. This effectively
inverts the behavior of the INPUT mode, where HIGH means the sensor
is off, and LOW means the sensor is on.
This is absolutely INCORRECT.
pinMode(xx, INPUT) and pinMode(xx, INPUT_PULLUP) only enable/disable the
internal pull up resistors.
They DON'T invert the behaviour of the input!
73 Allard PE1NWL
--
Michigan VHF Corp.
|
Re: W8TEE pending software release and port(?)
#w8tee
As I stated when I put it there, it came from the Arduino docs.
Vince.
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Show quoted text
On 10/01/2017 07:38 PM, Allard PE1NWL wrote: On Sun, Oct 1, 2017 at 04:01 pm, Vince Vielhaber wrote:
On the digital pins:
There are 20K pullup resistors built into the Atmega chip that can
be accessed from software. These built-in pullup resistors are
accessed by setting the pinMode() as INPUT_PULLUP. This effectively
inverts the behavior of the INPUT mode, where HIGH means the sensor
is off, and LOW means the sensor is on.
This is absolutely INCORRECT.
pinMode(xx, INPUT) and pinMode(xx, INPUT_PULLUP) only enable/disable the
internal pull up resistors.
They DON'T invert the behaviour of the input!
73 Allard PE1NWL
--
Michigan VHF Corp.
|
Raj vu2zap
Allard PE1NWL
Brent Seres/ VE3CUS