Wow, you must have a rock steady hand to parallel a through hole resistor alongside the SMD resistor. I would not say I have Parkinson disease but my hands are not that steady.

I think I will see if I can find out what the immediate amplifier is after the microphone and the ac component of the audio from the Mic is and see if I can bring about the idea of a pre-amp with gain control. I think the only real problem would be clipping but if you check everything out rather than just stick a guess in it should pan out.

By the way thanks 'all' for the info. I would probably take that route too If I could keep my hands steady.

Mike

On Fri, May 25, 2018, 6:53 PM iz oos <and2oosiz2@...> wrote:

Indeed, I initially thought to add a mic compressor, but reducing the value of R63 by adding a discrete resistor was the simplest thing to do. No smd was removed. It increased, probably doubled the average SSB power so I can more easily drive a small amplifier or whatever.

Il 26/mag/2018 00:14, "Mike aka KC2WVB" <rb5363@...> ha scritto:

Quick question. I think that what your doing is the following: Presumably the audio from the mic's audio line that carries the ac with a dc offset is first passed through a capacitor to block the dc and then used as input into a small preamp, perhaps an op-amp before anything else occurs. If so, then I imagine by changing the value of the named resistor you are increasing the gain associated with the op-amps behavior and consequently the audio's amplification above that of what otherwise occurs.

If my conjecture is near valid I am wondering if there is another way to do this such as by using a little stand alone pre-amp immediately after the microphone and prior to the assumed dc blocking filter. I only wonder because one could then control the gain and I do not have the right stuff for SMD removal or replacement.

On Fri, May 25, 2018, 8:30 AM iz oos <and2oosiz2@...> wrote:

I have changed just R63 so now it is 24 ohm (I added 2 ordinary 100ohms resistors in parallel) as suggested. I confirm it increases the average power to the right level given the stock mic element. Could it be further decreased, let's say 10 ohms?

Il 27/apr/2018 16:26, "Howard Fidel" <sonic1@...> ha scritto:

1K. Change one or the other, not both.

On 4/27/2018 10:14 AM, iz oos wrote:

If R63=24ohm what value should R65 be?

Il 27/apr/2018 16:03, "Skip Davis via Groups.Io" <skipnc9o=[email protected]> ha scritto:

Howard did you also change out R65 that was posted here too.

By the way the parts showed up here yesterday, thanks a lot. Now to find time to install them.

Skip Davis, NC9O?

On Apr 27, 2018, at 09:57, Howard Fidel <sonic1@...> wrote:

Yes. Change R63 to 24 ohms. The earlier rev boards had 100 ohms there, and V3 has 47. I put another 47 ohm resistor in parallel with the one on the board. Now I don't need to yell into the mic.

Howard WB2VXW


On 4/27/2018 3:22 AM, iz oos wrote:

I have checked SSB output for the Ubitx using a Softrock sdr receiver. The carrier is well aligned and the filter gives a very good shape. Whistling is gives full output with the stock mic element. The output seems clean but the average power during normal speech seems to me a bit low. Is there an easy way to increase it? 73, Franco

OK Ralph, I decided that I would learn how and reload the original software.? I have no idea what I am doing so I read a lot of web info and got the ch031 driver and the IDE loaded.? In the instructions it says to test driver by executing file, examples, basics and blink. I did and the little red led blinks with nothing on the display except the top line consists of full pixel squares.? This tells me IDE is working.? Problem is, I can’t get it to stop and go back to radio software.? Did my test overwrite the uBitx software?

I still cannot find step by step instructions for installing software.? This is the first time I have even seen IDE. Learning, I hope!

Thanks, Al

KB4RA

On May 25, 2018, at 4:54 PM, Ralph Mowery <rmowery42@...> wrote:

Right off hand I would say the BFO is way off, probably on the wrong sideband so to speak.

It is usually around 11.996.700, some? where around around 11.996 something instead of 12.something.

It may pay you to load in the original software from the ubitx web page.? That should get you close to calibration.

de ku4pt

On Fri, May 25, 2018 at 4:45 PM, allen west <kb4ra67@...> wrote:

Got uBitx set up a couple of weeks ago.? Audio quit, yes, I have the WX chip.? Getting audio from volume control via an external amp.? Made a couple of contacts but got terrible audio reports back.? I have calibration set correctly and get WWV on 10 and 15 MHz. Fine.? I cannot get BFO set.? Every time I think it is set, the station shows 1000 to 1200 cycles below the frequency of the actual station using a K3 as reference.? If I find a station on 7246 and set the dial on uBitx to 7246 and then set the BFO, I will find my station at 7244.8 or close.? I am following the procedure except the radio doesn’t respond tp PTT when in set up mode.? When I press function switch in set BFO, the display reads 12,665 and when I set it where I want it the PTT does nothing so I press function again.? Is that the problem?? Any ideas?

Thanks, Al

KB4RA

_

OK Ralph, I decided that I would learn how and reload the original software.? I have no idea what I am doing so I read a lot of web info and got the ch031 driver and the IDE loaded.? In the instructions it says to test driver by executing file, examples, basics and blink. I did and the little red led blinks with nothing on the display except the top line consists of full pixel squares.? This tells me IDE is working.? Problem is, I can’t get it to stop and go back to radio software.? Did my test overwrite the uBitx software?

I still cannot find step by step instructions for installing software.? This is the first time I have even seen IDE. Learning, I hope!

Thanks, Al

KB4RA

One last thing that I should have mentioned. The heavy yellow wire in the picture of how I wired the volume potentiometer is the wire that comes from the positive side of the power supply to the switch feature on the potentiometer which is the bottom two pin outs on the potentiometer.

I used my own wire and all I had was yellow. I probably should have used red or brown which I think is what the kit uses but to me it did not matter other than I wanted a heavier gage wire than provided.

On May 25, 2018 9:11 PM, "Mike aka KC2WVB" <rb5363@...> wrote:

I thought you were having trouble with sound coming out of the headphone jack while in receive mode???

If you are having issue with sound on receive:

Here are two pictures. One is a picture of the volume potentiometer and how it should be wired on the BitX40. The other is a picture of the audio headphone jack and how it should be wired on the BitX40.

If your having issues on the Mic:

I have not yet installed my microphone jack but it should be fairly easy and it probably goes like this.?

One pin out connector on the jack/receptor brings in probably 5 volts dc and probably has a 2.2K resistor in line with the wire providing the voltage. Another pin out on the jack/receptor corresponds with the shank of the 1/8 inch stereo plug and it is grounded. The last connector carries the ac audio signal on a dc offset voltage to a capacitor where the dc is stripped away leaving just ac that then probably goes into an amplifier before it goes anywhere else.

There are good 10 minute videos on YouTube that show how these electrec microphones work and it would probably surprise you to here that there is a jfet transistor in the microphone case but there is so you want to wire this thing exactly as told and not to deviate at all or it will not work.

On Tue, May 22, 2018, 1:22 AM <qonita.salimah@...> wrote:

Thanks for your reply..

I've already swap the leads of the electret mic. But the same thing is happened. What voltage suppose the capacitor showed exactly?
is there any limitation on how big the voltage is to make the mic work?

thank you very much

He says he put a "discrete" resistor in parallel.? Could be SMD or thru-hole.
Sticking a discrete SMD resistor on top of an existing SMD resistor is quite easy.
As Allison says, it's like stacking bricks.?
Easier on the board than trying to remove the old one first.


On Fri, May 25, 2018 at 05:05 pm, Mike aka KC2WVB wrote:

Wow, you must have a rock steady hand to parallel a through hole resistor alongside the SMD resistor. I would not say I have Parkinson disease but my hands are not that steady.

?

I think I will see if I can find out what the immediate amplifier is after the microphone and the ac component of the audio from the Mic is and see if I can bring about the idea of a pre-amp with gain control. I think the only real problem would be clipping but if you check everything out rather than just stick a guess in it should pan out.

?

By the way thanks 'all' for the info. I would probably take that route too If I could keep my hands steady.

?

Mike

. . .

?

On Fri, May 25, 2018, 6:53 PM iz oos <and2oosiz2@...> wrote:

Indeed, I initially thought to add a mic compressor, but reducing the value of R63 by adding a discrete resistor was the simplest thing to do. No smd was removed. It increased, probably doubled the average SSB power so I can more easily drive a small amplifier or whatever.

?

I thought you were having trouble with sound coming out of the headphone jack while in receive mode???

If you are having issue with sound on receive:

Here are two pictures. One is a picture of the volume potentiometer and how it should be wired on the BitX40. The other is a picture of the audio headphone jack and how it should be wired on the BitX40.

If your having issues on the Mic:

I have not yet installed my microphone jack but it should be fairly easy and it probably goes like this.?

One pin out connector on the jack/receptor brings in probably 5 volts dc and probably has a 2.2K resistor in line with the wire providing the voltage. Another pin out on the jack/receptor corresponds with the shank of the 1/8 inch stereo plug and it is grounded. The last connector carries the ac audio signal on a dc offset voltage to a capacitor where the dc is stripped away leaving just ac that then probably goes into an amplifier before it goes anywhere else.

There are good 10 minute videos on YouTube that show how these electrec microphones work and it would probably surprise you to here that there is a jfet transistor in the microphone case but there is so you want to wire this thing exactly as told and not to deviate at all or it will not work.

On Tue, May 22, 2018, 1:22 AM <qonita.salimah@...> wrote:

Thanks for your reply..

I've already swap the leads of the electret mic. But the same thing is happened. What voltage suppose the capacitor showed exactly?
is there any limitation on how big the voltage is to make the mic work?

thank you very much

Thanks for your reply..

I've already swap the leads of the electret mic. But the same thing is happened. What voltage suppose the capacitor showed exactly?
is there any limitation on how big the voltage is to make the mic work?

thank you very much

Hey, I'm new here. I just finished assembling my ubitx, and I was disappointed to find there was no audio. I double checked all my connections, and everything seems to be wired correctly.

I saw somewhere that the "WX" branded TDA2822M chips are of lower quality than others, and mine is a WX. Might this be the issue??

Indeed, I initially thought to add a mic compressor, but reducing the value of R63 by adding a discrete resistor was the simplest thing to do. No smd was removed. It increased, probably doubled the average SSB power so I can more easily drive a small amplifier or whatever.

Il 26/mag/2018 00:14, "Mike aka KC2WVB" <rb5363@...> ha scritto:

Quick question. I think that what your doing is the following: Presumably the audio from the mic's audio line that carries the ac with a dc offset is first passed through a capacitor to block the dc and then used as input into a small preamp, perhaps an op-amp before anything else occurs. If so, then I imagine by changing the value of the named resistor you are increasing the gain associated with the op-amps behavior and consequently the audio's amplification above that of what otherwise occurs.

If my conjecture is near valid I am wondering if there is another way to do this such as by using a little stand alone pre-amp immediately after the microphone and prior to the assumed dc blocking filter. I only wonder because one could then control the gain and I do not have the right stuff for SMD removal or replacement.

On Fri, May 25, 2018, 8:30 AM iz oos <and2oosiz2@...> wrote:

I have changed just R63 so now it is 24 ohm (I added 2 ordinary 100ohms resistors in parallel) as suggested. I confirm it increases the average power to the right level given the stock mic element. Could it be further decreased, let's say 10 ohms?

Il 27/apr/2018 16:26, "Howard Fidel" <sonic1@...> ha scritto:

1K. Change one or the other, not both.

On 4/27/2018 10:14 AM, iz oos wrote:

If R63=24ohm what value should R65 be?

Il 27/apr/2018 16:03, "Skip Davis via Groups.Io" <skipnc9o=[email protected]> ha scritto:

Howard did you also change out R65 that was posted here too.

By the way the parts showed up here yesterday, thanks a lot. Now to find time to install them.

Skip Davis, NC9O?

On Apr 27, 2018, at 09:57, Howard Fidel <sonic1@...> wrote:

Yes. Change R63 to 24 ohms. The earlier rev boards had 100 ohms there, and V3 has 47. I put another 47 ohm resistor in parallel with the one on the board. Now I don't need to yell into the mic.

Howard WB2VXW


On 4/27/2018 3:22 AM, iz oos wrote:

I have checked SSB output for the Ubitx using a Softrock sdr receiver. The carrier is well aligned and the filter gives a very good shape. Whistling is gives full output with the stock mic element. The output seems clean but the average power during normal speech seems to me a bit low. Is there an easy way to increase it? 73, Franco