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uBITX working, question about power, PTT pop, LOUD headphone output #ubitx

 

Hi all,

I got everything wired up and working, although I still need to assemble a keyer and PTT switch.? It's in an enclosure from an old lab power supply, which saved me quite a bit of drilling, and already has a fuse and chassis ground line installed:



So far I have three questions:?

First, if I use headphones the CW sidetone on transmit is painfully loud unless the volume level is very low.? Is there some means to reduce the sidetone to the headphones, or should I just not be using headphones??

Next, there is a significant pop in the headphones at any volume level when I push PTT---loud enough to make my ears ring.? Basically I can't have the headphones on when I press PTT.? I'm using the supplied electret mic wired between tip and ground, with PTT between ring and ground.?? Is there some obvious mic trick I should be trying to prevent this??

My third question is regarding power:?? has anyone been able to measure the power output on 20m?? I only have an MFJ 5W QRP wattmeter, and it's a bit....qualitative.? I can verify greater power output at lower frequencies, but I can't get an absolute power measurement.?

Thanks, Xcott K2CAJ
 

I hear a loud pop when I push PTT or key down my uBitx. I think that this may be the same kind of pop that the Bitx40 had. Do a search for "pop" to? find threads on this issue.
 

If what I read is correct of the chip tda2822 If you reduce the supply voltage it will bring the amplification down accordingly. Pin 2 is Vin. See page 5 http://www.st.com/content/ccc/resource/technical/document/datasheet/9e/18/f7/cd/2e/b8/43/62/CD00000134.pdf/files/CD00000134.pdf/jcr:content/translations/en.CD00000134.pdf
 

Hi,

I have yet to add a PTT switch, and I have a little cutout in the bottom right I can use for that.? I'm thinking I could just make a switch that disconnects the speaker line at the same time that I PTT.?? I'd prefer a low-tech hack over any tampering with the board.

That won't fix the sidetone, although it's also possible to make a pushbutton that attenuates the speaker line pretty easily, rather than cutting it out completely.?

Thanks, Xcott K2CAJ
 


So far I have three questions:?

First, if I use headphones the CW sidetone on transmit is painfully loud unless the volume level is very low.? Is there some means to reduce the sidetone to the headphones, or should I just not be using headphones??

Change the R253 from 10K to something like 100K or even 220K. I know it is painfully loud, our apologies to the early birds. i will ask the beavers to change that resistor in the next batch.
?
Next, there is a significant pop in the headphones at any volume level when I push PTT---loud enough to make my ears ring.? Basically I can't have the headphones on when I press PTT.? I'm using the supplied electret mic wired between tip and ground, with PTT between ring and ground.?? Is there some obvious mic trick I should be trying to prevent this??


i haven't experienced this pop. i hope this is not a 'feature' of this rig too :-( anyone else who has reported this?
?
My third question is regarding power:?? has anyone been able to measure the power output on 20m?? I only have an MFJ 5W QRP wattmeter, and it's a bit....qualitative.? I can verify greater power output at lower frequencies, but I can't get an absolute power measurement.?


It gives me 6 watts as measured on a 20 x 50 ohm (2 watt) resistors parallelled up. through a sniffer.
?
Thanks, Xcott K2CAJ


 

Ashhar

? I also have the PTT pop in my uBitx. It's particularly annoying in CW use.

I mounted my raduino separately. I think I could reduce the side tone volume with a resister in the CW_Tone wire without touching the main board.

BTW - the ubitx_keyer sketch refers to cwTxStart and cwTXStop, which I think were replaced by startTx and stopTx.

???? Bob
 

I use an external "station speaker" for all rigs. I installed a headphone jack in the speaker cabinet and feed it through a 470 ohm series resistor to make the headphones the same level as the speaker would be. I then put "anti-paralleled" 1N914s (or any other switching diodes) across the headphone jack to limit any surprises. The old landline telephones did this for decades. It works nicely. 73, ND6T
 

Ubitx arrived today and up and running. Not much going on the band at this time of the night in vk but tuned a few am stations in the broadcast band and all good. CW power out on 40m into a dummy load was 5W. Havent tested ssb yet as need a new plug on my mic. PTT pop there so that will be my first mod. Its in a case I got from Jaycar which looks the same as the Jameco case. A tight fit but enough room for a few mods.

Regards

Simon VK3ELH?
 

I'm thinking of just adding a PTT switch to the case, and making it an (on)-off-on switch:? the (on) will tie PTT to ground, the regular on will give regular audio, and the off in the middle will attenuate the speaker by patching in a series resistance.? That way I won't forget to attenuate before PTT, and I can use it separate from the PTT for the CW sidetone.
?
I'd rather do it that way than altering the board, since I've not yet decided whether I'm going to use phones or speakers or use it for digital modes and not care about the audio levels.

Also, thanks for the power readings.? It's pretty awesome that we can get that much power on 20m out of the box.

Thanks, Xcott K2CAJ
 

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That's good news Simon. Did it come India Post?

Bill, VK7MX


On 20/12/2017 2:07 AM, Kelly Jack wrote:

Ubitx arrived today and up and running. Not much going on the band at this time of the night in vk but tuned a few am stations in the broadcast band and all good. CW power out on 40m into a dummy load was 5W. Havent tested ssb yet as need a new plug on my mic. PTT pop there so that will be my first mod. Its in a case I got from Jaycar which looks the same as the Jameco case. A tight fit but enough room for a few mods.

Regards

Simon VK3ELH?
 

In terms of?reducing sidetone volume, perhaps a resistor to ground at the head of the RC chain (at R250) could work.
I don't have my uBITX yet so I can't confirm...may find it pulls the entire audio level down too much. For SMD incompetents such as myself it may be easier to tack resistor leads to ground than change an SMD out.?

Paul ZS2OE
 

Definitely a loud POP in both the headphones or a speaker if plugged in.? It is very annoying and occurs on both the PTT keying transition and on the first dot of the CW keying transition.? Also, the paddles are very difficult to send CW with as the keyer chops the first dot and the timing is NOT consistent between the dot and dash transitions in the keyer.? I've been a mostly CW operator for over 50 years and this rig will not meet my specs as a CW rig until that is fixed.? Also the hand key doesn't always key right either.? I polished the paddle contacts and the hand key contacts til they were squeaky clean.? They work perfectly with my Elecraft K3S giving no errors (that I don't make myself) in keying so they should do well with this rig too, but they don't.? The hand key occasionally will trigger the keyer into dots or dashes when first pressed.?
I did put the 4.7K pull up resistor right on the Raduino rather than on the key jack but that shouldn't affect the voltage divider operation if the software is working like is should. I actually added a separate paddle jack because I do not want to modify my Begali paddles by putting resistors in line.? That would lock them to just the uBITX and I'd be unable to use them with any other rig.

Jim Sheldon, W0EB
Park City KS

PS:? my uBITX made it's first QSO this morning on 40 meter SSB.? 7200KHz from KS to Tennessee on a very low mounted end fed Zepp antenna.? Signal report was 4-4 in QSB but we completed the QSO.? Hoping I can make a CW QSO now, but it's going to be tricky with the keying malfunctioning.? (I did check all wiring and it's good).?
 

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I found the same thing with a straight key, decent performance with a paddle. Yes, the pops going into transmit are a bit annoying. Perhaps a simple transistor switch to break the audio connection could be a mod to pursue - the KK7B R1 and R2 circuits used a 2N7000 transistor for this. A little research into the cause will probably find a cure.

Pretty amazed with it as it is - haywired it on the table and it's working pretty well. Operation is intuitive. However, I can't get the CW tone to change - hitting PTT doesn't seem to set it as the screen says. So I can't move that yet.

John K0JD
Milwaukee, WI


On 12/20/2017 15:41, Jim Sheldon wrote:

Definitely a loud POP in both the headphones or a speaker if plugged in.? It is very annoying and occurs on both the PTT keying transition and on the first dot of the CW keying transition.? Also, the paddles are very difficult to send CW with as the keyer chops the first dot and the timing is NOT consistent between the dot and dash transitions in the keyer.? I've been a mostly CW operator for over 50 years and this rig will not meet my specs as a CW rig until that is fixed.? Also the hand key doesn't always key right either.? I polished the paddle contacts and the hand key contacts til they were squeaky clean.? They work perfectly with my Elecraft K3S giving no errors (that I don't make myself) in keying so they should do well with this rig too, but they don't.? The hand key occasionally will trigger the keyer into dots or dashes when first pressed.?
I did put the 4.7K pull up resistor right on the Raduino rather than on the key jack but that shouldn't affect the voltage divider operation if the software is working like is should. I actually added a separate paddle jack because I do not want to modify my Begali paddles by putting resistors in line.? That would lock them to just the uBITX and I'd be unable to use them with any other rig.

Jim Sheldon, W0EB
Park City KS

PS:? my uBITX made it's first QSO this morning on 40 meter SSB.? 7200KHz from KS to Tennessee on a very low mounted end fed Zepp antenna.? Signal report was 4-4 in QSB but we completed the QSO.? Hoping I can make a CW QSO now, but it's going to be tricky with the keying malfunctioning.? (I did check all wiring and it's good).?

 

John,

The screen says to press PTT to set the new setting but I found the button on the encoder works.

Regards Simon VK3ELH
Gordon Gibby
 

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Going into transmit, C 63 should pass a big transient through C 50 into Q 70 base which still has power because nothing quickly discharges C52, and U1 always has power. ?

Sent from my iPhone

On Dec 20, 2017, at 20:14, John Seboldt K0JD <k0jd-l@...> wrote:

I found the same thing with a straight key, decent performance with a paddle. Yes, the pops going into transmit are a bit annoying. Perhaps a simple transistor switch to break the audio connection could be a mod to pursue - the KK7B R1 and R2 circuits used a 2N7000 transistor for this. A little research into the cause will probably find a cure.

Pretty amazed with it as it is - haywired it on the table and it's working pretty well. Operation is intuitive. However, I can't get the CW tone to change - hitting PTT doesn't seem to set it as the screen says. So I can't move that yet.

John K0JD
Milwaukee, WI


On 12/20/2017 15:41, Jim Sheldon wrote:
Definitely a loud POP in both the headphones or a speaker if plugged in.? It is very annoying and occurs on both the PTT keying transition and on the first dot of the CW keying transition.? Also, the paddles are very difficult to send CW with as the keyer chops the first dot and the timing is NOT consistent between the dot and dash transitions in the keyer.? I've been a mostly CW operator for over 50 years and this rig will not meet my specs as a CW rig until that is fixed.? Also the hand key doesn't always key right either.? I polished the paddle contacts and the hand key contacts til they were squeaky clean.? They work perfectly with my Elecraft K3S giving no errors (that I don't make myself) in keying so they should do well with this rig too, but they don't.? The hand key occasionally will trigger the keyer into dots or dashes when first pressed.?
I did put the 4.7K pull up resistor right on the Raduino rather than on the key jack but that shouldn't affect the voltage divider operation if the software is working like is should. I actually added a separate paddle jack because I do not want to modify my Begali paddles by putting resistors in line.? That would lock them to just the uBITX and I'd be unable to use them with any other rig.

Jim Sheldon, W0EB
Park City KS

PS:? my uBITX made it's first QSO this morning on 40 meter SSB.? 7200KHz from KS to Tennessee on a very low mounted end fed Zepp antenna.? Signal report was 4-4 in QSB but we completed the QSO.? Hoping I can make a CW QSO now, but it's going to be tricky with the keying malfunctioning.? (I did check all wiring and it's good).?

 

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How do you calibrate the frequency on uBit?

I have not figured out the menu yet!

I do get WWV now on about 15' of wire out the door.? I can Zero beat it and get the AM at 9.8 something?

?

Mike, WA6ISP


On 12/20/2017 5:14 PM, John Seboldt K0JD wrote:

I found the same thing with a straight key, decent performance with a paddle. Yes, the pops going into transmit are a bit annoying. Perhaps a simple transistor switch to break the audio connection could be a mod to pursue - the KK7B R1 and R2 circuits used a 2N7000 transistor for this. A little research into the cause will probably find a cure.

Pretty amazed with it as it is - haywired it on the table and it's working pretty well. Operation is intuitive. However, I can't get the CW tone to change - hitting PTT doesn't seem to set it as the screen says. So I can't move that yet.

John K0JD
Milwaukee, WI


On 12/20/2017 15:41, Jim Sheldon wrote:
Definitely a loud POP in both the headphones or a speaker if plugged in.? It is very annoying and occurs on both the PTT keying transition and on the first dot of the CW keying transition.? Also, the paddles are very difficult to send CW with as the keyer chops the first dot and the timing is NOT consistent between the dot and dash transitions in the keyer.? I've been a mostly CW operator for over 50 years and this rig will not meet my specs as a CW rig until that is fixed.? Also the hand key doesn't always key right either.? I polished the paddle contacts and the hand key contacts til they were squeaky clean.? They work perfectly with my Elecraft K3S giving no errors (that I don't make myself) in keying so they should do well with this rig too, but they don't.? The hand key occasionally will trigger the keyer into dots or dashes when first pressed.?
I did put the 4.7K pull up resistor right on the Raduino rather than on the key jack but that shouldn't affect the voltage divider operation if the software is working like is should. I actually added a separate paddle jack because I do not want to modify my Begali paddles by putting resistors in line.? That would lock them to just the uBITX and I'd be unable to use them with any other rig.

Jim Sheldon, W0EB
Park City KS

PS:? my uBITX made it's first QSO this morning on 40 meter SSB.? 7200KHz from KS to Tennessee on a very low mounted end fed Zepp antenna.? Signal report was 4-4 in QSB but we completed the QSO.? Hoping I can make a CW QSO now, but it's going to be tricky with the keying malfunctioning.? (I did check all wiring and it's good).? 


-- 
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID  "MotDog@..."
Mike@...
 

Hi all

This thread has a couple of topics but this comment about tbe PTT pop only.

This mod worked well on my bitx 40. ?/g/BITX20/wiki/AudioMute

Unfortunately it will require some on board modifications to keep the cw tone line alive.

Must say that for such a well known issue in the bitx20, then bitx40 I'm wondering why it hasnt been addressed at all in the ubitx.

Regards


Simon VK3ELH?
 

Correction. PTT does nothing but the encoder button only exits the menu. The change to CW tone does not take.

Regards Simon VK3ELH?
 

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Oddly, that didn't work for me - first thing I tried. No change in tone.

John


On 12/20/2017 19:32, Kelly Jack wrote:

John,

The screen says to press PTT to set the new setting but I found the button on the encoder works.

Regards Simon VK3ELH

 

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That looks like a good approach, and resembles the kind of MOSFET muting used in KK7B's R1 and R2 receivers.

John K0JD



On 12/20/2017 20:31, Kelly Jack wrote:

Hi all

This thread has a couple of topics but this comment about tbe PTT pop only.

This mod worked well on my bitx 40. ?/g/BITX20/wiki/AudioMute

Unfortunately it will require some on board modifications to keep the cw tone line alive.

Must say that for such a well known issue in the bitx20, then bitx40 I'm wondering why it hasnt been addressed at all in the ubitx.

Regards


Simon VK3ELH?

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