Date   
Re: #ubitx replaced Arduino Nano gives a lot of I2C interference during reception #ubitx

MVS Sarma
 

Alex, I now understand that you had used co-ax cables to connect the clocks to main board.
 if the raduno is farhans original, why not try direct connection once with no cables.
Secondly, I suppose (again I suppose) Farhan himself is using such Nanos only. Nothing vwery special.

Hence can you please to clatrify whether these clicks could also be due to CH340 USB chip in case you use computer related FT-8 etc?
 If so original nano has to be  checkd for whether original NANO used CH340 or FT232RL or any other chip.

Finally try to use a 1mH choke on the 12V dc line with proper filter. Also can you place 10nF  smd caps on the rotary encoder pins to ground. I suppose those clicks are due to encoder rotation.

 With these changes, perhaps the clicks can be minimized. Please don't feel that I am re-inventing the wheel, LoL
regards
sarma
vu3zmv


 


Regards
MVS Sarma
 

On Thu, Feb 22, 2018 at 7:01 PM, Alex Buurlage <pa1fox@...> wrote:
Hi all,

I have replaced the Nano in my homebrew rig as one of the IO ports was dead. Now, with the new Nano, same firmware, same rig, I have a lot of tuning clicks. 
When I disconnect the SI5351 the clicks are gone. When I disconnect the coax cables from the mainboard carrying the oscillator signals, clicks are nearly gone.

When I put back in the original Nano, clicks are hardly audible as it used to be until now. 

Has anyone found such differences in behaviour between cheap Nano boards from Ebay? Reviewing the method I2C works, I can't really imagine the big difference in behaviour as the output ports of the Nano seems to be open drain mosfets and the pull-up resistors at the SI5351 are the same.

Even with the volume pot completely down the clicks are very loud with the new Nano. One should think it is ground looping somewhere differently with this new Nano.

Any ideas?

73, Alex
PA1FOX


#ubitx replaced Arduino Nano gives a lot of I2C interference during reception #ubitx

Alex - PA1FOX
 

Hi all,

I have replaced the Nano in my homebrew rig as one of the IO ports was dead. Now, with the new Nano, same firmware, same rig, I have a lot of tuning clicks. 
When I disconnect the SI5351 the clicks are gone. When I disconnect the coax cables from the mainboard carrying the oscillator signals, clicks are nearly gone.

When I put back in the original Nano, clicks are hardly audible as it used to be until now. 

Has anyone found such differences in behaviour between cheap Nano boards from Ebay? Reviewing the method I2C works, I can't really imagine the big difference in behaviour as the output ports of the Nano seems to be open drain mosfets and the pull-up resistors at the SI5351 are the same.

Even with the volume pot completely down the clicks are very loud with the new Nano. One should think it is ground looping somewhere differently with this new Nano.

Any ideas?

73, Alex
PA1FOX

Re: Using external amp with µBitx

Richie Chambless
 

David - Thank you for pointing out that the top of the volume pot and wiper wires are reversed in the wireup diagram. I will try taking the audio from there.

Dexter - Yes, I have passed a ham exam. Only missed one question on the General. I have been building electronics for over 20 years, so I felt bad even having to ask a basic question like this one. Like I said in my earlier post, I've scratch built a single conversion Bitx with the same exact audio detector module with no issues.

Re: Erratic Tuning bitx40!

 

You are right Allard,

The pot would have smoked! Pot smoking has happened before here..

M0clscarl, please replace your 10T pot and wire it right there sill be no problem.

Raj

At 22/02/2018, you wrote:
So you have a 10-turn pot?
Then it should indeed be wired as shown here:

https://github.com/amunters/bitx40/blob/master/Vishay%20100K%2C%2010-turn%20pot%20wire%20up.jpg

On the purple wire (slider) the voltage should range from 0 - 5 Volts,
depending on the pot position.

73 Allard PE1NWL

On Thu, February 22, 2018 12:55, @M0CLS wrote:
I also noticed that the wiring for my tuning pot is different to the
online wiring guide. The tuning pot is a bourns (blue) pot so obviously
different to the guide, and this did work before so I assume this is
correct for this particular tuning pot. The purple wire goes to the
outermost pin, the yellow to the middle and the green to the innermost
pin. The cap is soldered over the yellow and purple.

Re: Erratic Tuning bitx40!

Allard PE1NWL
 

So you have a 10-turn pot?
Then it should indeed be wired as shown here:

https://github.com/amunters/bitx40/blob/master/Vishay%20100K%2C%2010-turn%20pot%20wire%20up.jpg

On the purple wire (slider) the voltage should range from 0 - 5 Volts,
depending on the pot position.

73 Allard PE1NWL

On Thu, February 22, 2018 12:55, @M0CLS wrote:
I also noticed that the wiring for my tuning pot is different to the
online wiring guide. The tuning pot is a bourns (blue) pot so obviously
different to the guide, and this did work before so I assume this is
correct for this particular tuning pot. The purple wire goes to the
outermost pin, the yellow to the middle and the green to the innermost
pin. The cap is soldered over the yellow and purple.

Re: Using external amp with µBitx

 

Davis, you are absolutely right! According to this diagram the wires are
interchanged.. the yellow should be pot TOP and ORANGE is pot middle.
That explains the crappy sound at low volumes.. never noticed! Thanks!

Raj

Emacs!


At 22/02/2018, you wrote:
Raj / Richie

That's odd, the orange wire on my Ubitx is the input to the audio amp, the wire colours and positions on the socket is the same as in the wire-up but the orange wire definitely goes to the TDA2822 pin 7, there's also a C78 connected to pin 7 that's not on the schematic.  The (full) audio feed is on the yellow wire, an oscilloscope confirms this. The orange wire need a DC path to ground for the TDA2822 to function correctly.  It seems there's an error on the wire-up drawing.

Regards

Davis S  G8DJM

Re: Erratic Tuning bitx40!

Don, ND6T
 

And when fully clockwise what do you read? If not near 5 volts, then trace that lug back to the source. If you do find 5 volts and the center (wiper) pin is still zero then replace that control. Any linear control from 1 K to 50 K will work. 10K is what it came with. You are running the original native software apparently.

Re: Erratic Tuning bitx40!

Jodannastreet1985@...
 

I also noticed that the wiring for my tuning pot is different to the online wiring guide. The tuning pot is a bourns (blue) pot so obviously different to the guide, and this did work before so I assume this is correct for this particular tuning pot. The purple wire goes to the outermost pin, the yellow to the middle and the green to the innermost pin. The cap is soldered over the yellow and purple.

Re: Variable power control

Roberto Vannucci
 


I want to suggest a circuit that I have tested to regulate the power in my previous self-built HF transmitter. It is based on an HSMP3816 QUAD PIN DIODE.
I enclose the circuit file 73 IK6BLO

2018-02-22 9:33 GMT+01:00 Walter <W9KJO@...>:

Thank you very much

That is a very nice schematic drawing and readable

Thank you,  I cant wait to get the parts and build it.

73, W9KJO, Walter


Re: Faulty K1 relay

Allard PE1NWL
 

I had exactly the same issue with my BitX40. Perhaps the supplied relays
are poor quality. I replaced the relay by:

brand: ZETTLER
type: AZ822-2C-12DE

http://www.conrad-electronic.co.uk/ce/en/product/507425/PCB-relays-12-Vdc-2-A-2-change-overs-Zettler-Electronics-AZ822-2C-12DE-1-pcs

When replacing the relays it's also a good idea to install standard 16 pin
DIL IC sockets. The relays fit in, so you can easily swap them should
they fail again.

73 Allard PE1NWL

On Thu, February 22, 2018 11:21, Glenn wrote:
For anybody trying to get their uBITX to work in Tx mode. Something to
check perhaps.

Mine was working then started to become intermittent. Key the Mic PTT
switch and the display shows it's in Tx mode, but no power out.

Tracing signals etc, I found that the K1 changeover relay was not
switching 12V to the Tx section. I could hear the relay 'operate' but it
didn't actually switch.

Replaced the relay and all is fine.

glenn
vk3pe

Re: Using external amp with µBitx

David S
 

Raj / Richie

That's odd, the orange wire on my Ubitx is the input to the audio amp, the wire colours and positions on the socket is the same as in the wire-up but the orange wire definitely goes to the TDA2822 pin 7, there's also a C78 connected to pin 7 that's not on the schematic.  The (full) audio feed is on the yellow wire, an oscilloscope confirms this. The orange wire need a DC path to ground for the TDA2822 to function correctly.  It seems there's an error on the wire-up drawing.

Regards

Davis S  G8DJM

Faulty K1 relay

Glenn
 

For anybody trying to get their uBITX to work in Tx mode. Something to check perhaps.

Mine was working then started to become intermittent. Key the Mic PTT switch and the display shows it's in Tx mode, but no power out.

Tracing signals etc, I found that the K1 changeover relay was not switching 12V to the Tx section. I could hear the relay 'operate' but it didn't actually switch.

Replaced the relay and all is fine.

glenn
vk3pe

Re: Erratic Tuning bitx40!

Jodannastreet1985@...
 

Ok I measured voltage and getting 0.9v from fully anti clockwise to fully clockwise. There is continuity from the center pin to ground... 

Raduino V1.01 is what flashes up momentarily when turning on. 

Re: Variable power control

Walter
 

Thank you very much

That is a very nice schematic drawing and readable

Thank you,  I cant wait to get the parts and build it.

73, W9KJO, Walter

Re: rv2- messed up setting and txing like mad!!!

Alan -MMØWXT
 

On Wed, Feb 21, 2018 at 07:43 pm, Raj vu2zap wrote:
Alan,

You had zero'd the RV1. Please bring it back to center and leave it there and forget it exists.
Check on a loud hallow with RV1 centered. If RV1 is fully clockwise then your output will be zero
due to no drive from RV1.

Raj

At 22/02/2018, you wrote:
Hi Jerry.
No effect on amps moving RV1.
100ma each on adjustment of RV1&2 whilst pressing PTT on mic
PA,Brown, supply 200 ma on PTT
12v,red, rail 250 in receive 550ma tx

A loud hallllow produces no change in current. Dont have swr so no idea of output to load.

But receive working and things are a beginning to click.

Thanks

Alan

 Gentlemen. You are wonderful!
Ubitx is alive. Low amps on PTT was mis wired Baofeng Mic.

Followed another thread and croc clipped the cw connector and grounded it for dit. Got 1.53A!!!

Still to try on Phone.

I have had a very good lesson. But more importantly I have learned a lot about the ubitx.

I cannot thank you ALL enough.

Thank you and 73's

Alan

Re: Using external amp with µBitx

 

Richie,

The only thing I can think of is that after disconnecting the ORANGE wire, you are taking output from the top of the volume control.
The audio signal is coming from the ORANGE wire. So from the volume control you will not hear anything!

You could leave the ORANGE wire alone and disconnect the YELLOW wire from the pot and take output from the center of the
volume control and that volume control will work for your external amp.

Raj

At 22/02/2018, you wrote:
I have run into an issue with taking the pre-amp audio signal from Q70 and using it with an external amplifier. When I remove VOL-H (Orange wire) from the top of the volume pot and run to another amplifier, I get nothing. I have a scratch-built Bitx v3 that I have used the low-level output to run an LM-380 with no issues, so I know it's not a level mis-match. I don't understand why the TDA2822 can "hear" the audio but nothing else I have can. Has anyone else modded their audio section?

Re: RD16HHF1 in the uBITX #ubitx

MVS Sarma
 

Allison,
Thanks for the very useful and detailed information on your implementation of IRF devices.

regards
 sarma
 vu3zmv

Regards
MVS Sarma
 

On Thu, Feb 22, 2018 at 9:43 AM, K9HZ <bill@...> wrote:
I would not argue with you on using IRF510s...  i simply choose to use real RF transistors because they typically have better characteristics for RF design work eg flatter capacitance curve vs frequency so no need for compensation tricks. I do question the 2N3904 claim though as they are easily good (flat gain) to 200+ MHz in a properly designed circuit.  Could it be that the rest of the circuit is actually the problematic part... like the stage coupling capacitors?


Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ

 

Owner - Operator

Big Signal Ranch – K9ZC

Staunton, Illinois

 

Owner – Operator

Villa Grand Piton - J68HZ

Soufriere, St. Lucia W.I.

Rent it: www.VillaGrandPiton.com


email:  bill@...

 


On Feb 21, 2018, at 5:19 PM, ajparent1 <kb1gmx@...> wrote:

There seems to be a belief that the IRF5xx parts have no capability at VHF...

I have an amp using 8 of them at 32V that puts out a mere 210W at 50mhz.  All of the parts are
IRF510s in a 4x4 push pull arrangement!  The amps gain over all is about 13db. 

I have also built the WA2eby push-pull HF amp and that design with 2w in gives me 55W at 40M
and 37W at 29mhz, that with a 28V supply.   Also IRF510s so the part has capability though
generally if performs better at 24V.

THe bias on the IRF510 is often lower than optimum, Both amps (and other HF/6M projects)
run far more bias current that specified as it produced more power.

The problem is the amplifier has matching issues from simplified transformers.  Additionally 
at 30mhz the AC  gain of the driver and predriver transistors (2n3904) is about 10 as compared
to an AC gain of 20 at 14mhz. So you seeing two problem one of driver that diminishes with
frequency and matching that is less than optimum with increasing frequency. 

I've also built amps around the RD16HHF part and at 13V its good but it requires different
components around it to get the power out they can deliver.  For a push pull pair with adequate
drive 20W is about it.

Before I'd go for changing parts I'd insure the driver and predriver are producing enough power.
It is also possible that the particular parts are on the low sid eof spec but the design is robust enough
to absorb that.

Another thing to insure is that your DC [pwer getting to the final is really 12-14V and not suffering
excessive voltage drop due to wiring  or worse the power source fading at higher currents.

So dropping in RD16HHF1 in without changes will likely not improve matters much and it may
lead to instability.   But if you have a pair you can try. 

I'd expect more like 4W or more so something is not right.


Allison/kb1gmx


Re: RD16HHF1 in the uBITX #ubitx

K9HZ <bill@...>
 

I would not argue with you on using IRF510s...  i simply choose to use real RF transistors because they typically have better characteristics for RF design work eg flatter capacitance curve vs frequency so no need for compensation tricks. I do question the 2N3904 claim though as they are easily good (flat gain) to 200+ MHz in a properly designed circuit.  Could it be that the rest of the circuit is actually the problematic part... like the stage coupling capacitors?


Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ

 

Owner - Operator

Big Signal Ranch – K9ZC

Staunton, Illinois

 

Owner – Operator

Villa Grand Piton - J68HZ

Soufriere, St. Lucia W.I.

Rent it: www.VillaGrandPiton.com


email:  bill@...

 


On Feb 21, 2018, at 5:19 PM, ajparent1 <kb1gmx@...> wrote:

There seems to be a belief that the IRF5xx parts have no capability at VHF...

I have an amp using 8 of them at 32V that puts out a mere 210W at 50mhz.  All of the parts are
IRF510s in a 4x4 push pull arrangement!  The amps gain over all is about 13db. 

I have also built the WA2eby push-pull HF amp and that design with 2w in gives me 55W at 40M
and 37W at 29mhz, that with a 28V supply.   Also IRF510s so the part has capability though
generally if performs better at 24V.

THe bias on the IRF510 is often lower than optimum, Both amps (and other HF/6M projects)
run far more bias current that specified as it produced more power.

The problem is the amplifier has matching issues from simplified transformers.  Additionally 
at 30mhz the AC  gain of the driver and predriver transistors (2n3904) is about 10 as compared
to an AC gain of 20 at 14mhz. So you seeing two problem one of driver that diminishes with
frequency and matching that is less than optimum with increasing frequency. 

I've also built amps around the RD16HHF part and at 13V its good but it requires different
components around it to get the power out they can deliver.  For a push pull pair with adequate
drive 20W is about it.

Before I'd go for changing parts I'd insure the driver and predriver are producing enough power.
It is also possible that the particular parts are on the low sid eof spec but the design is robust enough
to absorb that.

Another thing to insure is that your DC [pwer getting to the final is really 12-14V and not suffering
excessive voltage drop due to wiring  or worse the power source fading at higher currents.

So dropping in RD16HHF1 in without changes will likely not improve matters much and it may
lead to instability.   But if you have a pair you can try. 

I'd expect more like 4W or more so something is not right.


Allison/kb1gmx

Using external amp with µBitx

Richie Chambless
 

I have run into an issue with taking the pre-amp audio signal from Q70 and using it with an external amplifier. When I remove VOL-H (Orange wire) from the top of the volume pot and run to another amplifier, I get nothing. I have a scratch-built Bitx v3 that I have used the low-level output to run an LM-380 with no issues, so I know it's not a level mis-match. I don't understand why the TDA2822 can "hear" the audio but nothing else I have can. Has anyone else modded their audio section?   

Re: rv2- messed up setting and txing like mad!!!

 

Alan,

You had zero'd the RV1. Please bring it back to center and leave it there and forget it exists.
Check on a loud hallow with RV1 centered. If RV1 is fully clockwise then your output will be zero
due to no drive from RV1.

Raj

At 22/02/2018, you wrote:
Hi Jerry.
No effect on amps moving RV1.
100ma each on adjustment of RV1&2 whilst pressing PTT on mic
PA,Brown, supply 200 ma on PTT
12v,red, rail 250 in receive 550ma tx

A loud hallllow produces no change in current. Dont have swr so no idea of output to load.

But receive working and things are a beginning to click.

Thanks

Alan