Date   
Re: Higher voltage for Bitx40 Final

Vic WA4THR
 

Just finished building my BitX40 after playing with the circuit for a few weeks. Early tests on mine suggested that using the small booster I have and raising the PA voltage from around 14 to 24 did seem to increase the power by the square of the voltage ratio, so matching these experiences. Admittedly, I was trying to read this on a 450w dummy load meter, and yelling into the mic, s not very accurate. So this past weekend I did get a QRP wattmeter that could read 30w as full scale and get a better idea of how much I am increasing.

However, now when I apply 24v to the final the power output actually drops from 6w to 4w! The only significant cuircuit difference is that I am now running the other 2 power connections (main board and Raduino) through a 7812 regulator, and since it is not getting quite enough to regulate to 12v, it is delivering about 11.5v to those boards, which I assumed was just a bit safer. The voltage booster is not dropping voltage under load, so I am befuddled as to why the power actually drops when I apply the higher voltage. I did recheck the PA bias and raised it up closer to 100ma, but I notice it slowly increases from wherever it is set if I continue to hold the PTT. Any ideas? Perhaps I should short the input to the output of the little 7812 to see if that actually had an effect.

=Vic=

Re: #ubitx-help Strong Audio Tones in and outside audio receive passband #ubitx-help

John <passionfruit88@...>
 

Yes it has only been reported in two units so far. So it should not be a show stopper for anyone.

The radio is usable and I will simply add an audio low pass filter if need be.

For a radio aimed at experimenting it is as expected. I am certainly not complaining.

One point of clarification though. The disappearance of the tones within the passband is due to changing the Arduino, not mounting it on extension leads.

 

So I believe there were two (probably unrelated) issues, one with the Arduino which is resolved and the second one still present.

Thank you everyone for your feedback. I will digest all this and do more experimenting.

73, John (VK2ETA)

Re: uBITX woes, feeling disheartened. #ubitx

Jerry Gaffke
 

Read this old post, you should be able to follow along with your vom:
    https://groups.io/g/BITX20/message/40808


On Sun, Feb 4, 2018 at 12:31 pm, @AC8XZ wrote:
hello; ok I'm getting no 12 volts at D7 with ptt on and vom leads one on both des. sure do appicate all the help. so with no power at d7,where do I check next 73's de

Re: Higher voltage for Bitx40 Final

Jerry Gaffke
 

11.5v should be fine, make sure it is still 11.5 when PTT is pressed.
Quiescent IRF510 drain current changing somewhat as they get warm is normal

The drop from 6w to 4w when V+ to the IRF510's is bumped from 12v to 24v is very weird.
Have you tried simply switching the IRF510 V+ between the two with exactly the same setup, same instrumentation?
Hate to say it, but my first guess would be pilot error.


On Sun, Feb 4, 2018 at 01:10 pm, Vic WA4THR wrote:
Just finished building my BitX40 after playing with the circuit for a few weeks. Early tests on mine suggested that using the small booster I have and raising the PA voltage from around 14 to 24 did seem to increase the power by the square of the voltage ratio, so matching these experiences. Admittedly, I was trying to read this on a 450w dummy load meter, and yelling into the mic, s not very accurate. So this past weekend I did get a QRP wattmeter that could read 30w as full scale and get a better idea of how much I am increasing.

However, now when I apply 24v to the final the power output actually drops from 6w to 4w! The only significant cuircuit difference is that I am now running the other 2 power connections (main board and Raduino) through a 7812 regulator, and since it is not getting quite enough to regulate to 12v, it is delivering about 11.5v to those boards, which I assumed was just a bit safer. The voltage booster is not dropping voltage under load, so I am befuddled as to why the power actually drops when I apply the higher voltage. I did recheck the PA bias and raised it up closer to 100ma, but I notice it slowly increases from wherever it is set if I continue to hold the PTT. Any ideas? Perhaps I should short the input to the output of the little 7812 to see if that actually had an effect.

Re: ubitx receive audio troubleshooting

Mike Lichtman
 

Craig,
Just to eliminate audio vibration feedback (microphonics), disconnect an internal speaker and try and external one a short distance away from the circuit board and mic. 73 Mike KF6KXG

Re: ubitx receive audio troubleshooting

Nigel G4ZAL
 

If using an external speaker, make sure it has a stereo plug (not a mono one).
I mistakenly plugged a mono plug external speaker in and it squealed.

Re: I did it again.. i plugged the arduino pins on reverse

rlawson695@...
 

ok here is the entire problem.  
 When I press PPT hear click from relay.don't know which one. receive stops and TX comes up on screen. when I release PPT it goes back into recevive. My watt/swr meter is on the frzz. so I don't know if I have power out. also when I press I hear pop thur earphones, but belive that's normal. Iwill try things in youe  post,later tonight.         73's de AC8X

Re: uBITX woes, feeling disheartened. #ubitx

rlawson695@...
 

hello ok when I push PPT the rec will drop out and TX will show up on screen. I hear a relay clicking when I release the PPT it will go back in rec. I can't tell which relay is clicking.MY watt/swr meter is on the fizz so I can't tell if there any power going out. I will try what you posted after Super Bowl is over.  73's de AC8XZ

Anyone (US Only for now) need a uBITX Raduino repaired? #ubitx

Jim Sheldon
 

This is only for uBITX owners in the US right now as I don't want to get into the hassle of International shipping of repaired equipment as I am not sure how foreign customs handles repaired stuff duty and VAT wise and I don't have time to research it.  Also, international shipping rates from the US to other countries are extremely high so it isn't really practical.

Background - I just finished designing and building a Raduino test fixture that allows me to look at all the signals coming out of the board and also hook up all the digital controls to the board.  I have the equipment here to replace the Si5351 clock chip if it is bad and I can also replace a bad Nano (you provide the Nano).

Not sure how long I'll be able to offer this but I know there are a few of you out there that have somehow blown up your Raduino's and you can't easily get a new card yet.

For now, DO NOT send me your Raduino in need of repair without first contacting me outside of this group and discussing the problem with me.  I may refuse to work on it if it appears too badly damaged - that's at my discretion. 

The reason I built the test set was I blew up my own Raduino and with no new boards available it was either fix it or trash a completely good radio. 

The offered service is ONLY Raduino repair, not complete uBITX repair - that I don't have the desire to even think about.

Contact me via my QRZ address (email is listed there as well) if you are in need of Raduino repair service.

Jim Sheldon, W0EB
Park City, KS, USA

Re: uBITX woes, feeling disheartened. #ubitx

Arv Evans
 

If you look at the schematic you can see that D7 is directly across the windings of relay K1.  The cathode
end is connected directly to +12V.  The other end is connected to the collector of Q15.  If you do not have
+12V at the cathode of D7 you should check for +12V on pin-1 of your power plug.  If no +12V there you
may not have the power supply ON or it is not connected to the power plug.   Scroll down for more
troubleshooting suggestions.


​If you have +12V at the power plug but not +12V at the cathode of D7 you should trace the +12V from
power plug to the cathode of D7 by following the +12V through your power switch and back to the
+12V connection (RED wire) which is on P1 on your uBITX main circuit board.    At P1 the red wire
should have +12V.  With the PCB disconnected from power and the Raduino board unplugged you
can measure continuity from the RED wire (+12V) on P1 to the cathode of D7.

Connecting +12V to your uBITX is a bit complex if you are not used to following schematic drawings
and doing a little circuit tracing as you go. 

This excerpt is from the uBITX Wire up instructions on the web page:
  • Solder the 1N4007 diode across the DC connector. The ring of the diode should go to the
    positive tab of the DC connector, the other side of the diode goes to the ground tab. (See
    the picture below)
  • Solder the DC cable’s red and brown wires together to the positive lug of the DC connector
  • Solder the black wire to the ground.


It might be easier if this section of the Wire up instructions said something like this:
  • The red wire provides power to all uBITX circuit except the transmit power amplifier. 
    The brown wire is for power to the transmit power amplifier section.

  • The Red (+12V) wire and transmit +12V (brown wire) can be connected together by
    connecting both brown and red wires together on the cable connecting to P1.  Do this if
    you are running your transmit power amplifier section from the same +12V supply as the
    rest of your uBITX transceiver.

  • If running the transmit power amplifier section from a separate supply you should use
    the brown wire only for that purpose.  Do not connect the brown and red wires together if
    using separate power for the transmit power amplifier section.
    NOTE:  If you use the red +12V wire through the power switch and connect the brown +RF PA
    power directly from the power connector to P1 on your uBITX PCB, the transmit section
    will be powered even when your front panel power switch is OFF.


  • The loose diode provided with the uBITX connects between +12V (cathode end) and
    ground (anode end).  This is a reverse-voltage protection diode that should short if power
    is accidentally connected backwards.

  • The ground tab on your uBITX power connector should connect directly to uBITX P1
    via the black wire.  This is the ground for all uBITX circuits and should be reasonably
    short to minimize possibility of ground-loops.  If using a metal chassis you should add
    a black wire between the power connector ground tab and chassis ground. 


​This may, or may not, help. 

Arv K7HKL
_._



On Sun, Feb 4, 2018 at 2:16 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:
Read this old post, you should be able to follow along with your vom:
    https://groups.io/g/BITX20/message/40808


On Sun, Feb 4, 2018 at 12:31 pm, @AC8XZ wrote:
hello; ok I'm getting no 12 volts at D7 with ptt on and vom leads one on both des. sure do appicate all the help. so with no power at d7,where do I check next 73's de


RD16HHF1 in the uBITX #ubitx

Nick VK4PP
 

HI Group.
I have been searching and reading topics with regards to using the RD16HHF1 in the uBITX.
So far I have only been able to find suggesstions, but no actual implementations...

I was testing my uBITX and getting 9w on 40m but only 1W at 10m...
Would love to have 5w + higher up.

Can anyone provide more info/help?

Thanks.
73, Nick VK4PLN

Re: #ubitx-help Strong Audio Tones in and outside audio receive passband #ubitx-help

John Backo
 

Jerry is right.

This is a rather rare effect involving only a few nanos.
The use of a ceramic resonator would surely contribute to
the problem. The best solution is to replace the nano (maybe with a real one?).
The new one would most probably not have the problem...Alternatively,
one could build one's own version with a UNO (or other arduino) and check out how that works.

In any event, it comes down really to replacing with a better unit, or shielding
the offending signal away. I suspect many problems would disappear with
good shielding and short shielded leads, (which incidentally is among the
recommendations of Farhan also).

One could spend a lot of time figuring out just where the RFI is coming from.
but to what end? The important thing is to have a rig which communicates.
Finding a proper VFO is easy enough...but to each his own; some are intrigued by
just what is happening and are not satisfied until they know all. Fine enough.

john
AD5YE

Re: BITX QSO Afternoon/Night, Sunday, February 4, 3PM/7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere

Tom VE3THR
 

so looks like this afternoon was a bust, is there anybody going to stick around tonight 7pm / 0000Z ? There is a pile of AM broadcasters coming in up here tonight, playing around under 200 right now. When and where?

Re: RD16HHF1 in the uBITX #ubitx

John Backo
 

PA1FOX has done this, but I don't think he has
posted detailed results yet. (He has promised
to do so).

I have some, but have not gotten around to finding out what
they do. It looks very good, though.

john
AD5YE

Re: RD16HHF1 in the uBITX #ubitx

M Garza <mgarza896@...>
 

I am still waiting for mine.  Second order, last oder sat for over a week until I asked about them and was told they were out of stock...

So much for customer service.

Marco - KG5PRT 

On Feb 4, 2018 6:04 PM, "John Backo" <jabac@...> wrote:
PA1FOX has done this, but I don't think he has
posted detailed results yet. (He has promised
to do so).

I have some, but have not gotten around to finding out what
they do. It looks very good, though.

john
AD5YE



Re: RD16HHF1 in the uBITX #ubitx

John Backo
 

the Parts Place is a good place to get some. But they are now on back-order.

Also, it is noted that the prices have increased (~$US5.00 for RD16HHF1).
It looks like the market is catching up with what amateurs are realizing in
the capacity of these devices. Hi.

john
AD5YE

Re: RD16HHF1 in the uBITX #ubitx

M Garza <mgarza896@...>
 

That is where I placed my second order.  The other place was closer and I should have had them in a couple of days...  oh well.

Marco - KG5PRT 

On Feb 4, 2018 7:01 PM, "John Backo" <jabac@...> wrote:

the Parts Place is a good place to get some. But they are now on back-order.

Also, it is noted that the prices have increased (~$US5.00 for RD16HHF1).
It looks like the market is catching up with what amateurs are realizing in
the capacity of these devices. Hi.

john
AD5YE



Re: uBITX woes, feeling disheartened. #ubitx

William Londree
 

Arv,

I am glad you went to the trouble to post this. I have been puzzling how to do this myself because the switch connection did not make sense to me. Your sketches reflect the way I thought I should do it. Thanks for confirming for me.

73

Bill  W6SDI

Re: uBITX woes, feeling disheartened. #ubitx

Arv Evans
 

Bill

Glad my own uBITX work could be of value to someone else.

Arv
_-_




Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: William Londree <ventura_bill@...>
Date: 2/4/18 6:29 PM (GMT-07:00)
To: BITX20@groups.io
Subject: Re: [BITX20] uBITX woes, feeling disheartened.

Arv,

I am glad you went to the trouble to post this. I have been puzzling how to do this myself because the switch connection did not make sense to me. Your sketches reflect the way I thought I should do it. Thanks for confirming for me.

73

Bill  W6SDI

Re: #ubitx-help Strong Audio Tones in and outside audio receive passband #ubitx-help

Dave Bottom <ars.kd6az@...>
 


Genuine Nano with Quartz Crystals.  Replacing the Nano to remedy high frequency audio tone.

The official Arduino site says they are out of stock, however I found that the RobotDyn Nano ATmega328 (without headers installed) that has Quartz Crystals 12MHz USB and 16MHz ATmega328.
Without headers installed I can sacrifice the existing Nano without risking damage to the Radunio main PCB.

It is available on Amazon for $6.49.  Free Delivery if you have Amazon Prime.  

I just ordered one so I should be able to try it out replacing the current Nano on Tuesday before I head to Orlando for Hamcation. on Thursday morning.

Dave WI6R



On Sun, Feb 4, 2018 at 3:55 PM, John Backo <jabac@...> wrote:
Jerry is right.

This is a rather rare effect involving only a few nanos.
The use of a ceramic resonator would surely contribute to
the problem. The best solution is to replace the nano (maybe with a real one?).
The new one would most probably not have the problem...Alternatively,
one could build one's own version with a UNO (or other arduino) and check out how that works.

In any event, it comes down really to replacing with a better unit, or shielding
the offending signal away. I suspect many problems would disappear with
good shielding and short shielded leads, (which incidentally is among the
recommendations of Farhan also).

One could spend a lot of time figuring out just where the RFI is coming from.
but to what end? The important thing is to have a rig which communicates.
Finding a proper VFO is easy enough...but to each his own; some are intrigued by
just what is happening and are not satisfied until they know all. Fine enough.

john
AD5YE






--
73 Dave WI6R