Date   
Re: BITx 40 Frequency lock during transmit

 

David : 

You did remember to install the 0.1 uF disc cap across the tuning pot (where the yellow and violet wires attach) ? 

Michael VE3WMB 

P.S. I do also recommend upgrading the Raduino to use PE1NWLs code (it is backward compatible with the original code) as it will
give you a better tuning experience and will prevent any "FMing" on TX. 

Re: Lost audio from receiver

Jerry Gaffke
 

I think you're right, probably blew the LM386.
And nothing else.

Clipping leads and just leaving them in place sounds fine, or could 
heat them up and pull them out one by one using soldering iron and needle nose pliers.
I would not bother trying to suck the solder out of all those holes, just snip the bottom half of the legs off the new part
and solder it to the surface of the board.

An alternative is to buy some LM386 amp kit, and wire it into the existing volume control pot:
    http://www.kitsandparts.com/audioamp386v2.php


On Sun, Feb 11, 2018 at 12:52 pm, Vic WA4THR wrote:
After some other testing on a BitX40 that was working well, it is likely that 12v (or even 24v) touched one of the speaker leads. Now I have essentially no audio out from the radio. On very strong signals and at maximum volume I can hear a weak and very distorted sound out of either the speaker or a separate speaker/mic, but it is not copyable and only just recognizeable as a signal. Listening on another receiver and watching the output, transmit seems fine. It sounds clear and undistorted and the power out is pretty normal. I checked the voltages around Q16 and they are exactly as expected in receive and transmit. The suspicion to me is that the LM386 has "blown", but there are no obvious marks on the board on any components. Is there someplace else I should look before trying to replace that chip?

As to technique for repairing that IC, if it is the problem, I seem to recall a method that involved just cutting the legs off and soldering them to a new chip. Is that a viable way to go?

While I've never owned a barrel of monkees, it  is hard to imagine that could be more fun than the BitX, but I do seem to get myself in trouble playing with it.

=Vic=

Re: Blue display, white digits

Vince Vielhaber
 

That particular vendor has different sizes and orientations of the 1602 displays - even in the same color, be it black on white, white on black, white on blue, ...

As to I2C, I searched for those and the only serial that came up were 3 and 4 wire SPI. I didn't see any I2C, but you can get a PCF8574 board to convert the standard parallel to I2C. The I2C displays I bought just have that board attached to it and they work fine.

Vince.

On 02/11/2018 02:30 PM, Mike Woods wrote:
Should be plug compatible, but note that I've found that different
brands/colours of 1602 displays may be slightly differently size, so it
may be too tight or sloppy in your existing front panel cutout.

Mike ZL1AXG

On 12/02/18 6:56 AM, VE7WQ wrote:
Is this plug and play for the raduino?
3.3V/5V 16X2 1602 Character LCD Display,
White on Black,High Contrast
US$2.80 In stock
https://www.buydisplay.com/default/3-3v-5v-16x2-1602-character-lcd-display-white-on-black-high-contrast

--
Mike Woods
mhwoods@...

Re: uBITX woes, feeling disheartened. #ubitx

@AC8XZ
 

ok how about these readings;                              K1 Rec.   pin1=0volts   pin3=12volts pin5=12 volts  pin =8 12 volts  pin9=12 volts  pin12=0volts  pin14=0volts pin16=0 volts                                      K1 Trans   pin1=12  pin3=0volts  pin5=12volts  pin8=12volts  pin9=0volts  pin12=0volts  pin14=0volts  pin16=0 volts        K3 Trans.  pin1=0 volts  pin3=0 volts  pin5=0 volts  pin8=12 volts  pin9=0 volts  pin12=0 volts  pin12=0 volts  pin14=0 volts  pin16=0 volts  KT1 Trans. pin1=0 volts  pin3=0 volts  pin5=0 volts  pin8=12 volts  pin9=0 volts  pin12=0 volts  pin14=0 volts  pin16=0 volts       KT2  Trans.  pin1=0 volts  pin3=0 volts  pin5=0 volts  pin8=12 volts  pin9=0 volts  pin12=0 volts  pin14=0 volts  pin16=0 volts     KT3 Trans.   pin1=0 volts  pin3=0 volts  pin5=0 volts  pin8=12 volts   pin9=0 volts  pin12=0 volts  pin14=0 volts  pin16=0 volts.         VOM  Black to Antenna Ground    Red to pin being tested.     hope this is good readings       73's de AC8XZ

Re: Bitx40 - receiver works great, but do not transmit #bitx40help

Jerry Gaffke
 

Good advice, build a diode RF probe.
A germanium diode such as the 1n34a or 1n60 works well, but they are expensive now and hard to get.
A schottky diode (such as the Bat54s used on the Bitx40 diode mixers) works reasonably well.
A standard silicon diode such as a 1n4148 might be good enough for measuring fairly high RF power nodes 
such as at the antenna port of a working transmitter, but definitely will not see the expected RF voltage at the base of Q13.
The issue here is the forward voltage drop for small currents, perhaps 0.3v for the Schottky and 0.6v for the 1n4148.

The germanium diodes will be less than the Schottky but dependent on temperature.
The datasheet punts, and says 1 volt max at 5ma, should be good down to 100mv or so with the currents involved in an RF probe at 10megaohms:
    http://www.nteinc.com/specs/original/1N34A.pdf
    https://electronics.stackexchange.com/questions/223813/the-classic-1n34a-ge-diode-has-a-vf-of-1v-how-could-a-diode-with-such-a-high

N5ESE tries to explain the probe, but only goes so far.
That RF probe design assumes a voltmeter with an input resistance of 10megaohms,
some DVM's will have an input resistance that is considerably less.
So don't count on that probe reading RMS voltages accurately until somehow calibrated.
As the RF voltages approach the forward voltage drop across the diode it will become less and less accurate,
though can still be surprisingly useful (perhaps with a calibration chart) down to a few tens of millivolts if you have the right diode.
Also, N5ESE fails to mention that the capacitance between the probes into the DVM is an integral part of the design,
that capacitance along with his 4.7megaohm resistor forms a low pass filter so that the meter sees DC instead of rectified RF.


We should have a spare Bat54s plus cap and resistor into an analog Nano pin, 
so we can all have a common way of measuring RF voltages when debugging.
With different diodes and different voltmeters, we will all get different results and cannot usefully compare our measurements.

Jerry, KE7ER



On Sun, Feb 11, 2018 at 01:14 pm, M Garza wrote:
Since you do not have a watt meter, and you have a multimeter, you could build a rf probe.  You can see the rf voltage and calculate the wattage.
Here is a link to one you can build.  It is very easy:
 

Re: No power increase with higher voltage?

Nick VK4PP
 

HI Vic,
Interesting observations.... I am having a similar issue with my uBITX and a booster, Ill try the 24v battery solution....

73. Nik

Re: No power increase with higher voltage?

John Backo
 

Well, gentlemen, we have a true ham here.

If RF is getting back into your booster and changing the output voltage,
there are 2 solutions; either block the RF with a filter (and shielding),
or change to a linear power supply.

I like linear supplies because they are almost stone silent and
handle RF very well. But they are heavy and consume more power.

It should be a rather simple matter to block the RF back into the power
supply with an adequate filter. The problem is finding one that works
over the entire transmit range. But it can be done. Another problem
might be that your booster cannot handle the output wattage at higher
levels. You may need to replace it with something better.

Keep it up; you're doing fine.

john
AD5YE

Re: Blown by nearby transceiver #bitx40help

Joe Puma
 

Hey Jerry, I’ve had strange things like his happen to me with other equipment when transmitting even with a little Power like the bitx40.  I’ve zapped the inductors on a SpyVerter and SV1AFN upconverter, fried them completely, the spyverter has board damage too but nothing else, no other components. Heck, I’ve fried the SV1AFN a few times with my 100w radio and finally beyond repair because it killed the mixer and too many things I didn’t have parts for.  My SDR Antenna is near my long wire TX antenna I use for my Yaesu and the bitx40 when I had it. 

It happened mostly when I was tuning up, actually I think only when tuning up. And especially on 160. I’ve watched an inductor burn up right before my eyes when the tuner was chattering. Must of been throwing high voltages everywhere. RF sure is amazing lol. I’m still learning. 


Joe
KD2NFC 


On Feb 11, 2018, at 4:34 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:

From the photo, looks like a burned trace from C6 to L3.
From the Bitx40 schematic it's hard to imagine how that might have happened.
That node is isolated from other parts of the rig that might have significant DC power by multiple DC blocking caps.
RF power there should be milliwatts, even with a nearby QRO transmitter.
Even a loose wire with +12VDC on it striking that node would not blow the trace since there is no path to ground.
L3 is a toroid and thus inherently well shielded, I doubt significant RF was coupled directly into L3 somehow.

Could be that all you need to do is fix the trace.
But the cause is totally unexplained, and something with enough power to scorch a trace like that has enough power 
to blow out many other things.  Fixing this might require finding somebody with a scope and bag of spare parts.

Do let us know what parts had to be replaced once you get this fixed.
And any guesses as to how it happened.
For me at least, truly a mystery.

Jerry, KE7ER

On Sun, Feb 11, 2018 at 08:41 am, Gordon Gibby wrote:
Looks like L3, and possibly other series elements in the 40 m filter got way too much voltage. You’ll probably have to use an ohmmeter to test out each connection and see what has become non-conductive.  I suspect Q 13 got fried in the process, and there are two other transistors that would’ve been connected that might’ve been damaged as well from the schematic.  With some care, these can be replaced by ordinary 2N3904 transistors.
 

Re: Tinny sounding electric miss on uBitx

John Backo
 

Mike, Bill is probably right,

Check and adjust your BFO first. That is
almost always the reason for poor voice quality,
especially since others are using the more or
less the same setup and not reporting problems.

You will have to reload the software (maybe several times)
adjusting the BFO frequency until it sounds right. First,
use a frequency counter to find out what the present BFO
is. Record it so you can always reset it if the problem
turns out to be something different. Then find out what the
software says is your BFO and adjust it up or down by
500 Hz or so. Check the results and go from there...

It is relatively easy with a VFO, but using software makes
the job somewhat harder.

john
AD5YE.

Re: Bitx40 - receiver works great, but do not transmit #bitx40help

Joe Puma
 

I’m waiting for this to come in the mail 

image1.png



On Feb 11, 2018, at 5:08 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:

Good advice, build a diode RF probe.
A germanium diode such as the 1n34a or 1n60 works well, but they are expensive now and hard to get.
A schottky diode (such as the Bat54s used on the Bitx40 diode mixers) works reasonably well.
A standard silicon diode such as a 1n4148 might be good enough for measuring fairly high RF power nodes 
such as at the antenna port of a working transmitter, but definitely will not see the expected RF voltage at the base of Q13.
The issue here is the forward voltage drop for small currents, perhaps 0.3v for the Schottky and 0.6v for the 1n4148.

The germanium diodes will be less than the Schottky but dependent on temperature.
The datasheet punts, and says 1 volt max at 5ma, should be good down to 100mv or so with the currents involved in an RF probe at 10megaohms:
    http://www.nteinc.com/specs/original/1N34A.pdf
    https://electronics.stackexchange.com/questions/223813/the-classic-1n34a-ge-diode-has-a-vf-of-1v-how-could-a-diode-with-such-a-high

N5ESE tries to explain the probe, but only goes so far.
That RF probe design assumes a voltmeter with an input resistance of 10megaohms,
some DVM's will have an input resistance that is considerably less.
So don't count on that probe reading RMS voltages accurately until somehow calibrated.
As the RF voltages approach the forward voltage drop across the diode it will become less and less accurate,
though can still be surprisingly useful (perhaps with a calibration chart) down to a few tens of millivolts if you have the right diode.
Also, N5ESE fails to mention that the capacitance between the probes into the DVM is an integral part of the design,
that capacitance along with his 4.7megaohm resistor forms a low pass filter so that the meter sees DC instead of rectified RF.


We should have a spare Bat54s plus cap and resistor into an analog Nano pin, 
so we can all have a common way of measuring RF voltages when debugging.
With different diodes and different voltmeters, we will all get different results and cannot usefully compare our measurements.

Jerry, KE7ER



On Sun, Feb 11, 2018 at 01:14 pm, M Garza wrote:
Since you do not have a watt meter, and you have a multimeter, you could build a rf probe.  You can see the rf voltage and calculate the wattage.
Here is a link to one you can build.  It is very easy:
 

Re: Tinny sounding electric miss on uBitx

John Backo
 

Oops -- I noticed you said "tinny when
monitoring in another receiver..."

That would rule out the BFO in YOUR receiver.

It could be the voice quality of your mic amplifier.
There have been various solutions posited for
that, including Kang's replacing resistors in
the amp. He also noticed a similar thing and
posited a larger solution. See his website
Small Wonder QRP for clues.

john
AD5YE

Re: Bitx40 - receiver works great, but do not transmit #bitx40help

Jerry Gaffke
 

That's looks great if you want a high impedance probe for your oscilloscope or spectrum analyzer.
RF goes in, bigger RF at the same frequency goes out

But that is not a suitable RF probe for a DVM, where you want RF in, and a DC voltage out
that represents how strong the RF in was.

There are some similar AD8307 probes available on Ebay that I previously pointed to 
in response to one of your posts, they look much more suitable though I have not tried them.

Jerry, KE7ER


On Sun, Feb 11, 2018 at 02:45 pm, Joe Puma wrote:
I’m waiting for this to come in the mail: RF Active Probe 0.1-1.5GHz  analyzer oscilloscope

Re: Tinny sounding electric miss on uBitx

Jerry Gaffke
 

Transmit and receive are symetrical on the uBitx and Bitx40, uses the same bfo and IF filter.
Should have about the same audio characteristics on transmit as receive.

Assume the crystal filter has a passband from 11.998 to 11.996, the BFO is at 11.9955mhz
When transmitting, audio from the mike amp of 0 hz is at 11.9955mhz, audio that was 500hz is now 11.996mhz
and audio that was at 2500hz is now mixed with the BFO to create a signal at 11.998mhz.
Only stuff between 11.996 and 11.998 mhz will make it through the crystal filter.
So any audio from the mike between 500 and 2500 hz goes into the IF amp at frequencies between 11.996 and 11.998mhz.

On receive, the math is exactly the same.  The crystal filter only accepts incoming RF between 11.996 and 11.998,
when that RF is combined with our 11.9955mhz BFO we wind up with audio between 500 and 2500 hz.

Now if the BFO was at 11.9950 mhz but everything else was the same, the audio on transmit and receive
would be between 100 and 3000 hz, and perhaps sound a bit tinny.

Jerry, KE7ER


On Sun, Feb 11, 2018 at 02:49 pm, John Backo wrote:
Oops -- I noticed you said "tinny when
monitoring in another receiver..."

That would rule out the BFO in YOUR receiver.

It could be the voice quality of your mic amplifier.
There have been various solutions posited for
that, including Kang's replacing resistors in
the amp. He also noticed a similar thing and
posited a larger solution. See his website
Small Wonder QRP for clues.

Re: Tinny sounding electric miss on uBitx

Jerry Gaffke
 

<  would be between 100 and 3000 hz, and perhaps sound a bit tinny

Should be:
 >  would be between 1000 and 3000 hz, and perhaps sound a bit tinny


On Sun, Feb 11, 2018 at 03:39 pm, Jerry Gaffke wrote:
would be between 100 and 3000 hz, and perhaps sound a bit tinny.

Re: Bitx40 - receiver works great, but do not transmit #bitx40help

Joe Puma
 

Hmmm I didnt know this lol. I wanted to measure something with a RF millivolt meter that measures 8v?   So I saw that it can output a signal greater then 8v so I thought it had the range I was looking for. 

And now that you mention it I was reading my technical manual incorrectly and the voltage I was looking for is actually DC volts

image1.jpeg

I guess I will order the one that you linked me to because It’s the RF millivolts that I want to check on my radio at various test point Locations. 

And I guess I can check those DC voltages myself with my DVM now :) 

Joe
KD2NFC 


On Feb 11, 2018, at 6:28 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:

That's looks great if you want a high impedance probe for your oscilloscope or spectrum analyzer.
RF goes in, bigger RF at the same frequency goes out

But that is not a suitable RF probe for a DVM, where you want RF in, and a DC voltage out
that represents how strong the RF in was.

There are some similar AD8307 probes available on Ebay that I previously pointed to 
in response to one of your posts, they look much more suitable though I have not tried them.

Jerry, KE7ER


On Sun, Feb 11, 2018 at 02:45 pm, Joe Puma wrote:
I’m waiting for this to come in the mail: RF Active Probe 0.1-1.5GHz  analyzer oscilloscope

Re: Blown by nearby transceiver #bitx40help

Jerry Gaffke
 

Something like an airwound solenoid inductor will indeed pick up nearby RF
through magnetic coupling, perhaps enough to burn traces.   

I'd be surprised if a toroid could do that, at least with the fields we normally deal with.
A toroid has a circular field confined mostly to the donut shaped core, a magnetic field
from a nearby device would have little effect because coupling into one side of the toroid
would be nearly balanced out by coupling into the opposite side of the toroid.
On that opposite side, the toroid's internal magnetic field is pointed in the opposite direction,
but the relatively large field from your nearby equipment would be uniform across the toroid.

So does not seem likely to me.
But then I am often surprised.

Jerry


On Sun, Feb 11, 2018 at 02:38 pm, Joe Puma wrote:
Hey Jerry, I’ve had strange things like his happen to me with other equipment when transmitting even with a little Power like the bitx40.  I’ve zapped the inductors on a SpyVerter and SV1AFN upconverter, fried them completely, the spyverter has board damage too but nothing else, no other components. Heck, I’ve fried the SV1AFN a few times with my 100w radio and finally beyond repair because it killed the mixer and too many things I didn’t have parts for.  My SDR Antenna is near my long wire TX antenna I use for my Yaesu and the bitx40 when I had it. 
 
It happened mostly when I was tuning up, actually I think only when tuning up. And especially on 160. I’ve watched an inductor burn up right before my eyes when the tuner was chattering. Must of been throwing high voltages everywhere. RF sure is amazing lol. I’m still learning. 
 
 

Re: What firmware do you suggest for uBitx???

Michael Shreeve
 

Jack, I agree, the rig should be working before you do any software "mods".

If your writing your own, then, of course, change one thing at a time.

If you like most of us, not writing your own, then the following things seem to be the only important things about changes.
One, make sure the program your uploading has been tested using your hardware platform. If you've made changes to your hardware, you may be stuck with the software that came with the hardware , especially if it involves a new type of display or changing the display to I2C serial. You must be a programmer make any changes from that point on. Or, your going to be at the mercy of that programmer. But, with standard hardware, that's not a problem. You can do what you want. 

Well tested software is very important.

One thing that came up is that the eeprom in the Arduino may keep certain values from whatever version you had before. One guy offered a "eeprom wipe" , but it wasn't quite for the Nano, as it had been written for a larger Arduino. I'm fairly certain some may include a feature into new software just to make sure that isn't a problem.  Some are writing for a "change" rather than an entire new system, and I think that's how this is happening. If your worried about that, you should probably wait for things to get Ironed out. I'm so excited by the new features that I have already made some huge changes.
                                                       

On Sun, Feb 11, 2018 at 8:57 AM, Jack Purdum via Groups.Io <jjpurdum@...> wrote:
I think it's always a good idea to get the rig working with the "standard" software. Then look at a single mod you'd like to make. Making two or more mods at once complicates things if they don't work when you're done. Doing one at a time makes it easier to "undo" the mod and see what went wrong.

Jack, W8TEE



From: Paul Schumacher via Groups.Io <wnpauls=yahoo.com@groups.io>
To: BITX20@groups.io
Sent: Sunday, February 11, 2018 11:44 AM
Subject: [BITX20] What firmware do you suggest for uBitx???

Is the factory default recommended? 

Or one of the updates?

thanks,

Paul K0ZYV





--
Michael Shreeve N6GRG
15901 Cloverdale Road
Anderson, CA 96007
530-410-8678
"Don't worry about a thing, 'Cause every little thing gonna be all right!" -Bob Marley



Re: Tinny sounding electric miss on uBitx

Joe
 

I experienced similar tinny mic audio issues.  I had not realized the BFO affects both. 
After figuring out the BFO tx /rx relationship, I now just transmit and listen to my audio when transmitting.
While transmitting, I then tune the BFO 1199600 up or down until I hear the sound quality I desire.

Since I use the TFT Touch Control  display, the BFO is fully tune able from the touch display

Joe
VE1BWV



On Sun, Feb 11, 2018 at 7:41 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:
<  would be between 100 and 3000 hz, and perhaps sound a bit tinny

Should be:
 >  would be between 1000 and 3000 hz, and perhaps sound a bit tinny

On Sun, Feb 11, 2018 at 03:39 pm, Jerry Gaffke wrote:
would be between 100 and 3000 hz, and perhaps sound a bit tinny.


Re: BITX QSO Afternoon/Night, Sunday, February 11, 3PM/7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere

John P
 

Called CQ for a half hour this evening. Nothing but noise! 
--
John - WA2FZW

Re: uBITX woes, feeling disheartened. #ubitx

@AC8XZ
 

make that K1 Rec. pin3=0 volts   sorry   73's de AC8XZ