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Re: Bitx40 - Not Transmitting #bitx40help #bitx40

Timothy Fidler
 

Gary , JG has done a v good job of pointing out where you are at the moment. My tuppence worth and this is not very systematic is that if relay K1 has failed or the PTT line is not getting earthed properly? then you would see Rx and no Tx.? This could be from the relay not getting power or the relay failing in the coil (or mechanically) or? one of the components across the relay coil being in partial short and stealing power from the coil (unlikely as for this to be valid there would have to be a common decent resistance somewhere to cause the voltage to pull down.... but then this is all magic - it worked, it don't work. Electrons have changed their mind) .? ?You could first check power is avail to the relay K1 (not K2)



And if it is then put a screwdriver on the case and to your ear? and listen to? hear it pull in as PTT goes low.? (this crudity? avoids probing the PCB too much ) .? My guess is it may not.? If it does then you need to check the Tx? line is getting power.? If yes, then it was a good idea at the time and the best idea is to fish around on the site in particular the repository run by Mike to see where the list of voltage test points and voltages is.? Mostly these relate to uBitx but you might find a Bitx40 one.? ?Good luck?
Re: Bitx40 - Not Transmitting #bitx40help #bitx40

 

Thank you , Jerry.

I am going to try a completly new mike, including the wires to the jumper on the main board.

I also thought that I could try a CW transmission test if I wire up the CW keyer. ???

PS with regards to the Pop sound that when transmitting, it is not as loud as it used to be.
When i key the PTT it does switch off the receiving and I can hear a sort of a click sound as the speaker goes quiet.
I suppos this is because the audio transmitt is not making it through.

Thank you for your help so far.

I am a beginner on the electronics side with only self taught skills.

73
Gary
ZS5GI
Re: Antuino - the antenna analyzer

 

Farhan,

OK. so best thought of as a basic spectrum analyzer
Has a return loss bridge up front to measure SWR.
Not weird at all.
But does look very cheap and buildable.

I've been thinking of building a spectrum analyzer along those lines for a couple years now.
Snow on the ground here and it's darn cold, could be a good time for it.

The fact that this thing had to be small enough to fit into the cubesat
suggests it's still in there, flying madly about the earth.
And that you are using it to verify that some 440mhz antenna?
didn't get eaten by space aliens?

Jerry


On Thu, Dec 27, 2018 at 10:28 PM, Ashhar Farhan wrote:
The circuit here uses a resistive return loss bridge. the clock 1 drives the bridge through the R22 to a low level of -10dbm. If the bridge is perfectly balanced (that is, the antenna, R21, R29, R16, all the four are the same ohms), then, there will be no RF developed across pins 3 and 4 of the ADE mixer.?
..........
So, the ADE-1 mixer, Q2, Q1 together form a very simple superhet receiver with 25 MHz IF andCLK2 as the local oscillator. The RF at the IF is directly detected and converted to db range with the AD8307. This simple configuration makes this a very powerful instrument.
Re: Bitx40 - Not Transmitting #bitx40help #bitx40

 

That sounds like a broken mike connector.

Since it receives, the si5351 on the Raduino is doing everything it needs to on transmit.

When the Bitx40 transmits, it switches off power to the receiver audio amp
and turns on power to the transmitter audio amp for the mike.
This switching of power causes a quick surge of audio signal into the modulator
as the caps charge, and causes the characteristic Bitx pop which you see
on the meter.? So the transmitter is working from the modulator on out to the antenna.
All that's left is the mike amp, the mike, and the wires between.

Since you replaced the main board (and thus the mike amp) and also replaced the mike,
that leaves us with just the wires between.? Or perhaps you now have two bad mikes?

Could try driving the mike amp (or even the modulator directly) with some other source of audio.
Mike amp wants to see maybe 50mv pk-to-pk going in from the mike.

Jerry, KE7ER


On Thu, Dec 27, 2018 at 10:53 PM, <Gary.ingle@...> wrote:
Bitx40 - was working, but now does not transmit audio.

The device was working well with many QSOs on 40m.
All of a sudden it does not transmitt any audio.
Receiving is excellent.

To test or trouble shoot I did the following.
I attached a rf power meter to the rf out and noted that on transmission the needel jumped up initially and immediatly dropped to nil.
I suspected the microphone so I replaced it and got the same result.

It seems as though the audio is not getting into the system to trigger the carrier signal and trigger the transmitter.
(I have very limited knoledge so may be off, but this is my assumption)

I also replaced the main board (not audrino and LCD) as I had a spare - same results

Does any one have any ideas on what to test or how to trouble shoot further.

Regards
Gary
ZS5GI
Re: Antuino - the antenna analyzer

 

The AQRP Vector Impedance Analyzer, kit #25 towards the bottom of this webpage:
? ??
does something similar, but at audio frequencies.?
K5BCQ also did the AGC and PopFix kits for us.

Drives the antenna with a square wave? from an si5351 at the target frequency, detects the
voltage and current at the antenna port using two SA612 mixers with a local oscillator
that is 4khz away?from the target frequency.? The two resulting audio channels (for voltage
and current, relative phase is important) are digitized and inspected by DSP algorithms
on an ARM processor.? The algorithms filter the 4khz audio for inspection, discarding?
all the crud due to harmonics and other random signals.

The W5BIG AIM VIA does much the same thing, and comes with a very clear description:
? ? ?
Used DDS chips because the precise PLL tuning at reasonable cost offered by the si5351
and friends was not yet available.??

The AQRP VIA has managed to extend the technique for use as a 2 port network analyzer.
And uses si5351 harmonics to operate up through 440mhz, similar to your creation.

Jerry, KE7ER
Bitx40 - Not Transmitting #bitx40help #bitx40

 

Bitx40 - was working, but now does not transmit audio.

The device was working well with many QSOs on 40m.
All of a sudden it does not transmitt any audio.
Receiving is excellent.

To test or trouble shoot I did the following.
I attached a rf power meter to the rf out and noted that on transmission the needel jumped up initially and immediatly dropped to nil.
I suspected the microphone so I replaced it and got the same result.

It seems as though the audio is not getting into the system to trigger the carrier signal and trigger the transmitter.
(I have very limited knoledge so may be off, but this is my assumption)

I also replaced the main board (not audrino and LCD) as I had a spare - same results

Does any one have any ideas on what to test or how to trouble shoot further.

Regards
Gary
ZS5GI
Re: Antuino - the antenna analyzer

 

jerry,

first, thanks. there is substantially your code in there.

second, onto the circuit. it uses two clocks. not three. the third is a spare output. more on that later.

the circuit here uses a resistive return loss bridge. the clock 1 drives the bridge through the R22 to a low level of -10dbm. If the bridge is perfectly balanced (that is, the antenna, R21, R29, R16, all the four are the same ohms), then, there will be no RF developed across pins 3 and 4 of the ADE mixer. Under ideal match conditions, there is no RF across the R26. As the mismatch increases, so does the RF across R26.?

We could directly detect the voltage across the R26 with a diode detector. This is quite a popular configuration with most of the simple resistive kind of SWR bridges (like the one designed by Dan Tayloe). This simplicity comes at a cost. The problem is that the detector responds to all the RF between the arms. For instance, if another ham down the block starts to transmit, that energy will show up across the R26 and you will get crazy SWR. I had that problem with broadcast FM showing up on my 7 MHz dipole! Even if there was no RFI from elsewhere, harmonics and spurs from your own transmission can show false readings.?

Here is an example: a 7 MHz transmitter with a 14 Mhz harmonic that is 20 db down is connected to a 7 MHz dipole. The dipole is perfectly tuned to show 1:1 SWR, hence, it should show no RF across R26. However, as the antenna is reflecting back the 14 MHz energy, the 14 MHz shows up across the R26.

What's the solution to get a clean dip?The solution is to substitute a simple detector like a diode detector with a simple receiver that is tuned exactly to the frequency that you want to measure the antenna at.

So, the ADE-1 mixer, Q2, Q1 together form a very simple superhet receiver with 25 MHz IF andCLK2 as the local oscillator. The RF at the IF is directly detected and converted to db range with the AD8307. This simple configuration makes this a very powerful instrument.

Here are things you can do with it:
1. Switch off the CLK1, now you have a receiver that can very accurately measure RF levels at any specific frequency in db range. For instance, you connected your transmitter with a suitable RF attenuator to P3, you can tune to various harmonics and measure them very accurately. If you inject a two tone signal into an amplifier, you could easily measure the IMD and IIP3.?
2. With the CLK1 on, the instrument now measures the return loss. you can measure the SWR of an antenna, S11 parameters of an amplifier, filter, etc.
3. With CLK1 off, CLK 2 on, the CLK2 can now tune to the frequency tuned in by the receiver's LO (CLK0). By connecting a device/filter between P3 and P4, you can sweep it to measure the gain, frequency reponse.
4. As the diode mixer (ADE-1) has harmonic response, a local oscillator at 135 MHz, will also convert a 430 MHz signal into 25 MHz IF (430 - (135 x 3)). This is possible because we are driving the diode mixer with a square wave from the Si5351 and the local oscillator at 135 MHz also has a 405 Mhz harmonic in it. Hence, the range of this instrument extends to UHF.

The ADE-1 mixer is quite similar to the ubitx mixers. You could even use ubitx kind of discrete version of a diode mixer, it doesn't work too well beyond 50 MHz. The pins 4 and 3 of the ADE-1 are the primary winding of the RF-input side transformer. The documentation recommends that we must ground 4, but that is not essential. We need a differential drive between those two pins, that is what the bridge provides anyway.?

73, f

On Fri, Dec 28, 2018 at 11:05 AM Jerry Gaffke via Groups.Io <jgaffke=[email protected]> wrote:
Hmm.
Someday, you will have to tell us how it works.
"works on hetrodyne principle" does not quite do it.
Nor does digging around in your code.
That thing isn't on the HF bands, is it?

Curious that it takes all three clocks from the si5351 to measure SWR.
The Bruene bridge, MoniMatch, TandemMatch, and all those other bridges they sell
do it with zero clocks, and some can be quite a bit smaller than all of this.
What do P4 and P3 connect to???
At what frequency is the antenna system operating?
At what frequency are the three si5351 clocks?
And last but not lest, what the devil is going on around that ADE-1 mixer?

Is that spare raduino now circling the earth, waiting to drop on our heads?
If we catch it, do we get to keep it?

Regardless, very curious, and very cool.

Jerry, KE7ER



On Thu, Dec 27, 2018 at 08:28 PM, Ashhar Farhan wrote:
peeps,
?
while trying to measure the swr on the cubesats, i figured i couldnt use any of the analyzers i had access to. they were simply too big to be stuffed inside a 10 cm cube. my simple resistive bridge was too insensitive for any reasonable work. so, i sat down and made an antenna analyzer from a spare raduino.?
?
the code is wobbly and just about enough to get my work done. it works on a superhet principle. this is not my clever idea, rahul had mentioned this approach taken by a russian builder. i havent seen the original design. it would be interesting if rahul or someone can point me in the right direction.
?
the code and a pdf of the circuit is on?. i am attaching the circuit for the lazy bones.
?
have a great holiday and get some dx !!
?
Re: Antuino - the antenna analyzer

 

Jerry,

I remember Farhan mentioning that the clock out of the Si chip is not clean and
will cause wrong readings due to harmonics. To solve this, mix down and pass
through a filter and then take the reading which will not have harmonics? reflection
factored in!

Raj

At 28-12-18, you wrote:

Hmm.
Someday, you will have to tell us how it works.
"works on hetrodyne principle" does not quite do it.
Nor does digging around in your code.
That thing isn't on the HF bands, is it?

Curious that it takes all three clocks from the si5351 to measure SWR.
The Bruene bridge, MoniMatch, TandemMatch, and all those other bridges they sell
do it with zero clocks, and some can be quite a bit smaller than all of this.
What do P4 and P3 connect to??
At what frequency is the antenna system operating?
At what frequency are the three si5351 clocks?
And last but not lest, what the devil is going on around that ADE-1 mixer?

Is that spare raduino now circling the earth, waiting to drop on our heads?
If we catch it, do we get to keep it?

Regardless, very curious, and very cool.

Jerry, KE7ER



On Thu, Dec 27, 2018 at 08:28 PM, Ashhar Farhan wrote:
peeps,
?
while trying to measure the swr on the cubesats, i figured i couldnt use any of the analyzers i had access to. they were simply too big to be stuffed inside a 10 cm cube. my simple resistive bridge was too insensitive for any reasonable work. so, i sat down and made an antenna analyzer from a spare raduino.
?
the code is wobbly and just about enough to get my work done. it works on a superhet principle. this is not my clever idea, rahul had mentioned this approach taken by a russian builder. i havent seen the original design. it would be interesting if rahul or someone can point me in the right direction.
?
the code and a pdf of the circuit is on . i am attaching the circuit for the lazy bones.
?
have a great holiday and get some dx !!

Re: Antuino - the antenna analyzer

 

My ADE-1 document just says that pins 1,4,5 are all ground,?
3 is RF, 6 is LO, and 2 is IF. out.
Your schematic suggests that 4 is only the "ground" for the RF port,
and is not connected to the other two ground pins internally.

I suppose R21,R29,R16, and an antenna on P3 would form a balanced
bridge when the antenna is 50 ohms, CLK1 is driving the antenna and the top of the bridge.
The ADE-1 RF port sees any imbalance across the bridge.
CLK2 into the LO port is 25mhz above (or below) CLK1.

Still no idea what CLK0 and P4 are up to.

Jerry


On Thu, Dec 27, 2018 at 09:35 PM, Jerry Gaffke wrote:
And last but not lest, what the devil is going on around that ADE-1 mixer?
Re: Antuino - the antenna analyzer

 

Hmm.
Someday, you will have to tell us how it works.
"works on hetrodyne principle" does not quite do it.
Nor does digging around in your code.
That thing isn't on the HF bands, is it?

Curious that it takes all three clocks from the si5351 to measure SWR.
The Bruene bridge, MoniMatch, TandemMatch, and all those other bridges they sell
do it with zero clocks, and some can be quite a bit smaller than all of this.
What do P4 and P3 connect to???
At what frequency is the antenna system operating?
At what frequency are the three si5351 clocks?
And last but not lest, what the devil is going on around that ADE-1 mixer?

Is that spare raduino now circling the earth, waiting to drop on our heads?
If we catch it, do we get to keep it?

Regardless, very curious, and very cool.

Jerry, KE7ER



On Thu, Dec 27, 2018 at 08:28 PM, Ashhar Farhan wrote:
peeps,
?
while trying to measure the swr on the cubesats, i figured i couldnt use any of the analyzers i had access to. they were simply too big to be stuffed inside a 10 cm cube. my simple resistive bridge was too insensitive for any reasonable work. so, i sat down and made an antenna analyzer from a spare raduino.?
?
the code is wobbly and just about enough to get my work done. it works on a superhet principle. this is not my clever idea, rahul had mentioned this approach taken by a russian builder. i havent seen the original design. it would be interesting if rahul or someone can point me in the right direction.
?
the code and a pdf of the circuit is on?. i am attaching the circuit for the lazy bones.
?
have a great holiday and get some dx !!
?
Re: Antuino - the antenna analyzer

 

I gratefully acknowledge the latest sch and firmware, Fahan jee,
I had a golden opportunity to hear the circuit explanation during the 9th Dec 2018 eyeball meet of Lamakan amateur radio club? direct from you.
regards
sarma
vu3zmv
?


On Fri, Dec 28, 2018 at 9:58 AM Ashhar Farhan <farhanbox@...> wrote:
peeps,

while trying to measure the swr on the cubesats, i figured i couldnt use any of the analyzers i had access to. they were simply too big to be stuffed inside a 10 cm cube. my simple resistive bridge was too insensitive for any reasonable work. so, i sat down and made an antenna analyzer from a spare raduino.?

the code is wobbly and just about enough to get my work done. it works on a superhet principle. this is not my clever idea, rahul had mentioned this approach taken by a russian builder. i havent seen the original design. it would be interesting if rahul or someone can point me in the right direction.

the code and a pdf of the circuit is on?. i am attaching the circuit for the lazy bones.

have a great holiday and get some dx !!

- f
Re: Correct for Nextion display width & fill 2.8" screen

 

I fear , whether the hmi files there in may not fill in 3.2 and 3.5 displays, even though ewe can see the screens as reduced to 2.8 on a bigger screen.
regards
sarma
vu3zmv


On Fri, Dec 28, 2018 at 3:09 AM Evan Hand <elhandjr@...> wrote:
Try this site:


73
Evan
AC9TU

Re: The K5BCQ AGC and PopFix schematics as pdf's, list of parts from Mouser

 

As I recall, Kees was using EasyEDA.
They have an easy to use tool chain for schematics and gerbers.
Also a very reasonably priced fab service to build the boards.

Jerry



On Thu, Dec 27, 2018 at 08:56 PM, Jerry Gaffke wrote:
Kees also left gerber files in his directory, so if somebody wanted to build their own they could.
Should be possible to send them out to OSHPark here in Oregon, get boards in a few days.
However, I believe his gerbers are for lots and lots of boards in one big sheet, must be cut up by hand.
Perhaps new gerbers could be made for individual boards?
The K5BCQ AGC and PopFix schematics as pdf's, list of parts from Mouser

 

The AGC and PopFix kits are no longer being sold by Kees.
He had a run of nearly 1000 of each, and has moved on to other things.

But there still seems to be plenty of need for those boards.
Hopefully v5 of the uBitx will include these enhancements.

Kees left the schematics for those two boards in the K5BCQ directory of our files section,
? ??/g/BITX20/files/K5BCQ
but they are in an "emf" file type, which is some goofy MicroSoft thing.
I used a web utility to convert them to pdf's, since pdf's can be read on most anything.
Those pdf's are attached to this post.
Hopefully Kees will copy them to his K5BCQ directory.?

Kees also left gerber files in his directory, so if somebody wanted to build their own they could.
Should be possible to send them out to OSHPark here in Oregon, get boards in a few days.
However, I believe his gerbers are for lots and lots of boards in one big sheet, must be cut up by hand.
Perhaps new gerbers could be made for individual boards?

All the parts are quite common, easy to get on Mouser or Digikey.

Here's a list of parts, quantities are for both boards together, looks good but not verified:
Prices are around a $0.10 each for semiconductors, $0.05 for caps and resistors,? if buying 10 at a time.
Columns are:? quantity,? generic part number,? package,? Mouser part number.

2? 1N4148W? ? SOD-123? ??
1? MMBT3904? ?SOT-23? ??
5? 2N7002? ?SOT-23? ? ? ? ?
5? 10nF? ? ? ? 0805? ? ? ? ? ? ?
2? 100nF? ? ? 0805? ? ? ? ? ? ?
4? 1uF? ? ? ? 0805? ? ? ? ? ? ? ?
1? 1k? ? ? ? ? ?0805? ? ? ? ? ? ? ?
2? 10k? ? ? ? ?0805? ? ? ? ? ? ? ?
7? 100k? ? ? ?0805? ? ? ? ? ? ? ?
3? 330k? ? ? ?0805? ? ? ? ? ? ? ?
1? 1meg? ? ? 0805? ? ? ? ? ? ? ?

Again, this list has not been checked, but should be about right.
Part characteristics are not critical so long as you get the correct size part for the board Kees created gerbers for.

So long as you are paying shipping from Mouser, may as well get some other parts:
Maybe a dummy load using a bunch of? 283-510-RC? or 283-200-RC
And/Or build a diode RF probe using? ?621-1N5711W-F? ? or? ?511-1N5711

All of this stuff can be bought cheaper from shops in China, including board fab.
Instead of getting just the 0805 resistors needed, could get a kit of common values
for about $15, typically 30 each of 50 values.? Same with 0805 caps.
That 0805 device size is in imperial units,? so 0.080 inches long by 0.050 inches wide.
The 0805 parts fit well enough the bigger 1206 pads used by HFSignals.?

Jerry, KE7ER

Automatic_Gain_Control.pdf
Automatic_Gain_Control.pdf
RXTX_Click_Noise.pdf
RXTX_Click_Noise.pdf

Antuino - the antenna analyzer

 

peeps,

while trying to measure the swr on the cubesats, i figured i couldnt use any of the analyzers i had access to. they were simply too big to be stuffed inside a 10 cm cube. my simple resistive bridge was too insensitive for any reasonable work. so, i sat down and made an antenna analyzer from a spare raduino.?

the code is wobbly and just about enough to get my work done. it works on a superhet principle. this is not my clever idea, rahul had mentioned this approach taken by a russian builder. i havent seen the original design. it would be interesting if rahul or someone can point me in the right direction.

the code and a pdf of the circuit is on?. i am attaching the circuit for the lazy bones.

have a great holiday and get some dx !!

- f

antuino.png

Re: Bitx40 for visually inconvenienced ham #bitx40

 

I've seen that in the flesh and it is impressive.

Andy worked with a blind ham to make it work well?and be easily
used.? The base machine is Raduino with add ons and the whole
of its is available (see the site).

Allison
Re: Bitx40 for visually inconvenienced ham #bitx40

 

Correction:
The QCX CW Transceiver does not have CAT control.
The QSX SSB/CW/PSK31/... Transceiver will.

The KB1OIQ hacks for the uBitx pointed to by my first link
? ??/g/BITX20/topic/17349156
look ideal for the vision impaired.
Hadn't looked into that before, impressive!

Jerry, KE7ER



On Thu, Dec 27, 2018 at 03:56 PM, Jerry Gaffke wrote:
Don't have a QCX, so can't compare the two except to say the QCX does not do SSB.
The QSX should come out someday, and will do CW and SSB, and a bunch more.
Downside is that the firmware of the QCX/QSX is closed source.
Though both have a CAT interface, should be possible to use that to make it usable
for the visually impaired.? And if not, Hans may be inclined to make it usable
once he has some time.
Re: Bitx40 for visually inconvenienced ham #bitx40

 

Kb1oiq on April 14 describes mods he made for a visually impaired ham. Look up his message here for info.

Curt
Re: Bitx40 for visually inconvenienced ham #bitx40

 

Don't have a QCX, so can't compare the two except to say the QCX does not do SSB.
The QSX should come out someday, and will do CW and SSB, and a bunch more.
Downside is that the firmware of the QCX/QSX is closed source.
Though both have a CAT interface, should be possible to use that to make it usable
for the visually impaired.? And if not, Hans may be inclined to make it usable
once he has some time.

The Bitx40 can be clean, except for this spur:? /g/BITX20/message/62326
Reports vary on whether that spur is within legal limits, but it is fairly close,
so better than the v3,v4 uBitx in that regard.
Spur can be cured with a high side vfo by going to Allard's v2 firmware and mods:
? ??


The Bitx40, like the uBitx, could use AGC and a pop fix, as per the kits that Kees?
had out in the past (but no longer has).? Worth copying that stuff into any Bitx40/uBitx.?
Could also use protection for Q13 if a nearby transmitter or electrical storm might blow it.
Somewhere in this thread, Kees talks about those kits, and where he hid all the?
design notes up in our groups.io files section:
? ??/g/BITX20/topic/nd6t_agc_implementation_for/18098324
Or look for "AGC" and "pop fix" over on ubitx.net

The best thing about the Bitx40 for this application is that it is simple and open source.
So somebody competent in programming an Arduino could make it friendly to a blind person.
Or do away with the Arduino entirely and drive it from a RasberryPi,? has the computing power
and memory available to do most anything you want.?
With an easy path to the uBitx if more bands are ever wanted.

You might take a look at some of the previous work reported in this forum:
??/g/BITX20/topic/17349156
??/g/BITX20/topic/4181753
??/g/BITX20/topic/4192181

Jerry, KE7ER?

??

On Thu, Dec 27, 2018 at 02:58 PM, Mike Short wrote:
I am looking at options for a 40M qrp radio for a mostly blind ham. He would like to have SSB and CW if possible. Ease of use is paramount.?

He has looked at the qcx40. How does the bitx40 compare?

?I will be putting together whatever we come up with.?
Bitx40 for visually inconvenienced ham #bitx40

Mike Short
 

I am looking at options for a 40M qrp radio for a mostly blind ham. He would like to have SSB and CW if possible. Ease of use is paramount.?

He has looked at the qcx40. How does the bitx40 compare?

?I will be putting together whatever we come up with.?

Mike
AI4NS
54161 - 54180 of 116646