¿ªÔÆÌåÓý

  1. BITX20
  2. Messages
Expanded Topics Messages Polls
Date
Re: I need a V3 or V4 uBitx board.

Jack Purdum
 

Hi Joel:

Do you have a URL where we can find out more about it?

Jack, W8TEE

On Sunday, June 24, 2018, 1:12:24 PM EDT, Joel Caulkins <caulktel@...> wrote:


A couple of months ago I built a Steve Weber 'Slop Bucket' 20 meter Transceiver that is SSB/CW. It uses a 74HC4053, a triple DPDT analog switch driving some transistors for T/R switching. It is sweet, no clicking at all, just nice and quiet. That radio is a pleasure to use except for the hissy LM386. I guess I can't have it all my way.

Joel
N6ALT

Re: I need a V3 or V4 uBitx board.

 

A couple of months ago I built a Steve Weber 'Slop Bucket' 20 meter Transceiver that is SSB/CW. It uses a 74HC4053, a triple DPDT analog switch driving some transistors for T/R switching. It is sweet, no clicking at all, just nice and quiet. That radio is a pleasure to use except for the hissy LM386. I guess I can't have it all my way.

Joel
N6ALT
RFI from uBitx TX after AGC and other mods installed

 

I just finished installing:
1) ND6T AGC mod using Kees' kit.?
2) AGC off/med/long switch as described in ND6T's instructions
3) T/R LED (Sunil's approach)
4) An RF gain control with an on/off switch so I have front panel on/off using Sunil's enclosure.
5) A wire from J1 to the purple wire on the Digital connector for an S-meter reading

The good news is - no smoke and everything seems to be working.? But now when I transmit (so far just tried SSB), I get very loud RFI (my own garbled voice) in my headphones or speaker, so something I added is getting RF into the system.

I installed the AGC board right at the RF in/out point using the approach outlined by Kees.? I ran RG-174 to the RF gain control, grounded at the RF gain control but not grounded (per instructions) at the AGC board.

I used twisted pair for the runs from the AGC board to the audio gain pot and the +5/ground which I picked up from the green Raduino wire, tapped at the point where the green wire connects to the resistor at the Key jack.? The ground lead twisted to the +5V lead is connected to the ground "bus wire" that connects the front-panel PTT, Phones and Key jacks together.

The wires to select AGC hang time from the front panel switch are not twisted together.

Everything is connected to the AGC board using header pins and plug-in wires so I can disconnect easily from the AGC board, but not easily from the other end of the wire(s).??

Is there an obvious place to start troubleshooting this and/or since I'm already using coax and twisted pairs as recommended in ND6T's instructions, thoughts on a fix?

73,

Rowland K4XD
Keypad for Raduino...?

 

Hello

I got tired of the minimalist input button scheme for my uBITX Raduino.? Found this
on-line, and am now working on code to make use of it for a homebrewed Raduino.



More info later when I get everything working.

Arv
_._
Re: I need a V3 or V4 uBitx board.

 

Not being a mechanical engineer, I'm awfully suspicious of relays.
Especially cheap ones.
K1 and K2 can rattle quite a bit when working CW.

I'd much prefer to have K1 and K2 swapped out for solid state TR switching.
Hopefully get good CW QSK out of the deal.
The Bitx20A and Bitx17A (out of stock, perhaps permanently?) on qrpkits.com
look like they would do a good job of this.

And if I were building to my preferences,
might consider using plug in filters for the transmit LPF's.

Jerry


On Sat, Jun 23, 2018 at 11:01 pm, Glenn wrote:
I had similar problem some time ago. No Tx.? I could hear K1 pulling in but in actual fact it wasn't making contact. I replaced it with a different brand of relay and no problems since. But it does make me suspicious of the other relays in the uBITX. If they don't work then? a LPF may not be actually switching either.
glenn
Re: Raduino consumption #ubitx #radiuno

 

Curious, I still learn new stuff everyday.
I was expecting the REF pin to be high impedance.

I powered up a spare Nano??from 5v with some other project's code it it.
It draws around 17ma while the code boots,
Then after everything is initialized, it goes to 18ma.
We can expect that 18ma to vary by a few ma depending on what code is installed, but not much.

I then shorted the REF pin to ground.
Still 17ma while the code boots.
Then after a couple seconds, current from the 5v supply shoots up to 102ma and stays there.
When I remove the REF pin short to ground, the supply current then falls back to 18ma.

My code uses the ATMega328P's internal 5v rail for reference, just like all the uBitx code does.
I assume what happens is the code turns on an internal transistor switch that shorts the REF pin to 5v.
I have not tried it, but changing this line of code that gets executed during setup()
? ??analogReference(DEFAULT);
to this:
? ??analogReference(EXTERNAL);
should leave that pin in a high impedance state, and I'd expect the supply current on my Nano
to remain at 18ma even with the REF pin shorted to ground.
I may try that later today.

So, a shorted REF cap could go a long ways toward explaining why your Nano is drawing so much current.

But does not explain your 36 ohms from ground to 5V.
I measure over 1.05k on my good raduino with good Nano, and 3.1k on my spare Nano.
Neither changes when I swap my ohmmeter leads.
The Nano reading of 3.1k does not change when I short the REF pin to ground.
And your board is drawing way more than just an extra 84ma.
So you probably have a second problem on that Nano board, not just a shorted REF cap.

The Nano is tough to remove, if it comes to that.
I'd try a little rotary saw or grinder using my Dremel tool for all but the pins hiding
behind the LCD connector, then heat up those few pins on the Nano board to pull it free.
And then extract all the pins one-by-one from the Raduino.
And take care to wash all the metal bits from the Raduino.
If anybody has a better method, perhaps they could speak up.

You clearly know what you are doing, and are on the right track.
Good luck!

Jerry, KE7ER
?


Thanks for advice and links (i already looked at this ch340 datasheet but it's very short and incomplete -no data about 3v3 output voltage interval)
I've got something : only 36ohms between gnd and 5V, more than 1Kohm on a spare nano, no output data shorted to gnd or 5V
BUT only 6ohms between REF and gnd (about 3K on my spare nano) And REF pin is shown unlinked on Raduino board ->
- bad nano PCB with no space between gnd and ref
- short circuit on capacitor on the REF pin
but all that hard to check and correct without unsolder :-(
first easy thing that i can do easily is cut pcb between Atmega pin 21 and REF output of the board (but i will need later to replace the capa on the other side to enforce noise reduction on analog read)
second thing is to cut and remove this unused pin between nano and raduino (in case the short circuit is on the raduino solder part)
i will keep you informed
73 - Remi
Re: Raduino consumption #ubitx #radiuno

 


On Sat, Jun 23, 2018 at 6:28 PM f1mqj <f1mqj.fr@...> wrote:
I also found 3.5V on the 3V3 output of the Nano (that's in the range for FT232 or PL2303 : 3-3.6V, high but in the range -no datasheet for CH340)

bitx40 not working after case move

[email protected]
 

Hello, list!

I assembled my bitx40 last weekend and managed to play with it for
quite a while during field day yesterday morning. I got some great
contacts much further away that I thought I would given my hastily
assembled antenna, the nearby storms, and the terrible propagation.
Everything was going very well.

The "case" (cigar box) I had my bitx40 mounted in didn't work out as I
had hoped so I began cutting on a plastic container to house the rig.
The only modification I made to the bitx40 itself in this move was to
cut the mic wires and reverse their leads. All other hardware was left
unmodified.

The only mistake I made in wiring it back up was connecting the cable
for power and oscillators (DSS?) to the wrong side of the radioduino
pins where it belonged. I fear this may have smoked it because that
means that 12v and gnd ended up going to pins 2 and 3 (I think, judging
by the circuit diagram). But I get the same lights that I normally get
when powering up theradioduino.

Now, when I boot the radio, my screen has a single row of squares like
in this post: /g/BITX20/topic/4963925#25502

I hear static but it doesn't sound like radio static and when I turn
the tuning knob, it doesn't make any clicking sounds like it did before
when it was tuning. The volume pot clearly changes the volume of the
static still.

I don't believe this is a contrast issue because I can see the row of
squares clearly (and there's only one row). A visual inspection of the
board, display, and radioduino yield no visible damage. It does look
like pins D4 and D5 of the radiduino have a small piece of solder
conencting them but it's possible that is intentional as the radio
worked previously.

I've taken the display and radioduino out of the case and powered them
up via USB and the screen displays the same behavior. I attempted to
upload the bitx40 sketch but I'm having difficulty getting the arduino
software to talk to the radioduino nano ("programmer not responding").
My board model, processor type, port, etc. are all correct. It just
simply won't connect. I'll try to see if one of my other arduinos
works with cable I have.

It could also be the two digital pins that are bridged causing the
programmer issue. I seem to recall having a similar problem years ago
with an arduino that refused to connect because it had busy digital
pins.

If anyone has any troubleshooting tips, I'd greatly appreciate it!
Have a terrific weekend and thanks for your time!

72 DE KD5RYO

--
Happy Hacking!


GPG: 1200 0808 F968 47AB F489 91A3 FE26 6FFB 1A77 0868
Re: I need a V3 or V4 uBitx board.

 

Raj,

When the trace burned it also burned only the TX side contacts on K1 which didn¡¯t alow RF to get to the receiver. Replacing K1 solved all problems, everything is working good now. Fortunately I keep a stock of those relays for my homebrew Transceivers.

Joel
N6ALT
Ubitx schematic #ubitx

 

Has anyone marked up the schematic showing?rec and transmit paths via color. I recall seeing a bitx one last year

73
art N2AJO?
Re: Heat sink

VE7CWS WRSeiler
 

Thanks fellows!

I have performed the subject install and everything seems to work just fine.

Cheers and 73

Walt VE7CWS
FS- Unbuilt uBITX & Case

 

I have a late uBITX V3 (socketed) that I received 4 weeks ago & a Sunil Case for sale.? $150 for the pair shipped.
The uBITX comes with the Click & AGC Kees kit.? Both are brand new & unmolested.
Any questions/interest, please email me off group at W8RMV@....
Re: #bitx40 #bitx40

 

Try to see the link below and related previous history on that subject. you would get what you needed.


Regards
MVS Sarma
?

On Sun, Jun 24, 2018 at 2:42 PM, Pradeep Kumar <Vu3edg@...> wrote:
Hi,

Any suggestions or ready code to make bit 40 VFO to encoder please ...

Pradeep vu3edg

On Mon, Jun 18, 2018, 12:41 AM <victor.rodrigo.jimenez@gmail.com> wrote:
Hello. How are you?
Mr. I need the program of the mini arduino of my bitx40. since the one that I had was burned and I had to change it. your help is appreciated
Re: #bitx40 #bitx40

 

Hi,

Any suggestions or ready code to make bit 40 VFO to encoder please ...

Pradeep vu3edg

On Mon, Jun 18, 2018, 12:41 AM <victor.rodrigo.jimenez@...> wrote:
Hello. How are you?
Mr. I need the program of the mini arduino of my bitx40. since the one that I had was burned and I had to change it. your help is appreciated
Re: Raduino consumption #ubitx #radiuno

 

Thanks for advice and links (i already looked at this ch340 datasheet but it's very short and incomplete -no data about 3v3 output voltage interval)
I've got something : only 36ohms between gnd and 5V, more than 1Kohm on a spare nano, no output data shorted to gnd or 5V
BUT only 6ohms between REF and gnd (about 3K on my spare nano) And REF pin is shown unlinked on Raduino board ->
- bad nano PCB with no space between gnd and ref
- short circuit on capacitor on the REF pin
but all that hard to check and correct without unsolder :-(
first easy thing that i can do easily is cut pcb between Atmega pin 21 and REF output of the board (but i will need later to replace the capa on the other side to enforce noise reduction on analog read)
second thing is to cut and remove this unused pin between nano and raduino (in case the short circuit is on the raduino solder part)
i will keep you informed
73 - Remi
Re: I need a V3 or V4 uBitx board.

 

Glen,

The filter relays come in and out when PTT is pressed. Saves a bit of current if you are using on battery.
I just cut a track and wired the filter relays to operate during rx and stay there.

If anyone is interested I post this mod.

Raj

At 24/06/2018, you wrote:

I had similar problem some time ago. No Tx.? I could hear K1 pulling in but in actual fact it wasn't making contact. I replaced it with a different brand of relay and no problems since. But it does make me suspicious of the other relays in the uBITX. If they don't work then? a LPF may not be actually switching either.
glenn

On Sat,


Jun 23, 2018 at 04:55 pm, Joel Caulkins wrote:
Yay! K1 was indeed bad, I now have a working receiver and transmitter, however the output power is only 500mw compared to the 12 watts before. Do we think the IRF510's are shot? What would be the best way to check them or should I just replace them, I have plenty in stock.

Joel
N6ALT

Re: I need a V3 or V4 uBitx board.

 

I had similar problem some time ago. No Tx.? I could hear K1 pulling in but in actual fact it wasn't making contact. I replaced it with a different brand of relay and no problems since. But it does make me suspicious of the other relays in the uBITX. If they don't work then? a LPF may not be actually switching either.
glenn

On Sat,


Jun 23, 2018 at 04:55 pm, Joel Caulkins wrote:

Yay! K1 was indeed bad, I now have a working receiver and transmitter, however the output power is only 500mw compared to the 12 watts before. Do we think the IRF510's are shot? What would be the best way to check them or should I just replace them, I have plenty in stock.

Joel
N6ALT
Re: Bitx AGC circuit

 

¿ªÔÆÌåÓý

Willy,
Long time. Guess who I just Worked! W1LY 2A RI on 20m cw as K8GC my clubs call. Nice to hear ya on the band's.
73
Enjoy FD
David
?? N8DAH
From: [email protected] <[email protected]> on behalf of Willy <W1LY@...>
Sent: Tuesday, November 7, 2017 7:03:28 PM
To: [email protected]
Subject: Re: [BITX20] Bitx AGC circuit
?
I am using this circuit without the 10K between the diode and the 2N7000 which was not in Farhan's original schematic.
It works fairly well for me.
I have seen a number versions which have not worked. One has the 10 K at "audio in" replaced with a 100K and the 100 R at the anode of the 1N4148 shown as 100K
73 Willy? W1LY

On Tue, Nov 7, 2017 at 2:31 PM, Philip Thompson <pcteee@...> wrote:

Thanks guys...all understood..

It's just that I built one for my Bitx and it doesn't seem to work.
The voltage on the gate of the fet is going up and down in response to the audio level
but there seems to be little or no attenuation to the stronger signals....
Double checked and I made no mistakes..
Phil? G4JVF



--
David

?N8DAH
Re: I need a V3 or V4 uBitx board.

 

It could also be possible that the transistor might be short, permanently operating the said relay.

Regards
MVS Sarma
?

On Sun, Jun 24, 2018 at 10:14 AM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:
If K1 welded up inside such that there was no path from pin 12 to pin 14 when the coil was not energized,
then the receiver would not get RF from the antenna and be deaf.

K3 does most of the antenna T/R switching, during receive it passes signals from the antenna over to K1.
During receive, K1 is not energized and pins 12 and 14 are connected, sending RF up into the 30mhz LPF at L1,2,3,4

During transmit, there will be some capacitve coupling between K3 pin 12 and K3 pin 14 even though those contacts are open.
So during transmit, K1 shorts pin 12 to ground to avoid feedback from antenna back into Q90 creating an oscillator.

Jerry

On Sat, Jun 23, 2018 at 07:48 pm, Joel Caulkins wrote:
The receiver would not work until I changed the relay. I was wondering about that myself, why would the absence of TX voltage cause the receiver not to work unless a RX voltage was missing also. I checked all that I saw on the schematic and they were all there. Don¡¯t know.
Re: I need a V3 or V4 uBitx board.

 

If K1 welded up inside such that there was no path from pin 12 to pin 14 when the coil was not energized,
then the receiver would not get RF from the antenna and be deaf.

K3 does most of the antenna T/R switching, during receive it passes signals from the antenna over to K1.
During receive, K1 is not energized and pins 12 and 14 are connected, sending RF up into the 30mhz LPF at L1,2,3,4

During transmit, there will be some capacitve coupling between K3 pin 12 and K3 pin 14 even though those contacts are open.
So during transmit, K1 shorts pin 12 to ground to avoid feedback from antenna back into Q90 creating an oscillator.

Jerry


On Sat, Jun 23, 2018 at 07:48 pm, Joel Caulkins wrote:
The receiver would not work until I changed the relay. I was wondering about that myself, why would the absence of TX voltage cause the receiver not to work unless a RX voltage was missing also. I checked all that I saw on the schematic and they were all there. Don¡¯t know.
64101 - 64120 of 116772