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Re: TUNE signal for tuning tuners

Bob Lunsford
 

Simple way is to use the Manual Key option and CW mode to use the PTT for a +/-10W CW signal that will tell the tuner what frequency to center on for tuning. Maybe someone else can suggest a hard-wire way but this for me is the simplest way.

Bob — KK5R

On Tuesday, January 19, 2021, 6:30:47 PM EST, kg9hfrank@... <kg9hfrank@...> wrote:


This past weekend, I went back in time and reviewd posts back to 2018.

About half way through I started taking notes but... I did not take any notes on how to unbalance the balanced modular to get a signal out for using a tuner.

Anyone have that info available?  

If I recall the ham disabled a resistor causing an imbalance and a steady signal came out which he used to tune his tuner.  He turned it on and off with a toggle switch.

--
Frank, KG9H


TUNE signal for tuning tuners

kg9hfrank@gmail.com
 

This past weekend, I went back in time and reviewd posts back to 2018.

About half way through I started taking notes but... I did not take any notes on how to unbalance the balanced modular to get a signal out for using a tuner.

Anyone have that info available?  

If I recall the ham disabled a resistor causing an imbalance and a steady signal came out which he used to tune his tuner.  He turned it on and off with a toggle switch.

--
Frank, KG9H


Re: no audio beyond very quiet static #ubitxv6 #ubitxv6-help #v6

John Scarlett <John329@...>
 

The wires for volume control must be ok as the volume does adjust and all the wiring connectors match the photographs I had previously taken.
That being said it does seem likely that something must have been touched or dislodged while I was working possibly one of the many coils or even heat transferred to the wrong component while de-soldering.
I will check all the connection's around the PA transistors and look for touching wires on the coils as the video suggested and let you know the results.

73
John M7CPT


Re: no audio beyond very quiet static #ubitxv6 #ubitxv6-help #v6

Jerry Gaffke
 

Yes, get the receiver working first.

Here's an old video Farhan created to show how to take a meter of wire as an antenna to
pick up local QRN around the house, and strobe that wire to each stage of the receiver
progressing back from the audio amp until you reach a point where it no longer
makes scratchy noises in the audio.  That tells you about where the problem is.
    http://bitxhacks.blogspot.com/2016/12/troubleshooting-bitx40.html
The video is about the old Bitx40, but should work on the uBitx too.

Though first look for obvious stuff.  Maybe a wire broke off of your volume control?
Maybe a wiring harness got plugged back into the board wrong?
Are the RX stages getting 12v power? 
Note that the audio amp is powered from "12V", other receiver stages from "RX", but only when receiving.
    
If you replaced the PA transistors and now the receiver doesn't work,
sounds like you must have touched something else in the process.

Jerry, KE7ER



On Tue, Jan 19, 2021 at 11:36 AM, John Scarlett wrote:
Total loss of power output occurred 1st that Is why I replaced the PA transistors.
As it seemed likely that I'd blown my finals I replaced both with genuine RD16HHF1's.
After doing this I had no audio beyond very quiet static so also replaced audio chip and checked TX/RX relay.
Still no sound beyond very quiet static so didn't even try to TX.
Any ideas what else it could be would be appreciated?
 
73
John M7CPT


Re: I think I damaged my display.uBitx V3

Jerry Gaffke
 

For a clone Nano, do a web search for "nano ch340"
You don't want the headers soldered in place because they would be soldered on the wrong side for plugging into a Raduino.
Examples:
    https://www.amazon.com/ELEGOO-Arduino-ATmega328P-Without-Compatible/dp/B0713XK923
    https://www.banggood.com/Geekcreit-ATmega328P-Nano-V3-Controller-Board-Improved-Version-Module-Development-Board-p-940937.html

For the display, search for "1602 lcd", or maybe "1602 lcd HD44780"
You want the parallel interface for the v3 uBitx, not one with the i2c backpack.
Though if using it on other projects, the i2c backpack version is easier to wire up to the nano.
Examples of parallel interface:
    https://www.amazon.com/HiLetgo-Display-Backlight-Controller-Character/dp/B00HJ6AFW6
    https://www.banggood.com/2Pcs-1602-Character-LCD-Display-Module-Blue-Backlight-p-1370817.html
    https://www.taydaelectronics.com/lcd-display-16-x-2-blue-character-with-backlight.html


Ordering from China through Banggood can take a month, but usually cheaper than a distributor here in the US.
Tayda is cheap and has a warehouse in the US.  Some Banggood items are stocked in the US.

Maybe get two or three of each, they are fun to play with and you can make them do other useful stuff.
Having a couple Nano's allows you to program new code while leaving the one with the old code on the shelf..

Jerry


On Tue, Jan 19, 2021 at 11:18 AM, <bradkirk@...> wrote:
Thanks, do you know where I could buy a display or arduino? I've looked but I can't see a source.


no audio beyond very quiet static #ubitxv6 #ubitxv6-help #v6

John Scarlett <John329@...>
 

Total loss of power output occurred 1st that Is why I replaced the PA transistors.
As it seemed likely that I'd blown my finals I replaced both with genuine RD16HHF1's.
After doing this I had no audio beyond very quiet static so also replaced audio chip and checked TX/RX relay.
Still no sound beyond very quiet static so didn't even try to TX.
Any ideas what else it could be would be appreciated?
 
73
John M7CPT


Re: I think I damaged my display.uBitx V3

bradkirk@...
 

Thanks, do you know where I could buy a display or arduino? I've looked but I can't see a source.


Re: uBitx v6 board failure--suggestions? #ubitxv6 #v6

John Terrell
 

Thanks—I will look into all of that. I tested the 510s with a method found on the web alternating connections with a digital ohmmeter. I also tested the new ones before installing them. I also have not determined where the stove came from—none of the parts appeared charred.


Re: uBitx v6 board failure--suggestions? #ubitxv6 #v6

Jerry Gaffke
 

Did you figure out where the smoke was coming from?
The IRF510's are a good first guess, but could also have been a board trace, or L8,L9.

I find that going out of the room can bring my nose back to where it can smell a faint wiff of burning epoxy.
Then perhaps a soda straw from board to nose to help pinpoint where the smell is coming from.

Or, when I first shut down, immediately press the board with my hand to figure out what got hot.

Jerry



On Tue, Jan 19, 2021 at 08:13 AM, Jerry Gaffke wrote:
I smelled some smoke for a few seconds, and shut down,


Re: uBitx v6 board failure--suggestions? #ubitxv6 #v6

Jerry Gaffke
 

It is possible that those IRF510's are now drawing too much current for your power supply,
and this is causing the "cycling white-out of the screen".

Did you figure out for sure that the old IRF510's were damaged before replacing them?
If they did get damaged, it was probably heat.  They were likely too hot to touch when they failed.

Did you figure out why the IRF510's smoked?  That should not have happened.
Perhaps you were running for long periods of time at 10W in digital modes, and didn't have an adequate heat sink?
Perhaps the antenna system presented more than a 2:1 SWR?   (Due to heat, IRF510 damage would not be instantaneous) 
Perhaps you fed your rig well over 12v to get a little bit more power?  (Damage due to IRF510 heat)

The gate bias required varies with each IRF510, they are not manufactured to be exactly the same.
That's why we have RV2 and RV3.
Did you adjust RV2 and RV3 for the new IRF510's, 100ma quiescent drain current on each?
A good way to determine if IRF510's are damaged is to attempt setting quiescent drain current, 
if you succeed then they are OK.

A good way to blow out your new IRF510's is to just turn the rig on and try transmitting
without first setting RV2 and RV3 properly.

My suggestion on how to proceed:
Make sure your power supply is 12v, and has a 3A fuse.
Adjust RV2 and RV3 for minimum gate bias (minimum is fully clockwise, this is backwards of most such knobs in this world)
Power up, see if you are back to the display working properly, and hearing the driver when attempting to transmit.

Then follow the instructions on hfsignals.com to set the gate bias on each IRF510, specifically:
  Monitor power supply current, I'm guessing on the v6 it might be around 300ma on receive, 500ma on transmit with zero gate bias.  (Could somebody confirm?)
  With PTT pressed and no audio into the mike, adjust RV2 counterclockwise very slowly until supply current increases by 100ma.
  Then adjust RV3 counterclockwise till the power supply increases by another 100ma.

You must turn RV2 and RV3 slowly, nothing will happen till about 4/5'ths of the way around when drain current will suddenly shoot up.
You can measure the gate voltage with a DVM, watch it rise from 0v to 5v as you turn the pot, current suddenly shoots up at about 4v on the gate.
to transmit.

If rotating RV2 and RV3 fully clockwise does not bring back the display and the signal from the driver, then remove the 12v supply on the IRF510 drains.
On older rev uBitx's there were two 12v supply wires into the main board, one for the IRF510's and one for everything else.
Unfortunately v6 only has one wire, you might try unsoldering one end of L8 and L9 instead.
I hope that if there is a v7, it will again have a separate 12v supply wire for the IRF510 drains going into the board.

Once 12v to the IRF510 drains is removed, you can turn the rig on and try transmitting.
The IRF510's won't be getting hot, or drawing so much current from your power supply that it fails to give 12v.
But you should be able to see the gate bias of each IRF510 rise from 0v to 5v as you turn RV2 or RV3 counterclockwise.

Tell us what you learn when you try the above.

Good Luck,
Jerry, KE7ER


On Tue, Jan 19, 2021 at 07:38 AM, <N6LN@...> wrote:
My uBitx V6 worked well for a few hours, then the power output stopped. (I smelled some smoke for a few seconds, and shut down, but it was too late.) I then could still hear a weak signal on my other rig indicating that the unit was working ahead of the finals. I obtained new IRF510 MOSFETS and switched the both out. Now I can't hear even the weak signals from the drivers, and furthermore there is a cycling white-out of the screen--that's new--that repeats again and again when I key the CW or SSB microphone. Please see the short video. Any suggestions? Do I need to get a new board?


Re: Easy bitx20 by Inkits.

Jon
 

Skip
I thank you for that


uBitx v6 board failure--suggestions? #ubitxv6 #v6

John Terrell
 

My uBitx V6 worked well for a few hours, then the power output stopped. (I smelled some smoke for a few seconds, and shut down, but it was too late.) I then could still hear a weak signal on my other rig indicating that the unit was working ahead of the finals. I obtained new IRF510 MOSFETS and switched the both out. Now I can't hear even the weak signals from the drivers, and furthermore there is a cycling white-out of the screen--that's new--that repeats again and again when I key the CW or SSB microphone. Please see the short video. Any suggestions? Do I need to get a new board?


Re: Easy bitx20 by Inkits.

Skip Davis
 

Jon, here is a picture of the jack with labeling I made. 



Skip Davis, NC9O

On Jan 19, 2021, at 02:16, Jon <jon.kd3gz@...> wrote:

I was wondering if anyone has any ideas about wiring up the SP stereo jack & the MIC jack, because I can not figure this out of which pins and how to connect them??
A sketch or photo would be a great help.
Jon


Re: Easy bitx20 by Inkits.

ohwenzelph
 

Does anyone know what happened to WA2EBY Linear Amp PCB?

It looked really good but seems to have disappeared.


Re: Received my v6 the other day -- first impressions #ubitxv6 #v6

quad@...
 

Great work, Will. 
Speaker polarity should not matter, when used for mono audio


Easy bitx20 by Inkits.

Jon
 

I was wondering if anyone has any ideas about wiring up the SP stereo jack & the MIC jack, because I can not figure this out of which pins and how to connect them??
A sketch or photo would be a great help.
Jon


Re: QUESTION for All - EASY BITX - HP 2800 series Schottky Diodes for Mixer

Jerry Gaffke
 

One more comment here;
Making the local oscillator into the mixers a full 7dBm may not improve large signal 
performance of the uBitx receiver.  The first stage to overload on a large signal
would be the audio preamp at Q70.

Jerry, KE7ER


On Fri, Jan 15, 2021 at 07:20 AM, Jerry Gaffke wrote:
.... With the extra 33 ohm resistor plus the 6dB pad, the mixers are definitely not seeing 7dBm of
local oscillator energy, this will impact the maximum incoming signal that the mixers can deal with.
Even if that strong received signal is far out of band, as there is no front end bandpass filter on the uBitx.
On the Easy Bitx there is a front end bandpass filter, but any extremely loud signal in the roughly 500khz
of passband could overload the mixer.   ....  This stuff is more complicated than it looks. ....


Re: I think I damaged my display.uBitx V3

 

That cant cause any damage. If you unplugged the display then you could have inserted it back
with a pin bent?

Display are easily & cheaply available. Buy a new one, I particularly like black on white than the original green!

Raj

At 19/01/2021, you wrote:
To be more specific, it's the tuner encoder where it has the three connectors on one side. The center is ground, one side is black wire and the other side is a brown wire. In moving the tuner encoder out of it's mounting hole and putting it back in with the washer the black wire was evidently pulled across the ground connector next to it. That's what I noticed and fixed when the display lit up but there was nothing as far as numbers on the display. fixed that but still nothing on the display.


Re: I think I damaged my display.uBitx V3

bradkirk@...
 

To be more specific, it's the tuner encoder where it has the three connectors on one side. The center is ground, one side is black wire and the other side is a brown wire. In moving the tuner encoder out of it's mounting hole and putting it back in with the washer the black wire was evidently pulled across the ground connector next to it. That's what I noticed and fixed when the display lit up but there was nothing as far as numbers on the display. fixed that but still nothing on the display. 


Re: I think I damaged my display.uBitx V3

 

It is also likely that the washer has shorted some line on the display.

Raj

At 19/01/2021, you wrote:
The black on the raduino? Next to the black on mine is the brown which goes to the rotary encoder and on the raduino side, both are inputs to the nano, so nothing should have happened.

If you're talking about the black to the V3 board, I don't have that handy to look at. Sorry.

Vince.

On 01/18/2021 10:55 PM, bradkirk@comcast.net wrote:
I removed my VFO to add a washer behind it but in doing so the black
wire/tab was bent over the next tab which is ground. Without noticing
this I turned the radio on. The BG lighted up and the radio sounds
normal and tunes but there is no digital display on the screen. Any
ideas as to what I've damaged?
--
K8ZW http://www.metalworkingfun.com http://www.hamradio.fun

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