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#ubitx-help advice needed-display issue #ubitx-help

Fotis SY3BUB
 

Hi dear all,
i assembled my ubitx yesterday and i face two issues.
1. The volume potentiometer does not switch the device on/off. Is that supposed to be like that? As long as i connect the device to dc, it gets alive irrespective of the position of the potentiometer. It does however control the volume. Excuse my ignorance.
2.(and most important) the display shows only dots. From an elevated view angle i can see the numbers and letters but from the front view nothing! Even from the elevated angle, the numbers and letters of the lower line are not shown fully but only partially, that is their upper part is missing.
I attach some pics to demostrate the problem.
Further, i shall add that Rx is working, so far tested, menu is also working.
I appreciate any advice.
Thank you de SY3BUB
Fotis

chris gress <Chrisg0wfh@...>
 

You need to adjust the contrast control on the back of the aldreano and you need to connect the switch up on the volume control positive wire from the radio to the switch the other side of switch to positive on power supply that will do it chris

On 14 Jan 2018 09:11, "Fotis" <papakius@...> wrote:
Hi dear all,
i assembled my ubitx yesterday and i face two issues.
1. The volume potentiometer does not switch the device on/off. Is that supposed to be like that? As long as i connect the device to dc, it gets alive irrespective of the position of the potentiometer. It does however control the volume. Excuse my ignorance.
2.(and most important) the display shows only dots. From an elevated view angle i can see the numbers and letters but from the front view nothing! Even from the elevated angle, the numbers and letters of the lower line are not shown fully but only partially, that is their upper part is missing.
I attach some pics to demostrate the problem.
Further, i shall add that Rx is working, so far tested, menu is also working.
I appreciate any advice.
Thank you de SY3BUB
Fotis

Fotis SY3BUB
 

Dear Chris,
thank you very much for your quick advice, it did the trick indeed!
I adjusted the contrast and i can now see the display content.
I also fixed the on/off part of  the potentiometer. Great!

What remains problematic is the missing of the upper part of the letters and numbers of the lower display line. The upper display line works perfectly.
I attach a new picture.

William R Maxwell
 

on your first question, the volume potentiometer cannot switch the device on and off because you have not wired up the switch - the two connections on the rear of the pot.


On 14/01/2018 8:11 PM, Fotis wrote:
Hi dear all,
i assembled my ubitx yesterday and i face two issues.
1. The volume potentiometer does not switch the device on/off. Is that supposed to be like that? As long as i connect the device to dc, it gets alive irrespective of the position of the potentiometer. It does however control the volume. Excuse my ignorance.
2.(and most important) the display shows only dots. From an elevated view angle i can see the numbers and letters but from the front view nothing! Even from the elevated angle, the numbers and letters of the lower line are not shown fully but only partially, that is their upper part is missing.
I attach some pics to demostrate the problem.
Further, i shall add that Rx is working, so far tested, menu is also working.
I appreciate any advice.
Thank you de SY3BUB
Fotis

chris gress <Chrisg0wfh@...>
 

On the display I think the read out should be on the top line it is on my bitx 40 check that its connected correct I not got my micro bitx yet chris

On 14 Jan 2018 10:48, "William R Maxwell" <wrmaxwell@...> wrote:

on your first question, the volume potentiometer cannot switch the device on and off because you have not wired up the switch - the two connections on the rear of the pot.


On 14/01/2018 8:11 PM, Fotis wrote:
Hi dear all,
i assembled my ubitx yesterday and i face two issues.
1. The volume potentiometer does not switch the device on/off. Is that supposed to be like that? As long as i connect the device to dc, it gets alive irrespective of the position of the potentiometer. It does however control the volume. Excuse my ignorance.
2.(and most important) the display shows only dots. From an elevated view angle i can see the numbers and letters but from the front view nothing! Even from the elevated angle, the numbers and letters of the lower line are not shown fully but only partially, that is their upper part is missing.
I attach some pics to demostrate the problem.
Further, i shall add that Rx is working, so far tested, menu is also working.
I appreciate any advice.
Thank you de SY3BUB
Fotis

chris gress <Chrisg0wfh@...>
 

No I just look on u tube it should be the bottom line then I don't know chris 

On 14 Jan 2018 10:51, "chris gress" <Chrisg0wfh@...> wrote:
On the display I think the read out should be on the top line it is on my bitx 40 check that its connected correct I not got my micro bitx yet chris

On 14 Jan 2018 10:48, "William R Maxwell" <wrmaxwell@...> wrote:

on your first question, the volume potentiometer cannot switch the device on and off because you have not wired up the switch - the two connections on the rear of the pot.


On 14/01/2018 8:11 PM, Fotis wrote:
Hi dear all,
i assembled my ubitx yesterday and i face two issues.
1. The volume potentiometer does not switch the device on/off. Is that supposed to be like that? As long as i connect the device to dc, it gets alive irrespective of the position of the potentiometer. It does however control the volume. Excuse my ignorance.
2.(and most important) the display shows only dots. From an elevated view angle i can see the numbers and letters but from the front view nothing! Even from the elevated angle, the numbers and letters of the lower line are not shown fully but only partially, that is their upper part is missing.
I attach some pics to demostrate the problem.
Further, i shall add that Rx is working, so far tested, menu is also working.
I appreciate any advice.
Thank you de SY3BUB
Fotis

Fotis SY3BUB
 

Thank you both!
I will keep on researching and will update the post once i locate the answer.
Fotis

n5ib_2
 

It may be a poor contact issue between the actual LCD panel and its driver board.
I noticed it on a similar display here
While the display is powered up, try squeezing the LCD portion of the display unit against the driver board (not the Raduino board).
If you see the missing elements pop into view then gently tighten up the metal tabs on the back of the LCD board that hold it onto the driver board.
That did the trick on mine and it's been working fine ever since.

Jim, N5IB

John Backo
 

Fotis:

I think Jim hit on the real reason for your display issue. These are internally
connected with some line switches that are very fine, and rely on contacting
the lcd glass area. Most often tightening the contact between the switches
and the glass area by tightening the metal surrounding is the answer. If the
contact area is not enough, it shows up as partial line displays such as yours.

Sometimes it does not work very well. I have found usually that it is a whole lot easier
and more reliable to just replace the whole 1602 display. They cost only a few
dollars.

It is a general problem with these lcd displays. Most work ok, but some do not.
Some show temperature irregularities and will work ok at some temps and not others.
Go figure. It is an interesting but a little flaky technology.

john
AD5YE

Fotis SY3BUB
 

Dear John and Jim, thank you for your answer,

the lcd display does not want to recover so i did buy a replacement for 4 Euros here in Greece.

Guys, the support of this community here is great, thank you all.

Fotis, 73 de SY3BUB

KI7MWA
 

So, then, regarding the wire-up of the jack/switch/fuse/et cetera:  Positive pole of jack to one pole of fuse: other pole of fuse to one pole of switch: other pole of switch to red and brown wires of radio power connector.  That it???  Also, negative pole of jack to one pole of second fuse: other pole of second fuse to black wire of radio power connector, and to black end of diode: ring end of diode to positive pole of power jack.  Yes???

Jerry Gaffke
 

We've had some really long threads here about switches and fuses and diodes and such.
Here's a few of them:
    https://groups.io/g/BITX20/topic/7489182
    https://groups.io/g/BITX20/topic/19250730
    https://groups.io/g/BITX20/topic/21608328

It's one of those things were everybody has an opinion.
Most of them would work enough.

If you don't have a 3 Amp fuse in line with the power supply, the shunt diode scheme shown on the 
wireup page of hfsignals.com won't necessarily work.
You are describing a variation of this, with a fuse in the black wire between the shunt diode and the power jack, 
this would mostly work except that antenna ground is often somehow connected to power supply ground
which can give a path around a blown negative side fuse.
I'd say you want to fuse the positive side first.
Allison has suggested also fusing the negative side, but that is not often seen.


This is what I have implemented:


                                  +------0.5Afuse----Diode----------RedToMainUbitx12v
               jack               |                      bar
PowerSupply=====O-------Switch----|
                |                 +------3.0Afuse--------------------BrownToIrf510s 
                |
                +----------------------------------------------------BlackToGround


I am using polyswitches instead of fast-blow fuses, no need to replace them when a short occurs.
    https://www.taydaelectronics.com/circuit-protection/polyswitch-devices.html
Just power down to let the polyswitch cool and reset itself, fix the fault, then power back up.

Having a separate 0.5A fuse for most of the uBitx means less damage will occur on a fault
than the damage we would have if it was a 3.0A fuse to everything.

The power switch could be the one on the volume control provided.
Instead I put in a toggle switch right next to the power jack on the back of the chassis to avoid long wires.

I prefer a series diode as shown (not shunt) for polarity protection of the main uBitx board, we lose 
some fraction of a volt across that diode but it does not affect radio performance.
The provided Schottky diode could be used, or use anything from the 1n400x series such as the 1n4007.

The PA-PWR to the IRF510's is only protected by the 3.0Amp fuse, if polarity is reversed then the IRF510's
will conduct and blow the fuse, so this is a shunt protection scheme that avoids any diode voltage drop
A small drop in voltage here will reduce available power out when transmitting.
 
Jerry, KE7ER



On Sun, Jun 24, 2018 at 06:33 pm, <entilleser@...> wrote:
So, then, regarding the wire-up of the jack/switch/fuse/et cetera:  Positive pole of jack to one pole of fuse: other pole of fuse to one pole of switch: other pole of switch to red and brown wires of radio power connector.  That it???  Also, negative pole of jack to one pole of second fuse: other pole of second fuse to black wire of radio power connector, and to black end of diode: ring end of diode to positive pole of power jack.  Yes???