Date   
Re: Nextion with KA78T05

Werner de Vos
 

Probably a bad batch, I stopped order parts from AliExpress. Had the same with a batch of IRF510. Complete rubbish. 

Re: Nextion with KA78T05

MVS Sarma
 

I suffered with 10pcs of  bad 78t05 from ali seller and demanded refund and got it.


On Mon, 16 Sep 2019, 9:37 pm Herman Scheper, <Hsrscheper@...> wrote:
I am using the Nextion 5"display. When building my Ubitx V5 I used a small step down converter to generate the 5V for the Nextion display. It all worked 100%
Now the building is almost finished i want to replace the 5V stepdown converter. ( It is giving a little amountt of noise…)

I ordered ( Aliex..) 5 pcs of KA78T05 TO-220 stabilisors. ( is the 3A version-  )

Then I replaced the 7805 mounted on the Arduine and replaced it for the KA78T05 version…. No working Arduino and no working display.

I find input=12V output=0V.   Checked before and after the pinning  1=input / 2 = earth/ 3 =output   Find a datasheet on Internet and can not find what I am doiing wrong.

After that make a test print only for the KA78T05 and I can not get the 5V output. Output also on a 2nd KA78T05 is still 0Volt.   Frustrating.  ( I used a 7809 on the same test and output was 9.00 Volt!)

What I am doiing wrong...…….?     ( ordered today local few 78S05   ( = 1.5A version  )

So who knows what I am doiing wrong...?                       Tnx.  Herman

Nextion with KA78T05

Herman Scheper
 

I am using the Nextion 5"display. When building my Ubitx V5 I used a small step down converter to generate the 5V for the Nextion display. It all worked 100%
Now the building is almost finished i want to replace the 5V stepdown converter. ( It is giving a little amountt of noise…)

I ordered ( Aliex..) 5 pcs of KA78T05 TO-220 stabilisors. ( is the 3A version-  )

Then I replaced the 7805 mounted on the Arduine and replaced it for the KA78T05 version…. No working Arduino and no working display.

I find input=12V output=0V.   Checked before and after the pinning  1=input / 2 = earth/ 3 =output   Find a datasheet on Internet and can not find what I am doiing wrong.

After that make a test print only for the KA78T05 and I can not get the 5V output. Output also on a 2nd KA78T05 is still 0Volt.   Frustrating.  ( I used a 7809 on the same test and output was 9.00 Volt!)

What I am doiing wrong...…….?     ( ordered today local few 78S05   ( = 1.5A version  )

So who knows what I am doiing wrong...?                       Tnx.  Herman

Re: Project : Ubitx go box with batteries (topic will be updated upon works done)

Frank Dinger , EI7KS
 

On Mon, Aug 26, 2019 at 09:50 AM, Adrien F4IJA wrote:
I'll make a 3S battery pack (3x 4.2V fully charged, so 12.6V), and I've ordered 3300 mAh cells. I'm thinking about making a 3S4P battery pack, so the capacity will be 13200 mAh.
Lithium-Ion batteries have a voltage operating range of 4.2V (fully charged) down to 2.8V  , hence 1.4V.
 Question : would 3x2.8V= 8.4V be adequate to operate the Ubitx ?

If not I would suggest you use 4 sets of (parallel) cells in series . This would give an operating voltage range of  16.8 V - 11.2V , hence 5.7V    , assuming 16.8 V is acceptable for the complete radio .

Also ensure that you use  a max voltage equalising circuit to prevent overcharging of any of the cells being charged as part of the pack.

FYI : Chinese on-line retailers can supply (low cost) compact 18650 battery holders for either 1 or 4 cells permitting cells to be flipped-in (hence no soldering or spot welding)  These holders also enable easy cell replacement .

I have recovered good cells (capacity checked) from discarded laptop battery packs .
When a laptop pack is no longer usable for its intended purpose , often only 1 of the usually 6 cells is no longer OK , but the others still are.

Frank   ,    EI7KS

Re: Flipping Nextion display in software? #firmware #nextion #ubitx

Mark Hatch
 

You can load it into the Nextion editor (free download) and flip it (odd number of degrees, not just "180", maybe 270?). Then re-save.  Try to make sure that the sdcard slot is on top... Makes it possible to update the screen without disassembling your ubitx.

73
Mark
AJ6CU

Re: Flipping Nextion display in software? #firmware #nextion #ubitx

Sam Tedesco
 

Yes, you can. If you have the .hmi file, open it with the Nextion editor, select Device on upper right hand of command ribbon, select Display on left, select 270 horizontal, and recompile. I compile mine upside down so the sdcard port is reachable on the top. 

Re: Overvoltage to Ubitx - now no receive

MVS Sarma
 

I do work T 19v using a laptop adopter selected for low ripple. But , I DO TAKE CARE  that a 12v 2 amp regulator supplies to blance circuitry other than the final IRFs. There also the current is adjusted to say 80mA.
If the due care is not taken , obviously components would fail. Om Bose might take a cue from Allison's advise.

Satma vu3zmv



On Sun, 15 Sep 2019, 6:54 pm ajparent1/KB1GMX, <kb1gmx@...> wrote:
Sumit,

You grossly over voltaged the LM386 audio amp.
Other parts are likely suspect but start  there.

Start at the speaker and work back.

FYI: the only parts that would tolerate more than 15-16V would be the finals IRF510.

Allison

Re: Compliance Summary - other radios

Ted
 

Not a bad deal (as of date of this message) considering those "kits" on eBay that self-destruct upon contact with electricity:

  https://www.newegg.com/p/0TF-0002-00002

Re: Flipping Nextion display in software? #firmware #nextion #ubitx

Ted
 

Please don't think of me as obtuse, though, in what way is your rectangular opening "upside down" for the display? 

I would second the recommendation of using a surrounding bezel to take care of this, short of going with a larger size which might negatively alter the paradigm of the rig you're working toward.

Re: Fix for Spurs and Harmonics on V3 Board

Dale Hardin
 

Curt, 

Harmonics.--I have already ordered the new Axiom relays, so I will try replacing the relays first.  I have a good desoldering gun, solder wick, and chipquick, so I should be ok there.  If that doesn't do the job, I can alway add the outboard relays.  Allison mentioned moving the relays to the bottom of the board, so I may add that to the fix. 

Spurs.--Also, both she and Kees mentioned moving the toroids to the bottom of the board.  I may do that first before replacing them.   I do want to do Farhan's V5 fix; it seems simple enough.

 However, I don't know if there is a local spectrum analyzer available to check the results.  I'll have to pursue that with the local ham club. I am looking at using a rtl-sdr and Spektrum as a test instrument if I can't find a local spectrum analyzer.  I already have the rtl-sdr.

As to parts, I need the replacement toroids and parts to do Farhan's V5 fix.  I assume most hams are like me and order parts like that 10 at a time (just in case).  If you have parts to spare, please contact me privately to discuss.

Iz-oos,

I don't think I will attempt the trap fix until I hear from others who have done it.

Thanks for the input, Dale



On Mon, Sep 16, 2019 at 1:30 AM iz oos <and2oosiz2@...> wrote:

About the 12mhz spur, the trap I believe is not that simple. Please let me know a good design without affecting the 30 and 20m bands. Checking it on my SDR receiver is really very low.


Il 16/set/2019 03:54, "Curt via Groups.Io" <wb8yyy=yahoo.com@groups.io> ha scritto:
Dale

I can speak to v3 and v4 because they are similar in this regard.

First on harmonics an effective solution involves more isolation in the relays selecting the low pass filters. I am using the external board now kitted by N8DAH. It should make your ubitx compliant on 80 to 17 meters, both cw and ssb. CW tends to be okay on these upper bands without a fix, but not ssb or data modes using the ssb math. An alternative scheme is removing the relays and replacing them with Axicom parts. This tends to be more complex work.

The remedy of the ssb spurs on the upper bands is more challenging. Possibly the Axicom relays may help here along with shielded inductors to replace the toroids at the 45 MHz crystal filter. Others add a second 45 Mhz crystal filter, but without others mods this approach doesn't work for me.

I suggest choosing one of these approaches for harmonics, and working the other matter later.

Curt



--
Dale Hardin
24750 State St. Unit 487
Elberta, AL 36530
251-597-9256

--
Dale Hardin, KS4NS
Elberta, AL

Re: Flipping Nextion display in software? #firmware #nextion #ubitx

_Dave_ K0MBT
 

I don't know about reversal, that would be an elegant solution.

Have you considered elongating or opening in the case and covering it with a bezel.

Order the next larger Nextion and sell the one you have. For me it is only the 3.5" unit (or larger I suppose) that fits my fingers. Have tried all sizes below 3.5". They work if I use a pencil to touch  them but are very inaccurate with my fingers.
--
73
Dave
k0mbt
Ham_Made_Keys

Re: Project : Ubitx go box with batteries (topic will be updated upon works done)

Olivier Grand
 

Nice job Adrien !
73's Olivier

Le dim. 15 sept. 2019 à 22:31, Adrien F4IJA <adrien.grelet@...> a écrit :
So, my uBitx is almost finished !

I haven't made some QSO for now, but I tested it like a WSPR beacon and it's OK (6800km of report max).

Here some views of the beast :


--
73's
Adrien F4IJA
https://www.qrz.com/db/F4IJA

Re: Fix for Spurs and Harmonics on V3 Board

iz oos
 

About the 12mhz spur, the trap I believe is not that simple. Please let me know a good design without affecting the 30 and 20m bands. Checking it on my SDR receiver is really very low.


Il 16/set/2019 03:54, "Curt via Groups.Io" <wb8yyy=yahoo.com@groups.io> ha scritto:
Dale

I can speak to v3 and v4 because they are similar in this regard.

First on harmonics an effective solution involves more isolation in the relays selecting the low pass filters. I am using the external board now kitted by N8DAH. It should make your ubitx compliant on 80 to 17 meters, both cw and ssb. CW tends to be okay on these upper bands without a fix, but not ssb or data modes using the ssb math. An alternative scheme is removing the relays and replacing them with Axicom parts. This tends to be more complex work.

The remedy of the ssb spurs on the upper bands is more challenging. Possibly the Axicom relays may help here along with shielded inductors to replace the toroids at the 45 MHz crystal filter. Others add a second 45 Mhz crystal filter, but without others mods this approach doesn't work for me.

I suggest choosing one of these approaches for harmonics, and working the other matter later.

Curt

Re: Fix for Spurs and Harmonics on V3 Board

Curt
 

Dale

I can speak to v3 and v4 because they are similar in this regard.

First on harmonics an effective solution involves more isolation in the relays selecting the low pass filters. I am using the external board now kitted by N8DAH. It should make your ubitx compliant on 80 to 17 meters, both cw and ssb. CW tends to be okay on these upper bands without a fix, but not ssb or data modes using the ssb math. An alternative scheme is removing the relays and replacing them with Axicom parts. This tends to be more complex work.

The remedy of the ssb spurs on the upper bands is more challenging. Possibly the Axicom relays may help here along with shielded inductors to replace the toroids at the 45 MHz crystal filter. Others add a second 45 Mhz crystal filter, but without others mods this approach doesn't work for me.

I suggest choosing one of these approaches for harmonics, and working the other matter later.

Curt

Flipping Nextion display in software? #firmware #nextion #ubitx

Ben Miller-Jacobson
 

Hello everyone. I'm vuilding a uBitx. I screwed up and cut the hole for my Nextion display with it upside down. Does anyone know if there is a way to flip it in software? I intend to use the CEC firmware.

Fix for Spurs and Harmonics on V3 Board

Dale Hardin
 

I soon will be the owner of a v3 board.  After having read way too much information on correcting harmonics and spurs, I think the fixes come down to (1) replacing the relays and putting said replacements on the back side of the board and (2) inserting Farhan's low pass LC filter between the 45mhz IF and the D1,D2 mixer, increasing the 45mhz IF gain (to drown out the 12mhz coming in on CLK2), and a 12mhz trap installed after that mixer.  (Whew, that was a loong sentence)  I understand the first mod, but Farhan's mods as developed in v5 are not documented in ubitx.net (I don't think).  I note that several people have requested a kit of parts to make the fix.  Would some kind soul prepare a set of instructions and BOM for Farhan's v5 fix.  Lastly, are the above fixes likely to solve the harmonics and spurs issue? I really appreciate the work that preceeds this request and hope I can get my v3 board "up to snuff".  73 Dale 

Dale Hardin, KS4NS
Elberta, AL

Re: Amplifier Talk- Communications Concepts

 

Sorry for using "CB amp" as a description,

It isn't a real specification anyway.  I just meant a type of amplifier that was gererally of a simple design that doesn't have a lot of features.  As Alison says, e.g. the EB63 uses basic diode biasing which needs high current in order to maintain a stable bias.  This results in low efficiency and higher battery drain.

Such types might also might be considered a single band design, as there is often only one (or none) lowpass filter.  They also generally have no gain compensation, which means uneven power output has you change bands, which would require transmitter power adjustment to keep from overdriving and burning out the final transistors which are not cheap.

The latter point really makes it not a good match for the ubitx since the transciever already has quite uneven power ouput with good power on the low bands and less and less as you go up.  An uncompensated amplifier will also do the same thing so that can be a troublesome thing to handle.

The AN763 would be a better match up as it has gain compensation built into the design already (no need to figure it out on your own, or extra parts to buy).  It also has a more efficient design for both biasing and for the final transformer (less heat and lower current draw).

Alison, I don't quite get what you said about the copper heat spreader and the AN762?  Reading the construction notes for both the EB63 and the AN763, I couldn't find a mention of that, or that the AN763 would have any more rare parts than the EB63?  Both seemed to be complete kits that only required a large aluminum heatsink and a heatsink fan (besides a case and lowpass filters and switches).

73,


Mark.

Re: Project : Ubitx go box with batteries (topic will be updated upon works done)

Adrien F4IJA
 

So, my uBitx is almost finished !

I haven't made some QSO for now, but I tested it like a WSPR beacon and it's OK (6800km of report max).

Here some views of the beast :


--
73's
Adrien F4IJA
https://www.qrz.com/db/F4IJA

Amplifier board available - cheap

Woody
 

I have rebuilt my HF linear (case and all) and used a BLF-188XR.  Had smoked my previous amp board (AN-758) and just set it aside.  Hate to see it go to waste.  Keep in mind that it will need low pass output filters for the bands desired.
So, wonder if anyone would be interested in owning it... 
 
Asking $25 for the board, no shipping charge (Priority Mail) in the US lower 48, via PayPal  -  Needs new PA transistors, at least.

Minimum gain of the MRF429 is 13db.  For about 8 to 9 watts drive, should make at least 180 watts out.

See applications note (this board is one of the multiple boards shown in the note for a KW amp:
https://www.communication-concepts.com/content/AN758/AN758_Application_Note.pdf

The kit info and downloadable info can be found at:
http://www.communication-concepts.com/an758/
&
http://www.communication-concepts.com/an758-1/ 
They sell the kit for $159.35 (including transistors)

Replacement PAs :  http://www.communication-concepts.com/mrf429mp/   ($106 for matched pair)

The MFR429s must be replaced.  Other semiconductors (See * in image) must be checked and replaced if bad.
The bias regulator (Silver can in pix, is SG FTB016) operation should be verified before installing new PAs !   The regulator on board is a SG FTB016.   In the appnote schematic, the device is a MC1723.  See: https://www.utsource.net/itm/p/302661.html?digipart=1     I am not certain, but suspect any pin compatible 723 regulator, in a TO-100 can package would work  -  If it needs to be replaced.

email me if any questions...
 
Woody  -  KZ4AK   (email good on QRZ)


Re: Amplifier Talk- Communications Concepts

Gordon Gibby
 

Thank you very much for that information, I will try either 450 ohms or 900 ohms, Little noninductive dummy load and a step up balun to match, that should work in the 1 to 3 watt range if I my calculations are correct;  you’ve given me excellent guidance.




On Sep 15, 2019, at 09:21, ajparent1/KB1GMX <kb1gmx@...> wrote:

EXTERNAL EMAIL: Exercise caution with links and attachments.


Gordon,

Short form no.  The 6146 does require power to the grid to run though small.
the key thing is you need 25-50V p-p of RF and to do that across the grid resistor
and the 10-20pf of input capacitance.

The other part is that the bitx needs a stable load and the grid of 6146 is not that.

I'd think at several watts a 4:1 or maybe 9:1 would do.  However if yu want stability 
you have to load that transformer with resistance as the 6146 just like IRF510
is very intolerant of sloppy RF design and will oscillate to destruction.

Allison