Anyone of you having TFT file for 3.2 inch basic display?
The one which is in a zip package is too small, loads ok but looks strange in the upper right corner...and my fingers are way too
thick to press those small buttons. The previous one looks good.

Kai OH3WE

Couldn't get it even in as the display says it is not for this 3.2 standard.

How can this be so damn difficult?...

Kai OH3WE

Hi guys,

can't see any NOT ENHANCED tft file for 3.2 in screen which I use in my radio.
Tried 32E_F_0_2d.tft but no go...

Or do I just miss something?

73
Kai OH3WE

I was only citing K2 as example, yes now unobtainable or costly parts as I alluded to. Some of its circuits, like the uBITX, have legacy to discussion in those 2 W7ZOI et al books. The older one has lots of interesting concepts, but many unobtainium parts. What we can get cheap enough can change rather quickly.

I respect many folk around the world cannot afford a K2, hence the uBITX paradigm. Lets see how that new QSX related IRF510 PA works when it comes out.

73 curt

I just got done posting a couple of medium resolution videos of our 2.8" color display (touch screen) but with a "non-touch" feature, control by wired or wireless MOUSE.

The videos are not professionally done and were made using my Samsung phone's camera.? I had to really compress them (the on-camera raw videos were over 1 gigabyte each) so the screen resolution isn't the best but it is readable and does show the capabilities of using a mouse for control.

This display comes with a small plastic stylus which can be used for "Touch" control and I'll post a video or two later demonstrating the stylus for touch control of the uBITX.? On the small display though, the mouse is really easy to use and is actually my personal preference for controlling the rig.? With the mouse (or our optional wired/wireless keyboard) there is no need at all to touch the screen and also no need to use the encoder or function button to control the rig.? They still work though, we haven't eliminated them altogether.

The videos are posted on the TSW website, in the files section.? They are contained in a directory labeled Experimental Videos and are accessible to all.? We hope they are informative and that you get usable information on our display operation from watching them.

Thanks,
Jim Sheldon, W0EB
for the TSW team

Hello again to all HAM,

I should ask again because the Ubitx doesn't receive like it should, till till today..nothing has found but this should not right when see the?Ubitx v3 (FCI)?first batch first shematic from ubitx constructor Farhan and when look the pin in this doesn't contact toghether...

Please help me again the issue from bad receive like not able to hear ssb stations right and one other pointmi found, no AM stations can be hearable right only bad stuff that shows an idea of an AM radio station and this can not be...

Please help he

开云体育

Andy I just ordered a 3.2 screen. I’m excited. Can’t wait to get it. This radio has been a fun build so far despite any technical imperfections.?

Keep going back? as errors and adds may be part of life.

Allison

Curt,

Those would be good solutions if you can get 2sc2166s at acceptable price and quantity
without incurring the problem of fakes.? Its part of why the K1 was discontinued.

We cannot rely on unobtainium.? ?Not that that was not a good solution but the challange
is to find widely available inexpensive parts.? As a professional designer and home builder?
I have an acute realization for that.

HINT:? 3904 can be used it employed at a performance level it can do.? The other is
board layout in a multiband radio is more critical.? Particularly the PA area.

Allison
Engineers build what they want with things they can get.

Jim,

Replacing RV1 with a 10K is not good as it would put all the adjustment in the last 5 degrees of rotation.
A 500 ohm may be better.

But you begging 1 db of gain increase for what reason?? ?Replace the 3904 in that stage prior and the
performance jumps a greater degree and fixes the actual problem there.

Allison

On Fri, Sep 21, 2018 at 09:19 AM, Jeff Omundson wrote:
1)Keep amplifier intos and outofs away from each other.

This also applies to all RF systems.??

2)Keep amplifier gain stages reasonable.? Add more stages instead of upping gain.

This is a serious and common error, forcing or wishing for gain that is not predictably there.
Conservative design rules insure that.

3)Pick the right device for the desired frequencies.? Obviously 2n3904's don't work for this application.?

First the 2n3904 can if one does not apply wishful thinking and employs it within the devices capability.

***Does picking a part with an fT about 40 times the highest desired frequency a safe bet??
Oddly the answer is yes if the stages has to deliver at least part of the gain desired.? For a?
30mhz amp with a 20db stage gain you will need an Ft of something approaching 3000mhz!
The real question is does it makes sense when two 3904s at 10DB each can also do that?
at 30mhz.??

***Can you pick an FT that is too high (like a npn transistor with and fT of 10 gHz for a 3-30mHz radio)???
The answer is yes and maybe.? IF you using resistive feedback amps (nearly the entire transmitter and both IFs)
the required FT is a product of the gain and the frequency so at some point you really have to ask is that much
gain per stage reasonable and stable.? IT might be prudent to back down the gain and use a more reasonable
transistor.? Also for higher power stages the cost for a supergain high power device might break the bank.

A lot of QRP designs more so older one try to be minimal and get the most out of a very few parts.
If you making one this is ok as you can dial it in and hand pick parts.? For quantity builds this is terrible.
You want every one to be the same as the last.? So care in not trying to get 101% of capability is advised..
This shows more often in transmitter circuits as out of a group most doe the expected watts, a few do
more and a bunch never do that.? Multiband transmitters due to bandwidth, power and layout require
greater attention.

4)Keep RF wires/traces away from each other and from the dc path.
Again this works for RX and TX circuits.? We do not want o induce unwanted signals into the receiver.

From Crystal Sets to Sideband, a very good starting place.? My Favorite are Solid State Design For Radio Amateurs,
and Experimental Methods in RF Design (Both ARRL).? Neither are light bits and do require several reading through
passes to pick up that what was mentioned here is often elaborated and related to things there.

***Makes me wonder how the ft817 does hf, vhf and uhf...?

Lots of tuned filters, careful layout the use of the chassis as cooling, shielding, and mechanical support.

Its worth looking at Elecraft K1 and K2 as the manuals and detail in them is very good as examples.
I'd add KNQ7A? and the KD1JV Sopbucket 20 as a simple monoband, and a few other as well.? Generally
the designers are creative people so watch for solutions to problems not outwardly discussed as its
often not featured but important.? Cooling and layout are often not obvious without analysis.? Same can
be said for component choices.


Allison

Jeff

great question on what's a good transmit path design.? since I have the K2 manual here --

predriver is a 2n5109, feeding a (;3 transformer on a FT37-43

driver is a 2SC2166 NPN feeding a 12:8 transfomer on a FT37-43

maybe some soft equalization network here ?? that's all I see that might seek to flatten RF performance

the PA is push-pull pair of 2SC2166 into a transformer to achieve the desired output power to feed 50 ohms

these devices fit the original K2 price target but not now the primary, global uBITX users.

the FT817 uses different PA devices for VHF/UHF than HF I think.? I imagine the VHF/UHF PA module may cost more than a uBITX.? obviously the climb for HF to 50 MHz requires more savvy PA devices.?

on the uBITX PA, when details are revealed on the IRF510 PA designed by Allison and Hans for the QSX there will be something of value here for v5, and to see if we can improve use of the v4 board.?

73 Curt

I wonder if the JackAl will overcome the CW issues?? I have agc and 'thump' mods in place which help.? I still have issues with a delay on transmit, losing about half of the first letter sent and issues with getting the IF aligned properly. Granted, that last part is likely me.?

Thanks
Mark
KC4GIA?

For me at least, this is more conceptual, but I am interested in understanding more after reading about the issues? with the uBitx power amp driver and predriver problems.? What are the best practices for designing this portion of a transmitter when it is to cover such a wide range of frequencies?? I imagine it also applies to a monoband radio.

This is what comes to mind based on my limited knowlege and what I've gathered from reading stuff here.

1)Keep amplifier intos and outofs away from each other.
2)Keep amplier gain stages reasonable.? Add more stages instead of upping gain.
3)Pick the right device for the desired frequencies.? Obviously 2n3904's don't work for this application.? Does picking a part with an fT about 40 times the highest desired frequency a safe bet?? Can you pick an fT that is too high (like a npn transistor with and fT of 10 gHz for a 3-30mHz radio)?? I ask this last bit after looking through the digikey transistor offerings...

I suppose any device needs to be tested and tweaked for its application.

4)Keep rf wires/traces away from each other and from the dc path.??

Makes me wonder how the ft817 does hf, vhf and uhf...? I suppose it could be a good exercise to look at how others have done it successfully, like elekraft with the k2.? It will be interesting to see how the QSX does it.

Would making a transceiver optimized for one band and then making transverters for the other bands avoid some of these problems?? I'm thinking of what is outlined in the From Crystal Sets to Sideband book.

-Jeff
AG7NW

Acknowledged, I'll have a look to the wiki then.