Date   

Re: UBITX V3 TX GAIN VARIATIONS

Kees T
 

......and the "compensation capacitor", since it's across RF voltages, should be a 500V Mica in the 47pF to 150pF range.

73 Kees K5BCQ 


Re: Personal Best Distance, SSB Phone #ubitx

 

I worked a station in Antartica from my QTH in Oregon, a distance of 10,455 miles, on a Bitx17A running 8 watts into a EFHW antenna. I have the QSL card to prove it!

Joel
N6ALT


Re: calibration question #ubitx-help

Mike KK7ER
 

Thanks, Iz Oos!  Just to be sure I'm not missing something subtle, why not just use WWV?  It is AM, isn't it?  And I know for sure that it is on 10.000000 MHz which is more than I can say for AM shortwave broadcasts chosen at random.

--Mike


Re: UBITX V3 TX GAIN VARIATIONS

Kees T
 

.....and I would still parallel a 1nF-10nF capacitor across the existing 100nF DC bypass capacitors....including the 2 MOSFET bias voltage bypass capacitors.

73 Kees K5BCQ


Re: Nextion 3.2 for CEC 1.097 #ubitx

SV9CVJ Nikos
 

Thank you very much dear Art this is a great help for me .


Re: UBITX V3 TX GAIN VARIATIONS

Kees T
 

Allison,

All of the WA2EBY derived dual MOSFET Amp designs I've seen (IRF510, RD16HHF1, RD15HHF1) have a "compensation capacitor" across the output transformer primary.  Used to balance the 3-30MHz range gain. I used one on my 20W Amp kit (and the feedback loop if needed).

The uBITX PA does not have such a capacitor on the schematic .....why ?

73 Kees K5BCQ


Re: Personal Best Distance, SSB Phone #ubitx

George Wulf
 

Can anyone send me a pic of uBITX manager with the loaded information for a ver 3. The uBITX is loaded with 1.097 and the display is loaded. I’m unfamiliar with the information process. I have learned so much on this project and want to continue to do so. I read everything that is posted here. It is truly a learning experience. 73’s KN4LPH


Re: BITX40 Saving Settings Issue

Allard PE1NWL
 


Double-check the PTT-sense wiring and resistor value (10K).
Also check the ground connections of the BitX40 main board and the Raduino.
General rule: All ground wires shall be connected to ONE central ground point ("star" configuration). There should be NO ground loops.

73 Allard PE1NWL


Re: BITX40 Saving Settings Issue

Allard PE1NWL
 

Hi Gary,

Perhaps there is a problem with your PTT_sense line.
The CW options in the SETTINGS menu are only available when the PTT_sense mod is installed.
Double-check the PTT-sense wiring and resistor value (10K).

Background:
When you power on, the software first checks whether or not the PTT_sense mod is installed. It does this by testing the logic level on the PTT_sense input.
If the mod is installed, the PTT_sense line will be LOW. If it is NOT installed, the PTT_sense line will be HIGH.

73 Allard PE1NWL


Re: calibration question #ubitx-help

iz oos
 

It seems out of calibration. To be sure follow the hint of using AM broadcasts on shortwave. They are exactly on the frequency they are supposed to be. You can use either LSB or USB and tune exactly to the point where you 'zerobeat' the carrier, so you don't hear the carrier of the AM broadcast and the audio sounds good. Read that frequency, eg. If you read for instance 15248.5 instead of 15250 you may want to calibrate. My uBitx was only 150hz and I left that like this.


Il 30/ago/2018 18:44, "Mike KK7ER" <groupio@...> ha scritto:
Two questions:

When I tune in 10MHz WWV in LSB mode on the uBITX, the frequency reads 9.998.500.  Does it mean the rig is out of calibration or is it supposed to read like this in LSB mode?  I note that Fc-BW/2 is exactly what I'm reading on the display so it makes me suspicious.  Before I go through the calibration procedure and potentially screw things up further, I was hoping someone can confirm.

BTW, the calibration procedure on hfsignals.com just says find an AM broadcast signal and says nothing about the mode the rig is set to (USB/LSB).  Doesn't the mode matter during calibration?  Thanks!

73 Mike KK7ER


Re: Nextion 3.2 for CEC 1.097 #ubitx

Art Olson
 

John, Nikos

 

Worked on page px 11 and 0  – not everything is correct but is about 90 percent. ATT and IFS don’t function correctly yet. Could be some others. I will stopped for today. Nikos I guess you have control until I hear back from you. Give it a try

 

Art – N2AJO

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of SV9CVJ Nikos
Sent: Thursday, August 30, 2018 9:53 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Nextion 3.2 for CEC 1.097 #ubitx

 

HI John

I've done all the resizing except page 11 and 0 px which is a little complicated for me .

Nikos SV9CVJ


Virus-free. www.avg.com


Re: Any Gerber Experts Round Here? #kicad #ubitx

Jerry Gaffke
 

Garbage in, garbage out.
And when fabbing PC boards, you really don't want garbage.
This world has way to many coffee mug coasters already. .

A local software tool such as Gerbv or GerbView will allow you to preview the files and see what's wrong.

You might also look over OshPark, they have a great front end for ordering boards.
    https://docs.oshpark.com/submitting-orders/preorder-checklist/
They give a good rendering of exactly what the board will look like before you enter your credit card number and pull the trigger.
If you can get it to where the board passes their checks and looks right, you have a good chance of getting back a usable board.

Jerry


On Thu, Aug 30, 2018 at 11:45 AM, Ben Holmes wrote:
You might find this amusing, but I already did this... and Fiverr responded with the following:

Unfortunately, your Gig request "Gerber Files... Convert RS-274D to..." did not pass our review.

It was misleading or unclear. Please explain, in a clear way, what service you need.

Repeating these violations can result in your account being restricted.


Re: UBITX V3 TX GAIN VARIATIONS

Gordon Gibby <ggibby@...>
 

Thanks Alyson!


On Aug 30, 2018, at 14:44, ajparent1/KB1GMX <kb1gmx@...> wrote:

Gordon,

For better than 10W on 80 and at least 7 on 20....

Replace q90 with something better, BFR106 was good.
MMBT2369 is ok.

Replace the standing 3904s with 2n2222A(to18) part.
Hint installing them from the bottom makes for better and easy.
take care to get them oriented the right way.  Also the cans for
adjacent devices can touch as they get connected together
at the board.

Test results.  On 5 of 5 that got the power up with minimum fuss.
10M will be better but not great maybe 2-3 more watts.

IF you don't want the power to soar on 80 try 470 to 1000PF at C81
(470, 510, 680, 820, 910, 1000pf are standard parts).
Pick the one that gets 80 tamed and 40 and 20 decent.  Getting
12W at 80 and 8 at 20 should be easy.  IF 30M is down its the
output low pass filter as 30M is near the cutoff frequency but 
not less than 5W and I usually saw 7w or more.

Allison


Re: Any Gerber Experts Round Here? #kicad #ubitx

Doug W
 

try messaging sellers direct instead of posting a job
--
www.bitxmap.com


Re: CW PTT attack time to slow #ubitx

ajparent1/KB1GMX <kb1gmx@...>
 

Another user installed the KD8CEC software and found it to be an improvement.

Changing the pull up will not help the issue.  The factory code is slow in
recognizing keying.

Allison


Re: uBitx Unfiltered

Jerry Gaffke
 

Allison had some good pointers on some first easy fixes to the uBitx in post
     https://groups.io/g/BITX20/message/57649
First and foremost, either fix the on-board transmit LPF routing somehow
or add an external LPF between the uBitx and antenna appropriate to the band you are using.

Beyond that, she suggested replacing Q90 with a BFR106, reduce C81 to 470-1000pf and
replace Q911,912,92,93,96,97 with 2n2222's to get a more even power across the bands.
These mods are not of much use if you are just using it on the lower bands to avoid spurs.

 
But if the current power amp is coupling into the IF amps and creating extra spurs
and we need significant mods to get the uBitx power amp to give reasonably clean and flat power
across all of HF, then perhaps best for the power amp to be a separate board.

So clean up the local oscillators and signal levels into the mixers on the uBitx.
Then saw off (or disable) the back end of the uBitx where we have the power amp and LPF's and LPF relays.
Replace that back end with a separate board for the power amp and LPF"s.
Perhaps use kits that Kees has up at 
    http://www.qsl.net/k5bcq/Kits/Kits.html
Perhaps use Han's upcoming QSX 10W amp, which he is planning to sell separately:
    https://groups.io/g/BITX20/message/57420
    https://radioaficion.com/news/qsx-sdr-transceiver/
If required, add per-band filters between the exciter and the new power amp board.

Would be nice to have a simple analog SSB exciter and receiver that works well from 3-30 mhz.
The uBitx can fill that role.  The QSX may turn out to be a fine rig, but the uBitx can remain
the rig of choice for analog experimentation.  Not all of us want to play with DSP firmware.
 
Jerry, KE7ER


On Thu, Aug 30, 2018 at 10:32 AM, ajparent1/KB1GMX wrote:
I still believe "there is a pony out there" .....small handful of parts and a good dual relay switched LPF board.
73 Kees K5BCQ 

Isn't the rest of that is "I can smell it...."

Yes ferrite and a few more caps in the right places plus some top pour of copper
with stitching to tie it all down so ground (there is no such thing) has less
transverse current paths and lower surface resistance.  

Why say that...  Adding parallel caps is useless if the ground it goes to has
RF resistance (or inductance).  The DC lines start right next to the power amp
so ferrite and caps liberally spread about limits the distribution.  At one point the 
R18, R28, R38, and R48 were tried at 330 ohms with 9.6V Zener at each
corresponding cap to ground was added.  That stuffed the spurs (not the
primary ones) down by 6DB.   So yes there undesired RF on the switched
DC.

Allison


Re: Amplifier #ubitx #ubitx-help #parts

ajparent1/KB1GMX <kb1gmx@...>
 

Due to filtering issues and spurious outputs doing that is not recommended.

If you do, familiarize yourself with telecommunications rules that apply to your
country.  You may not be in compliance.


Allison


Re: Any Gerber Experts Round Here? #kicad #ubitx

Ben Holmes
 

You might find this amusing, but I already did this... and Fiverr responded with the following:

Unfortunately, your Gig request "Gerber Files... Convert RS-274D to..." did not pass our review.

It was misleading or unclear. Please explain, in a clear way, what service you need.

Repeating these violations can result in your account being restricted.



Re: UBITX V3 TX GAIN VARIATIONS

ajparent1/KB1GMX <kb1gmx@...>
 

Gordon,

For better than 10W on 80 and at least 7 on 20....

Replace q90 with something better, BFR106 was good.
MMBT2369 is ok.

Replace the standing 3904s with 2n2222A(to18) part.
Hint installing them from the bottom makes for better and easy.
take care to get them oriented the right way.  Also the cans for
adjacent devices can touch as they get connected together
at the board.

Test results.  On 5 of 5 that got the power up with minimum fuss.
10M will be better but not great maybe 2-3 more watts.

IF you don't want the power to soar on 80 try 470 to 1000PF at C81
(470, 510, 680, 820, 910, 1000pf are standard parts).
Pick the one that gets 80 tamed and 40 and 20 decent.  Getting
12W at 80 and 8 at 20 should be easy.  IF 30M is down its the
output low pass filter as 30M is near the cutoff frequency but 
not less than 5W and I usually saw 7w or more.

Allison


Re: Any Gerber Experts Round Here? #kicad #ubitx

Doug W
 

I've had some luck with hiring on fiverr.com for totally unrelated small tasks.  Might be worth seeing what you can find searching "convert gerber".  Contact anyone that has a listing close to what you need and see what they say.
--
www.bitxmap.com