Date   
Re: VOM Advice?

 

I have heard good things about this MM from several different sources. I don't think you can beat it for quality/features VS price.

https://www.ebay.com/itm/ANENG-AN8008-True-RMS-Wave-Output-Digital-Multimeter-9999-Counts-Backlight-AC-DC/222719150587?hash=item33db1889fb:m:mSCw_nrSk9gqavl1qMGdf8Q

Joel
N6ALT

Re: VOM Advice?

Gwen Patton
 

I have a couple of older Radio Shack VOMs around here, mostly for field use (from back when I did computer field service), but I lucked out for my bench VOM. I got a Fluke 27/FM, the military model, on Ebay. If not for a song, it was at least for a couple of choruses and a jingle -- a small percentage of the original price of the civilian model. This one was of a large batch that had been purchased for the military and never deployed, but instead had been warehoused. They maintained them well, calibrating them before they sold them off. I paid about $80 plus a little shipping. It has served me more than adequately, and is a True RMS meter with a HUGE display and more features than I'll ever use. I love the thing to pieces.

Keep an eye out for sales of such on Ebay. If you spot such a deal, pounce on it. You won't regret having such a wonderful device on your bench.

Gwen NG3P

Re: Transmitter Mods

Rob Snow
 

Sajid,

Just to lower your anxiety I'm going to post a pic of my mods so you can see how badly it can be done and still work.  May the soldering gods have mercy on my soul for posting this with my globs of dull solder!

This was done with a flat tipped soldering iron + wick, some vodka for my shakes (I'm old) and +3.0 eye glasses.  Note that the cap on top of R87 looks like it's not connected with solder, but if you zoom in you'll see it is.  I decided not to go back in with wick to clean it up as nobody will ever see it (until now). 

If I can do it, you can.   Start with R87 and R88, they are much easier as all you need to do is hold the cap down on top (I used the pointy end of my tweezers to stab it down) and dab some solder on one of the ends to get it to hold.

73 Rob AG5OV (prepared for the wrath of the soldering gods)

Re: Transmitter Mods

Art Olson
 

Howard

Would like to request the parts for the mod. What do you need from me

Art - N2AJO 


On Jun 15, 2018, at 10:27 AM, Rob Snow <rsnow@...> wrote:

Sajid,

Just to lower your anxiety I'm going to post a pic of my mods so you can see how badly it can be done and still work.  May the soldering gods have mercy on my soul for posting this with my globs of dull solder!

This was done with a flat tipped soldering iron + wick, some vodka for my shakes (I'm old) and +3.0 eye glasses.  Note that the cap on top of R87 looks like it's not connected with solder, but if you zoom in you'll see it is.  I decided not to go back in with wick to clean it up as nobody will ever see it (until now). 

If I can do it, you can.   Start with R87 and R88, they are much easier as all you need to do is hold the cap down on top (I used the pointy end of my tweezers to stab it down) and dab some solder on one of the ends to get it to hold.

73 Rob AG5OV (prepared for the wrath of the soldering gods)

<2018_06_13 19.15.00.jpg>

Re: How hot is too hot? #ubitx

Allen Merrell
 

Nextion  recommends using at least 500 ma supply for their display. 
--
Allen  Merrell

Re: Can't get my uBitX to transmit CW on the Dial frequency

Tim Gorman
 

Jerry,

On Thu, 14 Jun 2018 20:57:48 -0700
"Jerry Gaffke via Groups.Io" <jgaffke=yahoo.com@groups.io> wrote:

I'm not sure what you mean about shifting the BFO.
The BFO has nothing to do with transmit.
On receive, it can remain exactly where it was for SSB operation.
The original message says: "The uBITX is on CWU has a 700 Hz sidetone
set (ie offset) then the dial on the uBITX needs to be at 7.029.300
Mhz  so that it is receiving a the Flex with a 700hz audio tone."

If you are working CW at 7030 then why should you have to set the
receive frequency to 7.029.300? That just means you need to know
whether you are in CWL or CWU and do math in your head to know what
frequency you are actually listening to!

Why not just shift the BFO so the receive frequency can remain showing
7030 and you still get your 700hz tone?



And no idea what all the other software releases out there are doing.
Mine is rigged as follows

On transmit the dial shows the frequency of the CW carrier (of
course).

On receive (if RIT is not enabled) it still shows the same operating
frequency in the LCD. However, the VFO is tuned up in frequency by
however many hertz the cw sidetone is set up to be if operating in
LowerSideBand mode, and down in frequency by that many hertz if
UpperSideBand mode.
This is *exactly* what I am saying. You are doing it with the VFO. You
can do it with the BFO as well! It's why my homemade receivers always
had two BFO frequencies. It was easier to shift the BFO oscillator with
a switched-in capacitor than to try and shift the VFO frequency in an
analog vfo!

Apparently the software Michael is using utilizes neither of these
methods.

tim ab0wr

Re: SI5351 quadrature VFO

Jerry Gaffke
 

Hans,

Code for the uBitx has been using my si5351bx routines since day one. 
Allards Bitx40 code also uses these routines starting summer of 2017.
The uBitx routines are also 32 bit fixed point math. 
Precision was within about 10ppb as I recall.
So the uBitx tuning is correct within about 30e6/10e9 =  0.3 Hz when operating at 30mhz, is proportionally better as you go down in frequency,
the 25mhz reference oscillator will vary by far more than that with slight variations in temperature.
Of course, the calibration must be done correctly per post 35235 to approach this kind of accuracy.
Judging from all the posts to the forum about having to take multiple runs to calibrate vfo and bfo and clk1, 
most uBitx software releases out there have not yet gotten this right. 

Primary execution time constraint is shoveling all those i2c bits out to the si5351 at 100khz,
could be bumped up to 400khz if that's of concern.

The uBitx shuts down clk0 and clk1 when transmitting CW, this avoids any possibility of 
those mixer products getting out to the antenna.  A slight speed-up of maybe 10 milliseconds could be had
by only touching the clock-enable bits in si5351 register 3 to turn these off and on rather than 
loading all those msynth registers each time.  Doesn't really matter unless attempting 
full break-in for high speed CW with solid state TR switching.

Jerry, KE7ER



On Thu, Jun 14, 2018 at 10:27 pm, Hans Summers wrote:
Use of floating point arithmetic greatly increases the code size. And execution time - but generally I have found the execution time is not usually a constraint, neither is RAM or EEPROM... the biggest constraint I run into is the Flash program memory size. 64-bit arithmetic increases the code size even worse than floating point. Accordingly I use only 32-bit unsigned integer arithmetic in my Si5351A configuration routines in my firmware. It is possible to do all the calculations in 32-bit arithmetic without losing any precision (Floating point loses precision, 64-bit increases the code size too much). The result is compact code and accurate. 
 

Re: Transmitter Mods

Howard Fidel
 

Stamped self addressed envelope sent to my QTH.


On 6/15/2018 10:52 AM, Art Olson via Groups.Io wrote:
Howard

Would like to request the parts for the mod. What do you need from me

Art - N2AJO 


On Jun 15, 2018, at 10:27 AM, Rob Snow <rsnow@...> wrote:

Sajid,

Just to lower your anxiety I'm going to post a pic of my mods so you can see how badly it can be done and still work.  May the soldering gods have mercy on my soul for posting this with my globs of dull solder!

This was done with a flat tipped soldering iron + wick, some vodka for my shakes (I'm old) and +3.0 eye glasses.  Note that the cap on top of R87 looks like it's not connected with solder, but if you zoom in you'll see it is.  I decided not to go back in with wick to clean it up as nobody will ever see it (until now). 

If I can do it, you can.   Start with R87 and R88, they are much easier as all you need to do is hold the cap down on top (I used the pointy end of my tweezers to stab it down) and dab some solder on one of the ends to get it to hold.

73 Rob AG5OV (prepared for the wrath of the soldering gods)

<2018_06_13 19.15.00.jpg>


Re: Went Dead

Bill Watkins
 

Is there a troubleshooting guide with suggested voltages and resistance?  

Probing what I believe to be collector and emitter on the two IRF510, looking from the rear, the left shows no flow from collector to emitter,  but the right shows 37.4 from collector to emitter.

Forgive me if using wrong terms.  New learning experience.



On Jun 14, 2018, at 11:28 PM, Ashhar Farhan <farhanbox@...> wrote:

Something has shorted. take out the PA power line and check?

- f

On Fri, Jun 15, 2018 at 11:54 AM, Bill Watkins <kf7yxs@...> wrote:
Was in middle of wspr transmission. Radio went dark. Power source checks out good. When cycle off and on, display just slightly flashes. Display and raduino work fine with usb to computer.

What happened?  Where do I start?

Bill





Re: SI5351 quadrature VFO

Ashhar Farhan
 

Are you sure these work upto 290 mhz? 

Re: The BITeensio board is here. #ubitx

BruceN
 

Is the BITeensio board compatible with CEC software?  Looked on your page but didn't find and answer.  Maybe didn't look close enough.

Bruce, K4TQL

Re: uBitx has a bit too crispy / semi-distorted audio even on low signal levels #ubitx #ubitx-help

ajparent1/KB1GMX <kb1gmx@...>
 

There is distortion, sounds like clipping in the receiver due to overload
by a strong signal.

Also check to see if the Q70 mod is needed, it is listed in a different thread.

The last items is maybe the speaker itself is bad and distorting.

Allison

Re: The BITeensio board is here. #ubitx

Jim Sheldon
 

No it is not.  CEC only runs on a NANO and his I2C display is on I2C Wire 0 where our card (and software) runs on a Teensy 3.6 and uses Wire 2 for all I2C I/O. We have abandoned the NANO as too limited.

Jim

On Jun 15, 2018, at 10:41 AM, BruceN <k4tql@...> wrote:

Is the BITeensio board compatible with CEC software?  Looked on your page but didn't find and answer.  Maybe didn't look close enough.

Bruce, K4TQL

Re: The BITeensio board is here. #ubitx

Jim Sheldon
 

Hi Bruce,
Tried to answer this from my  iPAD but I don't think it sent.

NO, Ian's CEC software is NOT compatible with our BITeensio board - he handles his I2C in a totally different way than we do and his stuff will not work on our board.  Besides, we have abandoned the NANO as an MPU and are now using Teensy 3.6 MPU's so none of his stuff will run on our boards.  Our own software will, however work just fine.

Jim

------ Original Message ------
From: "BruceN" <k4tql@...>
Sent: 6/15/2018 10:41:01 AM
Subject: Re: [BITX20] The BITeensio board is here. #ubitx

Is the BITeensio board compatible with CEC software?  Looked on your page but didn't find and answer.  Maybe didn't look close enough.

Bruce, K4TQL

Re: The BITeensio board is here. #ubitx

BruceN
 

Thanks Jim for the fast reply.  Now, another question: what are the feature differences between your software and Ian's CEC software?  I'm sure I could find it somewhere but an answer from you would be a lot quicker.  I do like the idea of the Teensy for the expanded computing power.  Makes for expanding the system features more likely.

Bruce

Re: Went Dead

ajparent1/KB1GMX <kb1gmx@...>
 

They are mosfets and do not have have collector or emitter.

It looks like your probing Drain to Source and one way should be nesr open and the other
you should see the substrate diode.

IF the fets are shorted then will show near zero ohms Source to Drain. 

When you turn it on how many amps does it require?
What is the Voltage at the power supply after you turn it on?
If you disconnect the BROWN wire (power to the output transistors) does it power up?

Allison

Re: How hot is too hot? #ubitx

ajparent1/KB1GMX <kb1gmx@...>
 

Recommends or maximum of 500ma?  That seems like a very high
number and I'd expect it to be seriously bright.

The reason I ask as my 7" touch screen all total draws less than that with a
HDMI interface(video)  and USB( touch screen). 

As to 7805 heat... Keep it under 70C (168F) as the device has a thermal shutdown
and it lives longer.  

Allison

Re: How hot is too hot? #ubitx

Kees T
 

I would sure (and have) reduced the intensity of the backlight with a pot for any of those type displays. Then add a buck converter to reduce the 13.4V to about 7V for the poor ol' 5V regulator. 

73 Kees K5BCQ

Re: Went Dead

Bill Watkins
 

Did the quickest check first. When brown wire disconnected, it powers up. 

Btw, I appreciate your help very much. 

Bill
K0WHW




On Jun 15, 2018, at 12:06, ajparent1/KB1GMX <kb1gmx@...> wrote:

They are mosfets and do not have have collector or emitter.

It looks like your probing Drain to Source and one way should be nesr open and the other
you should see the substrate diode.

IF the fets are shorted then will show near zero ohms Source to Drain. 

When you turn it on how many amps does it require?
What is the Voltage at the power supply after you turn it on?
If you disconnect the BROWN wire (power to the output transistors) does it power up?

Allison

Re: How hot is too hot? #ubitx

Lawrence Galea
 

Simply add a 7808 or 7809 before the 7805
Regards
Lawrence

On Fri, Jun 15, 2018 at 7:17 PM, ajparent1/KB1GMX <kb1gmx@...> wrote:
Recommends or maximum of 500ma?  That seems like a very high
number and I'd expect it to be seriously bright.

The reason I ask as my 7" touch screen all total draws less than that with a
HDMI interface(video)  and USB( touch screen). 

As to 7805 heat... Keep it under 70C (168F) as the device has a thermal shutdown
and it lives longer.  

Allison