Date   
Re: Reverse Polarity Protection.

Evan Hand
 

Since it is 1 amp, I assume that it is only protecting the board, and not the PA.  When on 80 meters, my v4 and v5 boards will draw 2+ amps total.  That would be close to the trip point of the poly switch that you specified.

On my v5 rig, I have split the fuses, and have 2 1n4001 diodes in series from the 13.5 vdc supplying the rig and the separate feed to the board (red wire on the supplied connector).  The reverse protection is then on the fuse for the PA, since the two series diodes would protect the rest of the board from reverse power.  If i connect the power supply incorrectly, the 3 amp fuse in the PA lead will pop.  This arrangement also allows me to remove the PA fuse and power the rest of the transceiver for testing.  When doing this, the reverse protection is the diodes in series with the power supply to drop the voltage to just under 12 volts.

73
Evan
AC9TU

Re: Reverse Polarity Protection.

Denys VK3zyz
 

That is why I used a polyswitch. It is a resettable fuse :)

https://www.mouser.com/ProductDetail/Littelfuse/RXEF110?qs=hv6pn79dJPSCD61RjaQM8g%3D%3D

Re: Board Map/Layout, Test Points? (V5)

MVS Sarma
 

I don't remember, Farhan has ever released board  layout or its photo

Sarma   vu3zmv

On Tue, 26 Mar 2019, 10:49 pm ronmhauser via Groups.Io <ronmhauser=yahoo.com@groups.io wrote:
New Question:  I have the high res PDF schematic, and I have been searching around to see if I can find a high resolution board layout or graphic.  Is this out on the web somewhere? 

The answer may be "no."  I'm coming into this new uBitx world from working on old Kenwoods, where I had the service manual with schematic, board graphic, and level diagrams.  Of course I don't really expect these to exist for a hundred dollar kit radio, but it never hurts to ask before I put on the magnifying glasses and start tracing.  

Thanks!
--Ron
K0EIA

Re: Reverse Polarity Protection.

Evan Hand
 

I would agree, as I too had a reverse polarity issue.  For me it was a left over HP power brick; HP has for some reason reverse polarity on the barrel connectors.  I forgot this and plugged it in.  Never got to turn on the rig, as the power supply crow bar shut down the power supply.  Would have fried the rig if I had not wired up the diode as listed in the wiring directions.  The only thing I would add is make sure you have a fuse in line upstream of the diode.  This is really critical if your supply can provide more than 3 amps, and does not have a crow bar shutdown circuit.

73
Evan
AC9TU

Re: Shaking my head in disbelief....

Kelly Mabry
 

Oh, Raj, you were right about the red wire.. 

Thanks!
Kelly K5AID 

Re: Shaking my head in disbelief....

Kelly Mabry
 

 Well after a few hours of teardown and reassembly, I salvaged the encoder and the board. It tunes flaky, tends to jump around, very sensitive tune rate....I also was able to hear wwv on 5 mhz. It does not jump in and of menus.

I have my Carolina windom connected to the ubitx, and am hearing strong signals, but not many so I am encouraged only slightly. 

Next step is to relax, and fix the volume control..tomorrow.  At least it works and sounds like a radio!
73,

Kelly K5AID 

Re: Second Nano @ i2c for spectrum, meters, CW-decode, etc

Ted
 

Hi, Mike.

Thanks for reaching out.  I'll check out that YouTube tutorial; it's possible that I've seen it though a silent demo doesn't always reach me. I want to know why we're doing one thing instead of another that seemed OK but wasn't.

I'll look you up and give a ring Wed. afternoon or evening, hopefully.

Tnx agn & 73.

Ted
K3RTA

Re: Black Squares on Raduino Display Redux #bitx40 #raduino

Denys VK3zyz
 

It sounds like a good idea would be to buy a spare Arduino to play with. I have a couple so I have a going one, and one to fool with.
That is, I could play around with it before I hooked my uBitx V5 power up backwards :(
Now I'm just trying to get it fully going again.
(It now has the reverse polarity installed!)

Re: Black Squares on Raduino Display Redux #bitx40 #raduino

Pat Anderson <anderson5420@...>
 

Yes, already tried that. The Raduino unplugged powers up with the USB cord, no black squares, just a blank yellow display. I tried compiling and uploading the Blink example, and same result, the system messages say " programmer not responding." So, I am guessing there might be an issue with the bootloader on the Arduino, but this is pretty much beyond me at this point, and I don't want to try anything that might brick the Radiuino, assuming it is not already bricked. Pretty sure I did not do anything that might have bricked it. This all started when I had finished the assembly and on first power on got the black rectangles, which I found on the forum other people have had the black rectangles as well, and then I found on Arduino forums the same thing had occurred on Arduinos not used for radio. On those other forums, it seemed the consensus was that the bootloader was missing or corrupted. That is where things stand today. Don't really know if my bitx-40 assembly was good because without the Raduino I cannot tune it.


On Tue, Mar 26, 2019 at 6:30 PM <dendad51@...> wrote:
It sounds like the Arduino is blank or dead. Can you unplug the Arduino from the Raduino board and just load "Blink" to it to check ti is ok?

Re: Black Squares on Raduino Display Redux #bitx40 #raduino

Denys VK3zyz
 

It sounds like the Arduino is blank or dead. Can you unplug the Arduino from the Raduino board and just load "Blink" to it to check ti is ok?

Reverse Polarity Protection.

Denys VK3zyz
 

I recommend you do install reverse polarity protection.
My v5 board now has a 1.A polyswitch and a reverse diode. I wish it did earlier!! For some reason, I thought I'd put that mod on later, and of course, just after getting it fully calibrated, I plugged the 12V gell cell battery in the wrong way around :(
I've replaced the burnt track feeding the power amp, Q15 and the 5V reg on the control board. It sort off works, but has lost sensitivity and clarity so I think a mixer is suspect. So far, I've not figured out what is wrong.
So, put the reverse protection on FIRST!!!!!

Re: Mic distortion

Sam Tedesco
 

Thanks everyone. Def going to try the easy stuff first. Have tried multiple linears,  mics,  preamps, etc.  

Re: Mic distortion

Arv Evans
 

The 0.001 mfd bypass at the microphone cartridge was sort of standard way back in the early
days of BITX.  It worked then, so should be something to try now.

Arv
_._


On Tue, Mar 26, 2019 at 4:41 PM Martin Potter <ve3oat@...> wrote:
I wonder if an RF by-pass capacitor (disk 0.01 uF) at the mic connector would do the job.  Anyone tried that?



Re: Mic distortion

Evan Hand
 

Another question, what mic are you using?  A dynamic mic would need to be connected through an preamp or compressor and isolated from the electret bias voltage.

I found the stock mic to not have enough drive, so added an amplified mic, and verified that I was not over driving the rig.

73
Evan
AC9TU

Re: Mic distortion

Evan Hand
 

Is the problem only with the amp connected?  How is the signal running "barefoot".

Since you have another receiver, I would load the uBitx without the amp into a dummy load and verify the signal with your Kenwood.  If that does not have the distortion, then would check the linearity of the amp or the SWR between the uBitx and the amp.

I also had issues with distorted audio when I had a miss adjusted BFO.  Put the output right on one of the edges of the filter, causing high frequency cut off on one end, and excessive carrier on the other.

I have read some posts where multiple pots with relays were used to adjust the drive setting based on band selection.  As long as you shielded the connections with appropriate RF cables, I would think that you could have a switch with a resistor/pot to change value of drive.

Again, these are my experiences and ideas, yours may be different.
73
Evan
AC9TU

Re: Black Squares on Raduino Display Redux #bitx40 #raduino

Pat Anderson <anderson5420@...>
 

Martin, thanks, but the current problem is not the black squares, it is trying to upload Allard's sketch to the Raduino. The current error message is "programmer did not respond." Not a contrast issue! Scratching our heads over what it is! 


On Tue, Mar 26, 2019 at 3:50 PM Martin Potter <ve3oat@...> wrote:
Sorry if I missed your answer some where, but did you try adjusting the little blue Contrast pot on the back of the Raduino board??   It isn't labelled but is the only one there.
When I first powered up my v5 board, the Contrast pot needed a small adjustment to get a readable display, otherwise black squares.



Re: Mic distortion

Sam Tedesco
 

Dynamic mic setup does the same. I haven't tried a bypass cap.
 

Re: Black Squares on Raduino Display Redux #bitx40 #raduino

Martin Potter
 

Sorry if I missed your answer some where, but did you try adjusting the little blue Contrast pot on the back of the Raduino board?? It isn't labelled but is the only one there.
When I first powered up my v5 board, the Contrast pot needed a small adjustment to get a readable display, otherwise black squares.

Re: Mic distortion

Sam Tedesco
 

Running an end fed with an air wound coax choke about 15 feet out from shack. I don't have any rf on my kenwood at 100 watts. Put ubit on linear at 50w out and still muffled. All wires have snap on ferrite 

Re: Mic distortion

Martin Potter
 

I wonder if an RF by-pass capacitor (disk 0.01 uF) at the mic connector would do the job. Anyone tried that?