Date   
Re: SODA POP II update

ohwenzelph
 

figured out how to eliminate the display multiplexing noise from the audio without having to blank the display. All it took was adding a "Capacitor" multiplier circuit to power the mixers and op amp.”

So is this a mod that could(?should) be applied to the earlier soda pops? And if so, what would be the details for the older boards???

SODA POP II update

Steven Weber
 

Progress is being made. 

I ordered the final rev of the board today. It took 3 tries, but I think this one won't need any cuts and jumps. I finally figured out how to eliminate the display multiplexing noise from the audio without having to blank the display. All it took was adding a "Capacitor" multiplier circuit to power the mixers and op amp. 

I'm not sure I'll have these ready to ship before I take off for my spring hiking trip, which starts in about 3 weeks. I'll be back in time to go to Dayton and FDIM, so I hope to bring some there. LnR talked me into going this year, so you can find me in their booth. 

73, Steve KD1JV 

Re: New file uploaded to kd1jvdesigns@groups.io

John KG9DK
 

Thanks Steve, just what was looking for.   Very well done, I will be very useful to me. .
john kg9dk

New file uploaded to kd1jvdesigns@groups.io

kd1jvdesigns@groups.io Notification <kd1jvdesigns+notification@...>
 

Hello,

This email message is a notification to let you know that a file has been uploaded to the Files area of the kd1jvdesigns@groups.io group.

File: SB_II_BlockDiagram_voltage_chart.pdf

Uploaded By: Steven Weber

Description:
SBII functional block diagram and voltage charts

You can access this file at the URL:
https://groups.io/g/kd1jvdesigns/files/Slop%20Bucket%20II/SB_II_BlockDiagram_voltage_chart.pdf

Cheers,
The Groups.io Team

Re: Trouble shooting wish list for sb2

ajparent1/kb1gmx
 

If your using the radio for SSB and CW and no digital mode the heatsink is adequate.

IF the box is very tight (no airflow) then a larger heatsink is not an aid but an
external one would be with coupling to it.

its the FT8 and a few others that are the run to over heat or destruction mode.
The high duty cycle at full power is killing for many radio even commercial.

Allison

Trouble shooting wish list for sb2

John KG9DK
 

I am just passed the stage of turning on my slop bucket 2 for 40M.  happy to report I have a good display, did find one missed solder joint in the audio receive circuit.  I found that Q10 on the PCB is label Q23 in the schematic.
My wish list would be
1.Block  diagram showing signal flow and gain
2. DC voltage reading especially on the control transistors that is selecting the  receive and transmit signals. 

I have not install IRF510B yet, I am wanting to increase the heat sink, I am looking for a .6 x 1 x 1 piece of aluminum and I have not figures out the enclosure size yet.  I assume the heat sink that close to the toroids coils is not an issuse?
My enclosure will probably be made out of single sided PCB so I have some choices.  My unit will probably be use inside since I gotten to old do any camping so size and weight does not enter into the equation.
Thanks for any help with the above, remember this is a wish list not gripe list, I appricate the work Steve have put into this project is sharing it with us.
john kg9dk

Re: Just finished old TennaDipper Deluxe

ajparent1/kb1gmx
 

I have one with the then vendors case and its a handy item for check and tuning
mobile whips without bringing the MFJ259B.

Enjoy!

Allison

Just finished old TennaDipper Deluxe

 

Great little kit I got off a ebay sale. Wish it had the original case but the one I got works out pretty good, no internal battery.

Case is not a the type I normally get with the top and bottom separate but it worked out nice.

 

https://www.ebay.com/itm/Aluminum-Enclosure-Electronic-DIY-PCB-Instrument-Project-Box-Case-100x74x29mm/380783805864?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

Re: Troubleshooting the SB II

John AE5X
 
Edited

I will pull the processor out and re-install with the socket - didn't mean to skip the socket the first time around. I can remove it fairly easily with Chip-Quick that I have on hand. The Si5351 chip and display are installed correctly.

Re: Troubleshooting the SB II

Don, ND6T
 

Lacking a good variable supply for testing, try this instead: With pin 3 of U7 still isolated, attach a 100 ohm resistor from it to ground while measuring the voltage on the pin. This will provide a 33 ma current load. The chip is rated to 50 ma. It should present a nice 3.3 volts. If not, then replace the bad chip. If the voltage holds at 3.3 volts, remove the display and test.

Re: Troubleshooting the SB II

Steven Weber
 

 

Unless the display is in the wrong way around, I doubt that’s it. It’s a shame you didn’t socket the processor as pulling that could be telling. I doubt it’s the regulator, those are nearly indestructible. Could be the Si5351 chip is in the wrong way around.

 

There are only three things connected to the 3.3V supply, the processor, the display and the Si5351. Sorry I didn’t make the 3.3V supply track more accessible otherwise you could cut the track between the different pieces and see which one is pulling down the supply. Does the regulator get hot?

 

 

 

Two possibilities spring to mind: One is that the failure is a load with a breakdown voltage below 3.3 volts. That would look good on a low-voltage ohm meter but present an excessive current drain under operating voltage. This might be seen (or may not) by using the diode function on your DMM. Some DMMs have highter diode test voltages than others.
The other possibility is a bad regulator chip. It just might THINK that the load exceeds that 50ma rating and shuts down. Were you able to substitute the 3.3 volts and monitor the current as you increased it slowly from zero?
I would still suspect that the fault lies within the LCD display. I would remove it before anything else. Just a feeling.
Voltage regulators are extremely reliable.

 

Re: Troubleshooting the SB II

Don, ND6T
 

Two possibilities spring to mind: One is that the failure is a load with a breakdown voltage below 3.3 volts. That would look good on a low-voltage ohm meter but present an excessive current drain under operating voltage. This might be seen (or may not) by using the diode function on your DMM. Some DMMs have highter diode test voltages than others.
The other possibility is a bad regulator chip. It just might THINK that the load exceeds that 50ma rating and shuts down. Were you able to substitute the 3.3 volts and monitor the current as you increased it slowly from zero?
I would still suspect that the fault lies within the LCD display. I would remove it before anything else. Just a feeling.
Voltage regulators are extremely reliable.

Re: Troubleshooting the SB II

John AE5X
 
Edited

I finally had time to return to this...

With the output pin of the 3.3V regulator lifted I get 3.7V as shown in photo above. With it re-soldered to the board, I only get 0.4V indicating to me that something downstream is loading it down or shorted to ground. Ohmmeter readings of the pad show that not to be the case - I get from 800k-ohms to ground on the output pad (this value rises as C73 and C76 charge as a result of the meter's voltage).

I'm baffled...

Re: Blank display on SBII

Don, ND6T
 

I just realized that I had not tied up this string of messages. Please forgive me.
The issue was caused by a defective display. A new one, ordered from Amazon, performed just fine.
My groping about in the dark caused me further problems, though. When I "erased" the EEPROM settings upon re-loading the firmware I used the Arduino default of loading all zeros into EEPROM. Wrong! You need to load all ones for this firmware. Duh! Read the code, Don!
Dissection of the original display revealed a microscopic crack in the substrate of the LCD (not the carrier board). Likely it worked through any QC tests before it opened. The SB2 is an incredible rig. No one can tell that I am not using an Elecraft. AGC is superb. CW operation is a dream. This was a really fun build.

Re: SB II Final Transistor Heat Sink

ajparent1/kb1gmx
 

I said I didn't take a picture of SB-1 and SBII is uncased and pending so I've left it stock for now.
Likely I'll do something but first I want to decide if it  will stay on 40 or move to 80 or maybe
elsewhere.

No fan, on the SB1 or likely for SBII as I really am onto into FT-8, I'd rather plant grass and
watch it grow.

Allison

Re: SB II Final Transistor Heat Sink

n9dxp
 

Thank you very much Allison! That it all very helpful information. Would you by any chance have a picture of your radio? Did you use a fan?

 

Thanks,

 

George

Re: SB2 Q6 failure

ajparent1/kb1gmx
 

I went with the 4148. 

Based on older experience (and the SB1) I was more comfortable with that.


Allison

Re: SB II Final Transistor Heat Sink

ajparent1/kb1gmx
 

On my  SB1 20M whch had a very similar outline and layout just different display.

I used a block of aluminum behind the final to couple it to the aluminum front panel 
in place of a spacer and an Lshaped aluminum (1" Angle alumnum) to go from
behind the irf510 to the block on the other side of the board.  The Angle aluminum
was about .1 thick. The idea was conduct the heat to the front panel (.080 aluminum)
and take advantage of the surface area.  For voice it never even got warm.   
Sorry no pictures.

For digital work the heat sink must be huge compared to the supplied one as the
full power transmit time is 100% effectively.   Voice work the average power is
under 20% often less.  Also the box must have air flow to allow heat from the final
and its larger heatsink to escape the case.  Consider using a small 40 to 60mm
fan for cooling as well. The major trick is do not make the IRF510 leads longer
or stability may be compromised. also note the tab is the drain connection so
it has the main power on it and RF so it must be insulated from any cooling
structure (it must conduct heat) and that structure must be grounded.

The IRF510 can stand up and have a block of aluminum to couple the
heat to the back  of the case.  For that I'd say a block .625"W x1"D x1"H
might do well to get to the edge of the board and couple heat to a larger
finned heatsink.   the IRF510 is mounted to the .625" wise face and the
1"x1" face to the heatsink.  Again insulating kit and ground the heatsink.

Allison

SB II Final Transistor Heat Sink

n9dxp
 

Hello all,

 

I have enjoyed following the updates on the new Slop Bucket II projects. I have S/N 120 which will be used on 40 meters mostly digital modes. I have almost all of the surface mount components installed (I do them by hand). I am wondering if anyone might have any thoughts or suggestions on a more substantial heat sink for the digital modes.

 

Thanks,

 

George, N9DXP

Johnson City,TN

Re: SB2 Q6 failure

Steven Weber
 

 

Couldn’t hurt.

 

So, not having built my SB2 yet and planning on 40 meters, should I simply replace Q6 with a 4148?