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Sunday, April 22, 2018

KC1FSZ's Above Board, Al Fresco, Free Range, QRO, 4-Foot-Long, Wood-Based BITX



Hi Guys:

First off, congrats on back-to-back SPRAT covers.  

I’ve succeeded in my QRO quest.  Now I’m running the finals from 28V using a home-brew linear power supply and getting about 20W out.  LM723 + 2N3055’s.  I’m making a lot more contacts too.  The only problem is that the “Peppermint Line” is close to 4 feet long now! (Photo below).  I don’t know how N6QW gets his rigs packed into such small cases.  Putting the various boards in edge-wise will probably help a lot, so that’s going to be my approach to the final packaging job.


Bruce KC1FSZ

Saturday, April 21, 2018

Hyderabox! uBITX in a Lunch Box

Oh man, I'm sorry I missed this one.  John sent it to me in January, but it got lost amidst all the uBITX messages.  

I like it!  It shows that I am not the only one guilty of re-purposing Benton Harbor Lunch Boxes.  

But what should we call it?  It is now more Hyderabad than Benton Harbor.  How about Hyderabox?  That's it!   

  You mentioned in your last podcast recycling "Benton Harbor Lunch Boxs". Many decades ago I talked my Junior High shop teacher into letting me build a Twoer instead of his lame project. Over the years  2 meter AM and the Twoer faded away. 
I recently revived a Lunchbox case for my uBitx. I added a Sotabeams CW filter that is controlled by the old T/R knob. Down the filter is bypassed, up one is wide CW and up two is narrow CW. The green pilot light light is a CW tuning indicator. 
I use KD8CEC's code which cleans up many small problems and adds a memory keyer and CAT control to the uBitx.
I modded KD8CEC's code to remove the paddle sense segment so that it only works with a straight key. This makes the keying much cleaner. 
First contact with the modded uBitx was this morning. With 5 watts out I got a 599 from K3Y/7 (K7QBW) in Oregon back to me in Ohio.
    Bob    KD8CGH

Tuesday, April 17, 2018

N1AW's uBITX -- Cardboard Panels, and the Mic in a Sharpie

On Sunday night at 7 pm local on 7.277 MHz BITX users gather.   This week was the debut of my uBITX.  I was able to make only one contact before we were over-run by the Rookie Roundup, but that contact was a good one.  Above you can see N1AW's FB uBITX.   The front and back panels are made of cardboard.  The mic holder is from a re-purposed Sharpie marker.  FB Al.  Thanks for the contact.  

Sunday, April 15, 2018

Carpentry and Socketry for the uBITX

Yesterday I decided to spend some time at the bench -- I wanted to get the uBITX boxed up.  My basswood box had arrived from Amazon on Friday.  It was time for what George Dobbs G3RJV called "socketry."  

First, the back.  I figured I would need five connectors back there.   Connectors for 12V DC, speaker, and antenna would be needed right away (it is my preference to have the speaker connector on the back of the BITX).  Looking ahead, I might want to also have a jack for T/R control of my linear amplifier, and a jack for 24 VDC if I want to go wild and put more voltage on the drains of the IRF510s. So I put two extra holes in there.  

Basswood is SO easy to cut.  I put the LCD in the center of the front panel, and opted to put the board close to the front of the board.  This avoids the need for jumpers to connect the Raduino to the LCD, and it keeps the lines to the front panel controls and connectors very short. I mounted the board on the spacers that came with the BITX, drilling holes the bottom of the basswood box.  It all fit quite nicely. 

I would need to put two jacks on the front panels:  key jack and mic jack.  And I'd need two controls: main tuning and AF gain.  I used hole saws to cut holes big enough to accommodate the four items. 

The controls and jacks were then placed on two small pieces of copper clad board.  These then went on the front panel.  

Wiring up the uBITX was  easy.  I just followed Farhan's instructions.  I did the wiring AFTER placing the boards and controls in the box -- this helped me keep all the wires at their optimum length (not too long, and more important -- not too short!).  If you do it this way, put a cloth over the boards so you don't drop solder blobs on the uBITX. 

Farhan's uBITX fired up nicely as soon as I applied power.   The receiver really sounds nice.  I hope to make some contacts with it today. 

Three cheers for Farhan! 

Saturday, April 14, 2018

Boxing up my uBITX -- Question for the Group

Our friend Rogier and I are involved in an East Coast -- West Coast uBITX launch project -- we plan to assemble our uBITXs together (more or less, via Skype) and then get them on the air. 

As has been my recent practice, I have opted to put my uBITX in the same kind of wooden box that I used for my three scratch-built BITX projects.  See above. 

Now, due to Farhan's wizardry the uBITX is considerably smaller than the box.  This is, of course, a good thing. It leaves room in the box for many bells and whistles.  

But here is my first box design question

Should I put the uBITX board to the front of the box so that the LCD can be connected to the board DIRECTLY via the connector on the Raduino board (no jumpers needed), or should I put the uBITX board to the back of the box so that I can stick the PA heat sinks out the back?   In the later case I'd have to use 4 inch jumper cables to connect the LCD to the Raduino.  This use of jumpers seems to increase the possibility of noise from the display. 

What say the Knack Wizards?  Back of the box with LCD jumpers, or front of the box with no jumpers but heat sinks inside the box? 

Sunday, April 8, 2018

AMAZING 1999 Video on the Invention of the Transistor at "Hell's Bells Laboratory"

Thanks to Armand WA1UQO for alerting me to this.  I really liked the book -- "Crystal Fire" -- that this 1999 video is loosely based on. I'm also a fan of the narrator,  Ira Flatow, whose melodious voice is heard each week on NPR's excellent "Science Friday" radio show. 

A few observations and thoughts on the video: 

-- I liked the irreverant Calypso song "Hell's Bells Laboratory."  It looks like those folks had a lot of fun.  And wow, Shockly's secretary was named Betty Sparks.  TRGHS. 

-- I have the same big Variac on my bench.  And I have one of those "third hand" devices.  

-- I'd like to build my own replica of the point contact device with the triangular piece of lucite and the gold foil. 

-- While Shockley seems to be the real bad guy in this story (he seems to have all the bad characteristics of David Sarnoff,  Lee DeForest, and Steve Jobs),  I liked the his use of "physical intuition" to understand devices and the problems they were meant to solve.  

-- The image of the two Japanese founders of Sony working in the late 1940's in a bombed out department store was very powerful.   

-- Although I came on the scence a bit later, I WAS one of those kids who used a transistor radio and an earphone to surreptitiously listen to rock-and-roll music. 

-- "More transistors are made each year than raindrops fall on California."  Hmmm.... 

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Friday, April 6, 2018

Solder Haze -- Sing Along with N8NM and Jimi Hendrix

Back when some us were thinking of new names for the podcast, Steve, N8NM thought of Purple Haze by Jimi Hendrix and came up with this set of lyrics (listen to the video above to get the tune). 

Solder Haze, all in my brain
Making rigs, some don't work that great.
They're acting funny, but I don't know why
Kill some birds for that Legba guy.

Solder Haze, all around.
Don't if I should turn the bias down.
Or maybe I should raise the Vcc
Oh, it's a FET, that would make it Vdd.

Solder Haze, all in my eyes
Don't know if it's day or night.
You got me blowing, blowing my mind
Come tomorrow,  I won't be to work on time. 

Pete, WB9FLW took a more, well, defiant line.  He came up with new name for the podcast that sort of captures the shocking level of indignation that this completly bogus story generated.  Pete suggests that we simply call the new show: "FLUX YOU"

Thank you gentlemen.  You are both, in a way, poets.  And Hendrix would, I think, approve. 

Now, will the Wizard of Newbury Park pull out his guitar and get to work on this?   
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column