Date   
New uBitX - Start up Questions...

Steven
 

Hi All! I'm Steven KM4WIP. I have just completed assembly of a uBitX. It was my reward for passing the Extra Class exam last month.

The rig is built on a metal baking pan. When I plug in the 12v line, it lights up right away, that is good news. The on/off switch seems to only work with volume - is this correct? Volume does work.The VFO push button works, I can get to menu choices. I heard some garbled SSB and some clear CW on 40m. It won't transmit. And there is no CW sig at key down.

So here's my most obvious question. With the mike plugged in the VFO just sits on (I think ) 7.500 MHz. When I unplug the mike I can tune the VFO. Any clues?

Also is there an initial set up I need to run, or should this rig be able to plug in, tune in, and transmit?

Thanks!!!
Steven KM4WIP

Re: Cool cheap oscilloscope for troubleshooting

Lawrence Galea
 

How abut home brewing a digital wattmeter?

And a Capacitance / inductance meter
https://sites.google.com/site/vk3bhr/home/index2-html 

Enjoy 
Lawrence

On Thu, Aug 1, 2019 at 12:03 PM Tom, wb6b <wb6b@...> wrote:
Someone told me they saw an old Tektronix 465 scope on eBay for $50 (probably $150 shipping :) ). That could be a good route. Hard to imaging that those scope might have cost $20,000 or more in todays dollars, and can now be bought for less than $100. They definitely were made well.

My first scope was a Knight Kit scope. I saved all school year and when summer vacation came I spent $109, if it recall, to purchase the kit and spent the summer putting it together.

This scope was only about 2 Mhz tops. But, I learned so much from it being able to "see" how so many electronic circuits worked and then start trying out designing my own circuits and projects, and seeing how they worked, or needed improvement.

This scope was my first realization that professionally designed equipment could be improved and not accepted as correct without question.  

My first experience was when a electrolytic capacitor exploded with a loud bang when I first plugged the scope in, as I waited breathlessly for the thrill of seeing my summers's work come to life in a magic little green line.

I was able to reason out the voltage rating of the capacitor (part of a cathode resistor negative bias circuit) was exceeded momentarily, on start up, so I got on my bicycle, rode down to the local electronics store and was able to confidently buy a replacement was not the exact same value. But, higher voltage and a close, but larger, capacitance value.

My second design improvement came after I discovered the wonders of the Z axes. I was having a great time feeding the video from a TV set I was fixing for a neighbor into the Z axis, syncing up the horizontal and feeding in the vertical to the X axis, and watching TV on my oscilloscope screen.  

There was a little RCA plug that shorted the Z axis input on the back of the scope when it was not in use. 

I'd been using the scope and realized I'd not replaced the shorting plug. The Z axis input was essentially a .1uF capacitor connected to the cathode of the CRT at 1,200 volts. 

I reached over and behind the scope to plug in the shorting plug. I remember how the little plug made such a loud bang as it hit the wall on the opposite side of my room. And how stunning the jolt was traveling through me. 

My next design improvement was to solder a 1M ohm resistor across the Z axis connector, inside the scope, to let the capacitor charge and equalize to the 1,200 volts on its own. So I would not become a live demonstration of RC time constants and capacitor peak charging current again.

Tom, wb6b



Re: Cool cheap oscilloscope for troubleshooting

Jack, W8TEE
 

Here's a picture of a "miniature" version of the Nov, 2018, QST article. It substitutes a 200W RF resistor (hiding between the orange and black wire) for the resistor network/oil bath. It has a small heatsink on the back so it can handle 50W for about 30 seconds and costs less than $20 to build. It fits in your shirt pocket.

Inline image

Jack, W8TEE

On Thursday, August 1, 2019, 9:19:31 AM EDT, Lawrence Galea <9h1avlaw@...> wrote:


How abut home brewing a digital wattmeter?

And a Capacitance / inductance meter
https://sites.google.com/site/vk3bhr/home/index2-html 

Enjoy 
Lawrence

On Thu, Aug 1, 2019 at 12:03 PM Tom, wb6b <wb6b@...> wrote:
Someone told me they saw an old Tektronix 465 scope on eBay for $50 (probably $150 shipping :) ). That could be a good route. Hard to imaging that those scope might have cost $20,000 or more in todays dollars, and can now be bought for less than $100. They definitely were made well.

My first scope was a Knight Kit scope. I saved all school year and when summer vacation came I spent $109, if it recall, to purchase the kit and spent the summer putting it together.

This scope was only about 2 Mhz tops. But, I learned so much from it being able to "see" how so many electronic circuits worked and then start trying out designing my own circuits and projects, and seeing how they worked, or needed improvement.

This scope was my first realization that professionally designed equipment could be improved and not accepted as correct without question.  

My first experience was when a electrolytic capacitor exploded with a loud bang when I first plugged the scope in, as I waited breathlessly for the thrill of seeing my summers's work come to life in a magic little green line.

I was able to reason out the voltage rating of the capacitor (part of a cathode resistor negative bias circuit) was exceeded momentarily, on start up, so I got on my bicycle, rode down to the local electronics store and was able to confidently buy a replacement was not the exact same value. But, higher voltage and a close, but larger, capacitance value.

My second design improvement came after I discovered the wonders of the Z axes. I was having a great time feeding the video from a TV set I was fixing for a neighbor into the Z axis, syncing up the horizontal and feeding in the vertical to the X axis, and watching TV on my oscilloscope screen.  

There was a little RCA plug that shorted the Z axis input on the back of the scope when it was not in use. 

I'd been using the scope and realized I'd not replaced the shorting plug. The Z axis input was essentially a .1uF capacitor connected to the cathode of the CRT at 1,200 volts. 

I reached over and behind the scope to plug in the shorting plug. I remember how the little plug made such a loud bang as it hit the wall on the opposite side of my room. And how stunning the jolt was traveling through me. 

My next design improvement was to solder a 1M ohm resistor across the Z axis connector, inside the scope, to let the capacitor charge and equalize to the 1,200 volts on its own. So I would not become a live demonstration of RC time constants and capacitor peak charging current again.

Tom, wb6b



Re: AMP FOR UBITX

bill steffey NY9H
 

already got rid of one  k3 ./p3,,,,,,


bill

On 7/31/2019 11:09 PM, Skip Davis via Groups.Io wrote:
So your thinning out the crowd of equipment you have? Are you making room for the K4? Nice to see you are active on the reflectors.

Skip Davis, NC9O
On Jul 31, 2019, at 19:11, bill steffey NY9H <Ny9h@...> wrote:

FINALLY GIVING UP MY TT 405 AMP ... ON EBAY


WORKED GREAT WITH MY UBITX !!!

BILL NY9H



Re: AMP FOR UBITX

Ron Stauffer
 

I cannot find it on ebay


From: BITX20@groups.io <BITX20@groups.io> on behalf of bill steffey NY9H <Ny9h@...>
Sent: Thursday, August 1, 2019 8:39:10 AM
To: BITX20@groups.io <BITX20@groups.io>
Subject: Re: [BITX20] AMP FOR UBITX
 
already got rid of one  k3 ./p3,,,,,,


bill




On 7/31/2019 11:09 PM, Skip Davis via Groups.Io wrote:
> So your thinning out the crowd of equipment you have? Are you making room for the K4? Nice to see you are active on the reflectors.
>
> Skip Davis, NC9O
>> On Jul 31, 2019, at 19:11, bill steffey NY9H <Ny9h@...> wrote:
>>
>> FINALLY GIVING UP MY TT 405 AMP ...  ON EBAY
>>
>>
>> WORKED GREAT WITH MY UBITX !!!
>>
>> BILL NY9H
>>
>>
>>
>
>
>
>



Re: AMP FOR UBITX

Skip Davis
 

That’s good soooo..... are you on the list for the K4? I’m thinking about it still, if it sounds as good as the KX3 I’m on board. I primarily use the KX3 and really haven’t used the K3 in months.

Skip Davis, NC9O
847-331-4147

On Aug 1, 2019, at 09:39, bill steffey NY9H <Ny9h@...> wrote:

already got rid of one k3 ./p3,,,,,,


bill




On 7/31/2019 11:09 PM, Skip Davis via Groups.Io wrote:
So your thinning out the crowd of equipment you have? Are you making room for the K4? Nice to see you are active on the reflectors.

Skip Davis, NC9O
On Jul 31, 2019, at 19:11, bill steffey NY9H <Ny9h@...> wrote:

FINALLY GIVING UP MY TT 405 AMP ... ON EBAY


WORKED GREAT WITH MY UBITX !!!

BILL NY9H




Re: AMP FOR UBITX

Michael Wells
 

Re: Issues with ordering the BITX40

dk3ts@...
 

Really want the BITX40 but as I have a band specific use for it. The link still appears broken for purchasing since it's still taking me to a generic PayPal page.

Re: New uBitX - Start up Questions...

_Dave_ K0MBT
 

Congrats on the upgrade.

Definitely odd behavior. Is the radio going into transmit when you plug in the mic/ptt? That is what it sounds like to me. Check the wiring make sure that the resistor is across to the ptt.

Re: ubitx with Icom SM-6 desk mic

John Scherer
 

Awesome, thanks Skip!
--
John - N0CTL - Fulltime RV in a 40' motorhome

Re: New uBitX - Start up Questions...

Doug Hall
 

Hi Steven,

Congrats on the upgrade to Extra Class. 

It sounds like you didn't wire the switch contacts in series with your +12V power, but instead you have the +12V power and ground going directly to P1 on the board. If you want the on/off switch to turn the radio on and off then you'll need to run the +12V leads from the rear panel power jack to one side of the pot-mounted switch and then another wire back from the other side of the switch to the +12V connections on P1. The connection diagram shows a switch in series with the power lead - that switch is the one that is part of the volume control.

As far as not being able to tune when the mic is plugged in, it definitely sounds like the radio is going into transmit mode when you plug in the mic. You can't change frequency while the rig is in TX mode. Remove the mic and check between the ground of the mic plug and the ring connector. I'm betting your ohmmeter will show a short there.

As far as initial setup - I had to do the BFO frequency adjustment on my radio when I built it. This involves putting the radio into setup mode and then selecting BFO adjustment from the menu. Then you turn the VFO knob until the audio passband is in the right place - basically until a sideband signal "sounds" right. If it's too far in one direction the audio will sound very tinny with no low frequency response. If it's too far in the other direction it'll sound muffled. When you're happy with the setting you press the PTT button once to save it. So you're gonna have to fix that mic short before you do this part since you need a working PTT button.

Good luck,
Doug K4DSP

Re: Cool cheap oscilloscope for troubleshooting

Donald <donwestpwl@...>
 

David Wilcox,

I have seen several "how to use an oscilloscope" videos on youtube, while looking for various ham-related videos. I did not watch any, but just about any of them should show you what the controls do, and how to read the display scale. I would start with the shortest one, as that might show everything you need.--Donald, KB5PWL

P.S. If a scope has an AC-mains power supply, check to see if the probe shield (probe ground clip) is connected to earth ground in the scope. If so, we should be aware of this, every time we connect the probe to a circuit.

On 8/1/2019 4:39 AM, David Wilcox via Groups.Io wrote:
Has anyone information on how to use the Digilent analog scope?  The reference manual reads like a college text book on its features but using it for ham radio testing for a newbie I need a simple book  with lots of pictures..... ha!

David J. Wilcox K8WPE’s iPad

Re: Issues with ordering the BITX40

Mike Short
 

I have one I will sell

On Thu, Aug 1, 2019 at 12:04 <dk3ts@...> wrote:
Really want the BITX40 but as I have a band specific use for it. The link still appears broken for purchasing since it's still taking me to a generic PayPal page.

Re: Cool cheap oscilloscope for troubleshooting

Darwin EI3IHB
 

It would be great if HF Signals will produce & sell  an oscilloscope kit that will match the UBitX ...

Re: Cool cheap oscilloscope for troubleshooting

Donald <donwestpwl@...>
 

Okay, ignore my previous post. I just looked at the Digilent Analog Discovery2 and it appears to be a pc-based scope and will not have knobs and controls like a self-contained scope. The manual is large because of all the things the device will do. My apologies.

Re: AMP FOR UBITX

barry halterman
 

Been trying to sell my K3S, that is listed on QRZ, but no inquiring minds yet.

Re: AMP FOR UBITX

bill steffey NY9H
 

  ten tec 405      should come up  ...   works here...



On 8/1/2019 9:55 AM, Ron Stauffer wrote:
I cannot find it on ebay


From: BITX20@groups.io <BITX20@groups.io> on behalf of bill steffey NY9H <Ny9h@...>
Sent: Thursday, August 1, 2019 8:39:10 AM
To: BITX20@groups.io <BITX20@groups.io>
Subject: Re: [BITX20] AMP FOR UBITX
 
already got rid of one  k3 ./p3,,,,,,


bill




On 7/31/2019 11:09 PM, Skip Davis via Groups.Io wrote:
> So your thinning out the crowd of equipment you have? Are you making room for the K4? Nice to see you are active on the reflectors.
>
> Skip Davis, NC9O
>> On Jul 31, 2019, at 19:11, bill steffey NY9H <Ny9h@...> wrote:
>>
>> FINALLY GIVING UP MY TT 405 AMP ...  ON EBAY
>>
>>
>> WORKED GREAT WITH MY UBITX !!!
>>
>> BILL NY9H
>>
>>
>>
>
>
>
>



Re: AMP FOR UBITX

bill steffey NY9H
 

RF POWER AMP QRP TO 50 WATTS    BITX  &  TEN TEC 405   10 TO 80 METERS          is the title...


VERY SRI FOR THE BANDWIDTH

On 8/1/2019 1:03 PM, Michael Wells via Groups.Io wrote:
Quote: "I cannot find it on ebay"
try https://www.ebay.com/itm/RF-POWER-AMP-QRP-TO-50-WATTS-BITX-TEN-TEC-405-10-TO-80-METERS/113838277396

Re: AMP FOR UBITX

Vince Vielhaber
 

If all else fails, this should work anywhere:

https://www.ebay.com/itm/113838277396

Vince.

On 08/01/2019 04:29 PM, bill steffey NY9H wrote:
RF POWER AMP QRP TO 50 WATTS BITX & TEN TEC 405 10 TO 80
METERS is the title...

Re: New uBitX - Start up Questions...

Steven
 

Thank so much Doug and Dave.  Will let you know the results this weekend when I have time to mess with projects.

Steven-KM4WIP