Date   
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

Re: New uBitX - Start up Questions...

Christopher Ryan
 

Does anyone know the LO Drive level being used with the double balanced mixers off-hand? I suppose I could look it up on the data sheet for the synthesizer, but not in a place to do that at the moment.
Christopher

Antuino as a Spectrum Analyzer: Lots of birdies?

Jerry Gaffke
 

Looking at the latest schematic up on github:
    https://github.com/afarhan/antuino
it appears that Antuino does not have any filtering up front.

That would work fine as an antenna analyzer or scaler network analyzer
or to check a transmitter for harmonics and spurs.  In those cases the
incoming RF will be just a few signals, perhaps the main signal of interest
and a few harmonics.  The crystal filter will almost always knock out the false signals.

As a general purpose spectrum analyzer looking at noisy wideband incoming RF,
I'd expect a lot of false signals due to images and local oscillator harmonics.
In the discussion from Dec 28 of 2018 included below, Farhan suggests
that images could be dealt with in software.

Anybody have any comments on how well the Antuino works as a 
spectrum analyzer?

Jerry, KE7ER


On Fri, Dec 28, 2018 at 08:05 PM, Ashhar Farhan wrote:
the challenge would be to eliminate the if image. this could be done when you sweep to both sides and eliminate the image reading in software. here is an example :
 
1. lets imagine that there is a signal at 10 mhz. for this, we set the local oscillator at 35 mhz (as the IF is at 25 mhz). how can we be certain that the signal we are resolving is not at 60mhz (60mhz - 35 mhz = 25 mhz)?
2. we can take a second reading by setting the local oscillator at 85 mhz. in this csse, thr 60 mhz response (if any) should show up. else we can confirm that the signal we resolved in step 1 is indeed a 10 mhz signal.
 
one has to be aware that such a system will be slow. lets imagine that you have to sweep 30 mhz. the crystal filter is 10 khz wide. hence, we will need 30,000/5 = 6000 readings. if we can get, 100 readings a second, this will take a minute to complete the scan. an alternative would be to have two filters, a crystal filter and a 4 or even 5 section LC filter at around 12 mhz. we could switch to the lc filter for large sweeps. my specan circuit has a suitable design.
 
you are aking what happens if there was signal at 110 mhz in step two? aaaah, you tell me!
 
- f

Re: Antuino as a Spectrum Analyzer: Lots of birdies?

Jerry Gaffke
 

In those cases where the birdies are a problem,
a handful of external bandpass filters would cure it.


On Thu, Aug 1, 2019 at 04:41 PM, Jerry Gaffke wrote:
As a general purpose spectrum analyzer looking at noisy wideband incoming RF,
I'd expect a lot of false signals due to images and local oscillator harmonics.
In the discussion from Dec 28 of 2018 included below, Farhan suggests
that images could be dealt with in software.

Re: Cool cheap oscilloscope for troubleshooting

Paul KL7FLR
 

AS Jerry outlined, if you have nothing a DVM is high on the list of needed test equipment. I spotted this yesterday and if I had nothing this would be on my list to order. Not a high precision unit but gets you several things in one package.  My first (not cheap) DVM 40 years wasn’t to accurate but so I made an error correction chart from a lab precision 0-100 vdc/ac and it served me for many years. The Simpson 260 was my first meter in 1970 and still like it.

https://www.mpja.com/Digital-Multimeter-4-Digit-6000-count/productinfo/35525+TE/

Paul

Kl7FLR

Wasilla, AK

Re: AMP FOR UBITX

bill steffey NY9H
 

thanks Vince,,,'

On 8/1/2019 5:35 PM, Vince Vielhaber wrote:

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: Antuino as a Spectrum Analyzer: Lots of birdies?

Ashhar Farhan
 

Everything instrument has limits on its accuracy. While making the Antuino, I was well aware of its deficiencies. 
I made a decision to keep it simple to a point where a radio ham could throw this thing together in an evening or two.
In order to overcome the limitations inherent in the Antuino design, the complexity could have been prohibitively complicated and expensive.
On the other hand, it is an extremely useful instrument that grows on you. I no longer use a frequency counter or the specan. I rarely use the oscilloscope. Antuino does most of my measurements.

There are two very important things you must be aware of while using the Antuino :
1. In the power measurement mode (the problem is non existent on swr or sweep mode), any reading above 25 mhz could be an image. Thus, if you see something at 35 mhz, you will have to do some mental math to figure out if it is not an image. An easy way to know is to add an external low pass filter with 25 mhz cutoff.
You have to use it like a radio in this mode. If you want to measure the harmonics from your pixie radio with 7040 crystal, tune to 14080, 21120, 28160 and measure. It is as accurate as any spectrum analyzer with more than 80 db of usable bandwidth. Raj and I struggled to get this for a month.
2. Unlike a full fledged spectrum analyzer, Antuino has just one bandwidth of about 7 KHz. This is enough to made IMD measurements at 20 KHz tone separation. The sweep plot does only 128 readings. Thus, if  you sweep a low pass filter from 0 to 20 mhz, it will measure the filter response every 120 khz. If there is something lurking between the steps, it will miss it. This is a common challenge with spectrum analyzers. So, a crystal filter should be swept at less than 100 khz. 
There is a software hack to mitigate this. First : introduce another control for step size. This can slow down the plot. A 30 Mhz sweep at 5 khz steps will involve 30 x 200 =60000 readings.It could take minutes. The Second : write a more optimal Si5351 routine that changes frequencies faster. I know that smaller jumps can be instantaneous on Si5351. I don't know that hack. If someone wants to take a stab at it, I am willing to work with them.

In a nutshell, Antuino is a very useful instrument. You don't have to buy it. You can build it. It is just as challenging as a direct conversion receiver. It does a fabulous job though. It can measure oscillator frequencies, it can measure amplifier gain, distortion, frequency response, it can measure filter response, it can show mixer behaviour, it can tune your antenna, it can measure power from a few uV to 100 mv and more with attenuators. It does all this slowly but surely. Like any precision tool, you must know its limitations and use them as an aware user. I would wager that if you have to choose just instrument for your lab, it would be this; Apart from a DVM.
And (I repeat) don't buy it, build it (grin)

- f

On Fri 2 Aug, 2019, 5:29 AM Jerry Gaffke via Groups.Io, <jgaffke=yahoo.com@groups.io> wrote:
In those cases where the birdies are a problem,
a handful of external bandpass filters would cure it.

On Thu, Aug 1, 2019 at 04:41 PM, Jerry Gaffke wrote:
As a general purpose spectrum analyzer looking at noisy wideband incoming RF,
I'd expect a lot of false signals due to images and local oscillator harmonics.
In the discussion from Dec 28 of 2018 included below, Farhan suggests
that images could be dealt with in software.

Re: Issues with ordering the BITX40

Ashhar Farhan
 

Yup,  'Group, we have a problem'. I will fix this Paypal trouble in 24 hours. Aah, the joys of Paypal customer service, here we go again...
- f

On Fri 2 Aug, 2019, 12:47 AM Mike Short, <ai4ns.mike.spam@...> wrote:
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: Antuino as a Spectrum Analyzer: Lots of birdies?

Jerry Gaffke
 

The Antuino does look very useful for poking at radio gear.
Those wishing to build one could borrow the Raduino from a *Bitx* rig
and not bother building the Nano/Si531/Display part of the Antuino.
     https://github.com/afarhan/antuino/blob/master/antuino_schematic.pdf
Perhaps have the top line of the LCD show the current frequency, the bottom show the reading in dBm.
And ship all data off to the Arduino IDE via the USB cable for plotting, using Serial.print() calls:
     http://www.instructables.com/id/Ultimate-Guide-to-Adruino-Serial-Plotter/
Though the Antuino's 128x64 graphic display would be very handy,
making it a nice small standalone instrument.

A $20 JYE scope could still be quite useful.
For example, watching I2C and UART traffic on the Nano pins,
or watching a rotary encoder work.  Can't do that with an Antuino.
If the signals are too fast for your scope,
you can often modify the program to slow things down.

Jerry, KE7ER



On Thu, Aug 1, 2019 at 07:19 PM, Ashhar Farhan wrote:
Everything instrument has limits on its accuracy. While making the Antuino, I was well aware of its deficiencies. 
I made a decision to keep it simple to a point where a radio ham could throw this thing together in an evening or two.
In order to overcome the limitations inherent in the Antuino design, the complexity could have been prohibitively complicated and expensive.
On the other hand, it is an extremely useful instrument that grows on you. I no longer use a frequency counter or the specan. I rarely use the oscilloscope. Antuino does most of my measurements.

uBITX v5 Finished #3d_printing #calibration #v5

Doug Hall
 

I hesitate to say that it's actually finished, as I keep thinking of stuff to add to the hardware and firmware. But the cover is on and I'm making QSOs. Previously I had only used it on CW, but I 3D printed a mic case and got it wired up and my first SSB QSO was with S51DX. I'm pleased with how well the little radio hears. I'm sitting here listening to G0EVY on 40M SSB and he's just booming in. I haven't yet installed the AGC board so the static crashes are pretty harsh. It kinda reminds me of my old Heath HW-16 in that regard.

I calibrated the frequency against a 10 MHz GPSDO. Then, based on advice of some folks here, I used a PC audio spectrum analyzer program (Spectrum Lab by DL4YHF) to adjust the BFO frequency. That worked a treat, and I'm really happy with the way the audio sounds now.

It's just a very pleasing little radio.

73,
Doug K4DSP